Which sleep disorder involves involuntary movements and abnormal behavior during sleep?

The correct answer is parasomnia, which encompasses a range of sleep disorders characterized by abnormal behaviors, movements, emotions, and perceptions that occur during sleep or transitions between sleep and wakefulness. This includes sleepwalking, sleep talking, night terrors, and REM sleep behavior disorder.

In the context of the question, parasomnia specifically captures the essence of involuntary movements and abnormal behavior during sleep, as it refers to any undesired phenomenon during sleep. For instance, during sleepwalking, a specific type of parasomnia, an individual might walk or perform complex behaviors while in a state of sleep without being aware of their actions.

Other options refer to different aspects of sleep or related disorders. Sleepwalking, while a specific type of parasomnia, does not encompass the whole category. Insomnia is characterized by difficulty falling or staying asleep and does not typically involve abnormal behaviors. Narcolepsy is a neurological disorder that affects the control of sleep-wake cycles, resulting in excessive daytime sleepiness and sudden sleep attacks, which does not inherently include involuntary movements.

Thus, parasomnia is the most comprehensive term that accurately depicts a range of sleep disorders associated with involuntary movements and behaviors.