HOw HAVE THE DIAGNOSTIC CRITERIA FOR NARCOLEPSY CHANGED?

HOw HAVE THE DIAGNOSTIC CRITERIA FOR NARCOLEPSY CHANGED?

Understanding the changes to the ICSD-3 and DSM-5 criteria for narcolepsy.*

The ICSD-3* includes changes to how narcolepsy is classified and diagnosed.1

  • Classification changes include…
    • Narcolepsy with cataplexy is now classified as a subset of narcolepsy type 1, and may also be referred to as hypocretin deficiency syndrome, narcolepsy-cataplexy, or narcolepsy with cataplexy.1
    • Narcolepsy without cataplexy is now classified as narcolepsy type 2, and may also be referred to as narcolepsy without cataplexy.1
  • Changes to diagnostic considerations for narcolepsy type 1 include...
    • Excessive daytime sleepiness (EDS) continues to be an essential feature, but must occur daily in addition to being chronic (ie, present for at least 3 months).1
    • Cataplexy is also described as an essential feature.1
      • However, narcolepsy type 1 may be diagnosed without the presence of cataplexy in patients with EDS and cerebrospinal fluid (CSF) hypocretin-1 deficiency. Low or absent CSF hypocretin-1 is considered a fundamental marker of the condition.1
      • The presence of cataplexy alone, therefore, is not considered diagnostic for narcolepsy type 1. Diagnosis must now be confirmed with laboratory testing.1
    • A sleep onset rapid eye movement period (SOREMP) on an overnight polysomnogram (PSG) can replace one of the 2 SOREMPs needed on the multiple sleep latency test (MSLT).1
  • Changes to diagnostic considerations for narcolepsy type 2 include...
    • The absence of cataplexy. In patients who later develop cataplexy, the diagnosis should be changed to narcolepsy type 1.1
    • CSF hypocretin-1 levels are either not measured or, if measured, are found to be not deficient.1*
      • Most patients with narcolepsy type 2 will not have had CSF hypocretin-1 testing.1
      • In patients whose CSF hypocretin-1 levels are later tested and found deficient, the diagnosis should be changed to narcolepsy type 1.1
    • Symptoms identified are not better explained by other causes.1
      • Other causes include insufficient sleep, obstructive sleep apnea, delayed sleep phase disorder, or the effect of medication or substances or their withdrawal.1

The DSM-5* also includes changes to how narcolepsy is diagnosed.

  • Changes to diagnostic considerations for narcolepsy include...
    • EDS continues to be an essential feature, and must be chronic (ie, present for at least 3 months).2
      • In addition, EDS is now defined as recurrent periods of an irrepressible need to sleep, lapsing into sleep, or napping within the same day.2
      • The frequency of EDS has been changed to at least 3 times per week.2
    • Cataplexy also continues to be an essential feature.2
      • In patients with EDS, the presence of cataplexy is considered diagnostic for narcolepsy.2
    • The presence of any of the following laboratory findings is considered diagnostic for narcolepsy in the presence of EDS:
      • CSF hypocretin-1 levels of one-third or less of the values obtained in healthy subjects using the same standardized assay, or 110 pg/mL or less.2§
      • Multiple sleep latency test (MSLT) results showing a mean sleep latency of 8 minutes or less and at least 2 sleep onset rapid eye movement periods (SOREMPs).2
      • The occurrence of a SOREMP on an overnight polysomnogram (PSG).2

*ICSD-3 = International Classification of Sleep Disorders, 3rd ed. DSM-5 = Diagnostic and Statistical Manual of Mental Disorders, 5th ed.

CSF hypocretin-1 levels of 110 pg/mL or less, or less than one-third of mean values obtained in normal subjects using the same standardized assay.1

A SOREMP is defined as latency to REM sleep within 15 minutes of sleep onset. Sleep laboratory testing should be performed according to standard techniques, and results should be carefully interpreted in the context of the patient’s clinical history and the presence of EDS. At least 1 week of actigraphy assessment with a sleep log is strongly recommended prior to MSLT to determine factors that may bias results (eg, insufficient sleep, shift work, or other circadian rhythm disorder).1

§This does not include results obtained in the presence of acute brain injury, inflammation, or infection.2

THE NARCOLEPSY SCREENER APP

See how an app with 2
validated screening tools can
help identify symptoms.

THE NARCOLEPSY
SCREENER APP
Cataplexy

Learn about XYREM for
cataplexy and EDS in narcolepsy.

XYREM CLINICAL TRIALS