Narcolepsy

Narcolepsy is a neurologic disorder characterized by frequent, involuntary, episodes of sleeping during the day. Sleep attacks may occur while driving, talking or working.

Causes

The cause of Narcolepsy is unknown, but it is thought to have a genetic component.

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition.
  • Family members with narcolepsy
  • Head injury
  • Infection of the brain or spinal cord
  • Anesthesia

Symptoms

Symptoms of Narcolepsy usually start during the teenage years. Onset may range from 5 to 50 years old. Symptoms may worsen with aging, but 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

Diagnosis

The doctor will ask about your symptoms and medical history, and perform a physical exam.
Tests include:
Sleep Latency Test – measures the onset of rapid eye movement sleep, which occurs earlier than normal in narcolepsy
General Sleep Lab Study – helps rule out other causes of daytime sleepiness. The following things are monitored while you sleep:
  • 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

Treatment

Treatment may include:
  • Stimulant medications that increase levels of daytime alertness include:
    • Methylphenidate
    • Pemoline (requires regular blood testing for liver function)
    • Dextoamphetamine
    • Methamphetamine
    • Modafinil
  • Antidepressants – to help treat many symptoms of narcolepsy, including:
    • Cataplexy
    • Hallucinations
    • Sleep paralysis
  • Planned short naps throughout the day
  • Counseling to cope with issues of self esteem
  • Wearing a medical alert bracelet or pendant

Prevention

There are no guidelines for preventing narcolepsy itself. However, you can try to prevent symptoms.
  • Avoid activities that carry a risk of injury from a sudden sleep attack,such as:
    • Driving
    • Climbing ladders
    • Using dangerous machinery
  • Exercise on a regular basis.
  • Get adequate sleep at night.