//fpnotebook.com/
Narcolepsy
Aka: Narcolepsy
- Epidemiology
- Prevalence: 40 per 100,000 (0.02 to 0.18% of adults)
- Men and women affected equally
- Onset in adolescence to early 20s (rarely has onset after age 50 years)
- Pathophysiology
- Excessive Sleepiness
- Abnormal REM Sleep
- Causes
- Idiopathic
- Hereditary related to DR-2
- Secondary causes
- Head Trauma
- Encephalopathy
- Brain Tumor
- Cerebrovascular insufficiency
- Symptoms: Classic Tetrad
- Recurrent irresistible Daytime Sleepiness
- Occurs unexpectedly and at inappropriate times
- Cataplexy (25-30% of patients with Narcolepsy)
- Sudden decrease or loss of voluntary muscle tone following emotional trigger (e.g. laughing, surprise)
- Episodes last seconds to minutes
- Localized hypotonia (e.g. jaw drop, head nod, knee sag)
- Generalized hypotonia (full collapse onto floor)
- Hallucinations
- Hypnagogic Hallucinations (on falling asleep)
- Hypnopompic Hallucinations (on awakening)
- Sleep Paralysis
- Transient, generalized inability to move or speak during sleep-wake transition
- Differential Diagnosis
- See Hypersomnolence
- Sleep Apnea
- Other Primary Hypersomnia (uncommon)
- Idiopathic Hypersomnia
- Menstrual Hypersomnia
- Kleine-Levin Syndrome (rare syndrome of male teens)
- Evaluation
- See Hypersomnolence
- Diagnosis: Sleep Study (all patients)
- Sleep log or actigraphy for 2 weeks
- Multiple Sleep Latency Test (daytime nap test)
- At least 2 naps with early onset REM Sleep (Rapid transition to REM)
- Shortened REM latency (<8 minutes)
- Management: Standard Medications
- See Hypersomnia
- First-Line Stimulants
- Modafinil (Provigil)
- Best safety profile and lowest abuse potential of all stimulant agents
- Armodafinil (Nuvigil, generic)
- Solriamfetol (Sunosi, expensive)
- Other stimulants (risk of dependence)
- Methylphenidate (Ritalin)
- Dextroamphetamine (Dexedrine)
- Symptomatic management of Cataplexy, Sleep Paralysis or hypnagogic Hallucinations
- SNRI (e.g. Effexor) and SSRI agents suppress REM Sleep
- Other agents
- Gamma hydroxybutyric acid or Sodium oxybate (Xyrem)
- Given twice nightly
- References
- Billiard (2008) Neuropsychiatr Dis Treat 4(3):557-66 [PubMed]
- Pagel (2009) Am Fam Physician 79(5): 391-6 [PubMed]
- Thorpy (2006) CNS Drugs 20(1): 43-50 [PubMed]
- Ramar (2013) Am Fam Physician 88(4): 231-8 [PubMed]