What are the types of narcolepsies?
There are two types of narcolepsies. Narcolepsy type 1 is characterized by daily periods of an irrepressible need to sleep or daytime lapses into sleep occurring for at least 3 months. In addition, one or both of the following criteria must be met:
- 1. cataplexy with a mean sleep latency of less than or equal to 8 minutes and two or more sleep onset REM periods (SOREMPs) on MLST
- 2. cerebrospinal fluid (CSF) hypocretin 1 concentration is less than or equal to 110 pg/mL.
Narcolepsy type 1 is caused by a deficiency of hypothalamic hypocretin (orexin) signaling. Narcolepsy type 2 is similar to type 1 except there is no cataplexy; CSF hypocretin is not measured or is greater than 110 pg/mL.
For both types, the hypersomnolence and/or MSLT findings are not better explained by other causes such as insufficient sleep, sleep-disordered breathing, or effects of medications or substances.
