Hemispherectomy Ends Seizures In Many Older Children With Rare
Seizure Disorder
Researchers from the Johns Hopkins Children's Center
report that hemispherectomy – a procedure in which half the brain is
removed -– may reduce or eliminate severe seizures even in older
children with a rare congenital disorder associated with epilepsy. The
findings are published in the December issue of Neurology.
Contrary to results of previous studies, the Hopkins research found
that in children with Sturge-Weber syndrome, delaying hemispherectomy
even for years had no apparent effect on seizure control or learning
ability. Some 80 percent of Sturge-Weber patients develop epilepsy.
"In fact, older patients were statistically more likely to be
seizure-free after surgery," said the study's lead author, Eric Kossoff,
M.D., a pediatric neurologist at the Children's Center. "However, in
general, the child's age at surgery did not have an adverse effect on
either their intellectual abilities or seizure reduction."
Sturge-Weber syndrome is a rare disorder of unknown incidence and
cause that is characterized by a vascular birthmark known as "port wine
stain" and neurological abnormalities, including a weakening or loss of
use of one side of the body. For most patients, seizures begin before
the age of one year and are difficult to control. When the seizures do
not respond to anticonvulsant medications and stem from one side of the
brain, hemispherectomy may be advised.
While children with Sturge-Weber syndrome make up only a small
percentage of all hemispherectomy patients, results from this and other
studies suggest that older children may also benefit from the surgery,
regardless of the cause of their seizures, according to Kossoff.
Kossoff and his colleagues examined data from questionnaires
completed by the families of 32 Sturge-Weber patients identified by the
Sturge-Weber Foundation as having had a hemispherectomy from 1979 to
2001. Surgeries were done worldwide in 18 centers. Information was
collected regarding the child's preoperative condition, details of the
surgical procedure and hospital stay, and the child's current
neurological status.
The average age that patients began experiencing seizures was four
months and the median age at the time of surgery was just over one year.
Children averaged almost 400 seizures per month and had been
unsuccessfully treated with approximately four different kinds of
medications before the hemispherectomy was performed.
More than 80 percent of patients were reported to be seizure-free
following the surgery and more than half were off anticonvulsants. The
type of hemispherectomy that was performed, or the amount of brain
matter actually removed, did not influence the child's seizure outcome.
"Most interestingly, we found the child's cognitive skills were not
impacted by the child's age at operation or delay of surgery. This is
contrary to all other previous studies on Sturge-Weber s yndrome and
hemispherectomy, which emphasized early surgery to avoid cognitive
decline," said Kossoff. "However, there was a trend toward poorer
cognitive outcomes if seizures persisted after surgery."
Hemispherectomy is performed at Hopkins on children with Rasmussen 's
syndrome, a variety of developmental abnormalities on one side of the
brain, and on those who have had disabling strokes. First attempted by
Johns Hopkins surgeon Walter Dandy, M.D., in the late 1920s, the
operation was reintroduced at Hopkins in 1968 and refined in the
mid-1980s by Benjamin S. Carson, M.D., director of pediatric
neurosurgery.
John M. Freeman, M.D., a pediatric neurologist at the Children's
Center, and Carol Buck of the Sturge-Weber Foundation contributed to
this study.
Editor's Note: The original news release can be found
here.
Note: This story has been adapted from a
news release issued for journalists and other members of the public. If
you wish to quote any part of this story, please credit Johns Hopkins
Medical Institutions as the original source. You may also wish to
include the following link in any citation:
http://www.sciencedaily.com/releases/2002/12/021211084340.htm
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