1-A-D-1. Generator mechanisms of cortical tremor in patients with benign adult familial myoclonus epilepsy (BAFME): A corticomuscular coherence study

Abstract

Benign adult familial myoclonus epilepsy (BAFME) is an autosomal dominant disease characterized by cortical tremor and infrequent generalized seizures. We aimed to clarify the generator mechanism of cortical tremor in BAFME by means of corticomuscular coherence. We employed 15 patients with BAFME diagnosed based on clinical and electrophysiological findings. EEG, EMG and accelerometer were simultaneously recorded in all 15 patients. Among them, in addition, magnetoencephalography (MEG), EEG and EMG were also simultaneously recorded on different occasions in 3 patients. Patients were instructed to keep the hand in the outstretched posture with and without loading weight on the hand. We compared the power spectrum among tasks to judge whether the tremor was presumably of cerebral or peripheral origin. As the results, the frequency band showing significant corticomuscular coherence matched that of peak power spectrum of cortical tremor only in 3 patients. On the other hand, they differed in the remaining 12 patients. Thus, the cortical tremor in BAFME could not be initiated or regulated directly by cerebral cortex but possibly by other structures such as subcortical or cerebellum structures, like those responsible for essential tremor.