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Abstract

Plasticity is an intrinsic property of the human brain and represents evolution's invention to enable the nervous system to escape the restrictions of its own genome and thus adapt to environmental pressures, physiologic changes, and experiences. Dynamic shifts in the strength of preexisting connections across distributed neural networks, changes in task-related cortico-cortical and cortico-subcortical coherence and modifications of the mapping between behavior and neural activity take place in response to changes in afferent input or efferent demand. Such rapid, ongoing changes may be followed by the establishment of new connections through dendritic growth and arborization. However, they harbor the danger that the evolving pattern of neural activation may in itself lead to abnormal behavior. Plasticity is the mechanism for development and learning, as much as a cause of pathology. The challenge we face is to learn enough about the mechanisms of plasticity to modulate them to achieve the best behavioral outcome for a given subject.

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... This first spontaneous recovery often involves some areas of the healthy hemisphere (Saur et al., 2006;De Aguiar et al., 2015a). This occurrence is in line with the theory of interhemispheric inhibition (Liepert et al., 2000;Pascual-Leone et al., 2005), which claims that in the intact human brain, each hemisphere can inhibit the other one to keep an interhemispheric balance and to prevent an excessive interference between the activity of both hemispheres (Pascual-Leone et al., 2005). In the event of a brain damage, the ability of the left hemisphere to inhibit the right one is limited, and this could bring to an increase of the excitability of the healthy hemisphere, together with an increase of the inhibitory signal toward the damaged one (Saur et al., 2006). ...
... This first spontaneous recovery often involves some areas of the healthy hemisphere (Saur et al., 2006;De Aguiar et al., 2015a). This occurrence is in line with the theory of interhemispheric inhibition (Liepert et al., 2000;Pascual-Leone et al., 2005), which claims that in the intact human brain, each hemisphere can inhibit the other one to keep an interhemispheric balance and to prevent an excessive interference between the activity of both hemispheres (Pascual-Leone et al., 2005). In the event of a brain damage, the ability of the left hemisphere to inhibit the right one is limited, and this could bring to an increase of the excitability of the healthy hemisphere, together with an increase of the inhibitory signal toward the damaged one (Saur et al., 2006). ...
... In the event of a brain damage, the ability of the left hemisphere to inhibit the right one is limited, and this could bring to an increase of the excitability of the healthy hemisphere, together with an increase of the inhibitory signal toward the damaged one (Saur et al., 2006). Only at a later stage of recovery the healthy hemisphere would start sending excitatory signals toward the damaged areas, allowing the perilesional tissue to reactivate in a first attempt to restore the impaired functions (Pascual-Leone et al., 2005). These spontaneous dynamics occur in the first six months after injury, hence it is advisable the application of tDCS in chronic aphasic post-stroke patients rather than in the acute or subacute phase. ...
Article
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Aphasia is an acquired language disorder resulting from damage to portions of the brain which are responsible for language comprehension and formulation. This disorder can involve different levels of language processing with impairments in both oral and written comprehension and production. Over the last years, different rehabilitation and therapeutic interventions have been developed, especially non-invasive brain stimulation (NIBS) techniques. One of the most used NIBS techniques in aphasia rehabilitation is the Transcranial Direct-Current Stimulation (tDCS). It has been proven to be effective in promoting a successful recovery both in the short and the long term after a brain injury. The main strength of tDCS is its feasibility associated with relatively minor side effects, if safely and properly administered. TDCS requires two electrodes, an anode and a cathode, which are generally placed on the scalp. The electrode montage can be either unipolar or bipolar. The main aim of this review is to give an overview of the state of the art of tDCS for the treatment of aphasia. The studies described included patients with different types of language impairments, especially with non-fluent aphasia and in several cases anomia. The effects of tDCS are variable and depend on several factors, such as electrode size and montage, duration of the stimulation, current density and characteristics of the brain tissue underneath the electrodes. Generally, tDCS has led to promising results in rehabilitating patients with acquired aphasia, especially if combined with different language and communication therapies. The selection of the appropriate approach depends on the patients treated and their impaired language function. When used in combination with treatments such as Speech and Language Therapy, Constraint Induced Aphasia Therapy or Intensive Action Treatment, tDCS has generally promoted a better recovery of the impaired functions. In addition to these rehabilitation protocols, Action Observation Therapy, such as IMITAF, appeared to contribute to the reduction of post-stroke anomia. The potential of combining such techniques with tDCS would would therefore be a possibility for further improvement, also providing the clinician with a new action and intervention tool. The association of a tDCS protocol with a dedicated rehabilitation training would favor a generalized long-term improvement of the different components of language.
... 42 The pathophysiology of schizophrenia has been associated with abnormalities in brain plasticity, which refers to the ability of the brain to adapt in response to experience. 43 TMS and other noninvasive stimulation techniques are used to elicit plastic changes in synaptic organization, interfering with the function of specific cortical areas by inducing long-term potentiation or long-term depression. [44][45][46][47] For example, transcranial direct current stimulation (tDCS) is a neuromodulation technique that induces changes in cortical excitability by applying a small current over the scalp. ...
... We also found no significant difference in the degree of LICI and SAI between patients and healthy controls, although only 1 study examined each measure. The results for the duration of CSP were inconclusive: of the 9 studies that delivered monophasic TMS pulses to the motor cortex and recorded responses from the surface of the hand muscle, 4 43,86,93,95 detected no significant group difference (most or all patients were medicated; 6 patients were taking clozapine), 2 82,96 reported shorter CSP duration in both medicated and J Psychiatry Neurosci 2021;46(6) unmedicated patients, and 3 52,58,94 reported longer CSP duration in patients (most or all were medicated; 2 patients were taking clozapine). However, we found greater consistency in the data for the effect of antipsychotic treatment, especially clozapine, on increasing CSP duration. ...
... 44,45,89,96 Patients with chronic schizophrenia (most of whom were medicated) in Strube and colleagues 89 showed a deficit in focal long-term potentiation-like plasticity induced by paired associative stimulation, which emulates spike-timing-dependent plasticity. 52,180 Another study 43 reported deficient anodal tDCSinduced nonfocal long-term potentiation-like plasticity in patients with multiple psychotic episodes (most of them medicated) but not in those with a single episode (recent-onset schizophrenia; most of them medicated), suggesting "a neurodegenerative process of cortical plasticity in patients with schizophrenia." However, a recent meta-analysis reported that illness duration might not influence motor cortical plasticity in schizophrenia, and that altered plasticity may predate the manifestation of clinical symptoms. ...
Article
Background: Transcranial magnetic stimulation can be combined with electromyography (TMS-EMG) and electroencephalography (TMS-EEG) to evaluate the excitatory and inhibitory functions of the cerebral cortex in a standardized manner. It has been postulated that schizophrenia is a disorder of functional neural connectivity underpinned by a relative imbalance of excitation and inhibition. The aim of this review was to provide a comprehensive overview of TMS-EMG and TMS-EEG research in schizophrenia, focused on excitation or inhibition, connectivity, motor cortical plasticity and the effect of antipsychotic medications, symptom severity and illness duration on TMS-EMG and TMS-EEG indices. Methods: We searched PsycINFO, Embase and Medline, from database inception to April 2020, for studies that included TMS outcomes in patients with schizophrenia. We used the following combination of search terms: transcranial magnetic stimulation OR tms AND interneurons OR glutamic acid OR gamma aminobutyric acid OR neural inhibition OR pyramidal neurons OR excita* OR inhibit* OR GABA* OR glutam* OR E-I balance OR excitation-inhibition balance AND schizoaffective disorder* OR Schizophrenia OR schizophreni*. Results: TMS-EMG and TMS-EEG measurements revealed deficits in excitation or inhibition, functional connectivity and motor cortical plasticity in patients with schizophrenia. Increased duration of the cortical silent period (a TMS-EMG marker of γ-aminobutyric acid B receptor activity) with clozapine was a relatively consistent finding. Limitations: Most of the studies used patients with chronic schizophrenia and medicated patients, employed cross-sectional group comparisons and had small sample sizes. Conclusion: TMS-EMG and TMS-EEG offer an opportunity to develop a novel and improved understanding of the physiologic processes that underlie schizophrenia and to assess the therapeutic effect of antipsychotic medications. In the future, these techniques may also help predict disease progression and further our understanding of the excitatory/inhibitory balance and its implications for mechanisms that underlie treatment-resistant schizophrenia.
... The human brain remains in constant change, altering its functional and structural properties to adapt to changing demands (Budde et al., 2016b). This intrinsic characteristic of our brain is called neuroplasticity and allows the nervous system to adapt to environmental pressures, physiologic changes, and experiences by escaping the restrictions of its own genome (Pascual-Leone et al., 2005). Findings have shown a dynamic remodelling of grey matter throughout life characterized by the continuous creation and growth of neurons, dendrites, and new synapses as well as their elimination (Killgore et al., 2013). ...
... Findings have shown a dynamic remodelling of grey matter throughout life characterized by the continuous creation and growth of neurons, dendrites, and new synapses as well as their elimination (Killgore et al., 2013). This plastic capacity of the brain represents the normal constant state of the nervous system through the life cycle, and is understood as a human mechanism for learning (e.g., the asset of new skills (Hötting and Röder, 2013)) growth, and general development but it could also be a cause of pathology (Pascual-Leone et al., 2005). ...
Article
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A variety of organisms including mammals have evolved a 24h, self-sustained timekeeping machinery known as the circadian clock (biological clock), which enables to anticipate, respond, and adapt to environmental influences such as the daily light and dark cycles. Proper functioning of the clock plays a pivotal role in the temporal regulation of a wide range of cellular, physiological, and behavioural processes. The disruption of circadian rhythms was found to be associated with the onset and progression of several pathologies including sleep and mental disorders, cancer, and neurodegeneration. Thus, the role of the circadian clock in health and disease, and its clinical applications, have gained increasing attention, but the exact mechanisms underlying temporal regulation require further work and the integration of evidence from different research fields. In this review, we address the current knowledge regarding the functioning of molecular circuits as generators of circadian rhythms and the essential role of circadian synchrony in a healthy organism. In particular, we discuss the role of circadian regulation in the context of behaviour and cognitive functioning, delineating how the loss of this tight interplay is linked to pathological development with a focus on mental disorders and neurodegeneration. We further describe emerging new aspects on the link between the circadian clock and physical exercise-induced cognitive functioning, and its current usage as circadian activator with a positive impact in delaying the progression of certain pathologies including neurodegeneration and brain-related disorders. Finally, we discuss recent epidemiological evidence pointing to an important role of the circadian clock in mental health.
... De façon notable, des changements majeurs surviennent au niveau cortical avec une spécialisation de certaines aires polysensorielles en aires auditives sous l'influence de stimuli auditifs (e.g. Pascual-Leone et al. 2005 Toute surdité survenant en cours de cette période critique (i.e. surdité pré-linguale) risque de compromettre la maturation auditive de la périphérie jusqu'aux structures centrales (Kral et al. 2005, Trumpp & Kiefer 2018) et d'impacter la SA. ...
... manière générale, les résultats issus des modèles « sujet sain pluggé » doivent être interprétés avec précaution. En effet, la surdité induite par la pose d'un bouchon d'oreille induit une plasticité immédiate qui conduit à des réorganisations fonctionnelles rapides des circuits existants (modèle par levée d'inhibition GABA, voir pour revuePascual-Leone et al. 2005). A contrario, la plasticité des patients implantés se met en place sur le long terme car elle est basée sur une réorganisation en profondeur des circuits cérébraux (e.g.Strelnikov et al. 2015). ...
