The Experts below are selected from a list of 390 Experts worldwide ranked by ideXlab platform
Marie Vidailhet - One of the best experts on this subject based on the ideXlab platform.
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medical management of myoclonus dystonia and implications for underlying pathophysiology
Parkinsonism & Related Disorders, 2020Co-Authors: Conor Fearon, Kathryn J. Peall, Marie Vidailhet, Alfonso FasanoAbstract:Abstract Myoclonus-dystonia is an early onset genetic disorder characterised by subcortical myoclonus and less prominent dystonia. Its primary causative gene is the epsilon-sarcoglycan gene but the syndrome of “Myoclonic dystonia” has been shown to be a heterogeneous group of genetic disorders. The underlying pathophysiology of myoclonus-dystonia is incompletely understood, although it may relate to dysfunction of striatal monoamine neurotransmission or disruption of cerebellothalamic networks (possibly via a GABAergic deficit of Purkinje cells). A broad range of oral medical therapies have been used in the treatment of myoclonus-dystonia with a varying response, and limited data relating to efficacy and tolerability, yet this condition responds dramatically to alcohol. Few well conducted randomized controlled trials have been undertaken leading to an empirical ad hoc approach for many patients. We review the current evidence for pharmacological therapies in myoclonus-dystonia, discuss implications for underlying pathogenesis of the condition and propose a treatment algorithm for these patients.
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Treatment of Myoclonic dystonia
Current Clinical Neurology, 2019Co-Authors: Marie VidailhetAbstract:Myoclonic dystonia is defined by the combination of dystonia and Myoclonic jerks. Within this heterogeneous entity, a particular subtype, called “myoclonus dystonia” (MD), refers to a clinical syndrome characterized by rapid, brief, irregular jerky movements combined with dystonic contractions. Action and posture myoclonus is usually the most disabling feature, and predominates in the arms and axial muscles, and markedly impairs quality of life, as the disease usually starts in childhood and persists in adulthood. Mutations in the epsilon-sarcoglycan gene (SGCE) account for 30–50% of the MD cases. Myoclonus may be improved by alcohol; most of the drugs have limited efficacy and poor tolerability. A randomized, double-blind, placebo-controlled crossover study demonstrated that zonisamide (up to 300 mg/day) can improve myoclonus severity and functional disability in patients. In severe forms of MD, bilateral deep brain stimulation of the internal globus pallidus (GPi-DBS) is an effective option with a benefit lasting several years with a follow-up over 10 years. Behavioral disorders such as obsessive-compulsive disorder, depression, and anxiety have been described in MD and may require additional symptomatic treatments.
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myoclonus and dystonia in cerebrotendinous xanthomatosis
Movement Disorders, 2012Co-Authors: Julien Lagarde, Marie Vidailhet, Emmanuel Roze, Emmanuelle Apartis, Deepa Pothalil, Frederic Sedel, Philippe Couvert, Bertrand DegosAbstract:BACKGROUND: Cerebrotendinous xanthomatosis (CTX) is an inherited neurometabolic disorder. The main neurological manifestations of the disease are pyramidal syndrome, ataxia, peripheral neuropathy, cognitive impairment, epilepsy, and psychiatric disturbances. Myoclonic dystonia has been reported on in the setting of various neurometabolic diseases. Anecdotal reports describe movement disorders associated with CTX, but no dystonia with Myoclonic events. METHODS: We collected clinical, biochemical, electrophysiological, neuroradiological, and genetic data of 6 patients with myoclonus and mild dystonia associated with CTX. From a systematic literature review, we analyzed 31 patients with movement disorders secondary to CTX. RESULTS: Our 6 patients presented distal myoclonus with mild dystonia of the upper limbs. Myoclonus was of subcortical origin, based on neurophysiological recordings, and differed from oromandibular myoclonus previously described in CTX patients. CONCLUSIONS: These results expand the phenotype of CTX and suggest that myoclonus and/or dystonia are underdiagnosed. In keeping with our findings, tremors previously observed in CTX patients might actually correspond to Myoclonic events. We hypothesize that a dysfunction of the dentate nuclei-basal ganglia pathway may be involved.
