B Fierro

Università degli Studi di Palermo, Palermo, Sicily, Italy

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Publications (143)312.26 Total impact

  • Clinical neurophysiology: official journal of the International Federation of Clinical Neurophysiology 06/2015; DOI:10.1016/j.clinph.2015.05.028 · 2.98 Impact Factor
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    ABSTRACT: Despite an extensive literature on cognitive impairments in focal and generalized epilepsy, only a few number of studies specifically explored social cognition disorders in epilepsy syndromes. The aim of our study was to investigate social cognition abilities in patients with temporal lobe epilepsy (TLE) and in patients with idiopathic generalized epilepsy (IGE). Thirty-nine patients (21 patients with TLE and 18 patients with IGE) and 21 matched healthy controls (HCs) were recruited. All subjects underwent a basic neuropsychological battery plus two experimental tasks evaluating emotion recognition from facial expression (Ekman-60-Faces test, Ek-60F) and mental state attribution (Story-based Empathy Task, SET). In particular, the latter is a newly developed task that assesses the ability to infer others' intentions (i.e., intention attribution - IA) and emotions (i.e., emotion attribution - EA) compared with a control condition of physical causality (i.e., causal inferences - CI). Compared with HCs, patients with TLE showed significantly lower performances on both social cognition tasks. In particular, all SET subconditions as well as the recognition of negative emotions were significantly impaired in patients with TLE vs. HCs. On the contrary, patients with IGE showed impairments on anger recognition only without any deficit at the SET task. Emotion recognition deficits occur in patients with epilepsy, possibly because of a global disruption of a pathway involving frontal, temporal, and limbic regions. Impairments of mental state attribution specifically characterize the neuropsychological profile of patients with TLE in the context of the in-depth temporal dysfunction typical of such patients. Impairments of socioemotional processing have to be considered as part of the neuropsychological assessment in both TLE and IGE in view of a correct management and for future therapeutic interventions. Copyright © 2015. Published by Elsevier Inc.
    Epilepsy & Behavior 05/2015; DOI:10.1016/j.yebeh.2015.04.048 · 2.06 Impact Factor
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    ABSTRACT: Sound-induced flash illusions depend on visual cortical excitability. In this study, we explored whether sound-induced flash illusions are perceived differently in migraine, a condition associated with pathologic cortical hyperexcitability. Sound-induced flash illusions were examined in 59 migraine patients (mean age = 32 ± 16 years; 36 females), 32 without aura and 27 with aura, and in 24 healthy controls (mean age = 42 ± 17 years; 16 females). Patients were studied during attacks and interictally. Visual stimuli (flashes) accompanied by sounds (beeps) were presented in different combinations: a single flash with multiple beeps was given to induce the perception of multiple flashes ("fission" illusion), and multiple flashes with a single beep were used to reduce the number of perceived flashes ("fusion" illusion). For migraineurs, the fission illusion was reduced, especially during the attack, and almost abolished when a single flash was combined with 2 beeps (except for those without aura tested interictally); the fusion illusion was less consistently reported in both migraine groups, but not completely disrupted. Results from this study add novel clues to our understanding of visual cortex hyperexcitability in migraine, especially migraine with aura. Furthermore, these analyses underscore how pathologic changes in cortical excitability affect multisensory interactions. Cross-modal illusions represent a valid tool for exploration of functional connectivity between sensory areas, which likely has an important role in the pathophysiology of migraine. © 2015 American Academy of Neurology.
    Neurology 04/2015; 84(20). DOI:10.1212/WNL.0000000000001584 · 8.30 Impact Factor
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    ABSTRACT: In previous studies, rTMS has been successfully employed to interfere with the right posterior parietal cortex (rPPC) inducing neglect-like behavior in healthy subjects. Several studies have shown that the use of tools can modulate the boundaries between near and far space: indeed when far space is reached by the stick, far space can be remapped as near. The aim of the present study was to investigate whether once that rTMS on the rPPC has selectively induced neglect-like bias in the near space (but not in the far space), neglect can appears also in the far space when the subjects used a tool to perform the task. Fifteen right-handed healthy subjects executed a line length judgment task in two different spatial positions (60 cm: near space and 120 cm: far space), with or without rPPC on-line rTMS. In the far space condition, subjects performed the perceptual task while holding or not a tool. During rTMS, visuospatial performance significantly shifted toward right when the task was performed in the near space and in the far space when the tool was used. No significant effect was found when rTMS was delivered in the far space condition without tool use. Our results demonstrate that the application of rTMS on rPPC, specifically affect the representation of near space because it caused neglect both when the subjects acted in the near space and when they acted in a far space that was remapped as near by the use of a tool. Copyright © 2015 Elsevier Inc. All rights reserved.
