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Sensory tricks in dystonia. Shown is a sensorimotor integration mechanism explaining the temporary relief from dystonic symptoms. (A) Weakened proprioceptive signals alters the feedback control for the tonic innervation of agonist-antagonist muscle groups, resulting in dystonic postures. (B) Tactile feedback related to the same somatotopic region of the dystonic musculature innervates multimodal tactile-proprioceptive neurons, essentially amplifying the proprioceptive signals. This will improve feedback control of muscle tone, resulting in symptom relief as long as tactile feedback is present.
Source publication
Musician's dystonia (MD) is a neurological motor disorder characterized by involuntary contractions of those muscles involved in the play of a musical instrument. It is task-specific and initially only impairs the voluntary control of highly practiced musical motor skills. MD can lead to a severe decrement in a musician's ability to perform. While...
Similar publications
Focal hand dystonia in musicians is a movement disorder affecting highly trained movements. Rather than being a pure motor disorder related to movement execution only, movement planning, error prediction, and sensorimotor integration are also impaired. Internal models (IMs), of which two types, forward and inverse models have been described and mos...
Citations
... While the mechanisms behind the task-specificity of musician's dystonia are not fully understood, it is suggested to result from increased involvement of the cerebellum, the thalamus, and motor cortical regions, which appear altered during the management of motor execution [23]. Furthermore, altered proprioceptive and tactile feedback is suggested to influence voluntary motor control [24]. Resting-state (rs) fMRI offers the possibility to investigate FC without a given task, making it a useful tool when investigating network communication in different forms of dystonia. ...
Background
Musician’s dystonia is the most common form of focal task-specific dystonia and is suggested to be the result of dysfunctional communication among sensory-motor networks. Thus far, few functional connectivity studies have investigated musician’s dystonia specifically, leaving its exact pathophysiological mechanisms unclear. The goal of this study was to verify connectivity findings from other task-specific dystonias on a large sample of musician’s hand dystonia patients and to analyze associations with possible adverse childhood experiences, a suggested risk factor for dystonia.
Methods
Forty professional musicians suffering from musician’s hand dystonia and a matched control group of healthy musicians underwent resting-state functional magnetic resonance imaging and answered the childhood trauma questionnaire. Using a seed-to-whole brain approach, functional connectivity alterations between motor cortices, the prefrontal cortex, the basal ganglia and the thalamus were analyzed.
Results
Musician’s dystonia patients showed increased functional connectivity of the dorsolateral prefrontal cortex with the putamen and the pallidum, especially in right-side affected patients. Patients further displayed increased connectivity of the left thalamus and the right lateral premotor cortex. No associations between functional connectivity, duration of disorder and childhood adversity were observed.
Conclusion
The findings are consistent with previous research, highlighting the pathophysiological importance of the basal ganglia. Altered resting-state functional connectivity may reflect underlying neuroplastic changes in musicians with dystonia that lead to an altered flow of information, disrupting movement inhibition. Involvement of the dorsolateral prefrontal and premotor cortices further suggests that motor disturbances occur in the early planning phase of a movement. The findings indicate that a holistic re-training approach with and without the instrument could be beneficial for regaining motor control.
... In medicine literature (Biro et al., 1983;Buescher, 2007;Caldron et al., 1986;Hochberg et al., 1988;Konczak and Abbruzzese, 2013;Larsson et al., 1993;Newmark and Hochberg, 1987;Sataloff et al., 1991;Zeuner and Molloy, 2008), four main PRMDs were identified: overuse syndrome, temporomandibular joint disorders, focal motor dystopias and joint hypermobility. Overuse syndrome is defined as painful conditions induced by long and hard use of a limb beyond biological tolerance (Fry, 1986;Fry, 1993). ...
Introduction
Both professional musicians and conservatoire students are at significant risk of developing playing-related musculoskeletal disorders (PRMDs) during their career life. With the growing number of students pursuing a conservatory degree and graduating from music conservatory in China, the aims of this study were: (1) to identify the nature of PRMD and explore the prevalence of PRMD in Chinese conservatoire students; (2) to determine the relevant risk factors with the presence of PRMD among Chinese conservatoire students; and (3) to suggest preventive interventions for young pianists at their early career stage.
Methods
A self-reported online survey study was conducted among 363 Chinese conservatoire students who majored in piano performance.
Results
Of all respondents, 82.6% reported having had at least one PRMD. The wrist was proved to be the most affected body site, followed by the shoulder, finger and arm. Respondents who experienced PRMD reported “pain,” “fatigue,” and “stiffness” as the most frequent symptoms. The main risk factors associated with PRMD included gender, years of playing experiences, practice hours, warm-up habits before practice, and break-taking during practice.
