What is narcolepsy?

Narcolepsy is a chronic neurological disorder caused by the brain’s inability to regulate sleep-wake cycles normally. Narcolepsy affects 0.05% of the population. At various times throughout the day, people with narcolepsy experience irresistable bouts of sleep. If the urge becomes overwhelming, individuals will fall asleep for periods lasting from a few seconds to several minutes. In rare cases, some people may remain asleep for an hour or longer.

In addition to excessive daytime sleepiness (EDS), three other major symptoms frequently characterize narcolepsy:

  1. cataplexy, or the sudden loss of voluntary muscle tone;
  2. vivid hallucinations during sleep onset or upon awakening; and
  3. brief episodes of total paralysis at the beginning or end of sleep.

Narcolepsy is not definitively diagnosed in most patients until 10 to 15 years after the first symptoms appear. The cause of narcolepsy remains unknown.  It is likely that narcolepsy involves multiple factors interacting to cause neurological dysfunction and sleep disturbances.

Narcolepsy can result in:

  • excessive daytime sleepiness
  • falling asleep suddenly and without warning
  • temporary loss of muscle control resulting in weakness and possible collapse (cataplexy)
  • sleep paralysis: a temporary inability to move or speak when waking up or falling asleep
  • excessive dreaming
  • Interrupted sleep pattern
  • It has a negative effect on the quality of life of its sufferers
  • can result in careers and activities restrictions

What other medical conditions could present with narcolepsy symptoms?

  • Sleep deprivation,
  • sleep apnea,
  • idiopathic hypersomnia,
  • recurrent hypersomnia (Kleine–Levin syndrome),
  • restless legs syndrome, and
  • periodic limb movement disorder
  • Parkinson’s disease
  • Alzheimer’s disease
  • multiple sclerosis
  • stroke
  • epilepsy
  • neuromuscular disorders
  • chronic obstructive pulmonary disease and asthma
  • congestive heart failure
  • chronic renal failure
  • lupus
  • liver failure
  • schizophrenia
  • ADHD
  • Malingering

Management

There is no cure for narcolepsy.  In 1999, after successful clinical trial results, the U.S. Food and Drug Administration (FDA) approved a drug called modafinil for the treatment of EDS. Two classes of antidepressant drugs have proved effective in controlling cataplexy in many patients: tricyclics (including imipramine, desipramine, clomipramine, and protriptyline) and selective serotonin reuptake inhibitors (including fluoxetine and sertraline).  Drug therapy should be supplemented by behavioral strategies.  For example, many people with narcolepsy take short, regularly scheduled naps at times when they tend to feel sleepiest.  Improving the quality of nighttime sleep can combat EDS and help relieve persistent feelings of fatigue. Among the most important common-sense measures people with narcolepsy can take to enhance sleep quality are actions such as maintaining a regular sleep schedule, and avoiding alcohol and caffeine-containing beverages before bedtime.  The drug Xyrem (sodium oxybate or gamma hydroxybutyrate, also known as GHB) was approved in July 2002 for treating cataplexy and in November 2005 for EDS in people who have narcolepsy.  Due to safety concerns associated with the use of this drug, the distribution of Xyrem is tightly restricted.

References

  • Hong SB, Tae WS, Joo EY. Cerebral perfusion changes during cataplexy in narcolepsy patients. Neurology. 2006;66(11):1747–1749.
  • Boulos MI, Murray BJ. Current evaluation and management of excessive daytime sleepiness. Can J Neurol Sci. 2010;37(2):167–176.
  • Arnulf I. Excessive daytime sleepiness in parkinsonism. Sleep Med Rev. 2005;9(3):185–200.
  • Lee JH, Bliwise DL, Ansari FP, et al. Daytime sleepiness and functional impairment in Alzheimer disease. Am J Geriatr Psychiatry. 2007;15(7):620–626.
  • Ervik S, Abdelnoor M, Heier MS, Ramberg M, Strand G. Healthrelated quality of life in narcolepsy. Acta Neurol Scand. 2006;114(3):198–204.
  • Riemann D. Insomnia and comorbid psychiatric disorders. Sleep Med. 2007;8(Suppl 4):S15–20.
  • Naumann A, Bellebaum C, Daum I. Cognitive deficits in narcolepsy. J Sleep Res. 2006;15(3):329–338.
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