Action myoclonus following acute cerebral anoxia.

Action myoclonus secondary to posthypoxic encephalopathy is being seen increasingly with improved resuscitation techniques. A case report describes 5 specific physical and occupational therapeutic techniques for achieving independence in ambulation, transfers and self-care: (1) analysis and segmentation of complex motions into small steps; (2) controlled progression of training; (3) voluntary cessation of abnormal activity (pacing); (4) progressive densensitization to external stimuli; and (5) quantification of progress. Literature review suggests that posthypoxic action myoclonus is secondary to a loss of inhibitory synapses in the brainstem reticular formation due to low serotonin levels. The proposed therapeutic effect of clonazepam, the drug used in this patient, is decreased serotinin degredation. L-5-hydroxytryptamine, an investigative drug, is also therapeutic, for it stimulates increased serotonin production.