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Myoclonus and dystonia in cerebrotendinous xanthomatosis
Movement disorders : official journal of the Movement Disorder Society, 2012Co-Authors: Julien Lagarde, Marie Vidailhet, Emmanuel Roze, Emmanuelle Apartis, Deepa Pothalil, Frederic Sedel, Philippe Couvert, Bertrand DegosAbstract:Background: Cerebrotendinous xanthomatosis (CTX) is an inherited neurometabolic disorder. The main neurological manifestations of the disease are pyramidal syndrome, ataxia, peripheral neuropathy, cognitive impairment, epilepsy, and psychiatric disturbances. Myoclonic dystonia has been reported on in the setting of various neurometabolic diseases. Anecdotal reports describe movement disorders associated with CTX, but no dystonia with Myoclonic events. Methods: We collected clinical, biochemical, electrophysiological, neuroradiological, and genetic data of 6 patients with myoclonus and mild dystonia associated with CTX. From a systematic literature review, we analyzed 31 patients with movement disorders secondary to CTX. Results: Our 6 patients presented distal myoclonus with mild dystonia of the upper limbs. Myoclonus was of subcortical origin, based on neurophysiological recordings, and differed from oromandibular myoclonus previously described in CTX patients. Conclusions: These results expand the phenotype of CTX and suggest that myoclonus and/or dystonia are underdiagnosed. In keeping with our findings, tremors previously observed in CTX patients might actually correspond to Myoclonic events. We hypothesize that a dysfunction of the dentate nuclei-basal ganglia pathway may be involved. © 2012 Movement Disorder Society.
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Epsilon sarcoglycan mutations and phenotype in French patients with Myoclonic syndromes.
Journal of Medical Genetics, 2006Co-Authors: S. Tezenas Du Montcel, Marie Vidailhet, F. Clot, E. Roze, P. Damier, C.p. Jedynak, A. Camuzat, A. Lagueny, L. Vercueil, Diane DoummarAbstract:BACKGROUND: Myoclonus dystonia syndrome (MDS) is an autosomal dominant movement disorder caused by mutations in the epsilon-sarcoglycan gene (SGCE) on chromosome 7q21. METHODS: We have screened for SGCE mutations in index cases from 76 French patients with Myoclonic syndromes, including myoclonus dystonia (M-D), essential myoclonus (E-M), primary Myoclonic dystonia, generalised dystonia, dystonia with tremor, and benign hereditary chorea. All coding exons of the SGCE gene were analysed. The DYT1 mutation was also tested. RESULTS: Sixteen index cases had SGCE mutations while one case with primary Myoclonic dystonia carried the DYT1 mutation. Thirteen different mutations were found: three nonsense mutations, three missense mutations, three splice site mutations, three deletions, and one insertion. Eleven of the SGCE index cases had M-D and five E-M. No SGCE mutations were detected in patients with other phenotypes. The total number of mutation carriers in the families was 38, six of whom were asymptomatic. Penetrance was complete in paternal transmissions and null in maternal transmissions. MDS patients with SGCE mutation had a significantly earlier onset than the non-carriers. None of the patients had severe psychiatric disorders. CONCLUSION: This large cohort of index patients shows that SGCE mutations are primarily found in patients with M-D and to a lesser extent E-M, but are present in only 30% of these patients combined (M-D and E-M).
Yves Agid - One of the best experts on this subject based on the ideXlab platform.
