For Patients with Epilepsy--Half a Brain That Works
hen you first hear about the surgery known as hemispherectomy--removing
half a person's brain--it sounds too drastic to even consider as a treatment. But
between 1968 and 1996, that operation was performed 58 times, 57 of them at Hopkins,
on patients between 2 months and 20 years old who had been experiencing uncontrollable,
often life-threatening, seizures. Now, a long-term study of how they have fared since
the surgery shows that the hemispherectomy gave these young people a new lease on
"Parents agonized about whether to allow this radical surgery," reveals
pediatric neurologist Eileen P.G. Vining, M.D., lead author of the study. "The
data prove their courageous decision was correct." Patients presented with the
option of undergoing the hemispherectomy were far from ordinary epilepsy cases. All
were experiencing a burden of seizures the Hopkins team considered excessive -- commonly,
45 to 50 incapacitating seizures daily -- that stemmed from one of three causes:
the viral-like Rasmussen's encephalitis, irregular brain development or stroke. In
each case, extensive injury had occurred in only one of the brain's hemispheres.
And despite high doses of medication that left these children zombielike, the seizures
The hemispherectomy takes eight to 12 hours to perform. At Hopkins, pediatric
neurosurgeon Benjamin Carson, M.D., leads the team that does the job. One lobe at
a time, the surgeons remove the brain tissue, leaving the deep structures--the thalamus,
brain stem and basal ganglia-- intact. They then insulate the newly exposed areas
with a collagen-based material. Cerebrospinal fluid eventually seeps in, filling
the empty space in the skull.
Parents know to expect some long-term disabilities from the procedure: vision
defect and some paralysis of the limbs on the side opposite the operation. But the
surgery's benefits far outweigh its drawbacks, according to John Freeman, M.D., director
of Hopkins' pediatric epilepsy center. Eighty-nine percent of patients with Rasmussen's
syndrome, two-thirds of those with dysplasias, and two-thirds with vascular problems
now are either seizure-free or have only non-handicapping seizures.
Children suffer no intellectual impairment from the removal of so much brain tissue.
Many, in fact, actually improved academically, the study found, when their seizures
stopped and they were able to stop taking debilitating anticonvulsive drugs. And
in preschool-age children, in particular, the remaining brain easily picks up responsibility
"This is an incredible operation," Freeman declares unequivocally. "There's
absolutely no doubt that half a brain that works well is better than a whole brain
that's seizing constantly."*
Young Athletes in Training
number of our patients are young gymnasts, skaters or ballet
dancers, usually those with what some would call a 'Type A personality,'" says
pediatric anesthesiologist Sabine Kost-Byerly, M.D., who treats teenagers with complex
regional pain syndrome.
Also called causalgia or reflex sympathetic dystrophy, the disorder comes after
an injury--sometimes a minor one. Pain to an extremity persists after the injury's
healed and can be severe. "We'll find that a teenager suddenly refuses to use
a hand or foot," says Kost-Byerly. Atrophy of the extremity and joint changes
may come as well. Though the syndrome is most often seen in adults, Kost-Byerly and
a multidisciplinary team gathered by Hopkins' Anesthesiology and Critical Care Medicine
department specialize in treating teenagers with the problem. The team is one of
very few such units across the country.
||In some injured teenagers, Sabine Kost-Byerly says,
even a touch with a cotton ball causes pain.
"It's tricky to deal with in adults," Kost-Byerly adds, in part because
there's often a psychological element. "But with the added consideration of
a younger patient's psyche and physical development, it's even trickier."
Pediatric physical therapists, psychiatrists and neurologists, as well as anesthesiologists,
tailor diagnosis and care to the younger age. The favored ap-proach combines psychiatric
and physical therapy with medication: one or more blocks of appropriate sympathetic
ganglia via needle-inserted anesthetic or oral drugs. And since needles can be unnerving
to young patients, Kost-Byerly adds, "the team has developed techniques that
reduce teenagers' anxiety associated with treatment." *
Difficult Side Effect of Diabetes
isorders of diabetes are many and varied, but high on the list
for distress in patients is diabetic gastroparesis, where injury to stomach nerves
can all but wipe out gastric motility. The nausea, pain and constant feeling of fullness
are hard to bear. "In addition, it's one of the most common motility disorders
among patients wth diabetes," says gastroenterologist/psychiatrist Marvin
M. Schuster, M.D., "and one of the most difficult to treat."
At Hopkins Bayview's new Marvin M. Schuster Center for Digestive and Motility
Disorders, headed by Schuster himself, two promising ways to restore motility are
under scrutiny. The first, a drug-based approach, fine-tunes present medicines that
stimulate gastric muscles but have unacceptable drawbacks. One Phase III drug, for
example, stimulates specific serotonin receptors in the stomach--known to trigger
motility--but does it so precisely that sister receptors aren't touched and side
effects dwindle. Another test looks at erythromycin. The common antibiotic stimulates
receptors for motilin, a natural hormone that triggers GI motility. But as a medicine
purely for motility, Schuster explains, erythromycin has an undesirable antibiotic
effect. So researchers at the Center are helping develop and test a stronger, designer
version of erythromycin stripped of its antibacterial properties.
The other approach (now being tested) relies on a small, heart-pacemaker-size
device implanted beneath the skin over a patient's stomach. Electrodes from the pacemaker
deliver a constant signal to a nerve plexus in the curvature of the fundus--the stomach's
natural pacemaker. Output of the device is set to mimic the organ's own perastaltic
waves. "We can't talk about a cure where there's nerve destruction," says
Schuster, "but we hope these approaches will restore a more normal life."