Narcolepsy is a chronic, neurological sleep disorder with no known cause. It involves the body's central nervous system. Narcolepsy is a genetic disorder, but what causes narcolepsy is not yet known.
The main characteristic of narcolepsy is excessive and overwhelming daytime sleepiness, even after adequate nighttime sleep. A person with narcolepsy is likely to become drowsy or to fall asleep at inappropriate times and places, and sleep attacks may occur with or without warning.
Attacks can occur repeatedly in a single day, drowsiness may persist for prolonged periods of time, and nighttime sleep may be fragmented with frequent awakenings.
The following are the most common symptoms of narcolepsy. However, individuals may experience symptoms differently. Symptoms may include:
- excessive daytime sleepiness (EDS) - an overwhelming desire to sleep at inappropriate times.
- cataplexy - a sudden loss of muscle control ranging from slight weakness to total collapse.
- sleep paralysis - being unable to talk or move for about one minute when falling asleep or waking up.
- hypnagogic hallucinations - vivid and often scary dreams and sounds reported when falling asleep.
Secondary or auxiliary symptoms include:
- automatic behavior - performing routine tasks without conscious awareness of doing so, and often without memory of it.
- disrupted nighttime sleep, including multiple arousals
- Other difficulties that may be caused by primary symptoms may include side effects of medication, or result from one's continuing struggle to cope, including:
- feelings of intense fatigue and continual lack of energy
- difficulty in concentrating and memorizing
- vision (focusing) problems
- eating binges
- weak limbs
- difficulties in handling alcohol
In addition a complete medical history and physical examination, diagnostic procedures may include:
- combination of EDS and cataplexy provide for preliminary clinical diagnosis
- laboratory tests to confirm diagnosis and plan treatment, including:
- overnight polysomnogram (PSG) - to determine the presence of EDS and perhaps other underlying causes of this symptom.
- Multiple Sleep Latency Test (MSLT) - to measure sleep onset and how quickly rapid eye movement REM sleep occurs.
- genetic blood test - to measure certain antigens often found in people who have a predisposition to narcolepsy.
Specific treatment will be determined by your physician based on:
- your age, overall health, and medical history
- extent of the disease
- your tolerance for specific medications, procedures, or therapies
- expectations for the course of the disease
- your opinion or preference
The goal of treatment of narcolepsy is for the patient to remain as alert as possible during the day and to minimize any recurring episodes of cataplexy, while using a minimal amount of medication.
- medications - excessive daytime sleepiness and cataplexy are treated separately, with central nervous system stimulants usually prescribed for EDS and tricyclic antidepressants for cataplexy
- nap therapy - two or three short naps during the day to help control sleepiness and maintain alertness
- proper diet
- regular exercise