Which clinical feature is not associated with narcolepsy?

In narcolepsy, one of the hallmark features is the tendency to enter rapid eye movement (REM) sleep very quickly, often within 15 minutes of falling asleep. This abbreviated onset of REM sleep is termed decreased REM latency, rather than increased REM latency. Therefore, the clinical feature that is not associated with narcolepsy is increased REM latency, as people with the disorder commonly experience a reduced latency to REM sleep during nighttime sleep studies.

On the other hand, cataplexy, hypnagogic hallucinations, and sleep paralysis are all characteristic symptoms of narcolepsy. Cataplexy involves sudden, temporary loss of muscle tone, often triggered by strong emotions. Hypnagogic hallucinations occur when transitioning from wakefulness to sleep and can be vivid, frightening, yet often tied to sleep onset. Sleep paralysis is experienced during the transition between sleep and wakefulness, where the individual is temporarily unable to move or speak. These features collectively describe the dysfunctional aspects of sleep regulation seen in narcolepsy, further emphasizing the distinct nature of decreased REM latency in this condition.