The clinical features of cataplexy: a questionnaire study in narcolepsy patients with and without hypocretin-1 deficiency.

Background: Narcolepsy is often not recognized or accurately diagnosed. This may be due to the fact that cataplexy, a core symptom which is virtually 100% specific, can-in practice-only be diagnosed based on the patient's history. However, the current definition of cataplexy is not very precise and the common distinction between "typical" and "atypical" cataplexy is not well codified.