Long‐term GPi‐DBS improves motor features in myoclonus‐dystonia and enhances social adjustment

Abstract

Background Good short‐term results of pallidal deep brain stimulation have been reported in myoclonus‐dystonia. Efficacy and safety in the long term remain to be established. In addition, the actual impact of DBS treatment on social inclusion is unknown. The objective of this study was to assess the long‐term clinical outcome, quality of life, and social adjustment of GPi‐DBS in patients with ε‐sarcoglycan (DYT11)‐positive myoclonus‐dystonia. Methods Consecutive myoclonus‐dystonia patients with ε‐sarcoglycan mutations who underwent GPi‐DBS were evaluated at least 5 years postoperatively. Motor symptoms were assessed using the Burke‐Fahn‐Marsden Dystonia Rating Scale including the Disability Scale, a composite score combining the rest and action parts of the Unified Myoclonus Rating Scale and modified Abnormal Involuntary Movement Scale. Standardized video‐protocols were assessed by a blinded and external movement disorder specialist. Social adjustment, cognition, and mood were evaluated. Results Nine patients (5 women) with long‐term GPi‐DBS (8.7 ± 3.1 years) were included. There was significant improvement in the composite myoclonus score (94.1% ± 4% improvement; P = 0.008). Dystonia severity was also markedly improved (71.4% ± 28.33% improvement; P = 0.008) as well as motor disability (88.3% ± 20% improvement; P = 0.008) and abnormal involuntary movement score (71.1% ± 15.0% improvement; P = 0.008). No patients experienced postoperative speech or gait problems or any permanent adverse effects. Eight of the 9 patients had fully enhanced social adjustment and personal achievement, with little or no mood or behavioral disorders. Conclusions GPi‐DBS seems to be a safe and efficacious treatment for medically refractory ɛ‐sarcoglycan myoclonus‐dystonia, with sustained motor benefit, good quality of life, and social adjustment in long‐term follow‐up. © 2018 International Parkinson and Movement Disorder Society

Visual Sensory Processing is Altered in Myoclonus Dystonia

“…Interestingly, DBS of the internal globus pallidus (GPi) results in a dramatic and sustained improvement of both myoclonus and dystonia. This suggests that dysfunction of the striato‐pallido‐thalamo‐cortical network is critically involved in the generation of this motor phenotype . Metabolic neuroimaging and various neurophysiological studies point to a dysfunctional cerebello‐thalamo‐cortical pathway .…”

“…This suggests that dysfunction of the striato-pallido-thalamo-cortical network is critically involved in the generation of this motor phenotype. [20][21][22] Metabolic neuroimaging and various neurophysiological studies point to a dysfunctional cerebello-thalamocortical pathway. [23][24][25] Similar to other dystonic syndromes, 26 abnormal sensorimotor integration with hypoactivity within the premotor, sensory, and parietal cortices and the cerebellum has been shown in DYT-SGCE.…”

Quality of life outcomes after deep brain stimulation in dystonia: A systematic review

“…Intriguingly, GPi and Vim DBS had comparable beneficial effects on myoclonus, whereas improvement in dystonia was greater with GPi than Vim DBS. A recent prospective study showed the long-term efficacy of GPi DBS both on myoclonus and dystonia at a mean follow-up of 8.7 years [55].…”

A Case Report of Myoclonus-Dystonia with Isolated Myoclonus Phenotype and Novel Mutation Successfully Treated with Deep Brain Stimulation

“…There is no treatment that addresses the underlying cause of MD; therefore, treatment is entirely symptomatic. In recent years, deep brain stimulation (DBS) has shown significant promise in treating these patients [6,7]. Although patients with myoclonus or dystonia as the sole clinical feature have been described [8], there is only one report in the literature of a patient with positive SGCE mutation and isolated myoclonus phenotype who has been treated with DBS of the globus pallidus internus (GPi) [9].…”