Hypersomnia with sudden sleep attacks ("symptomatic narcolepsy") on the basis of vertebrobasilar artery insufficiency. A case report.

Report of a 56-year-old patient with a one-year-history of uncontrolable sleep attacks occurring at daytime and episodes of unsteadiness, dizziness, diplopia and dysarthria. The clinical evaluation revealed evidence of vertebrobasilar artery enlargement and insufficiency. He has become symptom-free under appropriate treatment. This raises the question of "symptomatic narcolepsy" caused by vascular brain stem disorder.