    Brain Stimulation 01/2015; DOI:10.1016/j.brs.2015.01.412 · 5.43 Impact Factor
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    ABSTRACT: Cortical excitability was investigated in patients with episodic cluster headache.•Motor cortical hyperexcitability was shown in patients both inside and outside bout.•Cortical excitability was asymmetric between the hemispheres.•Greater responses to TMS were shown in the hemisphere ipsilateral to the pain side.•Abnormal cortical excitability may play a role in cluster headache pathophysiology.
    Journal of Pain 10/2014; DOI:10.1016/j.jpain.2014.10.006 · 4.22 Impact Factor
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    ABSTRACT: Several studies have shown that transcranial direct current stimulation (tDCS) is able to enhance performances on verbal and visual working memory (WM) tasks. Available evidence points to the right dorsolateral prefrontal cortex (DLPFC) as a critical area in visual WM, but to date direct comparisons of the effects obtained by stimulating the left versus the right DLPFC in the same subject are lacking. Our aim was to determine whether tDCS over the right DLPFC can differently affect performance as compared with left DLPFC stimulation. Ten healthy subjects performed a memory-guided visuospatial task in three conditions: baseline, during anodal stimulation applied over the right and during anodal stimulation applied over the left DLPFC. All the subjects also underwent a sham stimulation as control. Our results show that only active stimulation over the right DLPFC is able to increase performance when compared to the other conditions. Our findings confirm the crucial role played by the right DLPFC in spatial WM tasks.
    Functional neurology 10/2014; · 1.86 Impact Factor
  • The Journal of Headache and Pain 09/2014; 15(Suppl 1):E11-E11. DOI:10.1186/1129-2377-15-S1-E11 · 3.28 Impact Factor
  • The Journal of Headache and Pain 09/2014; 15(Suppl 1):E5-E5. DOI:10.1186/1129-2377-15-S1-E5 · 3.28 Impact Factor
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    ABSTRACT: Background Transcranial direct current stimulation (tDCS) is a non-invasive technique used for modulating cortical excitability in vivo in humans. Here we evaluated the effect of tDCS on behavioral and electrophysiological aspects of physiological sucking and swallowing. Methods Twelve healthy subjects underwent three tDCS sessions (anodal, cathodal and sham stimulation) on separate days in a double-blind randomized order. The active electrode was placed over the right swallowing motor cortex. Repeated sucking and swallowing acts were performed at baseline and at 15 and 60 min after each tDCS session and the mean liquid bolus volume ingested at each time point was measured. We also calculated average values of the following electrophysiological parameters: 1) area and 2) duration of the rectified EMG signal from the suprahyoid/submental muscles related to the sucking and swallowing phases; 3) EMG peak amplitude for the sucking and swallowing phases; 4) area and peak amplitude of the laryngeal-pharyngeal mechanogram; 5) oropharyngeal delay. Results The volume of the ingested bolus significantly increased (by an average of about 30% compared with the baseline value) both at 15 and at 60 min after the end of anodal tDCS. The electrophysiological evaluation after anodal tDCS showed a significant increase in area and duration of the sucking phase-related EMG signal. Conclusions Anodal tDCS leads to stronger sucking of a liquid bolus in healthy subjects, likely by increasing recruitment of cortical areas of the swallowing network. This finding might open up interesting perspectives for the treatment of patients suffering from dysphagia due to various pathological conditions.
    Brain Stimulation 09/2014; 7(6). DOI:10.1016/j.brs.2014.09.007 · 5.43 Impact Factor
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    ABSTRACT: Abnormal increased cortical responsivity to various types of stimuli plays a major role in migraine pathogenesis. Neurophysiological studies, however, have provided ambiguous findings of either hypo or hyper cortical excitability. This is why the term “dysexcitability” has been recently proposed to indicate a more general dysregulation of cortical excitability. The aims of this review are: 1) to provide existing knowledge and research advances in migraine pathophysiology; 2) to propose a unitary interpretation of apparently conflicting neurophysiological findings. Data of studies conducted in migraine through various evoked potentials techniques and non-invasive brain stimulation methods are reviewed, and in some cases reinterpreted according to more recent findings on migraine pathophysiology. In particular, we emphasize the concept that various methods of testing brain excitability may induce different degrees of cortical activation depending on the stimulus parameters used (e.g., intensity, frequency, and duration of stimulation), so shedding light on different pathophysiological aspects. Finally, we try to reconcile apparently conflicting neurophysiological data in the light of a unitary pathophysiological model, suggesting that a condition of interictal cortical hyperresponsivity, possibly due to a glutamatergic dysfunction, could represent the primum movens of migraine pathogenesis.