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Clinical characteristics and topography of lesions in movement disorders due to thalamic lesions
Neurology, 2001Co-Authors: Stéphane Lehéricy, Yves Agid, Claude Marsault, Sylvie Grand, Pierre Pollak, F. Poupon, J.f. Le Bas, Patricia Limousin, Pierre Jedynak, Marie VidailhetAbstract:Objective: To determine which thalamic subnuclei are involved in symptomatic unilateral movement disorders due to localized thalamic infarction, and the clinical characteristics of these abnormal movements. Methods: The authors studied 22 patients with thalamic infarcts for their clinical presentation and the topography of the lesions, using three-dimensional T1-weighted MRI sequencing and stereotaxic analysis of the lesions. Results: Patients were divided into four groups: 1) absence of abnormal involuntary movements (AIM) (nine patients); 2) isolated dystonic posture (two patients); 3) Myoclonic dystonia (five patients); and 4) tremor or myoclonus (six patients). In patients with AIM, thalamic lesions were contralateral to the abnormal movements, involving the thalamogeniculate territory, centered on the ventral intermediate (Vim) and ventral caudal (Vc) nuclei. No significant difference in the volumes or center of mass of the lesions was found between patients with tremor and myoclonus and patients with dystonia, although the central nucleus and the internal part of the Vim nucleus were more consistently damaged in dystonic patients. Conclusion: Movement disorders related to thalamic lesions included: 1) Myoclonic dystonia with predominating myoclonus and “thalamic” hand associating dystonic posture and slow, pseudo-athetoid movements, both related to lesions in the Vim and Vc nuclei of the thalamus; and 2) postural and action tremor, also related to lesions in the Vim, similar to tremor associated with midbrain lesions, as a result of abnormal functioning of the cerebello-thalamic pathways.
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a major locus for several phenotypes of myoclonus dystonia on chromosome 7q
Neurology, 2001Co-Authors: Marie Vidailhet, Johann Tassin, Fabien Durif, A Nivelonchevallier, Alexis Brice, Yves Agid, Alexandra DurrAbstract:Myoclonus–dystonia is a genetically heterogeneous autosomal dominant disorder caused by a mutation in the D2 dopamine receptor on chromosome 11 and a locus on chromosome 7q21-q31. The authors tested linkage to the chromosome 7q candidate region in four families with either Myoclonic dystonia (n = 3) or essential myoclonus (n = 1). Age at onset ranged from 0.5 to 38 years. Only four patients from two families had a positive response to alcohol. Lod scores were positive in all four families, suggesting that chromosome 7q21-q31 is a major locus for myoclonus–dystonia with several phenotypes.
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A major locus for several phenotypes of myoclonus–dystonia on chromosome 7q
Neurology, 2001Co-Authors: Marie Vidailhet, Johann Tassin, Fabien Durif, A. Nivelon-chevallier, Alexis Brice, Yves Agid, Alexandra DurrAbstract:Myoclonus–dystonia is a genetically heterogeneous autosomal dominant disorder caused by a mutation in the D2 dopamine receptor on chromosome 11 and a locus on chromosome 7q21-q31. The authors tested linkage to the chromosome 7q candidate region in four families with either Myoclonic dystonia (n = 3) or essential myoclonus (n = 1). Age at onset ranged from 0.5 to 38 years. Only four patients from two families had a positive response to alcohol. Lod scores were positive in all four families, suggesting that chromosome 7q21-q31 is a major locus for myoclonus–dystonia with several phenotypes.
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Striatopallidal and thalamic dystonia : a magnetic resonance imaging anatomoclinical study
Archives of neurology, 1996Co-Authors: Stéphane Lehéricy, Marie Vidailhet, Didier Dormont, Laurent Pierot, Jacques Chiras, Pilar Mazetti, Claude Marsault, Yves AgidAbstract:Objective: To determine which brain structures are involved in symptomatic unilateral dystonia caused by localized cerebral infarction. Design: Three-dimensional T 1 -weighted magnetic resonance imaging sequence and stereotactic analysis were used to analyze the topography of the lesions. Stereotactic localization of thalamic lesions was conducted according to the atlas of Hassler with a Voxtool software (Advantage Windows Workstation, General Electric, Milwaukee, Wis) workstation system. Patients: Eight patients with hemidystonia, segmental dystonia, or focal dystonia were selected from among 51 consecutive patients (between January 1988 and May 1993) with symptomatic unilateral dystonia. Results: Patients had dystonic spasms (n=4) or Myoclonic dystonia (n=4). Lesions associated with dystonic spasms were located in the striatopallidal complex, and those with Myoclonic dystonia were in the thalamus contralateral to the dystonia. Lesions of the striatopallidal complex involved the putamen posterior to the anterior commissure in all patients and extended variably into the dorsolateral part of the caudate nucleus, the posterior limb of the internal capsule, or the lateral segment of the globus pallidus. These lesions were centered in the "sensorimotor" part of the striatopallidal complex, with a trend toward a somatotopical distribution. Lesions of the thalamus were located in the ventral intermediate and ventral caudal nuclei, while the ventral oral anterior and posterior nuclei (which receive pallidal efferents) were largely spared. Conclusion: These results suggest that striatopallidal and thalamic dystonia may have different pathophysiologic bases.
