Epilepsy Program

Other Surgical Procedures for Epilepsy

Corpus Callosum Resection (split-brain operation)

This separates the major band of fibers inter-connecting the left and the right hemisphere of brain. It rarely cures seizures, but may slow down the spread of the seizures. In such instances, people may be able to sit down or protect themselves. The split-brain operation can be viewed as a procedure to prevent injuries from seizures rather than a cure for seizures.

Hemispherectomy

This entails removal of the majority of one hemisphere (half) of the brain. The radical procedure is employed in individuals, usually children, who have severe damage to one hemisphere. Candidates may suffer from a type of encephalitis called Rasmussen's encephalitis, in which the local damage to a hemisphere is progressive over years. Although children are initially weak on the side of the body opposite surgery after the procedure, function usually recovers. Recovery is more complete for younger children under age 6 than for those in the teens or beyond. Children who recover well from a hemispherectomy grow up with only a clumsy hand and a limp.

Vagus Nerve Stimulation (VNS)

This procedure involves implantation of a cigarette-lighter-sized pacemaker under the skin of the chest, with a wire run subcutaneously to the left vagus nerve in the neck. No brain surgery is involved. Research has shown that intermittent stimulation of the vagus nerve can lower the frequency and intensity of seizures in 25-50% of individuals who use the technique. The stimulator is programmed to come on for 30 seconds of every 5 minutes, but the timing can easily be adjusted. In addition, patients or family can carry a magnet to turn the stimulator on when a seizure is being felt.

The main side effect of VNS is unpleasant sensations in the throat, and hoarseness of the voice when stimulation is on. Some individuals prefer this to the usual medication-related side effects such as drowsiness, unsteadiness and fuzzy thinking. However, VNS usually does not render a patient fully seizure-free and off seizure medications. It may permit a reduction in medications. VNS is not curative therapy, and so it is not a substitute for other epilepsy surgeries that have a good chance to cure.

VNS is not advised if seizures are easily controlled by medicines. Our clinic finds VNS most useful for people who do not respond to or cannot tolerate medicines, but who are not candidates for curative surgery. Partial (focal) seizures are the types of seizures most studied, but VNS may be useful for other types of seizures as well.

In addition, studies are underway to evaluate possible benefit of VNS for depression, pain, headaches and various other conditions. If the VNS is not working, it usually can be removed (sometime the neck wire has to remain). Batteries fail after about 5 years, and require replacement in a minor operation.

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