Thesis
La spatialisation auditive est un processus complexe qui participe à la construction de notre espace perceptuel. En collaboration avec d’autres afférences sensorielles telle que la vision, elle offre une expérience sensorielle unique. Son fonctionnement optimal passe par l’intégrité des structures auditives captant les sons en périphérie jusqu’à l’extraction et l’interprétation centrale. Toute surdité détériore ces étapes clés du traitement du signal sonore. L’innovation technologique a révolutionné la prise en charge des surdités profondes grâce auximplants cochléaires mais de nombreuses questions demeurent quant aux modalités de préservation et de réadaptation de la spatialisation auditive chez les patients implantés. Nos travaux de thèse se portent ainsi sur ces deux facettes de la localisation. Dans une 1ère étude, nous avons évalué dans les trois dimensions de l’espace les performances de localisation d’enfants bi-implantés cochléaires comparées à un groupe d’enfants normoentendant. Dans une 2ème étude, nous avons validé une forme courte en français du questionnaire pédiatrique « Speech, Spatial, and Qualities of hearing ». Dans une 3ème étude, nous avons développé et testé la faisabilité d’un protocole d’entraînement de la spatialisation auditive à destination d’adultes bi-implantés cochléaires. Chacune des études menées a permis de mieux caractériser les compétences spatiales dans chaque population testée. Les patients implantés conservent d’importantes difficultés soumises à variabilité inter-individuelle. Mais la mise en place d’un entraînement spatial apparaît comme une perspective d’avenir dans la modulation de ces difficultés.
... O desenvolvimento infantil engloba sistemas que se inter-relacionam para a aquisição de funções/habilidades que se desenvolvem e aperfeiçoam-se apoiadas no processo de maturação neurológica e na plasticidade cerebral, determinadas por fatores genéticos e por fatores ambientais (Pascual-Leone et al., 2005;Piovezana & Gonçalves, 2006). Portanto, o desenvolvimento infantil referese a uma transformação complexa, contínua, dinâmica e progressiva, em que a inter-relação do bebê com o ambiente é determinante para a expressão genética e aprendizagem (Brémond-Gignac et al., 2011;Gagliardo & Ruas, 2017;Graven & Browe, 2008). ...
... Posteriormente, entre 29 e 34 semanas, ocorre a eliminação das fibras em excesso e desnecessárias. Além disso, por ser uma função aprendida e necessitar de estímulos exógenos para seu pleno desenvolvimento, todo o primeiro ano de vida do bebê é considerado crítico para o desenvolvimento da visão (Brémond-Gignac et al., 2011;Graven & Browe, 2008;Huttenlocher, 1990;Lewis & Maurer, 2005;Pascual-Leone et al., 2005;Piovezana & Gonçalves, 2006). (Huttenlocher, 1990). ...
Article
A atuação do terapeuta ocupacional no campo da saúde ocular e visual para a promoção do desenvolvimento infantil e prevenção de deficiências, requer conhecimento amplo e sólido sobre a complexidade da fundamentação teórica que norteia e sustenta a prática clínica. Ao mesmo tempo, necessita de um olhar individualizado para as potências, comportamentos e características de cada criança, especialmente nos primeiros anos de vida. O presente editorial busca contextualizar conceitos fundamentais sobre processos de plasticidade e maturação neurológica, desenvolvimento ocular e de funções visuais/visuomotoras, relacionar saberes da saúde e educação com níveis de prevenção com base no conhecimento científico. Objetiva minimizar divergências teóricas e conceituais no campo em questão e oferecer suporte teórico para a clínica de terapeutas ocupacionais no processo de intervenção oportuna e habilitação visual de bebês e crianças com diagnóstico ou em risco para alterações no desenvolvimento da visão, a fim de potencializar experiências para a máxima expressão do desenvolvimento infantil.Palavras-chave: Terapia Ocupacional. Saúde Ocular. Prevenção de Doenças. AbstractThe work of the occupational therapist in the field of eye and visual health to promote child development and prevent disabilities requires broad and solid knowledge about the complexity of the theoretical foundation that guides and sustains clinical practice. At the same time, it needs an individualized look at the powers, behaviors and characteristics of each child, especially in the first years of life. This editorial seeks to contextualize fundamental concepts about processes of neurological plasticity and maturation, ocular development and visual/ visomotor functions and to relate health and education knowledge to prevention levels based on scientific knowledge. It aims to minimize theoretical and conceptual divergences in the field in question, and offer theoretical support to the clinic of occupational therapists in the process of timely intervention and visual enabling of babies and children diagnosed or at risk for changes in vision development, in order to enhance experiences for the maximum expression of child development. Keywords: Occupational Therapy; Eye Health; Disease Prevention.ResumenEl rol del terapeuta ocupacional en el campo de la salud ocular y visual para promover el desarrollo infantil y prevenir discapacidades requiere un conocimiento amplio y sólido sobre la complejidad del fundamento teórico que guía y sustenta la práctica clínica. Al mismo tiempo, necesita una mirada individualizada a los poderes, comportamientos y características de cada niño, especialmente en los primeros años de vida. Este editorial busca contextualizar conceptos fundamentales sobre plasticidad y procesos de maduración neurológica, desarrollo ocular y funciones visuales / visuomotoras y relacionar el conocimiento en salud y educación con niveles de prevención basados en el conocimiento científico. Tiene como objetivo minimizar las divergencias teóricas y conceptuales en el campo en cuestión, y ofrecer apoyo teórico a la clínica de terapeutas ocupacionales en el proceso de intervención oportuna y habilitación visual de bebés y niños diagnosticados o en riesgo de cambios en el desarrollo de la visión, con el fin de potenciar las experiencias para la máxima expresión del desarrollo infantil.Palabras clave: Terapia Ocupacional. Salud Ocular. Prevención de Enfermedades.
... It must be emphasized, however, that developmental, including behavioral, plasticity being the terms that refer to the functional explanation of the adaptation to the environment (the survival value of a trait), belongs to Tinbergen's ultimate level of explanation (Tinbergen, 1963) which focuses on the phylogeny and function of a phenotypic trait (Fitch, 2015). In contrast, neuronal plasticity as a physiological mechanism that allows the brain to modify the preexisting neuronal connections in response to changes in afferent inputs or efferent requirements (Pascual-Leone et al., 2005) represents Tinbergen's proximal level of explanation (Tinbergen, 1963), which concerns the mechanistic and developmental elucidations of how a phenotypic trait works and develops in ontogeny (Fitch, 2015). Therefore, although behavioral plasticity can be achieved by the means of neuronal plasticity, only the former refers to the gene-culture coevolutionary explanations of the appearance of musical creativity. ...
... This suggests that the evolution of hominins' auditory-motor synchronization has been achieved by the development of these cortico-subcortical connections. On the other hand, the possibility of sensing different periodicities as musical pulse along with flexibility in the use of rhythm measures became an area of behavioral plasticity, due to the fact that both the striatum and the neocortex belong to the major sites of synaptic plasticity in the brain enabling learning (Pascual-Leone et al., 2005;Surmeier et al., 2009;Perrin and Venance, 2019). Both the ability of beat extraction and the sense of different periodicities most probably became the first capacities which enabled divergent musical thought composed of rhythmic kernels of musical thinking (Webster, 2002). ...
... Plastic changes occur by modifying pre-existing neuronal connections through changes in cortico-cortical and cortico-sub-cortical networks in response to new afferent impulses or efferent demands. Changes have a place at the molecular and cellular levels and can be followed by the establishment of new dendritic growth (Pascual-Leone et al., 2005). In 2017, Amo et al., described an index of plasticity for the motor cortex as the ratio between gamma-band activity (GBA) induced to event relatedsynchronization (ERS) EEG obtained after a given task (e.g., moving a finger) divided by GBA at baseline condition (Amo et al., 2017). ...
Thesis
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Background: Repetitive transcranial magnetic stimulation (RTMS) has been suggested as a possible therapeutic alternative for patients with schizophrenia (SCZ) and treatment-resistant auditory verbal hallucinations (AVH). The aim of the studies presented here was to investigate how RTMS affects clinical symptoms, electroencephalographic responses, and brain functional networks. We suspected improvement of symptoms accompanied by changes in EEG activity, event-related potentials, and sensory gating. Subjects and methods: Ten patients with schizophrenia (mean age 32.4, SD = 6.85, 7m, 3f) and six healthy controls (mean age 30.3, SD = 7.5, 4m, 2f) participated in this study. Nine patients were on antipsychotic medication. The patients were randomly selected into two groups, the treatment group (TG) and the control group (CG). The active low-frequency 1Hz RTMS was delivered in ten daily sessions of 900 pulses at two different EEG locations: T3-P3 (TG) and Cz (CG). Clinical symptoms were investigated with psychometric scales like Quality of Life (QoL), Depression Anxiety Stress Scales (DASS), and Psychotic Symptom Rating Scale with Auditory Hallucinations Subscale (PSYRATS AHS). The neurophysiological tests employed were cortical and cutaneous silent period, mid-latency auditory evoked potentials (P50, N100, P200) using a paired click paradigm, P300 obtained with an auditory oddball paradigm, and the cognitively driven auditory-motor task (AMT). Time, frequency domains, and functional network organization of different neurophysiological markers were analyzed. P300 oscillatory activity was analyzed with EEG source connectivity (e.g., participation coefficient) and for the auditory-motor task-induced oscillations, we used network integration parameters of graph theory (i.e., characteristic path length - CPL and small worldness - SW). The patient's results obtained after the treatment (T2) were compared with data obtained at baseline condition (T1) and with data from the third group of healthy controls (HC). Results: There were no significant changes between TG and CG on QoL, DASS, and PSYRATS AHS scores or neurophysiological data after the RTMS treatment. We also calculated pre-post RTMS changes for all patients. N100 showed the most marked changes after RTMS in left temporoparietal region, from -0.57 μV (SD 0.97) to -2.39 μV (SD 1.59), (p = 0.006, η2 = 0.346) and in medial posterior region (p = 0.038, η2 = 0.218) suggesting a modulation of this marker over both stimulation sites. After RTMS, N100-P300 voltage increased for six patients, two in TG and four in CG, but also decreased in patients from TG who showed the best clinical outcome. The EEG power spectral density (PSD) during the auditory oddball paradigm increased in T2, mainly for the alpha band and beta band globally, for six subjects, two in TG and four in CG. The connectivity results for the frequent stimuli of the auditory oddball paradigm showed increased network segregation during T2 for the beta band, in seven patients, four in CG, and three in TG. The study revealed that patients with schizophrenia exhibit higher gamma PSD in a period between two auditory commands of AMT, compared to HC, which was modified by RTMS without being significant. The change was visible, locally, over the left temporoparietal region, when the task was done with the non-dominant hand, showing that during this condition, gamma synchronization is a marker of “neural effort” and workload during the working memory-related time and not during the auditory or motor cortical activation. Graph theory analyzed for low-gamma EEG activity elicited in between the auditory stimuli, an epoch of the auditory-motor task we called “non-cortical activation” and which is related to the working memory, showed a decreased SW index after RTMS when the task was performed with the non-dominant hand. This SW effect observed in the patients was similar to that of the HC group. Kendall's tau-b correlation showed a strong, negative correlation between the SW index of low-gamma phase oscillations and PSYRATS AHS scores in T1, which was statistically significant (τb = −0.788, p = 0.032). After RTMS (T2) the correlation was strongly positive (τb = 0.733, p = 0.039). Discussion: The sample size of this study was small to achieve TG-CG statistical significance (e.g., PSYRATS AHS pre-calculated N was 16). Individual data showed controversial results, sometimes with the improvement of AVH severity and neurophysiological data in patients treated at the Cz EEG location. N100 from the paired click paradigm showed the most marked changes at the left temporoparietal region. P300 was performed with a passive auditory oddball paradigm by “automatic” discrimination between two tones without asking the subject to move the finger or count the target stimuli. The findings we obtained with P300 amplitude, which in most cases decreased after RTMS, might be in direct relation to a habituation effect, which is seen in healthy subjects (Polich, 1989). Conclusion: Based on the patient ́s clinical evaluations and all the neurophysiological measurements presented in the studies of this thesis we cannot affirm that left temporoparietal (T3-P3) RTMS is more effective than vertex (Cz) RTMS in patients with schizophrenia and auditory verbal hallucinations. Some interesting neurophysiological observations were made, particularly changes of N100 amplitude at the left temporoparietal region and low gamma activity during the period in between auditory commands of a cognitively driven task. N100 amplitude measured from a paired click paradigm and low gamma activity measured in-between auditory stimuli of AMT performed with the non-dominant hand might be of interest to assess the neuromodulatory aftereffects of RTMS in patients with SCZ and AVH. The small-world network of low gamma activity showed a significant main effect of the condition (AMT and resting state) for HC and SCZ-T2 suggesting that RTMS might have influenced the network by restoring the SW index. Further, studies with a multimodal neurophysiological approach are necessary to assess RTMS effectiveness for patients with SCZ and AVH.