Stéphane Lehéricy - One of the best experts on this subject based on the ideXlab platform.
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Clinical characteristics and topography of lesions in movement disorders due to thalamic lesions
Neurology, 2001Co-Authors: Stéphane Lehéricy, Yves Agid, Claude Marsault, Sylvie Grand, Pierre Pollak, F. Poupon, J.f. Le Bas, Patricia Limousin, Pierre Jedynak, Marie VidailhetAbstract:Objective: To determine which thalamic subnuclei are involved in symptomatic unilateral movement disorders due to localized thalamic infarction, and the clinical characteristics of these abnormal movements. Methods: The authors studied 22 patients with thalamic infarcts for their clinical presentation and the topography of the lesions, using three-dimensional T1-weighted MRI sequencing and stereotaxic analysis of the lesions. Results: Patients were divided into four groups: 1) absence of abnormal involuntary movements (AIM) (nine patients); 2) isolated dystonic posture (two patients); 3) Myoclonic dystonia (five patients); and 4) tremor or myoclonus (six patients). In patients with AIM, thalamic lesions were contralateral to the abnormal movements, involving the thalamogeniculate territory, centered on the ventral intermediate (Vim) and ventral caudal (Vc) nuclei. No significant difference in the volumes or center of mass of the lesions was found between patients with tremor and myoclonus and patients with dystonia, although the central nucleus and the internal part of the Vim nucleus were more consistently damaged in dystonic patients. Conclusion: Movement disorders related to thalamic lesions included: 1) Myoclonic dystonia with predominating myoclonus and “thalamic” hand associating dystonic posture and slow, pseudo-athetoid movements, both related to lesions in the Vim and Vc nuclei of the thalamus; and 2) postural and action tremor, also related to lesions in the Vim, similar to tremor associated with midbrain lesions, as a result of abnormal functioning of the cerebello-thalamic pathways.
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Striatopallidal and thalamic dystonia : a magnetic resonance imaging anatomoclinical study
Archives of neurology, 1996Co-Authors: Stéphane Lehéricy, Marie Vidailhet, Didier Dormont, Laurent Pierot, Jacques Chiras, Pilar Mazetti, Claude Marsault, Yves AgidAbstract:Objective: To determine which brain structures are involved in symptomatic unilateral dystonia caused by localized cerebral infarction. Design: Three-dimensional T 1 -weighted magnetic resonance imaging sequence and stereotactic analysis were used to analyze the topography of the lesions. Stereotactic localization of thalamic lesions was conducted according to the atlas of Hassler with a Voxtool software (Advantage Windows Workstation, General Electric, Milwaukee, Wis) workstation system. Patients: Eight patients with hemidystonia, segmental dystonia, or focal dystonia were selected from among 51 consecutive patients (between January 1988 and May 1993) with symptomatic unilateral dystonia. Results: Patients had dystonic spasms (n=4) or Myoclonic dystonia (n=4). Lesions associated with dystonic spasms were located in the striatopallidal complex, and those with Myoclonic dystonia were in the thalamus contralateral to the dystonia. Lesions of the striatopallidal complex involved the putamen posterior to the anterior commissure in all patients and extended variably into the dorsolateral part of the caudate nucleus, the posterior limb of the internal capsule, or the lateral segment of the globus pallidus. These lesions were centered in the "sensorimotor" part of the striatopallidal complex, with a trend toward a somatotopical distribution. Lesions of the thalamus were located in the ventral intermediate and ventral caudal nuclei, while the ventral oral anterior and posterior nuclei (which receive pallidal efferents) were largely spared. Conclusion: These results suggest that striatopallidal and thalamic dystonia may have different pathophysiologic bases.
