There are 2 separate sets of diagnostic criteria that can be used to evaluate patients for narcolepsy.1,2
The American Academy of Sleep medicine (AASM) International Classification of Sleep Disorders - Third Edition (ICSD-3) contains diagnostic criteria for sleep disorders, including narcolepsy.
Excessive daytime sleepiness daily for ≥3 months*
One or both of the following:
Cataplexy and mean sleep latency ≤8 minutes and ≥2 SOREMPs on MSLT; SOREMP (≤15 min after sleep onset) on preceding nocturnal PSG may replace one of the SOREMPs on MSLT†
Low or absent CSF hypocretin-1 levels‡
Excessive daytime sleepiness and MSLT findings as above, but without cataplexy§
CSF hypocretin-1 levels are unknown or are above the threshold for narcolepsy type 1§
The hypersomnolence and/or MSLT findings are not better explained by other causes, such as insufficient sleep, OSA, delayed sleep phase disorder, or the effect of medications or substances or their withdrawal
*In young children, narcolepsy may sometimes present as excessively long night sleep or as resumption of previously discontinued daytime napping.
†If narcolepsy type 1 is strongly suspected clinically, but MSLT criteria are not met, consider repeating the MSLT.
‡Low or absent CSF hypocretin-1 levels = CSF hypocretin-1 concentration measured by immunoreactivity is either ≤110 pg/mL or <1/3 of mean values in healthy subjects using the same assay.
§If cataplexy develops later or low or absent CSF hypocretin-1 levels are discovered, reclassify as narcolepsy type 1.
CSF, cerebrospinal fluid; ICSD, International Classification of Sleep Disorders; MSLT, multiple sleep latency test; PSG, polysomnography; SOREMP, sleep-onset REM period.
The American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) contains diagnostic criteria for sleep-wake disorders, including narcolepsy, designed for use by mental health and medical clinicians.
Recurrent periods of an irrepressible need to sleep, lapsing into sleep, or napping occurring within the same day. These must have been occurring ≥3 times per week over the past 3 months
The presence of at least one of the following:
DSM, Diagnostic and Statistical Manual of Mental Disorders.