... Because trauma causes hypervigilance, chaos is created in the psyche of a person, causing physiological effects throughout the body (van der Kolk, 2014). Bodily effects are also manifested through weakened immune systems (van der Kolk, 2014) and various autoimmune diseases (Pascual-Leone, Amedi, Fregni, & Merabet, 2005). Neurologically, the brain's plasticity is also hindered by effects of stress and trauma superimposed on it, causing additional effects on the mind, emotions, and body through conditions such as PTSD and OCD (Pittman & Karle, 2015;Siegel, 2007;van der Kolk, 2014). ...
Research
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ABSTRACT The purpose of this study was to explore the Christian leader’s process of meaning-making after a traumatic event. A qualitative narrative inquiry was conducted with six participants to explore how perceived relational engagement with God during ritualized spiritual practices affected opportunities for posttraumatic growth. Questions sought to be answered pertained to identifying a sense of presence in rituals, one’s perceived relationship status of identity and role, how trauma affected one’s perception, what meaning was made that attributed to their growth, and how it influenced their leadership. Data collected included participant self-assessments on trauma and posttraumatic growth, as well as in-depth interviews. This study facilitated opportunity for participants to voice their liminal journey through trauma and beyond. Findings in this study revealed, while participants were looking for a way through their pain in their ritual performances, they needed to (a) be identified with in their pain; (b) be seen, heard, and known at a personal level; (c) have a continued steadfast presence with them; and (d) be met with compassion and grace in their brokenness. Perceiving this kind of presence during participation in ritualized spiritual practices gave indication that participation in rituals offered opportunity for ability of trust and hope to be restored (van der Kolk, 2014). In conclusion, perceiving this kind of presence in rituals offered opportunities of empowerment toward posttraumatic growth as well as a new approach to leading others. Implications and recommendations for further research are provided. Keywords: ritual, trauma, posttraumatic growth, sacred, secular, Christian, God, liminal, presence, spiritual practices, trust, hope, leadership
... Neuroplasticity is the brain's capacity to adapt and change in response to phenomena such as learning, developmental factors, and aging as well as injury or a loss of peripheral input (see Pascual-Leone, Amedi, Fregni, & Merabet, 2005). Cross-modal plasticity, a type of neuroplasticity, occurs after sensory deprivation, which could be a result of disease, brain damage, or other factors and can lead to the strengthening of one or more sensory systems to compensate for the lack of another, reflecting an adaptive strategy (see Merabet & Pascual-Leone, 2009). ...
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In the present study, we investigated the effect of short-term visual deprivation on discriminative touch, cardiac interoception, and thermosensation by asking 64 healthy volunteers to perform four behavioral tasks. The experimental group contained 32 subjects who were blindfolded and kept in complete darkness for 110 minutes, while the control group consisted of 32 volunteers who were not blindfolded but were otherwise kept under identical experimental conditions. Both groups performed the required tasks three times: before and directly after deprivation (or control) and after an additional washout period of 40 minutes, in which all participants were exposed to normal light conditions. Our results showed that short-term visual deprivation had no effect on any of the senses tested. This finding suggests that short-term visual deprivation does not modulate basic bodily senses and extends this principle beyond tactile processing to the interoceptive modalities of cardiac and thermal sensations.
... The concepts of increased vulnerability and neuroplasticity have been used to understand recovery from early traumatic brain injury (TBI), yet the interaction of the timing of brain insult with developmental factors that influence recovery remains unclear (1,2). Some have postulated early childhood TBI may critically disrupt subsequent synaptic organization and modify neural network formation, whereas later TBI may have more localized effects (3)(4)(5). In contrast, some children with acquired injury early in life have exhibited remarkable resiliency, suggesting a capacity for reorganization may also be present (6). ...
Article
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Plasticity is often implicated as a reparative mechanism when addressing structural and functional brain development in young children following traumatic brain injury (TBI); however, conventional imaging methods may not capture the complexities of post-trauma development. The present study examined the cingulum bundles and perforant pathways using diffusion tensor imaging (DTI) in 21 children and adolescents (ages 10-18 years) 5-15 years after sustaining early childhood TBI in comparison with 19 demographically-matched typically-developing children. Verbal memory and executive functioning were also evaluated and analyzed in relation to DTI metrics. Beyond the expected direction of quantitative DTI metrics in the TBI group, we also found qualitative differences in the streamline density of both pathways generated from DTI tractography in over half of those with early TBI. These children exhibited hypertrophic cingulum bundles relative to the comparison group, and the number of tract streamlines negatively correlated with age at injury, particularly in the late-developing anterior regions of the cingulum; however, streamline density did not relate to executive functioning. Although streamline density of the perforant pathway was not related to age at injury, streamline density of the left perforant pathway was significantly and positively related to verbal memory scores in those with TBI, and a moderate effect size was found in the right hemisphere. DTI tractography may provide insight into developmental plasticity in children post-injury. While traditional DTI metrics demonstrate expected relations to Wilde et al. Neuroplasticity 5-15 Years After Early TBI cognitive performance in group-based analyses, altered growth is reflected in the white matter structures themselves in some children several years post-injury. Whether this plasticity is adaptive or maladaptive, and whether the alterations are structure-specific, warrants further investigation.
... Corticospinal plasticity, the ability of the brain to modify neuronal connections, is essential for learning, motor control, improved memory, and recovery from brain injury (Kantak et al. 2012). It can be modified by conditions such as visual, auditory, and proprioception information through adapting the neural connections (Pascual-Leone et al. 2005). Motor training is a process of acquiring information from external sources and accomplishing movement, which is intrinsically associated with neuroplasticity. ...
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Purpose Long-term sports training, such as skill and endurance training, leads to specific neuroplasticity. However, it remains unclear if muscle stretch-induced proprioceptive feedback influences corticospinal facilitation/inhibition differently between skill- and endurance-trained athletes. This study investigated modulation of corticospinal excitability following rapid ankle dorsiflexion between well-trained skill and endurance athletes. Methods Ten skill- and ten endurance-trained athletes participated in the study. Corticospinal excitability was tested by single- and paired-pulse transcranial magnetic stimulations (TMS) at three different latencies following passive rapid ankle dorsiflexion. Motor evoked potential (MEP), short-latency intracortical inhibition (SICI), intracortical facilitation (ICF), and long-latency intracortical inhibition (LICI) were recorded by surface electromyography from the soleus muscle. Results Compared to immediately before ankle dorsiflexion (Onset), TMS induced significantly greater MEPs during the supraspinal reaction period (~ 120 ms after short-latency reflex, SLR) in the skill group only (from 1.7 ± 1.0 to 2.7 ± 1.8%M-max, P = 0.005) despite both conditions being passive. ICF was significantly greater over all latencies in skill than endurance athletes (F(3, 45) = 4.64, P = 0.007), although no between-group differences for stimulations at specific latencies (e.g., at SLR) were observed. Conclusion The skill group showed higher corticospinal excitability during the supraspinal reaction phase, which may indicate a “priming” of corticospinal excitability following rapid ankle dorsiflexion for a supraspinal reaction post-stretch, which appears absent in endurance-trained athletes.
... Active participation during the practice of the tasks is necessary if the aim is to induce neuroplastic changes and promote learning and function (22)(23)(24). To continue inducing neuroplastic changes, the task level of difficulty must also be progressively increased over time (25,26). ...
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Background: Effective science-based motor rehabilitation requires high volume of individualized, intense physical training, which can be difficult to achieve exclusively through physical 1-on-1 sessions with a therapist. Home-based training, enhanced by technological solutions, could be a tool to help facilitate the important factors for neuroplastic motor improvements. Objectives: This review aimed to discover how the inclusion of modern information and communications technology in home-based training programs can promote key neuroplastic factors associated with motor learning in neurological disabilities and identify which challenges are still needed to overcome. Methods: We conducted a thorough literature search on technological home-based training solutions and categorized the different fundamental approaches that were used. We then analyzed how these approaches can be used to promote certain key factors of neuroplasticity and which challenges still need to be solved or require external personalized input from a therapist. Conclusions: The technological approaches to home-based training were divided into three categories: sensory stimuli training, digital exchange of information training, and telerehabilitation. Generally, some technologies could be characterized as easily applicable, which gave the opportunity to promote flexible scheduling and a larger overall training volume, but limited options for individualized variation and progression. Other technologies included individualization options through personalized feedback that might increase the training effect, but also increases the workload of the therapist. Further development of easily applicable and intelligent solutions, which can return precise feedback and individualized training suggestions, is needed to fully realize the potential of home-based training in motor learning activities.
... The human brain retains a high degree of neuroplasticity into adulthood. Functionally dependent neuroplastic responses are maintained through the same mechanisms that allow for profound developmental and learning-dependent changes (Pascual-Leone et al., 2005). Additionally, the adult brain may be subject to mechanical forces that exert mass effects-changing the shape and microstructural organization of the brain (Laitinen et al., 2015). ...
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Humans undergo extreme physiological changes when subjected to long periods of weightlessness, and as we continue to become a space-faring species, it is imperative that we fully understand the physiological changes that occur in the human body, including the brain. In this study, we present findings of brain structural changes associated with long-duration spaceflight based on diffusion magnetic resonance imaging (dMRI) data. Twelve cosmonauts who spent an average of six months aboard the International Space Station (ISS) were scanned in an MRI scanner pre-flight, ten days after flight, and at a follow-up time point seven months after flight. We performed differential tractography, a technique that confines white matter fiber tracking to voxels showing microstructural changes. We found significant microstructural changes in several large white matter tracts, such as the corpus callosum, arcuate fasciculus, corticospinal, corticostriatal, and cerebellar tracts. This is the first paper to use fiber tractography to investigate which specific tracts exhibit structural changes after long-duration spaceflight and may direct future research to investigate brain functional and behavioral changes associated with these white matter pathways.
... For example, many adult stroke patients exhibit post-injury motor cortex plasticity and partial recovery of motor function. [1][2][3] However, the developing brain displays a greater capacity to recover following injury compared to its adult counterpart. [4][5][6][7] Cortical plasticity in the developing brain is readily observed in the case of motor cortex injury, as the motor cortex and/or corticospinal tract is a common site of brain damage, particularly in the pre-or immediately perinatal period. ...
