Narcolepsy in Saudi Arabia. Demographic and clinical perspective of an under-recognized disorder

OBJECTIVE: To assess the clinical and polysomnographic features of narcolepsy in Saudis.

METHODS: All patients diagnosed to have narcolepsy in the Sleep Disorders Center at King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia between March 1998 and December 2005 based on the International Classifications of Sleep Disorders Diagnostic and Coding Manual criteria were included. A data entry form collecting the demographic, clinical features, medications, referring specialty, prior diagnoses and daytime sleepiness was used. All patients underwent polysomnography followed by multiple sleep latency.

RESULTS: Forty-seven patients with a mean age of 28.9 +/- 1.9 years were included. The mean age at onset of symptoms was 20.5 +/- 1.4 years. The interval between symptoms onset and diagnosis was 8.4 +/- 1.2 years. While 22 (46.8%) of the patients were referred to the sleep disorders clinic by different specialties, 25 (53.2%) patients sought an appointment in the sleep disorders clinic directly. Only 3 patients were referred with the correct diagnosis. Nocturnal sleep quality was worse in narcoleptics with cataplexy compared to those without cataplexy.

CONCLUSION: Saudi patients with narcolepsy have the same clinical presentation as reported in the Western literature. Narcoleptics with cataplexy had disturbed quality compared to narcoleptics without cataplexy. A long time was reported between symptoms onset and diagnosis, which may reflect the under-recognition of the problem among physicians.