Getting Headaches? You Can't Sleep on It
June 26, 2000 -- The attacks can come on without warning -- a
stabbing pain on one side of your head, intense pain in and around one eye, a
stuffy nose -- and you usually feel worse when lying down. The pain usually
lasts up to an hour and then disappears, only to return again.
Doctors still don't know what actually causes these headaches,
often called cluster headaches, but a new study has found that they may be
triggered by a sleep disorder that also interferes with your breathing.
"Cluster headaches are a terrible problem, and people who
get them know that they're looking at a month of having recurrent attacks,"
says Todd Troost, MD. "For some people it just goes on and on. This study
is very interesting because it may give us information on how to prevent them
from occurring." Troost, who is chairman of the neurology department at
Wake Forest University School of Medicine, was not involved in the study.
Unlike migraines, which affect mostly women, cluster headaches
primarily afflict men. While they can strike during the daytime, most of them
tend to occur at night, usually waking the person from a sound sleep.
Researchers from the University of Michigan found that 80% of the people in
their study, which appears in the June 27 issue of the journal
Neurology, may have a sleeping disorder known as obstructive sleep
apnea, which might be responsible for triggering the attacks.
Obstructive sleep apnea is believed to affect the health of
about 20% of the adult population in the U.S., even though most people remain
undiagnosed. It occurs when a person's airway becomes blocked while sleeping.
This causes breathing to stop temporarily, which awakens the person briefly.
This pattern is then repeated throughout the night, and the number of
involuntary breathing pauses may be as high as 20 to 30 or more per hour.
The researchers assessed 25 individuals who had a history of
cluster headaches, using a sleep test called polysomnography, which monitors
brain waves, heart rate, breathing patterns, oxygen level, and muscle movements
while a person is asleep. The results of the polysomnography indicated that up
to 80% of the study subjects had some degree of sleep apnea.
None of the participants knew that they had sleep apnea before
taking part in this study, according to lead author Ronald Chervin, MD, an
assistant professor of neurology at the University of Michigan. It is important
for sleep apnea to be diagnosed, he said in a press release, because treatment
may be able to reduce or eliminate the cluster headaches, in addition to
preventing the problems that can result from sleep apnea itself.
Troost agrees, and says that the study results do suggest sleep
apnea may be related to cluster headaches, but that other studies are needed to
confirm this. "For the complete study to be important, I think you have to
take it to the next step and treat people for the sleep disorder and see if it
helps the headaches."
The researchers are still unsure why people with sleep apnea
get cluster headaches, but think that it may be due to the lack of oxygen in
the blood that occurs when breathing stops.