Article
The plasticity of the developing brain can be observed following injury to the motor cortex and/or corticospinal tracts, the most commonly injured brain area in the pre- or peri-natal period. Factors such as timing of injury, lesion size, and lesion location may affect a single hemisphere’s ability to acquire bilateral motor representation. Bilateral motor representation of single hemisphere origin is most likely to occur if brain injury occurs before the age of 2 years; however, the link between injury etiology, reorganization type, and functional outcome is largely understudied. We performed a retrospective review to examine reorganized cortical motor maps identified through transcranial magnetic stimulation in a cohort of 52 patients. Subsequent clinical, anthropometric, and demographic information was recorded for each patient. Each patient’s primary hand motor cortex center of gravity, along with the Euclidian distance between reorganized and normally located motor cortices, was also calculated. The patients were classified into broad groups including reorganization type (inter- and intra-hemispheric motor reorganization), age at time of injury (before 2 years and after 2 years), and injury etiology (developmental disorders and acquired injuries). All measures were analyzed to find commonalities between motor reorganization type and injury etiology, function, and center of gravity distance. There was a significant effect of injury etiology on type of motor reorganization (P < 0.01), with 60.7% of patients with acquired injuries and 15.8% of patients with developmental disorders demonstrating interhemispheric motor reorganization. Within the inter-hemispheric motor reorganization group, ipsilaterally and contralaterally projecting hand motor cortex centers of gravity overlapped, indicating shared cortical motor representation. Furthermore, the data suggest significantly higher prevalence of bilateral motor representation from a single hemisphere in cases of acquired injuries compared to those of developmental origin. Functional outcome was found to be negatively affected by acquired injuries and inter-hemispheric motor reorganization relative to their respective developmental lesions and counterparts with intra-hemispheric motor reorganization. These results provide novel information regarding motor reorganization in the developing brain via an unprecedented cohort sample size and transcranial magnetic stimulation. Transcranial magnetic stimulation is uniquely suited for use in understanding the principles of motor reorganization, thereby aiding in the development of more efficacious therapeutic techniques to improve functional recovery following motor cortex injury.
... It results from neuronal responses to environmental stimuli and internal human brain stimuli, which allows the central nervous system (CNS) to adapt to physiological changes and preexisting experiences. This culminates in a learning mechanism and an increase in and development of new input connections on the neural system [1]. The plasticity of the auditory mode can be defined as the alteration of nerve cells to adjust to the immediate environmental influences, resulting in behavioral changes. ...
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Background and objectives: Even a mild traumatic brain injury can impair the peripheral and central parts of the auditory system. The objective was to compare the performance of individuals with mild traumatic brain injury in behavioral and electrophysiological central auditory tests before and after formal auditory training, and to verify the stability of these measures over time. Subjects and methods: Ten 16- to 64-year-old individuals diagnosed with mild traumatic brain injury underwent behavioral and electrophysiological assessment of the central auditory processing in three stages: before, right after, and six months after formal auditory training. Results: Statistically significant differences were observed for speech by white noise, synthetic sentence identification, sound localization, verbal sequential memory, and duration pattern tests in the assessment six months after formal auditory training. No statistically significant differences were observed between the P300 assessments, either with tone-burst or speech stimulus, in N2 and P3 latencies, and P3 amplitude. Conclusions: The results of the behavioral assessment of the central auditory processing improved, while the P300 remained stable with both stimuli, six months after completing formal auditory training. This demonstrates that auditory training has long-term benefits for people with mild traumatic brain injury.
... The effects of neuroplasticity have been observed experimentally in functional and structural MRI (Magnetic Resonance Imaging), particularly following the acquisition of new motor, perceptual, linguistic, and cognitive skills. At the functional level, this is underpinned by an increase or decrease of regional activation and/or a modification of the functional connectivity between brain regions within a network (Kelly & Garavan, 2005;Pascual-Leone et al., 2005). At the structural level, neuroplasticity can modify white matter tracts linking brain regions, change the density of gray matter areas, and cortical thickness (Zatorre et al., 2012). ...
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Neuroarchaeology is an expanding research field that applies functional brain imaging techniques to participants in order to identify the cerebral regions involved in the production or perception of artefacts produced by past hominins. Neuroarchaeology allows making inferences about hominin cognitive abilities with regards to language, praxis, and cognitive control learning domains. As such, neuroarchaeology allows to postulate hypotheses about the evolution of cognition. This article reviews how neuroimaging techniques have been applied in neuroarchaeology and evaluates the novel insights gained from the merger of these fields. We further describe strategies to conduct research, propose a critical analysis of the results obtained to date, and discuss whether they could be used to propose evolutionary trends.
... As the embodiment of system reorganization, neural plasticity continues through the normal development, maturation, and degradation of the nervous system. In order to understand the essence of neurological or mental diseases, neuroplasticity is an important aspect that cannot be ignored [10,11]. ...
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Objective: Depression is a global mental health problem with high disability rate, which brings a huge disease burden to the world. Electroacupuncture (EA) has been shown to be an effective method for the treatment of depression. However, the mechanism underling the antidepressant effect of EA has not been clearly clarified. The change of synaptic plasticity is the focus in the study of antidepressant mechanism. This study will observe the effect of EA on LTP of hippocampal synaptic plasticity and explore its possible mechanism. Methods: The depression-like behavior rat model was established by chronic unpredictable mild stress (CUMS). EA stimulation (Hegu and Taichong) was used to treat the depressed rats. The depression-like behavior of rats was tested by weight measurement, open field test, depression preference test, and novelty suppressed feeding test. Long-term potentiation (LTP) was recorded at CA1 synapses in hippocampal slices by electrophysiological method. N-methyl-D-aspartate receptor subunit 2B (NR2B) and calmodulin-dependent protein kinase II (CaMK II) protein levels were examined by using western blot. Results: After the establishment of CUMS-induced depression model, the weight gain rate, sucrose preference rate, line crossing number, and rearing times of rats decreased, and feeding time increased. At the same time, the LTP in hippocampus was impaired, and the expressions of NR2B and CaMK II were upregulated. After EA treatment, the depression-like behavior of rats was improved, the impairment of LTP was reversed, and the expression levels of NR2B and CaMK II protein were downregulated. Conclusion: EA can ameliorate depression-like behaviors by restoring LTP induction, downregulating NR2B and CaMK II expression in CUMS model rats, which might be part of the mechanism of EA antidepressant.
... Future research could investigate whether the evolutionary loss of visual function enables the brain to improve the processing of other senses by redelegating neural structures and networks to other senses. There is extensive evidence for compensatory plasticity in blind individuals, such that the other senses have increased sensitivity due to increased use (Kupers and Ptito, 2011), though it has also been theorized that the high plasticity of the visual cortex is essential for these enhancements (Merabet and Pascual-Leone, 2010;Pascual-Leone et al., 2005). ...
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Research on the origin of vision and vision loss in naturally “blind” animal species can reveal the tasks that vision fulfills and the brain's role in visual experience. Models that incorporate evolutionary history, natural variation in visual ability, and experimental manipulations can help disentangle visual ability at a superficial level from behaviors linked to vision but not solely reliant upon it, and could assist the translation of ophthalmological research in animal models to human treatments. To unravel the similarities between blind individuals and blind species, we review concepts of 'blindness' and its behavioral correlates across a range of species. We explore the ancestral emergence of vision in vertebrates, and the loss of vision in blind species with reference to an evolution-based classification scheme. We applied phylogenetic comparative methods to a mammalian tree to explore the evolution of visual acuity using ancestral state estimations. Future research into the natural history of vision loss could help elucidate the function of vision and inspire innovations in how to address vision loss in humans.
... Obsessive-compulsive disorder (OCD) is a disabling condition with a lifetime prevalence of 2%23% (1), with only 40% 260% of patients achieving partial response to treatment (2). Noninvasive brain stimulation may represent an alternative novel treatment, which can modulate neuronal excitability, activity, and plasticity (3,4). The cortical-striatal-thalamiccortical (CSTC) loop circuit, which projects from the cortex to the striatum, from the striatum to the thalamus (via the globus pallidus), and then back to the cortex (5,6), has been implicated in OCD. ...
Article
(Appeared originally in American Journal of Psychiatry 2019; 176:931-938) Reprinted with permission from American Psychiatric Association Publishing.
... Several genetic, molecular, and cellular mechanisms can modulate the synapses of neuronal circuits and cause functional improvement, loss, and/or behavioral changes (Johnston, 2009). The plasticity of the nervous tissue after stimuli or injury is more evident during the early postnatal period, i.e., a time window known as the critical period (CP) for neuroplasticity (Pascual-Leone et al., 2005). This short postnatal time window is characterized by heightened nervous system receptivity for adapting to stimuli provides a stable and long-term experiential foundation (Wiesel and Hubel, 1965). ...
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The plasticity of the central nervous system (CNS) allows the change of neuronal organization and function after environmental stimuli or adaptation after sensory deprivation. The so-called critical period (CP) for neuroplasticity is the time window when each sensory brain region is more sensitive to changes and adaptations. This time window is usually different for each primary sensory area: somatosensory (S1), visual (V1), and auditory (A1). Several intrinsic mechanisms are also involved in the start and end of the CP for neuroplasticity; however, which is its duration in S1, VI, and A1? This systematic review evaluated studies on the determination of these time windows in small rodents. The careful study selection and methodological quality assessment indicated that the CP for neuroplasticity is different among the sensory areas, and the brain maps are influenced by environmental stimuli. Moreover, there is an overlap between the time windows of some sensory areas. Finally, the time window duration of the CP for neuroplasticity is predominant in S1.
... Cerebral plasticity is considered an intrinsic property of the human nervous system, one that is continuously changing as a consequence of all neural activity. In the instance of pathophysiologic processes, intra-and inter-hemispheric interactions may shift over time to promote the establishment of new structural or functional changes [1]. The brain's capability of reorganising itself in light of said processes has been particularly apparent in the clinical context of ischaemic stroke, whereby the sudden loss of specialized neural tissue may indicate a reorganisation of homologous functional architecture [2]. ...
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The infiltrative character of supratentorial lower grade glioma makes it possible for eloquent neural pathways to remain within tumoural tissue, which renders complete surgical resection challenging. Neuromodulation-Induced Cortical Prehabilitation (NICP) is intended to reduce the likelihood of premeditated neurologic sequelae that otherwise would have resulted in extensive rehabilitation or permanent injury following surgery. This review aims to conceptualise current approaches involving Repetitive Transcranial Magnetic Stimulation (rTMS-NICP) and extraoperative Direct Cortical Stimulation (eDCS-NICP) for the purposes of inducing cortical reorganisation prior to surgery, with considerations derived from psychiatric, rehabilitative and electrophysiologic findings related to previous reports of prehabilitation. Despite the promise of reduced risk and incidence of neurologic injury in glioma surgery, the current data indicates a broad but compelling possibility of effective cortical prehabilitation relating to perisylvian cortex, though it remains an under-explored investigational tool. Preliminary findings may prove sufficient for the continued investigation of prehabilitation in small-volume lower-grade tumour or epilepsy patients. However, considering the very low number of peer-reviewed case reports, optimal stimulation parameters and duration of therapy necessary to catalyse functional reorganisation remain equivocal. The non-invasive nature and low risk profile of rTMS-NICP may permit larger sample sizes and control groups until such time that eDCS-NICP protocols can be further elucidated.
... Experiencebased neuroplasticity studies have shown that repeated and frequent participation in a particular sport alters the relevant neural representations (Calvo-Merino et al., 2006;Koeneke et al., 2004;Naito & Hirose, 2014;Weisberg, van Turennout & Martin, 2007). Changes in neuroplasticity caused by sports training could explain why elite athletes outperform novices and non-athletes (Jellinger, 2007;Kelly & Garavan, 2005;Pascual-Leone et al., 2005;Raz & Lindenberger, 2013). The rapid disinhibition speed of table tennis players may be one of the manifestations of the changes in neuroplasticity caused by long-term sports training. ...
Article
Objective: To explore the mechanism behind the faster volitional reaction time (RT) of open skill sports athletes from the perspective of proactive inhibitory control, with the hypothesis that the superior response speed of athletes from open skill sports is related to their enhanced capacity for releasing inhibition. Methods: Participants were divided into two groups, an experimental group of 27 table tennis players and a control group of 27 non-athletes. By manipulating cue-target onset asynchrony (CTOA) in a simple cue-target detection task, the timing of target presentation occurred in different phases of the disinhibition process. The time needed for disinhibition were compared between groups. Results: For the experimental group, RT varied with CTOA at delays less than 200 ms; for CTOAs greater than 200 ms, RTs were not significantly different. For the control group, RT varied with CTOA for delays as long as 300 ms. Conclusions: Table tennis players took less time (200 ms) than non-athletes (300 ms) to complete the disinhibition process, which might partly explain their rapid response speed measured in unpredictable contexts. Significance: The study provided evidence for disinhibition speed as a new index to assess the capacity of proactive inhibitory control, and provided a new perspective to explore the superior RT of athletes from open skill sports. We also offered support for the fundamental cognitive benefits of table tennis training.
