changed the spelling on the title, in case the search is too spelling-sensitive.
Nikky,
thanks, this is a vital definition. i have seen documentary clips and news stories on it, the level of deep sleep for such long periods sends family into panic.
typically, IH is confused (and confusing) with N, or "Gellineau Syndrome". Some diagnosticians tell patients it is not "true N", or not "really N". i am not sure distinguishing between them CLINICALLY is a great idea, since they both can be completely disabling, research and treatment are still emerging and broad.
The two similar syndromes can exacerbate each other, imitate each other, or both truly exist in someone, for all we know.
As you see, the presence of C is considered to be proof of Gellineau, but C itself is not tested-for reliably. It has to be observed by an informed person, then reported by the person with the attack "correctly" (ie. "awake", reporting sounds and events, how it feels) and then reliably guessed-at in some. C severity comes and goes, and varies from person to person.
REM onset and sleep onset can vary so much, the sleep testing "to be sure of" N is flawed. When some people are desperate for treatment they go through the whole process and then some insensitive dummy sends them off with "just ideopathic hypersomnia".
There will be better research, definition and diagnosis someday, but for the present, i would prefer the "first best guess" were "N", because it will keep insurance and care open, and pave the way to help with finances; it is at that stage (years, decades of searching) that we can lose everything.
In a case like mine, long sleep time was a feature of N, untreated sleep apnea, severe sleep deprivation, and despondency. I have known other people with the same "symptom", who lay helpless and semiconscious for weeks, but turned out to have classic C as well, and were diagnosed with N. One had emphysema, one asthma, as it turned out, were not getting enough oxygen EVER, and were falling nearly into coma.
Dealing with one symptom at a time was necessary, before conventional tests and observation could secure a dx, and before treatment with stimulants, C medication, or provigil. Before then, i went through a parade of 12 sleep labs with such different quality and medical proficiency, it would shock your socks off. and i DID lose everything.
Idiopathic hypersomnia with long sleep time: disabling daytime sleepiness, despite an increased nightly sleep time of more than 10 hours.
Extended sleep 12 to 14 hours every night with few interruptions, then extreme difficulty waking. Once awake, may appear still partially asleep, confused or drunk. May appear to stare blankly, semi-responsive, automatic behavior, hallucinations, may appear to forget doing simple activities. Headaches in about 30 percent of cases.
IH can make you even sleepier than someone who has narcolepsy, irresistible daytime sleepiness can be more severe with narcolepsy. Naps are often longer, and not refreshing.