Narcolepsy’s most common major symptom, other than excessive daytime sleepiness (EDS), is cataplexy. Sleep paralysis and hallucinations are also common. About 25% of narcoleptics suffer from all four symptoms. Symptoms usually appear between the ages of 7-25.
Excessive daytime sleepiness is the most consistently experienced symptom of narcolepsy. People with EDS describe it as a persistent sense of mental cloudiness, lack of energy, and extreme exhaustion. The involuntary sleep episodes caused by it are usually very brief, and automatic behavior can occur. Automatic behavior involves performing a task during a short period of sleep without any apparent interruption.
Cataplexy is the sudden loss of muscle tone, which leads to a feeling of weakness and loss of muscle control. These attacks can occur at anytime during the individuals waking period. The loss of muscle tone can be barely noticeable, such as mild drooping of the eyelids. The most severe attacks result in complete loss of all voluntary muscles. But even during the most severe episodes, people remain fully conscious. Although cataplexy can occur spontaneously, it is often triggered by sudden, strong emotion.
Sleep paralysis is the temporary loss of movement and speech while falling asleep or waking up. This is similar to REM cycle induced inhibitions of muscle activity. However, even when severe cataplexy and sleep paralysis occur, they do not result in permanent dysfunction.
Hallucinations can accompany sleep paralysis or when the person is falling asleep or waking up. They are usually visual, but any of the senses can be involved....