... Although such pathological processes occur from the beginning of the disease, the accumulation of structural CNS damage typically remains subclinical and hardly detectable in the earliest phases of MS due to CNS plasticity. This phenomenon reflects the ability of the CNS to change and modulate its activity in response to pathological stimuli and damage by reorganizing its structure, functions, or connections [26,27]. Structural and functional CNS plasticity may be able, especially in younger MS patients, with milder structural damage and disease duration, to compensate the progressive accumulation of MS-related structural damage. ...
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Multiple sclerosis (MS) is a chronic and progressive neurological disease that is characterized by neuroinflammation, demyelination and neurodegeneration occurring from the earliest phases of the disease and that may be underestimated. MS patients accumulate disability through relapse-associated worsening or progression independent of relapse activity. Early intervention with high-efficacy disease-modifying therapies (HE-DMTs) may represent the best window of opportunity to delay irreversible central nervous system damage and MS-related disability progression by hindering underlying heterogeneous pathophysiological processes contributing to disability progression. In line with this, growing evidence suggests that early use of HE-DMTs is associated with a significant greater reduction not only of inflammatory activity (clinical relapses and new lesion formation at magnetic resonance imaging) but also of disease progression, in terms of accumulation of irreversible clinical disability and neurodegeneration compared to delayed HE-DMT use or escalation strategy. These beneficial effects seem to be associated with acceptable long-term safety risks, thus configuring this treatment approach as that with the most positive benefit/risk profile. Accordingly, it should be mandatory to treat people with MS early with HE-DMTs in case of prognostic factors suggestive of aggressive disease, and it may be advisable to offer an HE-DMT to MS patients early after diagnosis, taking into account drug safety profile, disease severity, clinical and/or radiological activity, and patient-related factors, including possible comorbidities, family planning, and patients’ preference in agreement with the EAN/ECTRIMS and AAN guidelines. Barriers for an early use of HE-DMTs include concerns for long-term safety, challenges in the management of treatment initiation and monitoring, negative MS patients’ preferences, restricted access to HE-DMTs according to guidelines and regulatory rules, and sustainability. However, these barriers do not apply to each HE-DMT and none of these appear insuperable.
... Changes in brain structure and function are not unexpected in these circumstances. When an uninterrupted recurrent task is executed with the overuse of motor and/or cognitive functions for a prolonged period of time, cerebral plasticity spontaneously reorganizes the brain circuitry and adapts to the newly desired behavioural outcome (see Pascual-Leone et al., 2005). ...
Article
This study aimed to investigate the impact of an extreme mountain ultramarathon (MUM) on spontaneous electrical brain activity in a group of 16 finishers. By using 4-minute high-density electroencephalographic (EEG) recordings with eyes closed before and after a 330-km race (mean duration: 125±17 hours; sleep duration: 7.7±2.9 hours), spectral power, source localization and microstate analyses were conducted. After the race, power analyses revealed a centrally localized increase in power in the delta (0.5-3.5 Hz) and theta (4.0-7.5 Hz) frequency bands and a decrease in alpha (8.0-12.0 Hz) power at the parieto-occipital sites. Higher brain activation in the alpha frequency band was observed within the left posterior cingulate cortex, left angular gyrus and visual association areas. Microstate analyses indicated a significant decrease in map C predominance and an increase in the global field power (GFP) for map D at the end of the race. These changes in power patterns and microstate parameters contrast with previously reported findings following short bouts of endurance exercises. We discuss the potential factors that explain lower alpha activity within the parieto-occipital regions and microstate changes after MUMs. In conclusion, high-density EEG resting-state analyses can be recommended to investigate brain adaptations in extreme sporting activities.
... Since our behavior is defined by our learning experiences, in addition to effective treatment for any organic pathology, recovery from cognitive and behavioral disorder requires relearning and more intensive positive stimulation than in normative learning in order to trigger a stronger neurophysiological response to rebuild stagnant cognitive neurocircuitry and/or rewire cognitive connections from negative (i.e., maladaptive or distorted) cognitive constructs to positive cognitive constructs (cognitive constructs = conceptual orientations) and override and transform negative behavioral patterns set through the previous negative experience. The design, content and application of such a more intensive positive stimulation or positive learning environment, is referred to as the 'enriched environment' (for studies on the enriched environment and its efficacy in recovery from cognitive and behavioral disorder, see, for example: Alwis & Rajan, 2014;Hannan, 2014;Kleim & Jones, 2008;Kleim, 2011;Sampedro-Piquero & Begega, 2017;Nithianantharajah &Hannan, 2006 andvan Praag, Kempermann, & Gage, 2000;Hebb, 1947;Taubert, Villringer, & Ragert, 2012;Draganski & May, 2008;May, 2011;Pascual-Leone, Amedi, Fregni, & Merabet, 2005;Woo, Donnelly, Steinberg-Epstein, & Leon, 2015;Sweatt, 2016). ...
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This study identifies the determining factors in the evolution of the uniquely human social brain by which the antecedents of the core behavioral framework of the anatomically modern human were molded. This study examines our core behavior and demonstrates 1) how it defines us as human and 2) how it forms the essential foundation upon which cognitive acuity/fluidity and mental health are maintained. From this revolutionary paradigm shift in the understanding of mental health, and its converse, mental disorder, a breakthrough neuroscience-informed modality of Cognitive Neuroeducation (CNE) has emerged for the prevention of and recovery from cognitive and behavioral disorder.
... The neuroplasticity hypothesis of depression is a recent neurobiological theory of major depressive disorder (MDD). Neuroplasticity is a phenomenon characterized by neuronal adaptation, i.e., the brain's ability to reorganize itself when facing an internal or external stimulus (4)(5)(6)(7)(8). MDD is strongly linked to abnormalities in neuroplasticity shown through neuroimaging and pharmacological studies (9,10). ...
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The mechanism of action underlying ketamine’s rapid antidepressant effects in patients with depression, both suffering from major depressive disorder (MDD) and bipolar disorder (BD), including treatment resistant depression (TRD), remains unclear. Of the many speculated routes that ketamine may act through, restoring deficits in neuroplasticity may be the most parsimonious mechanism in both human patients and preclinical models of depression. Here, we conducted a literature search using PubMed for any reports of ketamine inducing neuroplasticity relevant to depression, to identify cellular and molecular events, relevant to neuroplasticity, immediately observed with rapid mood improvements in humans or antidepressant-like effects in animals. After screening reports using our inclusion/exclusion criteria, 139 publications with data from cell cultures, animal models, and patients with BD or MDD were included (registered on PROSPERO, ID: CRD42019123346). We found accumulating evidence to support that ketamine induces an increase in molecules involved in modulating neuroplasticity, and that these changes are paired with rapid antidepressant effects. Molecules or complexes of high interest include glutamate, AMPA receptors (AMPAR), mTOR, BDNF/TrkB, VGF, eEF2K, p70S6K, GSK-3, IGF2, Erk, and microRNAs. In summary, these studies suggest a robust relationship between improvements in mood, and ketamine-induced increases in molecular neuroplasticity, particularly regarding intracellular signaling molecules.
... Similarly, learning processes promoted by behavioral training can lead to the strengthening of existing neural pathways and to new changes or adaptations, and thus, the expression of neuroplasticity (Pascual-Leone et al., 2005). Since noninvasive brain stimulation and behavioral therapies share similar mechanisms of action to induce neuroplastic changes in the human cortex, a possible conjecture is that their combined use can maximize their individual effects since the learning processes are accompanied by changes in cortical excitability and changes in synaptic efficacy. ...
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Background We investigated whether transcranial magnetic stimulation (rTMS) over the primary somatosensory cortex (S1) and sensory stimulation (SS) could promote upper limb recovery in participants with subacute stroke. Methods Participants were randomized into four groups: rTMS/Sham SS, Sham rTMS/SS, rTMS/SS, and control group (Sham rTMS/Sham SS). Participants underwent ten sessions of sham or active rTMS over S1 (10 Hz, 1,500 pulses, 120% of resting motor threshold, 20 min), followed by sham or active SS. The SS involved active sensory training (exploring features of objects and graphesthesia, proprioception exercises), mirror therapy, and Transcutaneous electrical nerve stimulation (TENS) in the region of the median nerve in the wrist (stimulation intensity as the minimum intensity at which the participants reported paresthesia; five electrical pulses of 1 ms duration each at 10 Hz were delivered every second over 45 min). Sham stimulations occurred as follows: Sham rTMS, coil was held while disconnected from the stimulator, and rTMS noise was presented with computer loudspeakers with recorded sound from a real stimulation. The Sham SS received therapy in the unaffected upper limb, did not use the mirror and received TENS stimulation for only 60 seconds. The primary outcome was the Body Structure/Function: Fugl-Meyer Assessment (FMA) and Nottingham Sensory Assessment (NSA); the secondary outcome was the Activity/Participation domains, assessed with Box and Block Test, Motor Activity Log scale, Jebsen-Taylor Test, and Functional Independence Measure. Results Forty participants with stroke ischemic ( n = 38) and hemorrhagic ( n = 2), men ( n = 19) and women ( n = 21), in the subacute stage (10.6 ± 6 weeks) had a mean age of 62.2 ± 9.6 years, were equally divided into four groups (10 participants in each group). Significant somatosensory improvements were found in participants receiving active rTMS and active SS, compared with those in the control group (sham rTMS with sham SS). Motor function improved only in participants who received active rTMS, with greater effects when active rTMS was combined with active SS. Conclusion The combined use of SS with rTMS over S1 represents a more effective therapy for increasing sensory and motor recovery, as well as functional independence, in participants with subacute stroke. Clinical Trial Registration [ clinicaltrials.gov ], identifier [NCT03329807].
... Nowadays the research focus is directed onto short-term and medium-term changes in the function of neural networks. Using brain imaging methods it was shown that training of various psychological functions leads to changed activation patterns both in terms of haemodynamic responses or electrophysiological activation (Pascual-Leone et al. 2005). Interestingly, even psychological interventions such as those used during psychotherapy lead to changed activation patterns to visual or auditory stimuli normally evoking neurotic responses (Straube et al. 2004;Straube et al. 2005). ...
... Thus, both functional and dysfunctional behaviors are susceptible of modifications [40], just as the neural networks can change through the processes of synaptogenesis and neurogenesis [10]. So, in a few words, such processes can be discussed along with the general conception of neural plasticity through which it is possible to modulate the individual responses to the environment [56]. ...
Article
Substance and behavioral addiction is a global health problem related to cognitive functioning and emotional responses like top-down control and craving. The present review discusses the role of non-invasive brain stimulation (NIBS) and cognitive-behavioural therapy (CBT) as evidence-based treatments for addiction disorders. The discussion spans between several evidence for both therapies, also considering the difference and heterogeneity among clinical protocols. Nowadays, literature is consistent in indicating the neurostimulation of the prefrontal cortex as effective for different kinds of addiction, corroborating the evidence that they rely on a common network in the brain. Likewise, within the CBT studies it is possible to observe a wide range of interventions that are overall effective in regulating the executive functions associated with addiction disorders. Nevertheless, the integration of NIBS and CBT in addictions has been scarcely considered in literature so far. For this reason, the present article is meant to foster empirical research in this field by highlighting the findings supporting these evidence-based interventions, both as stand-alone and integrated treatments. To this aim, psychological and neurophysiological mechanisms of NIBS and CBT in addictions are reviewed, and the rationale of their integration discussed. In particular, as evidence suggest these treatments affect top-down and bottom-up processes in different ways, with NIBS reducing craving and CBT boosting motivation and coping, we suggest their combination might better target the different components of addiction to promote abstinence.