Discussion
Female students, those with longer year of playing experience, those who practice longer hours, those who do not warm up before practice, and those who do not take breaks during practice were found to have more PRMD symptoms and higher level of severity. This study highlights the need to increase awareness of PRMD among conservatoire students and to understand the occurrence of PRMD; it is helpful for young pianists to prevent severe musculoskeletal disorders and implement preventive measures at early career stages. Further studies are suggested to follow up on music students who have had at least one PRMD at different stages of professional musical training.
... If somatosensory input is not properly processed both before and during movement, the resulting motor output exhibits abnormalities and/or inaccuracies (Riemann and Lephart, 2002;Cascio, 2010). Growing evidence indicates impairments in somatosensory function are a major contributor to the motor dysfunction commonly observed in neurologic injury or disorders such as Parkinson's disease, cerebral palsy, dystonia, ataxia, etc. (Conte et al., 2013;Elbert et al., 1998;Konczak & Abbruzzese, 2013;Zarkou et al., 2020). ...
Background
Emerging studies in humans have established the modulatory effects of repetitive transcranial magnetic stimulation (rTMS) over primary somatosensory cortex (S1) on somatosensory cortex activity and perception. However, to date, research in this area has primarily focused on the hand and fingers, leaving a gap in our understanding of the modulatory effects of rTMS on somatosensory perception of the orofacial system and speech articulators.
Objective
The present study aimed to examine the effects of different types of theta-burst stimulation—continuous TBS (cTBS), intermittent TBS (iTBS), or sham—over the tongue representation of left S1 on tactile acuity of the tongue.
Methods
In a repeated-measures design, fifteen volunteers participated in four separate sessions, where cTBS, iTBS, sham, or no stimulation was applied over the tongue representation of left S1. Effects of TBS were measured on both temporal and spatial perceptual acuity of tongue using a custom vibrotactile stimulator.
Results
CTBS significantly impaired spatial amplitude threshold at the time window of 16-30 minutes after stimulation, while iTBS improved it at the same time window. The effect of iTBS, however, was smaller than cTBS. In contrast, neither cTBS nor iTBS had any effect on the temporal discrimination threshold.
Conclusions
The current study establishes the validity of using TBS to modulate somatosensory perception of the orofacial system. Directly modifying somatosensation in the orofacial system has the potential to benefit clinical populations with abnormal tactile acuity, improve our understanding of the role of sensory systems in speech production, and enhance speech motor learning and rehabilitation.
Highlights
Theta-burst stimulation (TBS) can modulate somatosensation in the orofacial system
cTBS over S1 impaired spatial acuity of tongue
iTBS over S1 improved spatial acuity of tongue
... Tasks requiring somatosensory and motor integration such as reaching a specific object with the upper limb without vision suggested that patients with focal hand dystonia have an impaired integration of proprioceptive information with motor kinematics (i.e., longer deceleration phase and more inaccuracies) (Inzelberg et al., 1995). Since then, several studies showed that sensorimotor integration, proprioceptive information, and temporal/spatial somatosensory discrimination all play important roles in focal dystonia (see Conte et al., 2019;Desrochers et al., 2019;Konczak & Abbruzzese, 2013 for reviews on the topic). ...
The ability to manipulate objects is a critical skill for humans. Such function is carried out primarily by the motor system. However, such a process would not be possible without the continuous information provided by the somatosensory system. The somatosensory feedback is particularly important when a movement must be adjusted while performing an action. Effective interactions between the somatosensory and motor systems are paramount for performing fine motor behaviour, as made dramatically clear by brain damage. Somatosensory deficits following nervous system lesions have received little attention compared to motor control. Yet, patients suffering from somatosensory deficits usually show reduced recovery of motor functions, preserved somatosensation being a good predictor of motor recovery. Despite the importance of touch in shaping motor behaviour, the functional relationships between the somatosensory and motor systems remain unclear. Here we examine the potential role of somatosensory information in modulating motor behaviour. We focus on a series of empirical studies that investigated the crosstalk between the somatosensory and motor systems, specifically on the role of touch in shaping motor behaviour. We will start by describing, across different species, the anatomical and neurophysiological connections between these systems and the nature of these communications. We will then present evidence from neuropathological studies and the severe consequences of somatosensory signals' disruption on motor performance. Finally, we will examine the impact of short-and long-term tactile learning on the motor system as a promising approach for developing novel somatosensory-to-motor rehabilitation strategies, for people suffering from brain injury and other neurological conditions.
