Electrophysiological studies of myoclonus.

As myoclonus is often associated with abnormally increased excitability of cortical structures, electrophysiological studies provide useful information for its diagnosis and classification and about its generator mechanisms. The EEG-EMG polygraph provides the most essential information about the myoclonus of interest. Jerk-locked back averaging and evoked potential studies combined with recording of the long latency, long loop reflexes are useful to further investigate the pathophysiology of myoclonus, especially that of cortical myoclonus. A recent advance in magnetoencephalographic techniques has contributed significantly to the elucidation of some of the cortical mechanisms underlying myoclonus. Elucidation of physiological mechanisms underlying myoclonus in each individual patient is important for selecting the most appropriate treatment of choice. Copyright 2000 American Association of Electrodiagnostic Medicine.