Autosomal dominant nocturnal frontal lobe epilepsy: electroclinical picture

Abstract

Purpose: Nocturnal frontal lobe epilepsy is a disorder that is difficult to diagnose because its clinical presentation is often limited to motor behavior during sleep. For this reason, a misleading diagnosis of benign nocturnal parasomnias might be possible. Recently, an inherited form of nocturnal frontal lobe epilepsy was described in some families. The aim of our work was to describe the electroclinical pattern of a sample of familial cases with this syndrome.

Methods: We observed 33 patients, all complaining of frequent nocturnal motor attacks, from eight Italian families. The family trees were strongly supportive of autosomal dominant inheritance. We performed a full-night video-polysomnographic monitoring in 12 patients.

Results: The recordings showed attacks in all patients, there being a widespread pattern of motor activity. Ictal and interictal EEG abnormalities were often hidden and, unless associated with a video recording, were of no use for the final diagnosis. Intraindividual stereotypy, abrupt onset, and semiology of attacks allowed differentiation from healthy subjects' nocturnal motor behavior.

Conclusions: Autosomal dominant nocturnal frontal lobe epilepsy is probably not uncommon. Full-night video-polysomnographic monitoring is fundamental for the differential diagnosis of benign parasomnias and, consequently, for appropriate therapy.