    Clinical Neurophysiology 09/2014; 125(9). DOI:10.1016/j.clinph.2014.05.005 · 2.98 Impact Factor
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    ABSTRACT: Background and objectiveProgression of Parkinson's disease (PD) is frequently characterized by the occurrence of freezing of gait (FOG) representing a disabling motor complication. We aim to investigate safety and efficacy of transcranial direct current stimulation of the primary motor cortex of PD patients with FOG.Methods In this cross-over, double-blind, sham-controlled study, 10 PD patients with FOG persisting in “on” state underwent anodal and sham direct current stimulation for 5 consecutive days. Clinical assessment over a 1-month period was performed.ResultsA significant improvement of gait, as assessed by the Stand Walk Sit test, with reduction in number and duration of FOG episodes, along with a significant reduction in the Unified Parkinson's Disease Rating Scale score, were observed after anodal stimulation. Beneficial effects were more evident after the entire 5-day stimulation session, and persisted until the end of the observation period.Conclusions Anodal transcranial direct current stimulation of the motor cortex is safe and has therapeutic potential in PD patients with FOG. © 2014 International Parkinson and Movement Disorder Society
    Movement Disorders 07/2014; 29(8). DOI:10.1002/mds.25897 · 5.63 Impact Factor
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    ABSTRACT: In the past few years, noninvasive cerebral stimulations have been used to modulate language task performance in healthy and aphasic patients. In this study, a dual transcranial direct current stimulation (tDCS) on anterior and posterior language areas was applied for 2 weeks to a patient with a possible crossed aphasia following a right hemisphere stroke. Inhibitory cathodal stimulation of the right Brodmann areas (BA) 44/45 and simultaneous anodal stimulation of the left BA 44/45 improved the patient's performance in picture naming. Conversely, the same bilateral montage on BA 39/40 did not produce any significant improvement; finally, electrode polarity inversion over BA 39/40 yielded a further improvement compared with the first anterior stimulation. Our findings suggest that ipsilesional and contralesional areas could be useful in poststroke functional reorganization and provide new evidences for the therapeutic value of tDCS in aphasia.
    Neurocase 06/2014; 21(4):1-10. DOI:10.1080/13554794.2014.927508 · 1.38 Impact Factor
  • Clinical Neurophysiology 06/2014; 125:S288. DOI:10.1016/S1388-2457(14)50944-3 · 2.98 Impact Factor
  • Clinical Neurophysiology 06/2014; 125:S288. DOI:10.1016/S1388-2457(14)50943-1 · 2.98 Impact Factor
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    ABSTRACT: Dear Editor,Pisa Syndrome (PS) is clinically defined as a pronounced lateral flexion of the trunk (at least 10°), completely alleviated by passive mobilization or on lying supine [1]. PS has been described in patients with Parkinson’s disease (PD) and, until now, few studies have pointed out its possible relationship with either clinical evolution of disease and medical treatment. Although pathophysiology of PS still remains largely unexplained a dopaminergic impairment seems to play a major role in its onset. Accordingly, in some PD patients, PS may be triggered by starting of dopamine blocking agents, or by changes in dopaminergic medication (e.g., start of a new drug, and dose increase or decrease of existing medication). In addition, non-dopaminergic medications might also contribute for developing PS such as neuroleptics, lithium carbonate, valproic acid, antidepressants, anti-emetics, and cholinesterase inhibitors [1].Here we describe the case of a 73-year-old woman with a 5-year
    Neurological Sciences 04/2014; 35(10). DOI:10.1007/s10072-014-1806-5 · 1.50 Impact Factor
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    ABSTRACT: Neurophysiological studies in migraine have reported conflicting findings of either cortical hyper- or hypoexcitability. In migraine with aura (MwA) patients, we recently documented an inhibitory response to suprathreshold, high-frequency repetitive transcranial magnetic stimulation (hf-rTMS) trains applied to the primary motor cortex, which is in contrast with the facilitatory response observed in the healthy subjects. The aim of the present study was to support the hypothesis that in migraine, because of a condition of basal increased cortical responsivity, inhibitory homeostatic like mechanisms of cortical excitability could be induced by high magnitude stimulation. For this purpose, the hf-rTMS trains were preconditioned by transcranial direct current stimulation (tDCS), a noninvasive brain stimulation technique able to modulate the cortical excitability state. Twenty-two MwA patients and 20 patients with migraine without aura (MwoA) underwent trains of 5-Hz repetitive transcranial magnetic stimulation at an intensity of 130% of the resting motor threshold, both at baseline and after conditioning by 15 minutes of cathodal or anodal tDCS. Motor cortical responses to the hf-rTMS trains were compared with those of 14 healthy subjects. We observed abnormal inhibitory responses to the hf-rTMS trains given at baseline in both MwA and MwoA patients as compared with the healthy subjects (P < .00001).The main result of the study was that cathodal tDCS, which reduces the cortical excitability level, but not anodal tDCS, which increases it, restored the normal facilitatory response to the hf-rTMS trains in both MwA and MwoA. The present findings strengthen the notion that, in migraine with and without aura, the threshold for inducing inhibitory mechanisms of cortical excitability might be lower in the interictal period. This could represent a protective mechanism counteracting cortical hyperresponsivity. Our results could be helpful to explain some conflicting neurophysiological findings in migraine and to get insight into the mechanisms underlying recurrence of the migraine attacks.
