Myoklonus
Myoclonus refers to sudden brief, shock-like involuntary muscle contractions (positive myoclonus) or sudden suppression of muscle activity (negative myoclonus). The manifestations can be focal, multifocal, or generalized, and may occur at rest or with action. Myoclonic jerks are typically lasting only milliseconds but can occur in rapid succession, leading to a jerky or arrhythmic movement pattern. Negative myoclonus produces brief lapses in muscle activity resulting in a momentary lapse or cessation of movement.
Classification of myoclonus is clinical and etiological. It includes physiological myoclonus (e.g., sleep starts or hypnic
Causes span metabolic and structural brain disease, neurodegenerative disorders, autoimmune or infectious processes, and drug or
Diagnosis relies on history and video-EEG with EMG to characterize the timing and generator of the jerks,
Treatment targets the underlying cause where possible and may include antiseizure medications such as valproate, clonazepam,