Myoclonus-Dystonia

1. Myoclonus - Dystonia
Ade Wijaya, MD – November 2019

2. Outline:
• Introduction
• Clinical presentation
• Pathogenesis
• Diagnostic Criteria
• Treatment
• Summary

3. Introduction
• Clinical syndrome characterized by a particular combination of myoclonus
and dystonia.
• SGCE gene deficiency
• Dominant paternal transmission
• The disorder occurs before age 10 in the vast majority of patients whereas
onset after age 20 is very unusual
Roze E, Apartis E, Clot F, et al. Myoclonus-dystonia: clinical and electrophysiologic pattern related to SGCE mutations. Neurology 2008; 70: 1010–1016.
Zutt R, Dijk JM, Peall KJ, et al. Distribution and coexistence of myoclonus and dystonia as clinical predictors of SGCE mutation status: a pilot study. Front Neurol 2016; 7:72.
Peall KJ, Kurian MA, Wardle M, et al. SGCE and myoclonus dystonia: motor characteristics, diagnostic criteria and clinical predictors of genotype. J Neurol 2014; 261:2296–2304.
Carecchio M, Magliozzi M, Copetti M, et al. Defining the epsilon-sarcoglycan (SGCE) gene phenotypic signature in myoclonus-dystonia: a reappraisal of genetic testing criteria. Mov Disord 2013; 28:787–794.

4. Clinical Presentation
• Upper body myoclonus, which may be isolated or associated with dystonia
• When present, dystonia is mild to moderate, and usually spares the face, the larynx,
and trunk. Cervical dystonia and writer’s cramp are the most common dystonic
manifestations
• Improvement with alcohol
• Other psychiatric disorders, namely anxiety-related disorders (generalized anxiety
disorders, panic disorder, social phobia, specific phobia) and obsessive compulsive
disorder (compulsivity being the predominant component)
Roze E, Lang AE, Vidailhet M. Myoclonus-dystonia: classification, phenomenology, pathogenesis, and treatment. Current opinion in neurology. 2018 Aug 1;31(4):484-90.

5. Pathogenesis
• Dysfunction of the cerebello-thalamic pathways
• Basal ganglia and cortical pathogenic mechanisms
• Disruption of serotonin and dopamine homeostasis
Roze E, Lang AE, Vidailhet M. Myoclonus-dystonia: classification, phenomenology, pathogenesis, and treatment. Current opinion in neurology. 2018 Aug 1;31(4):484-90.

6. Diagnostic Criteria
Roze E, Lang AE, Vidailhet M. Myoclonus-dystonia: classification, phenomenology, pathogenesis, and treatment. Current opinion in neurology. 2018 Aug 1;31(4):484-90.

7. Treatment
• Zonisamide improves myoclonus and its associated disability
• Other drugs that should be considered include benzodiazepines and
anticholinergics. These drugs can also be used in combination
• Botulinum toxin
• Deep Brain Stimulation
Hainque E, Vidailhet M, Cozic N, et al. A randomized, controlled, double-blind, crossover trial of zonisamide in myoclonus-dystonia. Neurology 2016; 86:1729–1735.
Luciano AY, Jinnah HA, Pfeiffer RF, et al. Treatment of myoclonus-dystonia syndrome with tetrabenazine. Parkinsonism Relat Disord 2014; 20: 1423–1426.
Rughani AI, Lozano AM. Surgical treatment of myoclonus dystonia syndrome. Mov Disord 2013; 28:282–287.
Roze E, Vidailhet M, Hubsch C, et al. Pallidal stimulation for myoclonusdystonia: ten years’ outcome in two patients. Mov Disord 2015; 30:871–872

8. Summary
• SGCE gene
• Childhood onset
• Upper body myoclonus
• Improvement with alcohol
• Dysfunction of the cerebello-thalamic pathways
• Zonisamide; Botulinum toxin injection; Deep Brain Stimulation

9. THANK YOU