Narcolepsy associated with lesions of the diencephalon.

Although symptomatic narcolepsy, or narcolepsy due to identifiable brain lesions, was once thought to be common, there are few well-documented reported cases since the discovery of the association of REM sleep abnormalities with narcolepsy. Even fewer such reports have been accompanied by human leukocyte antigen (HLA) testing. We report 3 patients who fulfill criteria for symptomatic narcolepsy, 1 with a craniopharyngioma, the 2nd with a hypothalamic syndrome of unknown etiology, and the 3rd with obstructive hydrocephalus and a sarcoid granuloma in the region of the 3rd ventricle. The first 2 were positive for HLA-DR2 while the 3rd was negative for the HLA-DR2 and HLA-DQwl antigens. These findings suggest that diencephalic lesions can be associated with signs and symptoms of narcolepsy that are clinically indistinguishable from those of idiopathic narcolepsy, and that the HLA-DR2 antigen is not required in all cases of symptomatic narcolepsy.