... Motor output is abnormal or inaccurate when sensory input is not properly processed. Damage to the S1 may result in neurological conditions characterized by motor dysfunction [3][4][5]. Herein, we present the case of a patient who experienced motor recovery and involuntary movements following damage to the right S1 caused by an intracranial hemorrhage (ICH). This study used diffusion tensor imaging (DTI) to investigate the changes in sensorimotor-related brain areas affected by alterations in the S1. ...
This case study describes a patient who experienced motor recovery and involuntary movements following damage to the right primary somatosensory cortex caused by an intracranial hemorrhage. The patient initially suffered from paralysis in her left arm and leg, but exhibited significant motor recovery later, accompanied by multiple episodes of ballistic movement during the recovery process. A diffusion tensor imaging analysis was performed to investigate changes in sensorimotor-related brain areas in the patient. The patient had higher fractional anisotropy and lower mean diffusivity values in the ipsilesional red nucleus (RN) than age-matched controls. We assume that hyperactivity of the ipsilesional RN might play a role in motor recovery after damage to the primary somatosensory cortex, potentially through its involvement in sensorimotor integration. Our findings demonstrated the potential for adaptive changes in the ipsilesional RN following damage to the primary somatosensory cortex.
... We have put together the available evidence for the pathogenesis of musician's dystonia into a network model (Fig. 1), inspired by work of the group of Reza Shadmer [5] and of Konczak and Abbruzzese [38]. This model seems most suitable for comprehensively accommodating all of the evidence pointing to various involved brain regions including the cerebral cortex, basal ganglia, cerebellum, thalamus, and the limbic system [2]. ...
While the pathophysiology of embouchure dystonia, a sub-entity of musician's dystonia, is still not fully understood, recent research has shown that it involves alterations of several brain functions and networks. Maladaptive plasticity in sensorimotor integration, sensory perception, and deficient inhibitory mechanisms at cortical, subcortical, and spinal level seem to contribute to its pathophysiology. Furthermore, functional systems of the basal ganglia and the cerebellum are involved, clearly pointing toward a network disorder. We therefore propose a novel network model, based on electrophysiological and recent neuroimaging studies highlighting embouchure dystonia.
... therefore rely on the integration of sensory and motor neural processes (Lee et al., 2021). The observation that ST occurs only with a voluntary self-touch suggests that mechanisms of predicted sensory feedback (e.g., the output of a forward dynamics model) may also contribute to ST (Konczak and Abbruzzese 2013). We propose that encoding multiple sensory and motor neural processes associated with ST execution determines changes in parietal cortex activity, modulating sensorimotor integration encoding. ...
Patients with cervical dystonia (CD) often show an improvement in dystonic posture after sensory trick (ST), though the mechanisms underlying ST remain unclear. In this study, we aimed to investigate the effects of ST on cortical activity in patients with CD and to explore the contribution of motor and sensory components to ST mechanisms. To this purpose, we studied 15 CD patients with clinically effective ST, 17 without ST, and 14 healthy controls (HCs) who mimicked the ST. We used electroencephalographic (EEG) recordings and electromyography (EMG) data from bilateral sternocleidomastoid (SCM) muscles. We compared ST-related EEG spectral changes from sensorimotor and posterior parietal areas and EMG power changes between groups. To better understand the contribution of motor and sensory components to ST, we tested EEG and EMG correlates of three different conditions mimicking ST, the first without skin touch ("no touch" condition), the second without voluntary movements ("passive" condition), and finally without arm movements ("examiner touch" condition). Results showed ST-related alpha desynchronization in the sensorimotor cortex and theta desynchronization in the sensorimotor and posterior parietal cortex. Both spectral changes were more significant during maneuver execution in CD patients with ST than in CD patients without ST and HCs who mimicked the ST. Differently, the "no touch", "passive", or "examiner touch" conditions did not show significant differences in EEG or EMG changes determined by ST execution/mimicking between CD patients with or without ST. A higher desynchronization within alpha and theta bands in the sensorimotor and posterior parietal areas correlated with a more significant activity decrease in the contralateral SCM muscle, Findings from this study suggest that ST-related changes in the activity of sensorimotor and posterior parietal areas may restore dystonic posture and that both motor and sensory components contribute to the ST effect.
... Task-specific focal dystonia in musicians, which is called musician's dystonia [6], occurs frequently in a similar fashion to other forms of occupation-related dystonia. These are usually caused by repeated activities, such as handwriting, computer keyboard typing, or performing surgery [7,8]. ...
