In a recent video posted on Konbini, a young woman reports sleeping up to 6 p.m. every 24 hours. She suffers fromidiopathic hypersomnia, according to the examinations that have been carried out on his state of health. But what is the difference between this disease and narcolepsy?
Who affects these two diseases and what are the identified causes?
In France, it is estimated that the prevalence of narcolepsy is 0.025% according to the figures reported by the Vidal. Men are slightly more affected than women. In general, its symptoms appear in adolescence, around the age of 15. Narcolepsy can be explained by different hypotheses: a genetic predisposition, with a gene that has a particular allele, HLA DQB1*06:02 allele. “It would be responsible for an autoimmune mechanism, in which the body attacks its own components“, notes theInserm, orexin/hypocretin neurons (structures involved in wakefulness) are destroyed by the autoimmune mechanism. Environmental factors or past viral infections are also pointed out.
Idiopathic hypersomnia is, according to Inserm, a “rare disease that usually occurs before the age of 30, in 1 in 10,000 people when associated with long-term sleep (up to 10 hours) and in 1 in 100,000 people when associated with long-term sleep usual duration“It is less known and less studied, but a hypothesis exists about its occurrence.”Some patients would secrete an endogenous hypnotic substance, mimicking the action of benzodiazepines at the level of cerebral GABA receptors“. She could also be transmittedit is noticed in 15% of cases.
What are the symptoms of these two diseases?
Narcolepsy is manifested by bouts of sleep several times during the day, with an irrepressible drowsiness: the person literally falls asleep. But once awake, she benefits from her sleep, it is restorative. Narcolepsy is also defined by cataplexy. “These are brief losses of muscle tone (from one second to a few minutes), complete or partial (unlocking of the knees, dropping an object, blinking, exteriorized tongue in children, etc.), triggered by most often pleasant emotions such as giggles. They can lead to a fall, without loss of consciousness“, explains the Vidal. But also auditory, visual, sensory hallucinationssleep paralysis or poor nocturnal sleep.
“Idiopathic hypersomnia is another neurological disease responsible for severe hypovigilance. It results in great difficulty waking up in the morning, then all day by the feeling of not being fully awake“, notes the French Society for Sleep Research and Medicine (SFRMS). For its part, Inserm describes it as “characterized by constant excessive daytime sleepiness interspersed with restless naps and accompanied by nightly sleep of normal or increased duration but not restful.”
With idiopathic hypersomnia, nocturnal sleep is normal, both in its rhythm and in its duration. But revivals are extremely difficult. Inserm evokes a “sleep drunkenness“ which can last several minutes in the best case, up to several hours. Hypersomniacs tend to sleep during the day, over long periods of time, but never feel full.
The summary of the differences between narcolepsy and hypersomnia
Inserm summarizes the characteristics of the two diseases, and adds a third which affects sleep, Kleine-Levin syndrome.
- There narcolepsy is characterized by: irrepressible falling asleep during the day, drops in muscle tone (cataplexy), transient hallucinations and paralysis.
- I’idiopathic hypersomnia manifested by daytime drowsiness and hypovigilance, normal nocturnal sleep (but which may be longer)
- THE Kleine–Levin syndrome is for its part described by recurrent episodes of hypersomnia from 3 p.m. to 9 p.m. per day, for several days or several weeks. And associated cognitive and behavioral disorders.
How do I know what disease I have?
Faced with a sleep disturbance, there is first a clinical examination carried out, then a psychological one, before a series of tests. In particular, the patient is asked to fill out a “sleep diary” and can be measured using a bracelet that records his phases, this is called a acimetry.
“An iterative sleep onset latency test (TILE) assesses a patient’s ability to fall asleep repeatedly during the day while qualifying this sleep by electroencephalogram. A wakefulness maintenance test (TME) assesses the ability to stay awake during the day, in conditions favorable to falling asleep, but it is mainly used to assess the effectiveness of treatments.“, notes Inserm. Additional analyzes with brain imaging and blood tests can be carried out.
How are these diseases treated?
For idiopathic hypersomnia, such as narcolepsy, only symptomatic treatments exist. We use for example wakefulness stimulants to keep patients awake as much as possible, notes Inserm: modafinil, methylphenidate, amphetamines.
If a diagnosis of narcolepsy is made, “sodium oxybate is a nervous system depressant that increases deep sleep, reduces periods of daytime sleep and simultaneously limits the frequency of cataplexy episodes“. Of the tricyclic antidepressantsor selective serotonin reuptake inhibitors may also be options.
Sources:
- When to consider narcolepsy or idiopathic hypersomnia? VidalApril 14, 2022
- Hypersomnia and narcolepsy – When too much sleep is pathological, InsermDecember 2017
- French Society for Sleep Research and Medicine
-1694788780.jpg "Narcolepsy: how to recognize the signs in your child?")
