Online edition:ISSN 2758-089X

Benign Adult Familial Myoclonic Epilepsy (BAFME)

Fourteen of the 26 members of two families with hereditary myoclonic epilepsy were studied, and the following findings were obtained. The disease was transmitted by autosomal dominant inheritance, and the onset was observed after adolescence with tremulous finger movement and/or myoclonus of the extremities. The clinical course was nonprogressive and neither dementia nor cerebellar ataxia developed during observation of over 10 years. The myoclonus appeared predominantly in the four extremities, not only at rest but also on posturing or in action, and it was increased by fatigue, insomnia or photic stimulations. Epileptic seizures appeared in 12 patients, though the frequency of seizures was relatively rare. Usually, increased diffuse myoclonic jerks were followed by generalized tonic-clonic convulsions. Electroencephalograms showed generalized spikes or polyspikes and wave complexes, and some patients exhibited photosensitivities. The amplitudes of somatosensory and visual evoked potentials increased, and the C reflex, which is a long-loop reflex, could be recorded in all cases at rest. By the jerk-locked averaging method, a positive spike time-locked to the myoclonic jerk was demonstrated in four patients before 15-20 msec of myoclonic jerk. These findings indicated "cortical reflex myoclonus". Valproates were markedly effective for its treatment. I proposed the new term "benign adult familial myoclonic epilepsy (BAFME)" for this disease.

Yasuda T.