Tipu Z Aziz - One of the best experts on this subject based on the ideXlab platform.
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Use of surface electromyography to assess and select patients with idiopathic dystonia for bilateral pallidal stimulation
Journal of neurosurgery, 2006Co-Authors: Shouyan Wang, Xuguang Liu, John F. Stein, Ralph Gregory, Peter G. Bain, John Yianni, Alexander L. Green, Carole Joint, Tipu Z AzizAbstract:Object. The object of this study was to identify a preoperative physiological index by using surface electromyography (EMG) signals that would correlate with clinical outcome in dystonic patients following bilateral pallidal stimulation. Methods. In 14 patients with spasmodic torticollis, generalized dystonia, and Myoclonic dystonia, surface EMG signals were recorded from the most affected muscle groups. Although the dystonia affected different body segments, the EMG signals in all patients could be decomposed into bursting and sustained components. Subsequently, a ratio of the EMG amplitude was calculated between the two components and then correlated with clinical outcome. Patients who experienced rapid improvement following bilateral pallidal stimulation had a significantly higher EMG ratio compared with those who did not. Furthermore, a significant correlation was found between the EMG ratio and clinical improvement during the 12-month period following pallidal stimulation. Conclusions. The authors concluded that surface EMG studies could be used to predict the clinical outcome of and to select patients for pallidal stimulation for dystonia.
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involvement of the medial pallidum in focal Myoclonic dystonia a clinical and neurophysiological case study
Movement Disorders, 2002Co-Authors: Xuguang Liu, Ivan C. Griffin, Christopher R. Miall, Simon Parkin, Jeremy Rowe, Ralph Gregory, Richard B Scott, Tipu Z Aziz, John F. SteinAbstract:We successfully treated a patient with familial myo- clonic dystonia (FMD), which primarily affected his neck muscles, with bilateral deep brain stimulation (DBS) to the medial pallidum, and investigated the role of the medial palli- dum in FMD. A patient with FMD underwent bilateral implan- tation of DBS electrodes during which field potentials (FPs) in the medial pallidum and electromyograms (EMGs) from the affected neck muscles were recorded. The effects of high- frequency DBS to the medial pallidum on the FMD were also assessed by recording EMGs during and immediately after im- plantation, as well as 6 days and 8 weeks postoperatively. Dur- ing spontaneous Myoclonic episodes, increased FPs oscillating at 4 and 8 Hz were recorded from the medial pallidum; these correlated strongly with phasic EMG activity at the same fre- quencies in the contralateral affected muscles. The EMG ac- tivity was suppressed by stimulating the contralateral medial pallidum at 100 Hz during the operation and continuous bilat- eral DBS from an implanted stimulator abolished Myoclonic activity even more effectively postoperatively. The phasic pal- lidal activity correlated with and led the Myoclonic muscle activity, and the myoclonus was suppressed by bilateral pallidal DBS, suggesting that the medial pallidum was involved in the generation of the Myoclonic activity. High-frequency DBS may suppress the myoclonus by desynchronising abnormal pallidal oscillations. This case study has significant clinical implica- tions, because at present, there is no effective treatment for focal Myoclonic dystonia. © 2002 Movement Disorder Society
John F. Stein - One of the best experts on this subject based on the ideXlab platform.
