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A Strain on
The Brain
Does a malfunction of the
thalamus and the hypothalamus
lead to the excessive hunger
and sleep that characterize
Kleine-Levin syndrome?
The pituitary gland is the
headquarters of the
endocrine system—the
system that releases
hormones into the body.
The pituitary gland releases
at least nine hormones that
have important effects on
the body.
The thalamus is a region that
relays information from the sense
organs (eyes, ears, nose, and
so on) to the cerebral cortex.
The thalamus is also involved
in generating sleep.
The cerebral cortex is the
layer of gray matter that
covers the brain. It is the
center of learning, language,
and memory.
The hypothalamus is a region of the
brain that regulates body temperature,
thirst, hunger, and sleep. The prefix
hypo- means “below” or “under”; the
hypothalamus is located beneath the
thalamus. The hypothalamus works by
sending signals through the nervous
system and by triggering the nearby
pituitary gland to release hormones.
Eric Haller photos: Andrew Templeton; Head: Alfred Pasieka/Photo Researchers, Inc.; Brain: Mittermeier/Getty Images
BRAIN MALFUNCTION
The abnormal hunger and sleep patterns of people with
KLS suggest to Mignot that two areas of the brain—
the thalamus and hypothalamus—are affected by the
disorder. (See “A Strain on the Brain.”) Those areas
are involved in the regulation of hunger and sleep.
Mignot also suspects that some people with KLS
may have a genetic vulnerability to the disease. Genes
are short segments of DNA that control human traits
and are passed down from parents to children. KLS
seems to affect Jewish people more than it does others.
Israel has more cases of the condition than any other
country in the world. (Eric is not Jewish.) “There seems
to be an inherited component to this disease, and we are
very excited about this discovery,” says Mignot.
MISSED SCHOOL
Though people with Kleine-Levin are out cold most of
the day, their condition is still disruptive. Eric can’t be
left alone, says his mother, Lori Haller, because he
might accidentally harm himself. When he is awake,
his mind floats in a haze that she compares to coming
out of unconsciousness after surgery. “A nurse would
never let someone alone who is coming
out of anesthesia,” she says. Noise and light also
bother Eric while he is awake. When friends visit him,
he is often irritable with them.
Because teens with KLS miss so many days of
school, some fail to finish school or graduate on time.
Eric is fortunate. His teachers are sympathetic, and he
manages to catch up on missed schoolwork. His grade
point average is 3.5. He also has a girlfriend and a busy
social life when he isn’t confined to his bed. He loves
sports, fast food, and loud music.
Eric is philosophical about his disorder and hasn’t let
it ruin his life. “My friends are used to it,” he says, “and
my parents and grandparents are very understanding.”
His condition has even led to a small brush with fame.
Earlier this year he was featured in a local newspaper
and in May appeared on CNN.
Still, Eric dreads the onset of an episode, which can
happen at any time. Each episode lasts about two weeks,
and so far this year, he has had several.
The odds are that Eric will outgrow KLS. He will
then go on to be known for other things, says his mother,
“instead of poster boy for Kleine-Levin syndrome.” CS
C URRENT SCIENCE October 20, 2006 5