Electroencephalographic features of benign adult familial myoclonic epilepsy

•Benign adult familial myoclonic epilepsy (BAFME) is an autosomal dominant disease characterized by infrequent generalized seizures and tremulous myoclonus resembling essential tremor.•We analyzed the EEG findings of BAFME who were treated at a tertiary referral center.•Faster frequency of GSW, compared with that in epilepsy with generalized tonic–clonic seizure only (EGTCS), accompanied by PPR may lead to the diagnosis of BAFME.

ObjectiveTo investigate electroencephalographic (EEG) features of benign adult familial myoclonic epilepsy (BAFME).MethodsWe reviewed interictal EEG features in patients with BAFME treated between April 2005 and November 2012 at a tertiary referral center. The diagnostic criteria for BAFME were the presence of infrequent generalized tonic–clonic seizures, myoclonus or myoclonic seizures, and autosomal dominant inheritance. Interictal EEG findings of epilepsy with generalized tonic–clonic seizure only (EGTCS) were reviewed for comparison. We randomly selected 10 generalized spike/polyspike and wave complexes (GSW) for each BAFME patient and measured the duration of them. Photic stimulation and hyperventilation were performed in all.ResultsNineteen (eight men, 11 women) patients with BAFME were included in this study. The mean frequency of GSW was 4.3 ± 1.0 Hz (mean ± SD, n = 14) in BAFME and 3.2 ± 0.8 Hz (n = 10) in EGTCS. There was a statistically significant difference (p = 0.008) between the two. Photoparoxysmal responses (PPR) were noted in 18 (95%) patients with BAFME but 1 (10%) with EGTCS.ConclusionFaster frequency of GSW, compared with that in EGTCS, accompanied by PPR may be characteristic EEG features of BAFME.SignificanceThese findings may lead the diagnosis of BAFME.