What are the symptoms of narcolepsy?
Excessive sleepiness
Excessive sleepiness is usually the first symptom of narcolepsy to develop.
Cataplexy
This is exclusive to narcolepsy and is a sudden loss of muscular control, ranging from slight weakness (such as a drooping jaw) to total collapse, and lasting for a few seconds to a few minutes, during which the person is awake and aware of what is happening. It is usually triggered by strong emotions, such as laughter, fear, anger, or surprise.
Sleep paralysis
This involves being unable to talk or move for up to several minutes while falling asleep or waking up. It tends to disappear if the person is touched.
Hallucinations
Vivid images or sounds that occur when falling asleep or upon waking respectively. Such hallucinations, which appear very real, may be confused with symptoms of mental illness.
Other symptoms
The four symptoms described above are the "classic" symptoms of narcolepsy, but do not always occur together. Other symptoms may also occur, including: automatic behaviours (carrying on routine tasks as if in a trance), disturbed night-time sleep, double vision, and memory and concentration problems.
How is narcolepsy recognised?
Not all people with narcolepsy show all four of the "classical" symptoms, and diagnosis may require specific tests as well as verbal history-taking and examination.
The main tests used (carried out in a specialist sleep laboratory or clinic) are: