Parasomnias

Parasomnias: Overview & Classification - Sleep's Odd Show

Parasomnias: Undesirable physical events (e.g., movements, vocalizations) or cognitive experiences (e.g., vivid dreams, hallucinations) occurring during sleep onset, within sleep, or during arousals. Often involve complex behaviors with subsequent amnesia.

Key Types:

• NREM-Related (Disorders of Arousal):
  • Sleepwalking (Somnambulism)
  • Sleep Terrors (Pavor Nocturnus)
  • Confusional Arousals
• REM-Related:
  • REM Sleep Behavior Disorder (RBD)
  • Nightmare Disorder
  • Recurrent Isolated Sleep Paralysis
• Other Parasomnias:
  • Exploding Head Syndrome
  • Sleep Enuresis
  • Sleep-Related Groaning (Catathrenia)

⭐ Most childhood parasomnias, particularly NREM disorders of arousal like sleepwalking, tend to resolve spontaneously with age.

NREM Parasomnias - Deep Sleep Deeds

Occur during NREM Stage N3 (slow-wave sleep), typically in the first third of the night. Features: incomplete arousal, ↓ responsiveness, and amnesia for the event.

• Disorders of Arousal (DoA):

  • Common Triggers: Sleep deprivation, fever, stress, alcohol, certain medications (e.g., sedatives, stimulants).
  • 📌 Mnemonic: No Real Event Memory (for NREM parasomnia amnesia).

  Feature	Confusional Arousals	Sleepwalking (Somnambulism)	Sleep Terrors (Pavor Nocturnus)
  Key Features	Disorientation, confusion upon awakening. Minimal motor activity.	Complex motor acts (e.g., walking) while asleep. Blank stare.	Sudden arousal with intense fear, screaming, autonomic signs (↑HR, ↑RR). Difficult to console.
  Typical Age	Children <5 yrs; can persist.	Children 4-8 yrs; resolves by adolescence.	Children 3-7 yrs; resolves by adolescence.
  Amnesia	Complete	Complete	Complete

• Sleep-Related Eating Disorder (SRED):

  • Recurrent involuntary eating/drinking during NREM sleep; amnesia. Often consumes peculiar/inedible items.

⭐ Sleepwalking and sleep terrors typically occur in the first third of the night, during slow-wave sleep (NREM Stage N3).

REM & Other Parasomnias - Dream Stage Drama

• REM Sleep Behavior Disorder (RBD):

  • Acting out dreams (often vivid, violent).
  • Key: REM sleep without atonia.
  • Strongly linked to α-synucleinopathies (e.g., Parkinson's, LBD). 📌 RBD: "Run, Bite, Defend" (in dreams).
  • Rx: Clonazepam (0.25-2 mg), Melatonin.

• Nightmare Disorder:

  • Recurrent, distressing dreams; detailed recall.
  • Occurs late night/early morning (REM).
  • No significant motor activity.

• Table: RBD vs. Nightmare Disorder

  Feature	RBD	Nightmare Disorder
  Motor Activity	Present (acting out)	Absent
  Muscle Atonia	Lost	Intact
  Key Risk	Future neurodegeneration (synucleinopathy)	PTSD, stress
  Onset Age	Typically >50 yrs	Any, common in children

• Recurrent Isolated Sleep Paralysis:

  • Temporary inability to move/speak at sleep onset/awakening.
  • Conscious, often with hallucinations.

• Other Parasomnias:

  • Exploding Head Syndrome: Sudden loud noise sensation in head.
  • Sleep Enuresis: Primary (never dry) vs. Secondary (relapse after ≥6 months dry; investigate underlying cause).

⭐ REM Sleep Behavior Disorder (RBD) is a strong predictor for future development of neurodegenerative diseases like Parkinsonism or Lewy Body Dementia.

Parasomnias: Dx & Mx - Calming Night Chaos

• General Management:
  • Patient/family education; reassurance.
  • Safety: Secure environment (remove hazards, lock doors/windows).
  • Triggers: Avoid sleep deprivation, stress, alcohol/drugs.
• Specific Treatments:
  • Childhood NREM: Reassurance; scheduled awakenings if persistent/injurious.
  • RBD: Clonazepam (0.25-2 mg), Melatonin (3-12 mg).
  • Nightmare Disorder: Psychological therapies (IRT); Prazosin (PTSD-related).

⭐ Polysomnography is essential for diagnosing REM Sleep Behavior Disorder by demonstrating REM sleep without atonia.

High‑Yield Points - ⚡ Biggest Takeaways

• NREM parasomnias (sleepwalking, night terrors): N3 sleep, first third of night, amnesia, common in children.
• REM Sleep Behavior Disorder (RBD): Dream enactment from loss of REM atonia; strong link to α-synucleinopathies.
• Nightmare Disorder: REM sleep, latter half of night, vivid recall of distressing dreams.
• Sleep Paralysis: REM-associated; transient inability to move at sleep-wake transitions, often with hallucinations.
• Confusional Arousals: NREM disorder; disorientation upon awakening.
• Management: Prioritize safety; Clonazepam for RBD.