Excessive transient muscle activity found in REM sleep indicates which of the following sleep disorders?

Excessive transient muscle activity found in REM sleep indicates which of the following sleep disorders?

• A. Rhythmic movement disorder
• B. REM behavior disorder
• C. Amyotrophic lateral sclerosis
• D. Obstructive sleep apnea disorder

Answer: (B)

During REM sleep, the body normally experiences atonia—muscle paralysis that keeps you from acting out dreams. When excessive transient muscle activity occurs in REM, it signals a failure of that REM atonia mechanism, which is the hallmark of REM Behavior Disorder. In this condition, people enact dreams, sometimes with vigorous or violent movements, because the usual muscle inhibition is absent or incomplete. The other conditions don’t fit this pattern. Rhythmic movement disorder involves repetitive, stereotyped movements (often in children) that occur during sleep but are not specifically tied to REM sleep and the loss of atonia. ALS is a neurodegenerative disease affecting voluntary muscles with weakness and spasticity, not a REM-specific motor phenomenon. Obstructive sleep apnea involves repeated airway obstruction during sleep with snoring and arousals, not heightened motor activity during REM. So the best answer is REM Behavior Disorder.

During REM sleep, the body normally experiences atonia—muscle paralysis that keeps you from acting out dreams. When excessive transient muscle activity occurs in REM, it signals a failure of that REM atonia mechanism, which is the hallmark of REM Behavior Disorder. In this condition, people enact dreams, sometimes with vigorous or violent movements, because the usual muscle inhibition is absent or incomplete.

The other conditions don’t fit this pattern. Rhythmic movement disorder involves repetitive, stereotyped movements (often in children) that occur during sleep but are not specifically tied to REM sleep and the loss of atonia. ALS is a neurodegenerative disease affecting voluntary muscles with weakness and spasticity, not a REM-specific motor phenomenon. Obstructive sleep apnea involves repeated airway obstruction during sleep with snoring and arousals, not heightened motor activity during REM.

So the best answer is REM Behavior Disorder.