Narcolepsy is characterized by excessive daytime sleepiness, extreme fatigue, and irresistible episodes of sleep.
There are three subtypes.
1 Narcolepsy with cataplexy. The irresistible episodes of sleep are accompanied by a sudden bilateral loss of skeletal muscle tone, usually triggered by emotion or surprise.
2 Narcolepsy without cataplexy.
3 Narcolepsy secondary to a medical condition. The condition must be a significant underlying medical or psychiatric disorder which could account for the sleepiness.
It is linked to low hypocretin levels in the CSF. Narcolepsy is not particularly rare; the majority of cases are with cataplexy, and have a prevalence of 0.4 per 1000.
Males and females are equally affected. Narcolepsy tends to be present from birth, and may present from 5 to 50 years of age. It is a chronic disorder which tends to be lifelong.
The classical tetrad of excessive sleepiness, cataplexy, sleep paralysis, and hypnagogic hallucinations is actually very rare. The sleepiness is present every day, and tends to worsen gradually until there is an irresistible and refreshing short episode of sleep.
These are uncontrollable, and may occur at inappropriate times. The frequency of these naps is highly variable, from a few per day to one every couple of minutes.
Cataplexy is triggered by specific emotional, stressful, or surprising stimuli in the environment, and all voluntary muscles except the respiratory and extraocular musculature are involved. The patient may fall to the ground, or merely become suddenly very weak. Consciousness is preserved during the attack, and there is rapid recovery.
Other symptoms include:
Narcolepsy interferes with every part of life, and can be very incapacitating. Secondary depression, anxiety, and underachievement at school or work are very common.
Narcolepsy is essential a clinical diagnosis, as there is no specific diagnostic test. Patients should be referred to a specialist to undergo investigations which can help confirm a suspected case.
Polysomnography shows a distinctive pattern of a short sleep latency (time to get to sleep), short periods of REM sleep, increased stage 1 NREM sleep, and frequent awakenings
Human leucocyte antigen (HLA) typing. The HLA-DR2 haplotype is found in 80 to 90 per cent of patients with narcolepsy. Reduced hypocretin-1 concentration in the CSF is a highly sensitive and specific marker for narcolepsy.
This is especially the case if cataplexy limits activities that can be undertaken (e.g. driving). Scheduled naps. Short 20-minute naps should be built into the .
CYCLAMEN: Great inclination to lie down, and to sleep. No desire to work. Great dejection and melancholy.
HYDROCYANIC ACID: Narcolepsy. Irresistible drowsiness. Yawning and shivering.
KALI BROMATUM: Extreme drowsiness. Drops asleep in char.
KALI NITRICUM: Drowsiness and sleepiness in day time. Disturbed sleep at night, constant dreaming, with frequent awakening.
MERCURIUS: Great sleepiness during the day, which is not relieved from long sleep.
NATRUM MURIATICUM: Sleepy in afternoon. Nervous jerking during sleep. Sobs during sleep. Sleepiness and drowsiness after meals.
NATRUM SULPH: Sleepiness during day, especially while reading.
NUX MOSCHATA: Narcolepsy. Irresistibly drowsy, sleepy, muddled, as if intoxicated. Great drowsiness and sleepiness. Sleepy attacks, sudden with vertigo. Great sleepiness with all complaints. Dreams of falling from high place of being pursued.
NUX VOMICA: Drowsy after meals and in early evening. Better after a nap, unless aroused. Yawning. Weeping and talking during sleep. Anxious dreams, pursued by animals, dogs, and cats.
OPIUM: Great drowsiness. Falls into heavy deep sleep.