[Effectiveness of valproic acid for postanoxic action myoclonus (Lance-Adams syndrome)].

We describe the case of a patient who experienced postanoxic action myoclonus after a transient cardiopulmonary arrest. Whereas benzodiazepines (clonazepam, midazolam, diazepam) were inefficient, valproic acid allowed a full control of the myoclonus. It is essential that the distinction between postanoxic action myoclonus and posthypoxic seizures is made early to avoid a delayed appropriate therapy and erroneous prognostic conclusions.