Narcolepsy associated with arteriovenous malformation of the diencephalon.

Narcolepsy associated with localized brain lesions is rare, and few reports of well-documented cases have been published. We describe the case of a 20-year-old male (HLA DQw1 negative) who fulfilled clinical and polygraphic criteria of symptomatic narcolepsy. Narcolepsy in this patient was associated with an arteriovenous malformation involving the structures around the third ventricle. Clinical symptoms improved after embolization and radiosurgery. These findings support the hypothesis that lesions in the vicinity of the third ventricle can cause symptomatic narcolepsy.