Implant Device Helps Many Untreatable Epilepsy Patients
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What was most exciting about the results, says DeGiorgio, is the fact that, unlike many drug treatments that can wear off after a while, the vagus nerve stimulation patients actually seemed to improve over time. He attributes this to two factors. "One is that the device's setting are being adjusted [for the best results] by the doctor, and the second is the cumulative effect of the device," he tells WebMD. "The more the brain 'sees' the device, the greater the effectiveness."
All the patients in DeGiorgio's study were taking one or more anti-epilepsy medications during the trial. That's because even patients with severe epilepsy do derive some benefit from medication, says Martha Morrell, MD, professor of neurology at Columbia University, in New York, and chair of the Epilepsy Foundation. "These patients' seizures are not completely controlled by medication, but if they were not on medicine at all, they would be a lot worse," she tells WebMD. "[Vagus nerve stimulation] should be thought of as an [addition] to medication."
The only major side effect of the vagus nerve stimulation device is hoarseness and throat discomfort, which occurs because the nerve being stimulated also controls certain speech functions. However, this problem can be lessened by having the physician adjust the device so that less current is generated, DeGiorgio says.
Another study, done by Ravish V. Patwardhan, MD, a resident in the division of neurosurgery at the University of Alabama at Birmingham, and colleagues, shows that vagus nerve stimulation is also effective in children. Patwardhan's study involved implanting vagus nerve stimulation devices in 38 children, aged 11 months to 17 years. The researchers found that nearly two-thirds of the children treated with vagus nerve stimulation experienced a 50% or greater reduction in seizures.
One possible reason that children seem to do even better with vagus nerve stimulation than adults is that their brains have not had as much damage as older patients, who have suffered from epilepsy longer. "Patients who keep suffering from seizures have a poorer outcome than if the seizures are stopped," Patwardhan tells WebMD. "One patient had had seizures 15 years before the device was put in. That's probably too long to wait." Patwardhan presented his study in San Antonio, Texas, this week at a meeting of the Congress of Neurological Surgeons.