Doctors study brain surgery as treatment of first resort

Medical Matters

Medicine & Science

December 22, 2003|By Judy Foreman | Judy Foreman,SPECIAL TO THE SUN

Chelsea Henrie first knew something was wrong when, at age 16, she poured cereal into her shoe. "I also stuck my hand in the toaster once," recalls Henrie, now 20 and a student at the University of New Mexico in Albuquerque. "That was the worst thing that happened."

Like 2.8 million other Americans, Chelsea Henrie has epilepsy, a disorder characterized by seizures, or sudden electrical storms, in the brain. Though rarely fatal unless a seizure is severe and prolonged, or occurs while a person is swimming or driving, epilepsy can be a life-wrecker.

But today, Henrie is seizure-free, thanks to a promising kind of brain surgery that some specialists see as a treatment of first, not last, resort.

At a meeting of the American Epilepsy Society in Boston this month, researchers discussed a number of new approaches.

The kind of surgery Henrie had is the focus of a $30 million study at 19 medical centers funded by the National Institute of Neurological Disorders and Stroke. It will determine whether early surgical removal of a small piece of the brain's temporal lobe is better than aggressive treatment with drugs.

The underlying causes of seizures are well-documented: head trauma, infections, genetic defects and problems that occur as a child's brain grows. In women, seizures often strike just before menstruation. Sleep deprivation can provoke seizures, too.

As seen on an EEG, or electroencephalogram, the brain's electrical activity changes drastically during a seizure. Unlike the heart, whose electrical activity normally appears simple and coordinated, the brain normally appears to be chaotic. But during a seizure, brain activity becomes more regular and brain function becomes impaired.

Surgeons have known for years that a hemispherectomy, removing half the brain, can reduce seizures. So in cases where seizures are confined to a smaller region of the brain, the idea is to remove less brain tissue. A pivotal Canadian study published in 2001 showed that surgery to remove an ice-cube-sized portion of the brain was more likely to eliminate seizures than drug therapy. So why not do it sooner?

"Most people wait 18 [years] to 22 years to have surgery, partly out of the ... fear of having part of their brains removed, and partly because doctors feel it is an intervention of last resort," says Dr. Daniel Hoch, an epileptologist at Massachusetts General Hospital.

A less invasive surgical approach is implanting a "pacemaker" under the skin on the chest. Wires from the pacemaker are threaded, under the skin, to the vagus nerve in the neck. The Vagus Nerve Stimulator, which is made by Cyberonics Inc. and costs $15,000, is programmed to fire for 30 seconds every five minutes or so.

When it fires, it stimulates the vagus nerve, which transmits the signal to the brain, yielding good seizure control in more than a third of the cases and at least some relief in another third.

Scientists are also working on a skull implant device from NeuroPace Inc. that would detect abnormal brain activity before it becomes a seizure, then stimulate the brain to abort it.

A lower-tech approach is the ketogenic (or low-carbohydrate, high-fat) diet, which allowed some children in a study at Johns Hopkins University to reduce their medications.

Increasingly sophisticated, dual-action medications such as Zonegran, Topamax, Lamictal and Keppra can also help by simultaneously decreasing brain excitation and boosting the brain's dampening signals. Traditional medications treated one symptom or the other.

But for many people, the ultimate answer might be surgery, sooner rather than later. John Davies, 60, an accountant who lives in Salem, Mass., endured decades of seizures before having brain surgery 1 1/2 years ago. "I haven't had an attack since," he says.

Judy Foreman is a lecturer at Harvard Medical School.

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