M05.08.08 Parasomnias

Parasomnias are sleep disorders characterized by abnormal behaviors, emotions, or perceptions occurring during sleep or sleep-wake transitions. They often involve unwanted physical or verbal actions, and they are typically classified based on the sleep stage in which they occur. Understanding the different types of parasomnias, their features, and treatments is crucial for appropriate management.

Common Types of Parasomnias

1. Night Terrors

Sleep Stage: Non-REM, Stage 3

• Features:
  • Common in young boys
  • Familial predisposition
  • Sudden arousal from sleep with intense fear, screaming or thrashing
  • Inability to recall the event after waking
• Treatment:
  • Benzodiazepines (may help reduce episodes)
• Memory for Event:
  • No

2. Nightmares

Sleep Stage: REM sleep

• Features:
  • Frequent during periods of stress or emotional turmoil
  • Vivid, distressing dreams that awaken the individual
  • Full recall of the dream after waking
• Treatment:
  • Antidepressants (for stress-related or chronic nightmares)
• Memory for Event:
  • Yes

3. Somnambulism (Sleepwalking)

Sleep Stage: Non-REM, Stage 3

• Features:
  • The person appears confused and disoriented if awakened
  • Common in children
  • Risk of injury due to walking or performing other activities while asleep
• Treatment:
  • Benzodiazepines (reduce the frequency of episodes)
• Memory for Event:
  • N/A

4. Bruxism (Teeth Grinding)

Sleep Stage: Non-REM, Stage 2

• Features:
  • Often related to stress
  • Repetitive grinding or clenching of teeth during sleep
• Treatment:
  • Use of teeth guards to prevent dental damage
• Memory for Event:
  • N/A

Table: Summary of Parasomnias

Points to Remember

• Parasomnias are classified based on the sleep stage in which they occur (REM or non-REM).
• Night terrors and somnambulism are common in children and are associated with non-REM sleep.
• Nightmares occur during REM sleep and are often stress-induced.
• Bruxism is associated with non-REM Stage 2 sleep and is often linked to stress.
• Memory for the event varies by type: nightmares are remembered, while night terrors and somnambulism are not.

Bibliography

• American Academy of Sleep Medicine. (2021). The International Classification of Sleep Disorders. 3rd ed.
• Mahowald, M. W., & Schenck, C. H. (2018). “Parasomnias.” Sleep Medicine Clinics, 13(2), 137-151.
• Zucconi, M., & Ferri, R. (2020). “Sleep disorders.” Handbook of Clinical Neurology, 160, 413-426.