Definition

Narcolepsy is a sleep disorder. It causes excess sleepiness during the day. Sudden attacks of sleep can happen while driving, talking, or working.

Causes

Causes may be:

• Low levels of a chemical called hypocretin in the body
• Problems that affect the central nervous system, such as multiple sclerosis and birth defects of the brain

Risk Factors

This problem often starts in people who are 10 to 20 years of age. Things that may raise the risk are:

• Genetic factors, including having other family members with the disorder
• A history of certain strep infections

Symptoms

People with the disorder have 1 or more of these problems:

• Excessive daytime sleepiness
• Muscles that go limp without warning when a person is awake (often triggered by strong emotions like laughter)
• Brief times when the person cannot move while waking up or falling asleep
• Sudden attacks of sleep that may happen many times during the day without control
• Vivid dreams that happen while waking up or falling asleep

Brainstem—Area of Brain Related to Alertness

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Diagnosis

The doctor will ask about your symptoms and health history. A physical exam may be done.

Tests that may be done to diagnose the disorder include:

• Multiple sleep latency test (MSLT) to assess daytime sleepiness
• Polysomnography to study brain waves and how the body works during sleep
• A lumbar puncture to measure the level of hypocretin around the brain and spinal cord

Treatment

There is no cure. The goal of treatment is to manage symptoms. Options are:

• Medicines to treat excessive daytime sleepiness and sudden loss of muscle control
• Lifestyle changes, such as taking short naps during the day and using good sleep hygiene

Prevention

There are no guidelines to prevent this problem.