... Foveal scotoma due to macular photoreceptor atrophy in AMD has caused vision loss and blindness for a large number of individuals globally, particularly in developed countries (Rosengarth et al., 2013;Wong et al., 2014). Previous studies in animals (Kaas et al., 1990;Darian-Smith and Gilbert, 1995;Giannikopoulos and Eysel, 2006) and humans (Pascual-Leone et al., 2005;Liu et al., 2007) have demonstrated altered cerebral functions in response to reduced visual input, but the extent of cerebral changes associated with AMD remains unclear and has attracted the attention of many researchers. Our study has indicated that FC values are significantly increased in the IFG, SFG, IPL, RTG, and SPL, and decreased in the CPL, MCG, MDL, CAL, and TLM in AMDs compared with HCs (Figure 6). ...
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Objective Age-related macular degeneration (AMD) causes visual damage and blindness globally. The purpose of this study was to investigate changes in functional connectivity (FC) in AMD patients using resting-state functional magnetic resonance imaging (rs-fMRI). Subjects and Methods A total of 23 patients (12 male, 11 female) with AMD were enrolled to the AMD patients group (AMDs), and 17 healthy age-, sex-, and education-matched controls (9 male, 8 female) to the healthy controls group (HCs). All participants underwent rs-fMRI and mean FC values were compared between the two groups. Results Significantly higher FC values were found in the inferior frontal gyrus (IFG), superior frontal gyrus (SFG), inferior parietal lobule (IPL), rectal gyrus (RTG), and superior parietal lobule (SPL) in AMDs compared with HCs. Conversely, FC values in the cerebellum posterior lobe (CPL), middle cingulate gyrus (MCG), medulla (MDL), cerebellum anterior lobe (CAL), and thalamus (TLM) were significantly lower in AMDs than in HCs. Conclusion This study demonstrated FC abnormalities in many specific cerebral regions in AMD patients, and may provide new insights for exploration of potential pathophysiological mechanism of AMD-induced functional cerebral changes.
... It was long postulated that neuroplasticity was limited only to the critical period during brain development (Michelini & Stern, 2009). However, during the past decades, it has been widely recognized that neuroplasticity is the normal ongoing state of the human brain throughout the life span (Pascual-Leone et al., 2005). This feature of the brain is considered as one of the foundations for acquisition of new motor skills. ...
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Motor training is a widely used therapy in many pain conditions. The brain’s capacity to undergo functional and structural changes i.e., neuroplasticity is fundamental to training-induced motor improvement and can be assessed by transcranial magnetic stimulation (TMS). The aim was to investigate the impact of pain on training-induced motor performance and neuroplasticity assessed by TMS. The review was carried out in accordance with the PRISMA-guidelines and a Prospero protocol (CRD42020168487). An electronic search in PubMed, Web of Science and Cochrane until December 13, 2019, identified studies focused on training-induced neuroplasticity in the presence of experimentally-induced pain, 'acute pain' or in a chronic pain condition, 'chronic pain'. Included studies were assessed by two authors for methodological quality using the TMS Quality checklist, and for risk of bias using the Newcastle–Ottawa Scale. The literature search identified 231 studies. After removal of 71 duplicates, 160 abstracts were screened, and 24 articles were reviewed in full text. Of these, 17 studies on acute pain (n = 7) or chronic pain (n = 10), including a total of 258 patients with different pain conditions and 248 healthy participants met the inclusion criteria. The most common types of motor training were different finger tasks (n = 6). Motor training was associated with motor cortex functional neuroplasticity and six of seven acute pain studies and five of ten chronic pain studies showed that, compared to controls, pain can impede such trainings-induced neuroplasticity. These findings may have implications for motor learning and performance and with putative impact on rehabilitative procedures such as physiotherapy.
Thesis
The main goal of neuroscience is to bridge the gap from “membrane” to “mind” via empirical research that elucidates the functional processes from neuron to brain, or theoretical models that frame the cognitive flow from thought to action. Yet, in spite of great, technology-enabled advances in our knowledge of basic neural mechanisms, we still struggle to understand how abstract higher-order cognitive functions such as intention formation finally give rise to goal-directed behavior. Likewise, how external stimuli may precipitate subconscious, yet purposeful action remains unclear. The reasons for these difficulties are both methodological and conceptual in nature and might, in both cases, stem from neglect to account for the multiscale organizational elements in the human brain: for instance, connectivity analyses based on functional MRI (fMRI) routinely pre-process data with an arbitrarily selected single spatial filter, thereby obscuring cortical activity at other observation scales; similarly, signal sampling for BCI applications is usually limited to single lower-order processing areas, although neuronal correlates of intention are more likely to be distributed across higher-order association regions. This doctoral thesis investigates the spatial multiscale dimension of neocortical network activity as observed via fMRI recordings and devises an integrative hierarchical model of intention formation informed by neuroscientific evidence and philosophical concepts established in the field of action theory. Multiscale, surface-constrained pre-processing of movement-related data reveals spatiotemporal features of the hemodynamic response previously unknown in spite of the ubiquitous use of fMRI as an investigative tool: the biphasic response function underlying the majority of fMRI studies in the past 20 years is called into question, as the post-stimulus response undershoot is shown as a surround effect absent from higher-order processing areas; these multiscale data sets also lend themselves to the analysis of cortical networks and the scale-dependent variability of interregional network connections, indicating a possible relation to different levels of the processing hierarchy. Finally, the current neuroscientific and philosophical theories on intention formation are contrasted with each other, and suggested to reflect two opposed, yet complementing streams of top-down and bottom-up influences that scale across time and brain regions as they become integrated in a dynamic process before resulting in intentional, goal-directed action.
Chapter
It is very often reported that 85–90% of driving clues come from vision (Senders et al., 1967; though see also Sivak, 1996). Despite this claim, and many others suggesting the importance and even ‘dominance’ of vision on our daily activities, research in the field of psychology and neurosciences has clearly shown that the large majority of our interactions with the world are actually ‘multisensory’ in nature (e.g., Calvert et al., 2004; see also Ghazanfar & Schroeder, 2006, for a discussion on the multisensory architecture of our brain cortex). Our brain continuously processes information from several sensory sources and integrates them into neural representations that are used to direct our movements and organize more or less complex forms of behaviors. This should not come to a surprise to the average sailor who often experiences the importance of all the senses in their beloved activity. That does not come as a surprise either to those who tried sailing for the very first time, and certainly not to the many visually disabled people who have, at least once, enjoyed sailing activities. Actually, as a sailor and neuroscientist, I would be in trouble to try and choose what ‘the most important sense’ for sailing is.
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Das Gehirn des Menschen bestimmt unser Denken, Handeln und Fühlen. Ebenso wie außergewöhnliche kognitive und motorische Leistungen werden psychiatrische und psychopathologische Probleme durch neurophysiologische und neuroanatomische Besonderheiten des Gehirns bestimmt. Eine Idee, psychische oder neurologische Störungen zu behandeln ist, die Gehirnaktivität durch unterschiedliche invasive oder nicht-invasive Verfahren zu beeinflussen.
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This chapter summarizes recent neuroimaging findings of the brain mechanisms related to dental fear/anxiety. It first outlines the theoretical framework of brain mechanisms of pain, which has been substantially influenced by the concept of ‘neuromatrix’. The chapter then outlines the brain mechanisms of chronic pain, especially the difference of brain activation between chronic and acute pain. It briefly discusses the role of neural plasticity in pain and behaviour. Specifically, the chapter focuses on the mechanisms of central sensitization and on the recent neuroimaging findings on the brain mechanisms of chronic orofacial pain. Particularly, it also focuses on the potential brain mechanisms of pain related to temporomandibular disorder and trigeminal neuropathy, two major challenges in the clinical management of orofacial pain. Finally, the chapter discusses a hotly debated question in translational medicine, i.e. if one can find an objective neuroimaging marker to predict one's feeling about pain.
Chapter
This chapter discusses the mechanisms of neuroplasticity and briefly summarizes the advantage of neuroimaging in studying brain plasticity. It looks into how individuals adapt to oral sensory stimuli. The chapter highlights the role of the brain in such an adaptive process. The functional adaptation of mastication and swallowing, which aim to improve the performance of feeding under environmental challenges (e.g. tooth loss), may be associated with complicated mechanisms of sensorimotor, cognitive and affective processing of oral functions. This chapter discusses recent neuroimaging evidence of brain plasticity associated with the adaptation of oral functions. Research design of this topic is discussed. The chapter also discusses the association between mastication and masticatory muscle pain, in which adaptation may play a key role. It provides information on the association between brain plasticity, functional adaptation and the approaches to improve oral functions.
