The Role of Cerebrospinal Fluid Hypocretin Measurement in the Diagnosis of Narcolepsy and Other Hypersomnias

To delineate the spectrum of the hypocretin deficiency syndrome and to establish CSF hypocretin-1 measurements as a diagnostic tool for narcolepsy.

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 was used to determine the CSF hypocretin-1 levels best predictive for International Classification of Sleep Disorders (ICSD)-defined narcolepsy (blinded criterion standard). Clinical and demographic features were compared in narcoleptic subjects with and without low CSF hypocretin-1 levels.