[Three cases of benign myoclonus of early infancy]

Benign myoclonus of early infancy (BMEI) is a non-epileptic paroxysmal phenomenon. Some patients with BMEI were mistakenly treated as infantile spasms, because the fits resemble to tonic spasms in infantile spasms and they occur in cluster. However, the patients have normal development and no abnormal electroencephalograms (EEG), and the fits spontaneously subside without sequelae. There are only a few reports on BMEI, and it is not widely recognized in Japan. We report three cases of BMEI. All the cases were suspected to have infantile spasms from the characteristic features of paroxysmal events, and the parents had strong anxiety because of recurrent fits. However, the fits decreased dramatically in about three months, and spontaneously disappeared within one year without any sequelae. BMEI might be included in cases of suspected infantile spasms, and such patients should be followed by monthly EEG examinations and close observation for other seizure phenomena. To avoid unnecessary treatments, such patients should be observed without any therapeutic trials including antiepileptic drugs.