Context Narcolepsy, a neurological disorder affecting 1 in 2000 individuals, is associated
with HLA-DQB1* 0602 and low cerebrospinal fluid (CSF) hypocretin (orexin) levels.
Objectives To delineate the spectrum of the hypocretin deficiency syndrome and to establish
CSF hypocretin-1 measurements as a diagnostic tool for narcolepsy. Design Diagnosis, HLA-
DQ, clinical data, the multiple sleep latency test (MSLT), and CSF hypocretin-1 were studied
in a case series of patients with sleep disorders from 1999 to 2002. Signal detection analysis …