A sudden loss of muscle tone is called

• A. narcolepsy.
• B. REM paralysis.
• C. cataplexy.
• D. somnambulism.

Answer: (C)

Verified step by step guidance

1. Begin by understanding the key terms related to sleep disorders: narcolepsy, REM paralysis, cataplexy, and somnambulism.
2. Narcolepsy is a chronic sleep disorder characterized by overwhelming daytime drowsiness and sudden attacks of sleep.
3. REM paralysis refers to the temporary inability to move or speak while falling asleep or upon waking, often associated with REM sleep.
4. Cataplexy is a sudden and transient episode of muscle weakness accompanied by full conscious awareness, typically triggered by emotions such as laughter or anger.
5. Somnambulism, commonly known as sleepwalking, involves performing complex behaviors while in a state of sleep.