The past few years have brought advances in our understanding of chronic fatigue syndrome, but a cause has yet to be found. CREDIT: Dreamstime |
A new treatment may help people with a bizarre medical condition that
makes them perpetually sleepy. The findings, detailed Nov. 21 in the journal
Science Translational Medicine, may provide relief for the people who sleep
constantly and feel exhausted despite caffeine, other stimulants, and several
alarm clocks.
People with hypersomnia need to sleep about 70 hours a week and have trouble rousing from sleep. When
they are awake, they usually feel as if they've pulled an all-nighter, and
describe it as walking around in a fog. Most people come to a diagnosis after
conditions like depression, sleep apnea or
thyroid problems have been ruled out, said study co-author David Rye, a sleep
researcher at Emory University. "You look for the typical causes, and then
once you rule all those out, you're left with people who still sleep 12, 13,
14, 15 hours," Rye told LiveScience.
For obvious reasons, intense sleepiness can put
a crimp in patients' work and social lives. While no one knows exactly how many
people have this condition, Rye estimates that roughly 1 in 800 people might be
afflicted. Doctors often prescribe patients stimulants such as Ritalin or
Adderall, but they don't usually work. So Rye's team wondered whether brain
chemicals could cause hypersomnia. Because spinal fluid provides a snapshot of
the chemicals floating around the brain, the team took spinal taps from 32
patients with the disease and 16 healthy subjects. When they put the spinal
fluid in a dish with human cells, nothing happened.
So the researchers added a chemical called gamma-aminobutyric acid
(GABA), which helps the body shut down. The spinal fluid of the ultra-sleepy
amplified the effects of GABA, making it bind much more often to the human cells. (Past research
showed a link between GABA and sleep paralysis, or the phenomenon in which one wakes up while his or her muscles
are still frozen.) The sleepy patients were producing a brain chemical that
kept them half-sedated all of the time, Rye said.
In a petri dish, adding a drug called flumenazil, which revives patients
who have overdosed on sedatives such as Valium, reversed the effects of the
sleepy peoples' spinal fluid. They then tested flumenazil in the sleepy
patients. Before taking the drug, hypersomniacs performed as well as the
extremely sleep-deprived or slightly inebriated on a test of alertness. "They're
walking around essentially legally drunk all day," he said. Afterwards,
the sleepy cohort performed almost as well as healthy individuals. The findings
suggest that the drug could be an effective treatment for those with
hypersomnia, but a follow-up study needs to prove that they actually sleep less
at night, he said.
Currently, the drug is only used to treat drug overdoses or to awaken
patients unconscious from anesthesia, so the amount of the drug currently
produced could only treat a handful of patients. Production would need to
increase before it could be widely used, he said.
Source: Live Science
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