Narcolepsy: unequivocal diagnosis after split-screen, video-polysomnographic analysis of a prolonged cataplectic attack.

The clinical diagnosis of narcolepsy often depends on the coexistence of pathologic sleepiness and cataplectic attacks. We present a case of narcolepsy unequivocally diagnosed after daytime, split-screen, video-polysomnographic monitoring captured a prolonged cataplectic event during which the patient was coherent, conversant, and in electroencephalographic rapid eye movement sleep.