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© 2002 Movement Disorder Society Involvement of the Medial Pallidum in Focal Myoclonic dystonia: A Clinical and Neurophysiological Case Study
2013Co-Authors: Xuguang Liu, Ivan C. Griffin, Simon G. Parkin, Christopher R. Miall, John F. SteinAbstract:Abstract: We successfully treated a patient with familial Myoclonic dystonia (FMD), which primarily affected his neck muscles, with bilateral deep brain stimulation (DBS) to the medial pallidum, and investigated the role of the medial pallidum in FMD. A patient with FMD underwent bilateral implantation of DBS electrodes during which field potentials (FPs) in the medial pallidum and electromyograms (EMGs) from the affected neck muscles were recorded. The effects of highfrequency DBS to the medial pallidum on the FMD were also assessed by recording EMGs during and immediately after implantation, as well as 6 days and 8 weeks postoperatively. During spontaneous Myoclonic episodes, increased FPs oscillating at 4 and 8 Hz were recorded from the medial pallidum; these correlated strongly with phasic EMG activity at the same frequencies in the contralateral affected muscles. The EMG activit
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Use of surface electromyography to assess and select patients with idiopathic dystonia for bilateral pallidal stimulation
Journal of neurosurgery, 2006Co-Authors: Shouyan Wang, Xuguang Liu, John F. Stein, Ralph Gregory, Peter G. Bain, John Yianni, Alexander L. Green, Carole Joint, Tipu Z AzizAbstract:Object. The object of this study was to identify a preoperative physiological index by using surface electromyography (EMG) signals that would correlate with clinical outcome in dystonic patients following bilateral pallidal stimulation. Methods. In 14 patients with spasmodic torticollis, generalized dystonia, and Myoclonic dystonia, surface EMG signals were recorded from the most affected muscle groups. Although the dystonia affected different body segments, the EMG signals in all patients could be decomposed into bursting and sustained components. Subsequently, a ratio of the EMG amplitude was calculated between the two components and then correlated with clinical outcome. Patients who experienced rapid improvement following bilateral pallidal stimulation had a significantly higher EMG ratio compared with those who did not. Furthermore, a significant correlation was found between the EMG ratio and clinical improvement during the 12-month period following pallidal stimulation. Conclusions. The authors concluded that surface EMG studies could be used to predict the clinical outcome of and to select patients for pallidal stimulation for dystonia.
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involvement of the medial pallidum in focal Myoclonic dystonia a clinical and neurophysiological case study
Movement Disorders, 2002Co-Authors: Xuguang Liu, Ivan C. Griffin, Christopher R. Miall, Simon Parkin, Jeremy Rowe, Ralph Gregory, Richard B Scott, Tipu Z Aziz, John F. SteinAbstract:We successfully treated a patient with familial myo- clonic dystonia (FMD), which primarily affected his neck muscles, with bilateral deep brain stimulation (DBS) to the medial pallidum, and investigated the role of the medial palli- dum in FMD. A patient with FMD underwent bilateral implan- tation of DBS electrodes during which field potentials (FPs) in the medial pallidum and electromyograms (EMGs) from the affected neck muscles were recorded. The effects of high- frequency DBS to the medial pallidum on the FMD were also assessed by recording EMGs during and immediately after im- plantation, as well as 6 days and 8 weeks postoperatively. Dur- ing spontaneous Myoclonic episodes, increased FPs oscillating at 4 and 8 Hz were recorded from the medial pallidum; these correlated strongly with phasic EMG activity at the same fre- quencies in the contralateral affected muscles. The EMG ac- tivity was suppressed by stimulating the contralateral medial pallidum at 100 Hz during the operation and continuous bilat- eral DBS from an implanted stimulator abolished Myoclonic activity even more effectively postoperatively. The phasic pal- lidal activity correlated with and led the Myoclonic muscle activity, and the myoclonus was suppressed by bilateral pallidal DBS, suggesting that the medial pallidum was involved in the generation of the Myoclonic activity. High-frequency DBS may suppress the myoclonus by desynchronising abnormal pallidal oscillations. This case study has significant clinical implica- tions, because at present, there is no effective treatment for focal Myoclonic dystonia. © 2002 Movement Disorder Society