    Headache The Journal of Head and Face Pain 04/2014; 54(4):663-74. DOI:10.1111/head.12249 · 3.19 Impact Factor
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    ABSTRACT: The primary brain dysfunctions leading to the onset of a migraine attack remain largely unknown. Other important open questions concern the mechanisms of initiation, continuation, and termination of migraine pain, and the changes in brain function underlying migraine transformation. Brief trains of high-frequency repetitive transcranial magnetic stimulation (rTMS), when applied to the primary motor cortex at suprathreshold intensity (⩾ 120% of resting motor threshold, RMT), elicit in healthy subjects a progressive, glutamate-dependent facilitation of the Motor Evoked Potentials (MEP). Conversely, in conditions of increased cortical excitability, the rTMS trains induce inhibitory MEP responses likely mediated by cortical homeostatic mechanisms. We enrolled 66 migraine without aura (MwoA) patients, 48 migraine with aura (MwA) patients, 14 patients affected by chronic migraine (CM), and 20 healthy controls. We assessed motor cortical response to 5-Hz rTMS trains of 10 stimuli given at 120% RMT. Patients with episodic migraine (EM) were studied in different phases of the migraine cycle, i.e. interictal, preictal, ictal and postictal state. Results showed a facilitatory MEP response during the trains in patients evaluated in the preictal phase, whilst inhibitory responses were observed during and after a migraine attack, as well as in CM patients. In the interictal phase, different responses were observed depending on attack frequency: facilitation in patients with low and inhibition with those with high attack recurrence. Our findings suggest that changes in cortical excitability and fluctuations in the threshold for inhibitory metaplasticity underlie the migraine attack recurrence, and could be involved in the process of migraine transformation.
    Pain 03/2014; 155(6). DOI:10.1016/j.pain.2014.02.024 · 5.84 Impact Factor
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    ABSTRACT: Objective To evaluate the effects of transcranial direct current stimulation (tDCS) on esophageal peristalsis in patients with gastroesophageal reflux disease (GERD). Methods Patients with GERD preliminary diagnosis were included in a randomized double-blind sham-controlled study. Esophageal manometry was performed before and during transcranial direct current stimulation (tDCS) of the right precentral cortex. Half of patients were randomly assigned to anodal, half to sham stimulation. Distal waves amplitude and pathological waves percentage were measured, after swallowing water boli, for ten subsequent times. Last, a 24 h pH-bilimetry was done to diagnose non-erosive reflux disease (NERD) or functional heartburn (FH). The values obtained before and during anodal or sham tDCS were compared. Results Sixty-eight patients were enrolled in the study. Distal waves mean amplitude increased significantly only during anodal tDCS in NERD (p = 0.00002) and FH subgroups (p = 0.008) while percentage of pathological waves strongly decreased only in NERDs (p = 0.002). Conclusions Transcranial stimulation can influence cortical control of esophageal motility and improve pathological motor pattern in NERD and FH but not in erosive reflux disease (ERD) patients. Significance Pathophysiological processes in GERD are not only due to peripheral damage but to central neural control involvement as well. In ERD patients dysfunctions of the cortico-esophageal circuit seem to be more severe and may affect central nervous system physiology.
    Clinical Neurophysiology 01/2014; DOI:10.1016/j.clinph.2013.12.110 · 2.98 Impact Factor
  • Pain 11/2013; DOI:10.1016/j.pain.2013.11.012 · 5.84 Impact Factor
  • Journal of the Neurological Sciences 10/2013; 333:e70. DOI:10.1016/j.jns.2013.07.522 · 2.26 Impact Factor