[Psychotropic drug-induced myoclonus]

Based on five case studies, the suggestion is that, if physiological myoclonus can be excluded, antidepressant - or neuroleptic-induced myoclonus must as a rule be presumed to be a most subtle indication of increased cerebral exitability, an epileptic fragment or, in some instances, a myoclonus epilepsy. In each of the reported cases EEG recordings reflected epilepsy-specific potentials. Whether, however, the scope of differences in the EEG recordings and the N1/P1 amplitude increase of the SSEP may be used as an additional diagnostic criterion to determine the risk of epileptic seizures, should depend on the type of myoclonus chiefly induced. This would require more extensive neurophysiological examinations which should mainly include the back-averaging to permit, beside the EEG, a better evaluation of the relatively easily obtainable SSEP findings.