Electroencephalographic features of benign adult familial myoclonic epilepsy

Abstract

Objective: To investigate electroencephalographic (EEG) features of benign adult familial myoclonic epilepsy (BAFME).

Methods: We 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.

Results: Nineteen (eight men, 11 women) patients with BAFME were included in this study. The mean frequency of GSW was 4.3±1.0Hz (mean±SD, n=14) in BAFME and 3.2±0.8Hz (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.

Conclusion: Faster frequency of GSW, compared with that in EGTCS, accompanied by PPR may be characteristic EEG features of BAFME.

Significance: These findings may lead the diagnosis of BAFME.

Keywords: Benign adult familial myoclonic epilepsy; Electroencephalography; Epilepsy with generalized tonic–clonic seizure only; Generalized spike and wave complexes.