A sensory trick is a specific maneuver that temporarily improves focal dystonia. We describe a case of musician’s dystonia in the right-hand fingers of a patient, who showed good and immediate improvement after using an electrical stimulation-mimicking sensory trick. A 49-year-old professional guitarist presented with chronic involuntary flexion of the right-hand third and fourth fingers that occurred during guitar performances. Electrical stimulation with a frequency of 40 Hz and an intensity of 1.5 times the sensory threshold was administered on the third and fourth fingernails of the right hand, which facilitated fluent guitar playing. While he played guitar with and without electrical stimulation, we measured the surface electromyograms (sEMG) of the right extensor digitorum and flexor digitorum superficialis muscles to evaluate the sensory-trick-like effects of electrical stimulation. This phenomenon can offer clues for developing electrical stimulation-based treatment devices for focal dystonia. Electrical stimulation has the advantage that it can be turned off to avoid habituation. Moreover, the device is easy to use and portable. These findings warrant further investigation into the use of sensory stimulation for treating focal dystonia.
... For example, a miniature magnetic sensor successfully recorded motions of a ball on the order of milliseconds, and a series of experiments with it uncovered various features of skillful ball-throwing motions [10,11]. However, sensors attached to a tool can alter physical properties, such as weight and inertia, and affect tactile and proprioceptive feedback in motion, the latter of which matters particularly in the assessment of the symptoms of focal hand dystonia due to sensory trick [12,13]. Therefore, the development of contactless or noncontact sensors that enable one to record motions of a tool to be manipulated at high spatiotemporal resolution is needed to fully unveil expert motor skills in dexterous tool use. ...
Dexterous tool use is typically characterized by fast and precise motions performed by multiple fingers. One representative task is piano playing, which involves fast performance of a sequence of complex motions with high spatiotemporal precision. However, for several decades, a lack of contactless sensing technologies that are capable of precision measurement of piano key motions has been a bottleneck for unveiling how such an outstanding skill is cultivated. Here, we developed a novel sensing system that can record the vertical position of all piano keys with a time resolution of 1 ms and a spatial resolution of 0.01 mm in a noncontact manner. Using this system, we recorded the piano key motions while 49 pianists played a complex sequence of tones that required both individuated and coordinated finger movements to be performed as fast and accurately as possible. Penalized regression using various feature variables of the key motions identified distinct characteristics of the key-depressing and key-releasing motions in relation to the speed and accuracy of the performance. For the maximum rate of the keystrokes, individual differences across the pianists were associated with the peak key descending velocity, the key depression duration, and key-lift timing. For the timing error of the keystrokes, the interindividual differences were associated with the peak ascending velocity of the key and the inter-strike variability of both the peak key descending velocity and the key depression duration. These results highlight the importance of dexterous control of the vertical motions of the keys for fast and accurate piano performance.
... Specific dystonia is a motion disease that involves abnormal postures of the body. Some regression analysis studies discovered that S1 was markedly connected with variability in fundamental frequency signals related to dystonic symptoms and that somatic assessment portrayed essential distinctions in the right somatosensory cortex (30,31). Researchers used fMRI data to assess brain activity and physical therapy. ...
Objective
The percent amplitude of fluctuation (PerAF) technique was utilized to evaluate the neural functions of specific cerebrum areas in patients with toothache (TA).
Patients and Methods
An aggregation of 18 patients with TA (eight males and 10 females) were included in the study. We also recruited 18 healthy controls (HCs; eight men and 10 women) aligned for sex and age. Resting functional magnetic resonance imaging (rs-fMRI) scans were obtained. Then, we utilized the PerAF method and a support vector machine (SVM) to analyze the image data and measure neural abnormalities in related cerebrum areas. Receiver operating characteristic (ROC) curve analysis was utilized to appraise the two data sets.
Results
The PerAF signals in the right dorsolateral superior frontal gyrus (RDSFG) and the right posterior central gyrus (RPCG) of TA sufferers were lower than HC signals. These results may reveal neural dysfunctions in relevant cerebrum regions. The AUC values of PerAF in the two areas were 0.979 in the RDSFG and 0.979 in the RPCG. The SVM results suggested that PerAF could be utilized to distinguish the TA group from HCs with a sensitivity of 75.00%, a specificity of 66.67%, and an accuracy of 70.83%.
Conclusion
Patients with TA had marked differences in PerAF values in some regions of the cerebrum. Changes in PerAF values represented distinctions in blood oxygen level dependent semaphore intensity, which reflected the overactivity or inactivation of some cerebrum areas in those suffering from TA. At the same time, we analyzed the PerAF values of TAs with ROC curve, which can be helpful for the diagnosis of TA severity and subsequent treatment. Our results may help to elucidate the pathological mechanism of TA.