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Study Objectives To determine whether sleep at baseline (before therapy) predicted improvements in language following either language therapy alone or coupled with transcranial direct current stimulation (tDCS) in individuals with primary progressive aphasia (PPA). Methods Twenty-three participants with PPA (mean age 68.13 ± 6.21) received written naming/spelling therapy coupled with either anodal tDCS over the left inferior frontal gyrus (IFG) or sham condition in a crossover, sham-controlled, double-blind design (ClinicalTrials.gov identifier: NCT02606422). The outcome measure was percent of letters spelled correctly for trained and untrained words retrieved in a naming/spelling task. Given its particular importance as a sleep parameter in older adults, we calculated sleep efficiency (total sleep time/time in bed x100) based on subjective responses on the Pittsburgh Sleep Quality Index (PSQI). We grouped individuals based on a median split: high versus low sleep efficiency. Results Participants with high sleep efficiency benefited more from written naming/spelling therapy than participants with low sleep efficiency in learning therapy materials (trained words). There was no effect of sleep efficiency in generalization of therapy materials to untrained words. Among participants with high sleep efficiency, those who received tDCS benefitted more from therapy than those who received sham condition. There was no additional benefit from tDCS in participants with low sleep efficiency. Conclusion Sleep efficiency modified the effects of language therapy and tDCS on language in participants with PPA. These results suggest sleep is a determinant of neuromodulation effects. Clinical Trial: tDCS Intervention in Primary Progressive Aphasia https://clinicaltrials.gov/ct2/show/NCT02606422
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102 постинсультных больных. Были проанализированы кли-нические данные пациентов, результаты нейровизуализационного исследования, степень пареза по 6-балльной шкале оценки мышечной силы, уровень когнитивных нарушений по шкале скрининг-исследования когнитивных функций Mini-Mental State Examination (MMSE). В двух группах проводилась многоуровневая и транскраниальная магнитная стимуляции по разработанным нами методикам, а в третьей группе проводилась ложная транскра-ниальная магнитная стимуляция. Результаты и их обсуждение. Оценка результатов показателей шкалы MMSE после лечения выявила увеличение среднего балла по пунктам ориентации, восприятия, внимания и калькуляции, памяти, речи в обеих лечебных группах (р<0,05). Отмечалось достоверное увеличение на 17,8% суммарной средней оценки выше 24 баллов в группе с многоуровневой магнитной стимуля-цией, которое расценивалось как значительный позитивный эффект в улучшении когнитивных функций. При распределении средней оценки по шкале MMSE по восстановительным периодам инсульта отмечалась положительная динамика на всех этапах заболевания в группах с многоуровневым и транскраниальным воз-действием, в группе плацебо изменения не выявлены. Выводы. Применение лечебных методик ритмической транскраниальной и многоуровневой магнитной стимуляции у постинсультных пациентов способствует улучшению клинического течения заболевания, регрессу моторного дефицита, способствует уменьшению степени когнитивных расстройств-нарушений памяти, внимания, ориентации, речи, чтения, уменьшению дезадаптации и за счет этого повышению уровня повседневной бытовой активности. Ключевые слова: церебральный инсульт, постинсультные пациенты, транскраниальная магнитная стимуляция, многоуровневая магнитная стимуляция, экспресс-оценка состояния когнитивных функций, когнитивные нарушения. Для ссылки: Мамедова, М.Ю. Влияние ритмической транскраниальной и многоуровневой магнитной стимуляции на когнитивные нарушения у постинсультных больных / М.Ю. Мамедова // Вестник современной клинической медицины. Abstract. Background. Cognitive impairment in post-stroke patients is often a major cause of social limitations. They seem insignificant and are masked by prominent post-stroke motor disorders, but negatively affect rehabilitation outcomes with loss of learning skills. Application of transcranial magnetic stimulation using multiple variations of schemes, its feature of noninvasive influence on the central and peripheral nervous system and modification of plasticity processes, appears effective for therapy in post-stroke patients, both in the acute and recovery periods. Aim. The aim of the study was to investigate the effect of the developed therapeutic techniques of rhythmic transcranial and multilevel magnetic stimulation on cognitive functions in post-stroke patients. Material and methods. An open placebo-controlled clinical trial of 102 post-stroke patients was conducted. Clinical data of patients, results of neuroimaging study, degree of paresis according to 6-point muscle strength rating scale, and level of cognitive impairment according to Mini-Mental State Examination-MMSE cognitive screening scale were analyzed. Two groups underwent multilevel and transcranial magnetic stimulation according to our developed methods, and the third group underwent false transcranial magnetic stimulation. Results and discussions. Evaluation of the MMSE scale scores after treatment revealed an increase in the mean scores on the items of orientation, perception, attention and calculation, memory, and speech in both treatment groups (p<0,05). There was a significant 17,8% increase in the cumulative mean score above 24 points in the group with multilevel magnetic stimulation, which was regarded as a significant positive effect in improving cognitive function. The distribution of the mean MMSE score by stroke recovery periods showed positive dynamics at all stages of the
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Riassunto La gestione e la rieducazione delle lesioni nervose periferiche richiedono una stretta collaborazione tra chirurgo e rieducatore, entrambi specialisti, uno in microchirurgia e l’altro in rieducazione sensorimotoria. Sul piano chirurgico, le lesioni dei nervi periferici devono essere riparate sotto ingrandimento ottico, o mediante sutura diretta o mediante innesto o guida della ricrescita del nervo. La valutazione e la rieducazione sensitivomotoria devono essere precoci. La conoscenza dei meccanismi fisiologici postlesionali è necessaria per condurre con successo questa gestione. Per la sensibilità, ricercheremo i territori ipoestesici, disestesici o allodinici utilizzando test di discriminazione e quantificazione. La motricità, dal canto suo, sarà valutata muscolo per muscolo e quantificata tramite una griglia di valutazione muscolare. Prima di ogni rieducazione è necessaria una fase preventiva, durante la quale si possono implementare delle ortesi. Si tratta di mantenere il trofismo muscolare e la flessibilità articolare. In un secondo tempo, la rieducazione diviene più complessa e si intensifica in funzione dei progressi sensoriali e motori. L’adesione da parte del paziente e la comprensione del suo trattamento sono fondamentali. Quando non è possibile un ritorno allo stato precedente, saranno realizzati degli adattamenti per consentire lo svolgimento delle attività della vita quotidiana. La prognosi è generalmente buona, ma sono spesso presenti sequele funzionali sensitive e/o motorie di cui occorre tenere conto per realizzare un reinserimento socioprofessionale ottimale.
Thesis
Touch plays a fundamental role in our daily activities. It has long been known that, thanks to brain plasticity, tactile acuity can be improved following training. Another form of tactile improvement, independent from training, can be achieved through a simple mechanical stimulation of a small region of the skin, called repetitive somatosensory stimulation (RSS). RSS of a finger was well known to improve tactile acuity locally (on the stimulated finger) and also remotely (on the face). However, topography of tactile improvement, especially on other unstimulated fingers, was unknown. In addition, the hypothesis of applying the RSS to another body region (notably the face) and investigate the possible effects, both in face and fingers, was not explored. The aim of this work of thesis was therefore investigating the topography of the RSS-induced tactile improvement within and between body regions. One first study revealed that RSS of a finger induces tactile improvement both locally and remotely in fingers. The second study showed that, when applied on the face, RSS is able to induce tactile improvement both locally, on the face, and remotely, in the hand, demonstrating that the tactile improvement between the hand and the face is bidirectional. Overall, the experimental data I provide constitute a significant contribution to the study of the topography of RSS-induced tactile changes
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Resumen El tratamiento y la rehabilitación de las lesiones de los nervios periféricos requieren una estrecha colaboración entre los cirujanos y los especialistas en rehabilitación, uno especializado en microcirugía y el otro en rehabilitación sensitivomotora. Desde el punto de vista quirúrgico, las lesiones de los nervios periféricos deben repararse bajo aumento óptico, bien mediante sutura directa, bien mediante injerto o tratamiento de regeneración nerviosa. La evaluación y la rehabilitación sensitivomotora deben llevarse a cabo en una fase temprana. El conocimiento de los mecanismos fisiológicos posteriores a la lesión es necesario para el éxito del tratamiento. En cuanto a la sensibilidad, se buscarán territorios hipoestésicos, disestésicos o alodínicos mediante pruebas de discriminación y cuantificación. La motricidad se evaluará músculo por músculo y se cuantificará mediante un sistema de puntuación muscular. Antes de cualquier rehabilitación, es necesaria una fase preventiva, durante la cual es posible el uso de dispositivos ortopédicos. El objetivo es mantener la troficidad muscular y la flexibilidad articular. En una segunda fase, la rehabilitación se hace más compleja y se intensifica en función de los progresos sensitivos y motores. La adhesión del paciente y la comprensión de su tratamiento son esenciales. Cuando no sea posible volver al estado anterior, se pondrán en marcha adaptaciones que permitan realizar las actividades de la vida diaria. El pronóstico suele ser bueno, pero a menudo hay secuelas funcionales sensitivas y/o motoras que deben tenerse en cuenta para garantizar una reinserción socioprofesional óptima.
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I’m writing from the perspective of a neuroscience teacher and researcher with a systems level approach rather than a molecular approach to nervous system concepts and principles. Furthermore, I’ve placed emphasis on information that may be most relevant to those who aspire to be, or are, healthcare professionals that choose rehabilitation as the entry point into patient care. I’ve included “classic” information as well as more recent discoveries that build on or challenge the “classics.” As an instructor, I find teaching neuroscience to be a wonderful challenge to make such information accessible to students at many levels of education: from undergraduate to graduate predoctoral, doctoral and professional doctoral students. I do not have a mathematical mind although I have great respect for those who understand nature “by the numbers.” I use what one might call a “mechanistic” approach. I’ve found most learners I have encountered can follow and use this approach as an analogy for often complex processes that are likely to be probabilistic (mathematically speaking) in their actual occurrence. Also you may notice I provide a sprinkling of humor in my writing much as I do in the classroom because an engaged brain retains a sense of humor even if it is not explicitly expressed for others to appreciate. Of course many topics related to nervous system dysfunction are deadly serious for the healthcare provider as well as for the patient and are treated as such. Many students find science to be “dry, abstract, intimidating, irrelevant, boring, esoteric, incomprehensible, etc.’ and neuroscience, in particular, to fit all those descriptions and worse. However, if the nervous system can be presented as a dynamic structural and functional entity, the learner will tend to be more engaged in and out of the classroom. That’s why I’ve included many movies and interactive media to make points about particular dynamic concepts or processes. I may not be the sharpest tack in the pack of neuroscientists but I do have a point that, pushed hard enough by inquisitive students, can attach a memo to their cerebral gray cork boards. Note: I know grey is a classic spelling of this color but as an anatomist I prefer gray. GMOMM does not tell you everything you need to know about neuroscience; such a book has yet to be written. I’ll never be able to provide a comprehensive picture at all levels of research in this enticing field of study. As a researcher I have moments of exhilaration in discovery but everyday I am humbled by the extraordinarily complex “simplicity” of nature.
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Background Nowadays, increasing evidence has found transdiagnostic neuroimaging biomarkers across major psychiatric disorders (MPDs). However, it remains to be known whether this transdiagnostic pattern of abnormalities could also be seen in individuals at familial high-risk for MPDs (FHR). We aimed to examine shared neuroanatomical endophenotypes and protective biomarkers for MPDs. Methods This study examined brain grey matter volume (GMV) of individuals by voxel-based morphometry method. A total of 287 individuals were included, involving 100 first-episode medication-naive MPDs, 87 FHR, and 110 healthy controls (HC). They all underwent high-resolution structural magnetic resonance imaging (MRI). Results At the group level, we found MPDs were characterized by decreased GMV of the right fusiform gyrus, the right inferior occipital gyrus, and the left anterior and middle cingulate gyri compared to HC and FHR. Of note, the GMV of the left superior temporal gyrus was increased in FHR relative to MPDs and HC. At the subgroup level, the comparisons within the FHR group did not return any significant difference, and we found GMV difference among subgroups within the MPDs group only in the opercular part of the right inferior frontal gyrus. Conclusion Together, our findings uncover common structural disturbances across MPDs and substantial changes in grey matter that may relate to high hereditary risk across FHR, potentially underscoring the importance of a transdiagnostic way to explore the neurobiological mechanisms of major psychiatric disorders.
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Chapter
Neuro-plasticity describes the ability of the brain in achieving novel functions, either by transforming its internal connectivity, or by changing the elements of which it is made, meaning that, only those changes, that affect both structural and functional aspects of the system, can be defined as “plastic.” The concept of plasticity can be applied to molecular as well as to environmental events that can be recognized as the basic mechanism by which our brain reacts to the internal and external stimuli. When considering brain plasticity within a clinical context–that is the process linked with changes of brain functions following a lesion- the term “reorganization” is somewhat synonymous, referring to the specific types of structural/functional modifications observed as axonal sprouting, long-term synaptic potentiation/inhibition or to the plasticity related genomic responses. Furthermore, brain rewires during maturation, and aging thus maintaining a remarkable learning capacity, allowing it to acquire a wide range of skills, from motor actions to complex abstract reasoning, in a lifelong expression. In this review, the contribution on the “neuroplasticity” topic coming from advanced analysis of EEG rhythms is put forward.
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Four experiments were carried out to determine the accuracy with which early-blind and blind-folded sighted subjects could indicate the remembered positions of objects. Experiment 1 showed that the position of a single object can be recalled, usually with little decline in accuracy, for at least 24 min. Experiment 2 indicated that the recalled position of one object exerts little, if any, influence on the recalled position of an adjacent object. Experiments 3 and 4 dealt with “updating,” the ability to examine objects from one location, then walk to a new location, and from there indicate the positions of the objects. Both groups of subjects demonstrated good updating ability when the method of responding was to replace objects in their original positions; when required to point to objects, however, blind subjects made significantly larger errors than sighted subjects. The pattern of errors suggested distorted recall of the stimulus field rather than an inability to transform spatial information.
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A key issue in developmental neuroscience is the role of activity-dependent mechanisms in the epigenetic induction of functional organization in visual cortex. Ocular blindness and ensuing visual deprivation is one of the rare models available for the investigation of experience-dependent cortical reorganization in man. In a PET study we demonstrate that congenitally blind subjects show task-specific activation of extrastriate visual areas and parietal association areas during Braille reading, compared with auditory word processing. In contrast, blind subjects who lost their sight after puberty show additional activation in the primary visual cortex with the same tasks. Studies in blind-raised monkeys show that crossmodal responses in extrastriate areas can be elicited by somatosensory stimulation. This is consistent with the crossmodal extrastriate activations elicited by tactile processing in our congenitally blind subjects. Since primary visual cortex does not show crossmodal responses in primate studies, the differential activation in late and congenitally blind subjects highlights the possibility of reciprocal activation by visual imagery in subjects with early visual experience.
