Therapy of myoclonus.
The treatment of myoclonus is mainly based on the pathophysiological origin of the neuronal discharges producing the jerks. Myoclonus of cortical origin responds best to treatment. Drugs commonly used to treat epilepsy are usually capable of controlling action and stimuli-sensitive cortical myoclonus. Piracetam (6-20 g/day), clonazepam (2-12 mg/day), sodium valproate (1,200-3,000 mg/day), and primidone (500-1,000 mg/day) are the most useful ones, often given in combination. Myoclonus of non-cortical origin, i.e. reticular reflex myoclonus or spinal myoclonus, may respond to serotoninergic drugs and clonazepam, but there is much less scientific documentation and rationale behind the therapeutic approach to these different forms, and hence greater variability in the response. No specific drug treatment is yet available for negative myoclonus (Asterixis and postural lapses).