Sleep disorders — Flashcards

Flashcard 11: cataplexy

Answer: Sudden loss of muscle tone triggered by strong emotional stimulus (e.g., laughter)

Flashcard 12: Pathophysiology of narcolepsy type 1

Answer: Decreased levels of **orexin (hypocretin)** in the lateral hypothalamus (loss of orexin-producing neurons).

Extra: Associated with **HLA-DQB1*0602**. **Symptoms (Tetrad):** 1. Excessive daytime sleepiness (EDS) 2. Hypnagogic/hypnopompic hallucinations 3. Cataplexy (sudden loss of muscle tone triggered by strong emotions) 4. Sleep paralysis **Treatment:** - Daytime stimulants (e.g., Modafinil, methylphenidate) - Nighttime sodium oxybate (for cataplexy)