Surgery May Be the Right Choice for Epilepsy

pilepsy is a disease without predictability. In some people, seizures can be controlled with drugs; in others, no matter what anticonvulsant medication they take, their seizures go on.

Thirty-one-year-old Dawn Donahue fell into the latter group. For three years following her first grand mal episode in 1995, she faithfully took every drug prescribed by a series of neurologists, but her seizures and blackouts struck at exactly the same frequency. Still, no physician ever mentioned the word “surgery” until Donahue met neurologist Gregory Bergey, the recently arrived director of Hopkins’ adult epilepsy division.

That’s typical, says Bergey. Even in 1999, surgery is an underutilized treatment for epilepsy. Patients and physicians, even neurologists, usually either dismiss it as too risky or see it only as a last resort, and repeatedly rely on drugs.

But Bergey points out that when the seizures emanate from the temporal lobe of the brain, half of the cases don’t respond to medication. “And if you’ve failed with three or more drugs, the chances of a new one controlling your seizures is only about 5 to 10 percent.” Meanwhile, the odds of controlling those seizures with surgery can be 70 or 80 percent. Dawn Donahue is a case in point. Since surgery in June 1998 to remove the small section of her brain where the epilepsy was focused, she has been seizure free, resumed driving and is back at her job as a computer technician.

But Donahue’s outcome, Bergey stresses, couldn’t have worked without the assistance of a tricky brain-mapping technique. In some patients, for whom he considers surgery a good possibility, he makes absolutely certain that the regions of the brain from which the seizures emanate can be safely removed without affecting vital motor or sensory functions. By putting the person through an astonishing process in which a grid is placed over the exposed brain surface, or cortex, he is able to watch the seizures as they occur.

He also observes the person’s responses to electrical stimulation of the surrounding areas in the brain. In Donahue’s case, he found that a scar on the temporal lobe was the epicenter of her seizures. And although the lesion was near the region of the brain that controls speech, speech-mapping from the grid showed that it would be safe to remove the tissue there.

Bergey’s NIH-funded lab focuses on these “signal” searches to give patients who fail drug therapies a shot at surgery. The technique, he says, not only is unearthing the origin of seizures, but also how they start, spread and stop. “It’s helping us understand how we can provide better treatment.”

-- Gary Logan