| Condition | Diagnostic Criteria | North American Prevalence | Pathophysiology and Etiology |
|---|---|---|---|
| Narcolepsy with cataplexy | Presence of definite cataplexy; usually abnormal MSLT results | 0.02–0.18% | Hypocretin deficiency; 90% with low CSF HCRT-1 and positive for HLA-DQB1*0602 |
| Narcolepsy without cataplexy | MSLT: mean sleep latency less than or equal to 8 minutes, 2 or greater SOREMPs; no or doubtful cataplexy | 0.02%; many undiagnosed | Unknown, probably heterogeneous; 7– 25% with low CSF HCRT-1, 40% HLA-DQB1*0602 positive |
| Secondary narcolepsy or hypersomnia | As above, but due to other known medical conditions (e.g., neurological) | Unknown | With or without hypocretin deficiency |
| Idiopathic hypersomnia with prolonged sleep | MSLT: short mean sleep latency, greater than two SOREMPs; long (10 hours or greater) unrefreshing nocturnal sleep | Rare, maybe 0.01–0.02% | Unknown, probable heterogeneous etiology |
| Idiopathic hypersomnia with normal sleep length | MSLT: short mean sleep latency, less than two SOREMPs; normal nightly sleep amounts (less than 10 hours) | Probably common, unknown prevalence | Unknown, probable heterogeneous etiology |
| Periodic hypersomnia (includes Kleine-Levin syndrome) | Recurrent (more than 1 time per year) sleepiness (lasting 2 to 28 days), normal function between occurrences | Rare, probably less than one per one million people | Unknown, probable heterogeneous etiology |
SOURCE: AASM (2005).
From: 3, Extent and Health Consequences of Chronic Sleep Loss and Sleep Disorders
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