Hypersomnias

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Hypersomnias - Sleepy Saga Starts

  • Excessive Daytime Sleepiness (EDS): Inability to stay awake/alert during major waking episodes, resulting in unintended sleep.

    ⭐ Excessive Daytime Sleepiness (EDS) is the cardinal symptom of all hypersomnias.

  • ICSD-3 Central Disorders of Hypersomnolence:
    • Narcolepsy (Type 1 & 2)
    • Idiopathic Hypersomnia
    • Kleine-Levin Syndrome
    • Hypersomnia due to medical/psychiatric disorder or substance
    • Insufficient Sleep Syndrome
  • Types:
    • Primary: CNS origin (e.g., Narcolepsy, Idiopathic Hypersomnia).
    • Secondary: Due to other medical/psychiatric conditions, drugs, or insufficient sleep syndrome (most common).

Hypersomnias - Sudden Snooze Fest

  • Hypersomnias: Conditions characterized by Excessive Daytime Sleepiness (EDS) not due to insufficient sleep or circadian rhythm disorders.

  • Narcolepsy: Primary hypersomnia.

    • Type 1: EDS + Cataplexy (sudden, brief loss of muscle tone triggered by emotions). Associated with low CSF hypocretin-1 levels.
    • Type 2: EDS without cataplexy. Normal CSF hypocretin-1 levels.
  • Symptoms 📌 CHESS pentad:

    • Cataplexy (esp. Type 1)
    • Hallucinations (hypnagogic/hypnopompic)
    • Excessive Daytime Sleepiness (EDS)
    • Sleep Paralysis
    • Sleep Disruption (fragmented nocturnal sleep)
  • Diagnosis:

    • Polysomnography (PSG): Rules out other sleep disorders (e.g., sleep apnea).
    • Multiple Sleep Latency Test (MSLT): Done day after PSG.
      • Mean sleep latency ≤8 minutes.
      • ≥2 Sleep Onset REM Periods (SOREMPs) (one SOREMP can be from preceding PSG).

⭐ Narcolepsy Type 1 is strongly associated with HLA-DQB1*06:02 and low CSF hypocretin-1 levels.

  • Management:
    • Pharmacological: Modafinil/Armodafinil, Solriamfetol, Pitolisant for EDS. Sodium oxybate for cataplexy, EDS, and disrupted sleep. Antidepressants (TCAs, SSRIs, SNRIs) for cataplexy.
    • Behavioral: Scheduled naps, good sleep hygiene.

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Hypersomnias - Other Sleepy Syndromes

FeatureNarcolepsy Type 2Idiopathic Hypersomnia (IH)Kleine-Levin Syndrome (KLS)
EDSYesYes (persistent, severe; sleep inertia common)Yes (episodic, ~2-10 times/year, lasting days-weeks)
CataplexyNoNoNo
MSLTMean sleep latency ≤8 min, ≥2 SOREMPsMean sleep latency ≤8 min, <2 SOREMPsNormal inter-episode; during episode often non-diagnostic
Other Key Features-Prolonged nocturnal sleep (≥10 hrs), unrefreshing napsRecurrent hypersomnia + cognitive/behavioral disturbances (megaphagia, hypersexuality, derealization). Adolescent male predominance.
ManagementStimulants (Modafinil), Sodium oxybateStimulants (Modafinil), Flumazenil (off-label)Supportive; Lithium (prophylaxis), Stimulants (symptomatic)

Hypersomnias - The Why of Yawn

Characterized by Excessive Daytime Sleepiness (EDS).

  • Diagnostic Approach:
    • Detailed history, sleep diary.
    • Epworth Sleepiness Scale (ESS): score >10 indicates significant EDS.
    • Actigraphy for sleep-wake patterns.
    • Polysomnography (PSG) & Multiple Sleep Latency Test (MSLT) for objective confirmation and specific diagnosis (e.g., narcolepsy, idiopathic hypersomnia).
  • Common Secondary Causes:
    • Insufficient Sleep Syndrome (ISS) - 📌 Most common, check sleep hygiene!
    • Sleep-Related Breathing Disorders (e.g., Obstructive Sleep Apnea - OSA).
    • Psychiatric conditions (e.g., depression).
    • Medications (e.g., sedatives, beta-blockers).
    • Medical conditions (e.g., hypothyroidism, anemia, neurological disorders).

⭐ Insufficient sleep syndrome is a common cause of EDS and is diagnosed by history and improvement with extended sleep; it's a diagnosis of exclusion after ruling out other sleep disorders.

Algorithm for evaluating Excessive Daytime Sleepiness

High‑Yield Points - ⚡ Biggest Takeaways

  • Narcolepsy Type 1: cataplexy & low CSF hypocretin-1.
  • Narcolepsy Type 2: no cataplexy, normal CSF hypocretin-1.
  • Idiopathic Hypersomnia: EDS despite long sleep; sleep inertia common.
  • Kleine-Levin Syndrome: recurrent hypersomnia, cognitive/behavioral issues; mainly adolescent males.
  • MSLT (narcolepsy): latency ≤8 min, ≥2 SOREMPs. IH: latency ≤8 min, <2 SOREMPs.
  • Modafinil/Armodafinil: first-line for EDS in narcolepsy/IH.
  • Sodium oxybate: treats cataplexy, EDS, disrupted sleep in narcolepsy_._

Practice Questions: Hypersomnias

Test your understanding with these related questions

A 32-year-old man comes to the physician complaining of excessive sleepiness for the past several months. He reports falling asleep while dealing with customers and had a near accident when he fell asleep while driving. The patient reports that he occasionally hears voices while falling asleep and finds himself "temporarily frozen" and unable to move upon awakening. Which of the following is the most appropriate treatment for this patient?

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Flashcards: Hypersomnias

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OSA, causes hypoventilation and resulting _____ hypoxia and hypercapnia

TAP TO REVEAL ANSWER

OSA, causes hypoventilation and resulting _____ hypoxia and hypercapnia

transient

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