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Narcolepsy
Narcolepsy is the abnormal tendency to sleep during the day. The condition is characterised by uncontrollable sleep attacks and persistent sleepiness. Sleep episodes can occur without warning and can put the person and others at risk of accidental injury if they occur during activities such as driving a car or operating machinery.
In New Zealand it is estimated that narcolepsy affects up to 3000 people. Men and women are equally affected. Narcolepsy most commonly starts between 15 to 25 years of age and rarely begins after the age of 40. Narcolepsy tends to remain a life-long condition.
In 1999 researchers identified the gene that causes narcolepsy. This gene causes the sleep centre in the brain to malfunction and produce abnormal sleeping patterns. Lifestyle and environmental factors, such as shift work, may aggravate the condition.
Signs and Symptoms
Narcolepsy causes people to fall asleep suddenly - anytime, anywhere. They may sleep for only a few seconds or for more than an hour . They wake refreshed but become sleepy again within an hour or so. These sleep episodes occur on average 2 to 6 times per day, especially after meals. Occasionally people may continue to perform tasks during these episodes of sleep but have no recollection of this when they awake.
The symptoms of narcolepsy most commonly become apparent during adolescence but the condition may not be diagnosed at this time. Narcolepsy symptoms usually develop one at a time and sometimes up to years apart. Generally symptoms do not appear in any specific order.
Signs and symptoms include:
- Abnormal tendency to sleep during the day
- Desire to sleep longer than the usual 7 to 8 hours
- Memory loss
- Dream-like hallucinations. Approximately 40% of people with narcolepsy experience intense dreamlike imagery. Most sleep-related hallucinations are visual and incorporate elements of the actual environment
- Sudden loss of voluntary muscle tone called cataplexy. Cataplexy is usually triggered by a strong emotional factor, such as laughter, anger, crying or surprise. When cataplexy occurs, the patient may experience weakening of the knees, the jaw will drop, and the patient may fall to the floor. Speech and movement become difficult or impossible, although there is no loss of consciousness. Cataplexy can last from several seconds to 30 minutes. It affects up to 75% of people with narcolepsy
- After a night’s sleep the patient may be unable to move for a few minutes (sleep paralysis). This can also occur when just falling off to sleep. Approximately 30% to 50% of people with narcolepsy experience sleep paralysis. Sleep paralysis can last for seconds to a few minutes and finish spontaneously
- Waking during the night due to nightmares, the need to go to the toilet, and/or temporary repeated interruptions of breathing (sleep apnoea). At times there is no apparent reason for awakening, and there may be a craving for food.
Diagnosis
To be diagnosed with narcolepsy, the sleep episodes must have occurred daily over a period of at least 3 months. Your doctor will obtain a detailed history of your sleeping patterns. You may be asked to keep a sleep-wake diary over a period of time. The diary will specify time and quality of sleep. Your doctor will also look for any underlying cause.
You may also be referred to other health professionals for sleep tests which monitor the brain, muscle activity and breathing throughout all the stages of sleep. If there are symptoms of depression, anxiety or mental disorder, you may be referred to a psychiatrist.
Narcolepsy is a complex disorder and may take several years to correctly diagnose.
Treatment
Treatment for narcolepsy is usually in the form of medications, which help to control symptoms. The doctor may prescribe medications that stimulate the central nervous system. The dosage will be as low as possible to minimise any side affects.
For cataplexy and sleep paralysis, an anti-depressant may be prescribed to suppress the attacks of rapid-eye-movement (REM) sleep, or dream sleep.
The doctor may also recommend referral to a Sleep Clinic or Sleep Management Centre.
Self Help
Sleep habits are important. Here are a few tips:
- Maintain a regular bedtime hour and get an adequate amount of sleep at night.
- Eliminate anything that is likely to interrupt sleep
- Planned naps during the day may help to control daytime sleepiness
- Eat light meals during the day and avoid a heavy meal before an important activity
- Caffeine containing beverages, such as coffee, tea or cola should be avoided for several hours before bed time
- Avoid driving unless you have been certified fit to drive by your Doctor in accordance with Land Transport Safety Authority (LTSA) guidelines.
Support Groups
The Narcolepsy Support Group of New Zealand can provide support and information for people suffering from narcolepsy. They can be contacted by e-mail or via their website.
E-mail: info@narcolepsy.org.nz
Website: www.narcolepsy.org.nz
The Sleep Apnoea Association of NZ Inc. (SAANZ) promotes awareness and provides up to date information of sleep apnoea and sleep disorders.
Sleep Apnoea Association of NZ Inc.
PO Box 88
Hamilton 3240
Phone: (07) 858 4378
References
Anderson, K.N., Anderson, L.E. & Glanze, W.D. (eds.) (2006) Mosby’s Medical, Nursing, & Allied Health Dictionary (6th ed.) St. Louis: Mosby-Year Book, Inc.
Brandt, M. L. and Odle, T. G (2006) Narcolepsy. The Gale Encyclopedia of Medicine. Third Edition. Jacqueline L. Longe, Editor. Farmington Hills, MI. Thompson Gale.
Neurological Foundation of New Zealand (2002) Sleep: A Dynamic Activity. “Headlines” Article, Vol. 74. Neurological Foundation of New Zealand. http://www.neurological.org.nz/html/article.php?documentCode=5411
Last Reviewed – March 2009
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