Most of us have experienced it: that dull, dragging semi-conscious state of
deadened awareness and desperate urge to nap that comes from sleep deprivation.
For people with primary hypersomnia, however, this is the way they go through
life, constantly feeling only half-awake but never able to get enough good sleep
to arise truly refreshed. Also known as “Sleeping Beauty Syndrome,” the
condition leaves those with the worst cases languishing in bed in what seems
like the opposite of a fairy tale, without a prince’s kiss to cure them.
But a new study, published in Science Translational Medicine, suggests
both a possible cause and a potential treatment for the condition, which may
ultimately lead to treatments for other sleep disorders. The origin of primary
hypersomnia, which has some genetic components is still unknown, as is the
number of people who are affected by it.
One particularly striking form of the disease, Kleine-Levin syndrome,
produces such tiredness and sleep-drunkenness that people are unable to attend
school or work. In males, it can include hypersexual behavior, compulsive
masturbation, a desire for promiscuous sex or making inappropriate sexual
advances, all while in a sleepy, semi-conscious state.
In the latest study, researchers led by David Rye of Emory University in
Atlanta studied 10 men and 22 women seeking treatment for primary hypersomnia.
In the patients’ spinal fluid, the scientists discovered a previously
uncharacterized chemical that stimulates the GABA-A receptor. This receptor is
best known as the site where sleep-inducing drugs like Valium and Xanax have
their effects, since activating GABA-A receptors can result in drowsiness.
The finding suggested a possible treatment. A drug, known as flumanezil can
treat Valium and Xanax overdoses or to reverse the effects of related compounds
used in anesthesia. Could it block or reverse the effects of the unknown agent
that was activating GABA-A receptors in primary hypersomnia?
The authors conducted a brief placebo controlled trial with seven
patients—including one with Kleine-Levin symptoms — to find out. Indeed,
injections of flumanezil improved the participants’ ability to pay attention and
remain alert. One participant has now taken the drug daily for four years.
“Although her nightly sleep duration remained at 9 to 10 hours, she nearly
always awakened refreshed without an alarm and daytime sleepiness was markedly
reduced,” the researchers write.
Further research is needed to see whether flumanezeil or a similar drug can
be an effective treatment for primary hypersomnia. And more studies are needed
to understand the chemical in these patients that is influencing the GABA-A
receptors in the first place. Figuring out what it is and how it changes with
normal sleep and wake cycles might also lead to the discovery of better drugs to
treat not just “sleeping beauties” but abnormal sleepiness and insomnia as
well.