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Candia V, Schäfer T, Taub E, Rau H, Altenmüller E, Rockstroh B, Elbert T. Sensory motor returning: a behavioral treatment for focal hand dystonia of pianists and guitarists. Arch Phys Med Rehabil 2002;83:1342-8. Objective: To evaluate the long-term effectiveness of sensory motor retuning (SMR), a new treatment for focal hand dystonia in musicians. Design: Prospective case series with an (adventitious) comparison group with 3-to 25-month follow-up in piano and guitar and 0-to 4-month follow-up in flute and oboe players. Setting: General community in Germany. Participants: Eleven professional musicians. Intervention: Immobilization by splints of 1 or more digits other than the focal dystonic finger. This finger carried out repetitive exercises in coordination with 1 or more of the other digits for 1 1 ⁄2 to 2 1 ⁄2 hours a day for 8 consecutive days under therapist supervision. The subjects then were instructed to continue practice for 1 hour daily for 1 year. Main Outcome Measures: Spectral analysis of the output of a dexterity-displacement device that continuously recorded digital displacement during finger movements and a dystonia evaluation scale on which patients rated how well they had just performed dystonic movement sequences and repertoire passages. Results: The 3 wind players (adventitious placebo controls) did not improve substantially. However, each pianist and guitarist showed marked and significant improvement in spontaneous repertoire performance without the splint. The first subject is now 25 months posttreatment. Conclusions: Results suggest that SMR is of value for the treatment of focal hand dystonia in pianists and guitarists.
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This paper reviews findings from cognitive and sport psychology, as well as from neurophysiology, concerning mental simulation of movement. A neuropsychological hypothesis is advanced to explain why mental practice can improve motor skill learning. Mental practice activates certain brain structures selectively as shown by measurements of regional cerebral blood flow. It appears likely that this activation improves the subsequent control of execution of movements. It is pointed out that the study of simulation of movements may not only be of value for sport training but also have importance for the rehabilitation of patients with motor disturbances following lesions of the central nervous system.
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Hand movement recovery and cortical reorganization were studied in 10 subjects with chronic stroke using functional MRI (fMRI) before and after training with an intensive finger movement tracking programme. Subjects were assigned randomly to a treatment or control group. The treatment group received 18–20 sessions of finger tracking training using target waveforms under variable conditions. The control group crossed over to receive the same treatment after the control period. For comparison with a healthy population, nine well elderly females were also studied; however, the well elderly controls did not cross over after the control period. The dependent variables consisted of a Box and Block score to measure prehensile ability (subjects with stroke only), a tracking accuracy score and quantification of active cortical areas using fMRI. For the tracking tests, the subjects tracked a sine wave target on a computer screen with extension and flexion movements of the paretic index finger. Functional brain images were collected from the frontal and parietal lobes of the subject with a 4 tesla magnet. Areas of interest included the sensorimotor cortex (SMC), primary motor area (M1), primary sensory area (S1), premotor cortex (PMC) and supplementary motor area (SMA). Comparison between all subjects with stroke and all well elderly subjects at pre‐test was analysed with two‐sample t ‐tests. Change from pre‐test to post‐test within subjects was analysed with paired t ‐tests. Statistical significance was set at P < 0.05. Stroke treatment subjects demonstrated significant improvement in tracking accuracy, whereas stroke control subjects did not until after crossover treatment. At pre‐test, the cortical activation in the subjects with stroke was predominantly ipsilateral to the performing hand, whereas in the well elderly subjects it was contralateral. Activation for the stroke treatment group following training switched to contralateral in SMC, M1, S1 and PMC. The stroke control group’s activation remained ipsilateral after the control period, but switched to contralateral after crossover to receive treatment. All well elderly subjects maintained predominantly contralateral activation throughout. Transfer of skill to functional activity was shown in significantly improved Box and Block scores for the stroke treatment group, with no such improvement in the stroke control group until after crossover. We concluded that individuals with chronic stroke receiving intensive tracking training showed improved tracking accuracy and grasp and release function, and that these improvements were accompanied by brain reorganization.
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WE measured regional cerebral blood flow (rCBF) with positron emission tomography to study changes in anatomical structures during the course of learning a complicated finger sequence of voluntary movements. Motor learning was accompanied by rCBF increases in the cerebellum, decreases in all limbic and paralimbic structures, and striatal decreases which changed to striatal increases as the motor skill was learned. Simultaneously, activations of initially contributing non-motor parts of the cerebral cortex vanished. Both cerebellar circuits and striatal circuits appear important for the storage of motor skills in the brain.
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To explore the neural networks used for Braille reading, we measured regional cerebral blood flow with PET during tactile tasks performed both by Braille readers blinded early in life and by sighted subjects. Eight proficient Braille readers were studied during Braille reading with both right and left index fingers. Eight-character, non-contracted Braille-letter strings were used, and subjects were asked to discriminate between words and non-words. To compare the behaviour of the brain of the blind and the sighted directly, non-Braille tactile tasks were performed by six different blind subjects and 10 sighted control subjects using the right index finger. The tasks included a non-discrimination task and three discrimination tasks (angle, width and character). Irrespective of reading finger (right or left), Braille reading by the blind activated the inferior parietal lobule, primary visual cortex, superior occipital gyri, fusiform gyri, ventral premotor area, superior parietal lobule, cerebellum and primary sensorimotor area bilaterally, also the right dorsal premotor cortex, right middle occipital gyrus and right prefrontal area. During non-Braille discrimination tasks, in blind subjects, the ventral occipital regions, including the primary visual cortex and fusiform gyri bilaterally were activated while the secondary somatosensory area was deactivated. The reverse pattern was found in sighted subjects where the secondary somatosensory area was activated while the ventral occipital regions were suppressed. These findings suggest that the tactile processing pathways usually linked in the secondary somatosensory area are rerouted in blind subjects to the ventral occipital cortical regions originally reserved for visual shape discrimination.
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Publisher Summary To extract information derived from one sensory modality and used in another, shape can be known by touch and then can be identified correctly by sight. The chapter discusses the issue of internal versus experiential influences in the organization of the brain. The impressions generated by different sensory modalities can be integrated into a richer percept. The ventriloquism effect broadly refers to this phenomenon on which much of the knowledge of the world and an entire entertainment industry is based. Multimodal association areas that contain multisensory neurons are thought to provide a neural substrate for integrating sensory experiences, modulating the saliency of stimuli, assigning experiential and affective relevance, and providing the substrate for the true perceptual experience of the rich world. The chapter presents the hypothesis that the brain might actually represent a metamodal structure organized as operators that execute a given function or computation regardless of sensory input modality. Such operators might have a predilection for a given sensory input based on its relative suitability for the assigned computation. Such predilection might lead to operator-specific selective reinforcement of certain sensory inputs, eventually generating the impression of a brain structured in parallel, segregated systems processing different sensory signals.
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The lifelong ability to adapt to environmental needs is based on the capacity of the central nervous system for plastic alterations. In a series of neurophysiological experiments, we studied the impact of music and musical training in musicians on the specific functional organization in auditory and somatosensory representational cortex. In one such study, subjects listened to music from which one specific spectral frequency was removed. This led to rapid and reversible adaptation of neuronal responses in auditory cortex. Further experimental evidence demonstrated that long years of practice and training by professional musicians to enable them to reach their capacity is associated with enlarged cortical representations in the somatosensory and auditory domains. This tuning of neuronal representations was specifically observed for musical tones and was absent when pure sinusoidal tones were used as stimuli. In the somatosensory cortex, plastic changes proved to be specific for the fingers frequently used and stimulated. These changes were not detected in the fingers of the hand that were not involved in playing the particular instrument. Neuroplastic alterations also may be driven into a domain where they may become maladaptive. The clinical syndrome of focal hand dystonia that may occur in musicians who engage in forceful practice may be one such consequence. We will discuss the possibilities of reversing maladaptive responses leading to the successful treatment of focal hand dystonia, which relies on basic research about cortical reorganization. This example elucidates how neuroscientific progress can guide the development of practice guidelines and therapeutic measures for the benefit of professional musicians.
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Treatment-induced plastic changes were investigated in the brains of stroke patients in the subacute stage of illness. Nine patients participated in 1 week of conventional physiotherapy. In the subsequent week conventional physiotherapy was combined with forced-use therapy. Focal transcranial magnetic stimulation was used to determine the motor output areas of the abductor pollicis brevis muscles prior to the treatment and after the first and after the second week. Motor performance was evaluated using the Nine Hole Peg Test, the Frenchay Arm Test and vigorometry to measure the grip strength. Before treatment the cortical representation area of the paretic hand muscle was significantly smaller than the contralateral side. This difference persisted after the first week of physiotherapy. In contrast, the motor output map in the affected hemisphere was significantly enlarged after forced-use therapy. This increase in motor cortex excitability was accompanied by a significant improvement in dexterity. Across the two treatment weeks the centres of the motor output maps shifted significantly stronger in the affected hemisphere than in unaffected hemisphere, suggesting the recruitment of adjacent brain areas. We conclude that the combination of forced-use therapy and conventional physiotherapy enhances motor cortex excitability and improves motor performance compared to a preceding conventional physiotherapy alone. Due to the small number of patients and the lack of a control group, these results are preliminary observations and require replication in a larger sample.
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Blind subjects who learn to read Braille must acquire the ability to extract spatial information from subtle tactile stimuli. In order to accomplish this, neuroplastic changes appear to take place. During Braille learning, the sensorimotor cortical area devoted to the representation of the reading finger enlarges. This enlargement follows a two-step process that can be demonstrated with transcranial magnetic stimulation mapping and suggests initial unmasking of existing connections and eventual establishment of more stable structural changes. In addition, Braille learning appears to be associated with the recruitment of parts of the occipital, formerly `visual', cortex (V1 and V2) for tactile information processing. In blind, proficient Braille readers, the occipital cortex can be shown not only to be associated with tactile Braille reading but also to be critical for reading accuracy. Recent studies suggest the possibility of applying non-invasive neurophysiological techniques to guide and improve functional outcomes of these plastic changes. Such interventions might provide a means of accelerating functional adjustment to blindness.
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The ventral pathway is involved in primate visual object recognition. In humans, a central stage in this pathway is an occipito-temporal region termed the lateral occipital complex (LOC), which is preferentially activated by visual objects compared to scrambled images or textures. However, objects have characteristic attributes (such as three-dimensional shape) that can be perceived both visually and haptically. Therefore, object-related brain areas may hold a representation of objects in both modalities. Using fMRI to map object-related brain regions, we found robust and consistent somatosensory activation in the occipito-temporal cortex. This region showed clear preference for objects compared to textures in both modalities. Most somatosensory object-selective voxels overlapped a part of the visual object-related region LOC. Thus, we suggest that neuronal populations in the occipito-temporal cortex may constitute a multimodal object-related network.
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These experiments examined motor cortical representation patterns after forelimb postural adjustments in rats. The experiments tested the hypothesis that postural adjustments that stretch muscles that are most strongly activated from the primary motor cortex (MI) enlarge their cortical representation. Intracortical electrical stimulation within MI, forelimb muscle activity and movements, and vibrissa movements were used to evaluate the border between the MI forelimb and vibrissa representations before and after forelimb position changes in anesthetized adult rats. The forelimb was originally maintained in retraction (wrist extension and elbow flexion) and then changed to protraction (wrist flexion and elbow extension). Movements and forelimb EMG evoked by electrical stimulation were evaluated during this period (up to 3 hr) through a set of four electrodes implanted in layer V of MI. Changing the forelimb configuration had both immediate and delayed effects on forelimb muscle activity evoked from MI. At some sites, the magnitude of evoked forelimb muscle activity immediately increased with forelimb protraction. At one-quarter of all sites, forelimb muscle activity was evoked where it was not previously detected following an average delay of 22-31 min after forelimb protraction. This change can be interpreted as an expansion of the forelimb area into the vibrissa representation. These data further support the hypothesis that motor cortical representations are flexible and show that sustained changes in somatic sensory input to MI are sufficient to reorganize MI output.