Idiopathic hypersomnia (IH) is a rare condition characterized by excessive daytime sleepiness which is not relieved even after long naps and a good night’s sleep.
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A state of sleep drunkenness is often experienced by sufferers of IH, making waking up and “getting going” difficult.
This condition can be very dangerous obviously, and spontaneously improves in just up to one fourth of patients.
Do you suffer from idiopathic hypersomnia?
You may be suffering from idiopathic hypersomnia if:
- you’re experiencing excessive daytime sleepiness despite sleeping plenty (more than 10 hours in a 24-hour period).
- you wake up from sleep unrefreshed and confused (“sleep drunkenness”). It is hard to wake you and you may even become aggressive and confused if awakened. It may take you 2-3 hours to “get going” in the morning.
- naps are unrefreshing and are followed by sleep drunkenness
- sleep attacks – rarely, involuntary naps occur (often longer than 1 hour)
Idiopathic hypersomnia usually begins in young adulthood, often between the ages of 15 and 25 years. It may run in the family.
If you’re tired because you don’t normally get enough sleep or if you’re getting lots of poor quality sleep, then you’re not suffering from idiopathic hypersomnia – doesn’t matter how tired you are. When people with IH go through a sleep study, they exhibit normal, healthy sleep patterns. They fall asleep easily though and can sleep for long hours (sometimes more than 10-11 hours).
Other symptoms may include:
- lightheadedness on standing up
- postural hypotension (blood pressure drops when standing or sitting)
- cold hands or feet
- Raynaud syndrome (reduced blood flow due to spasm of arteries, making the fingers and toes turn temporarily white, then blue, with numbness and pain.)
- Migraine- and tension-type headaches
Other less common symptoms:
- Sleep paralysis, hallucinations, cataplexy-like episodes, and nightmares
- Mood changes (e.g., depressive symptoms), but not a full-fledged disorder, such as major depression
What is idiopathic hypersomnia?
Sleep scientists have limited understanding of this condition. One theory which attempts to explain it is known as the Two-Factor Model, proposed by Bonnet and Arand in 1997. The two factors are:
- Basal Arousal Level – What is your normal level of arousal relative to others? (The level of arousal reflects your level of wakefulness and alertness.) Is your basal arousal level lower of higher than that of others?
- Sleep Requirement – How much sleep do you require relative to others? Do you require a shorter or longer sleep than most other people?
Arising from different combinations of these factors are 4 distinct conditions:
- People who have a high basal arousal level and a short sleep requirement may suffer from psychophysiological insomnia or idiopathic insomnia.
- People who have a high basal arousal level and a long sleep requirement may suffer from paradoxical insomnia, characterized by complaints regarding sleep that are not supported by objective measures which show adequate sleep, and without the level of daytime impairment expected.
- People who have a low basal arousal level and a short sleep requirement may suffer from excessive daytime sleepiness.
- People who have a low basal arousal level and a long sleep requirement may suffer from idiopathic hypersomnolence.
Long story short, according to the Two-Factor Theory, idiopathic hypersomnia characterizes people who require a relatively long sleep duration, while having a low basal arousal level. The low basal arousal level makes them constantly tired, yet are getting plenty of sleep. Indeed, people suffering from idiopathic hypersomnia often experience an irresistible need to sleep or even daytime sleep episodes. At night, it often takes them no more than 8 minutes to fall asleep and they can sleep 12-14 hours per day.
In the Epworth Sleepiness Scale, sufferers of IH score higher (sleepier) than even people who suffer from narcolepsy. Distinguishing idiopathic hypersomnia from narcolepsy without cataplexy may require going through a sleep study.
Excessive daytime sleepiness can result from other conditions, such as:
- Upper airway resistance syndrome
- Sleep deprivation/Poor quality sleep
- Behaviorally Induced Insufficient Sleep Syndrome
- Being a long sleeper
- Hypersomnia associated with psychiatric disorders (such as depression)
- Chronic fatigue syndrome
- Sleep-related movement disorders, such as RLS and PLMD
- Circadian disorders
- Neurological disorders, such as brain tumors, encephalitis, stroke, lesions, Alzheimer disease, Parkinson disease, and multiple-system atrophy
- Genetic disorders
- Hormonal disorders, such as obesity, diabetes, hypothyroidism, and acromegaly.
- Head trauma
- Postviral syndrome
- Parasites, such as African trypanosomiasis (“African sleeping sickness”)
- Kleine-Levin syndrome
- Menstrual-related hypersomnia
- Drugs, such as beta blockers, other antihypertensive agents, dopaminergic agents, antidepressants, and opioids
Why does idiopathic hypersomnia happen?
Science doesn’t currently know what causes this condition, which may be more common in women. 1-2 thirds of cases appear to be familial. Idiopathic hypersomnia usually begins insidiously over several weeks or months between ages 10 and 30 years.
Occasionally, idiopathic hypersomnia have been reported to follow acute insomnia, abrupt changes in sleep-wake habits, overexertion, mood change, general anesthesia, viral illness, or mild head trauma.
There may be an association between IH and diabetes, obesity, and an increased body mass index.
The condition may involve a delayed start (and decline) of melatonin and cortisol secretion.
Treatment of idiopathic hypersomnia
First, don’t fight the sleepiness, especially when you’re about to drive, operate heavy machinery, or do anything that can be dangerous when overly tired. If you need a nap, take one to avoid dangerous episodes of severe drowsiness and automatic behavior. It may be wise though to plan naps in advance and make them short.
Behavioral approaches and sleep hygiene are recommended to prevent insufficient sleep and may include restriction of time in bed as well as avoiding alcohol, exercise, heavy meals, and warm environments.
Caffeine is a widely available alerting agent, effective when used intermittently at doses of 200 mg or more. Sources include coffee (Coffea arabica), tea (Camellia sinensis), cocoa (Theobroma cacao), Yerba mate (Ilex paraguayensis), Guarana (Paullinia cupana), and Cola acuminata. Tolerance develops with chronic use.
Other natural nervous system stimulants include:
- Erythroxylum coca
- Rosemary (Rosmarinus officinalis)
- Peppermint (Mentha piperita)
Another herbal approach to treat IH is to stimulate the body’s innate vitality by using herbs such as:
- Artemisia spp.
- Hops (Humulus lupulus)
- Chamomile (Matricaria recutita)
- St. John’s wort (Hypericum perforatum)
- Skullcap (Scutellaria lateriflora)
- Gentiana lutea
- Horehound (Marrubium vulgare)
- Rue (Ruta graveolens)
- Tansy (Tanacetum vulgare)
- Oat (Avena sativa)
Because the underlying causes of IH are unknown, the medical treatment is symptomatic and involves ingesting stimulant drugs and awake-enhancing medications, such as modafinil (first-line treatment), armodafinil, methylphenidate, pitolisant, mazindol, and dextroamphetamine. Also sometimes used are tricyclic antidepressants, MAOIs, SSRIs, clonidine, levodopa, bromocriptine, selegiline, and amantadine. Atomoxetine and reboxetine (in Europe) are slightly wake promoting and reduce REM sleep.
If sleep apnea may underlie the symptoms, try using CPAP and see if it improves the daytime sleepiness.