Symptoms usually start during the teenage years. Onset may range from 5 to 50 years old. Symptoms may worsen with aging. They may improve in women after menopause.
Symptoms include:
- Excessive daytime sleepiness
- Daytime involuntary sleep attacks
- Unrefreshing sleep
- Sudden loss of muscle tone without loss of consciousness (cataplexy)
- Temporary paralysis while awakening
- Frightening mental images that appear as one falls asleep
- Memory problems
-
Symptoms may be triggered by:
- A monotonous environment
- A warm environment
- Eating a large meal
- Strong emotions
The doctor will ask about your symptoms and medical history. A physical exam will be done. If narcolepsy is suspected, you may be referred to a specialist in sleep disorders.
Tests may include:
- Multiple sleep latency test (MSLT)—measures the onset of rapid eye movement sleep, which occurs earlier than normal in narcolepsy
-
General sleep lab study—often performed the night before an MSLT; helps to rule out other causes of daytime sleepiness by monitoring:
- Brain waves
- Eye movements
- Muscle activity
- Respiration
- Heart beat
- Blood oxygen levels
- Total nighttime sleep
- Amount of nighttime REM sleep
- Time of onset of REM sleep
- Degree of daytime sleepiness