I'm usually more of a TIPS "lurker" than "poster," but since I do sleep research
I'm feeling compelled to answer the questions on narcolepsy....
>What causes it?
Recent research indicates that human narcoleptics have a significant reduction
in the number of hypocretin (also called orexin) neurons in the hypothalamus
(investigated post-mortem), as well as a significant reduction in hypocretin
levels in the cerebrospinal fluid. Animals with narcolepsy show a reduction in
narcoleptic symptoms with administration of hypocretin. The current thinking is
that narcolepsy and the associated hypocretin cell loss may be the result of an
autoimmune disorder, but the details haven't been worked out yet.
>What happens?
There are a number of symptoms of narcolepsy, including excessive daytime
sleepiness and associated irresistible sleep attacks, occasional cataplexy
(muscle weakening), hypnagogic hallucinations (visual hallucinations/dreams
experienced at sleep onset), and sleep paralysis (total or partial paralysis of
skeletal muscles at sleep onset). Most sleep researchers agree that narcolepsy
is a disorder of REM sleep, in that most symptoms of the disease are
manifestations of REM sleep occurring during wakefulness.
>Do people who are having an attack retain any sense of their surrounds?
That depends on exactly what is meant by an "attack." In the case of the
irresistible sleep attacks, no -- the sleep is normal except for the fact that
it occurs at any time during the day. In the case of cataplexy, yes. People
with severe cataplexy, even though they are unable to move any skeletal muscles,
are completely aware of what is going on around them. (Cataplexy this severe,
however, is rare. Most narcoleptics who have cataplexy have muscle weakness in
the jaw and neck muscles, not full-body muscle weakness.)
>Does it have any known detrimental effects on memory or on the heart?
Not that I'm aware of. (Of course, that doesn't mean there aren't any -- just
that I don't know about it. :-))
Amy J. Silvestri, PhD
Assistant Professor, Department of Psychology
Neff Hall
Indiana-Purdue University at Fort Wayne
Fort Wayne, IN 46805
219-481-6404
fax: 219-481-6972
The most exhausting thing in life is being insincere.
--Anne Morrow Lindbergh
