Epilepsy - Surgery

Hemispherectomy. Hemispherectomy is the removal of half the brain, leaving the deep structures intact. Surgery can take 12 hours and there is always some paralysis on one side of the body. There is also a small risk for hydrocephalus, coma, or even death. Quality of life is almost always improved, however, and the surgery does not reduce intelligence.

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Corpus Callosotomy. Corpus callosotomy involves cutting the nerve fibers that connect one side of the brain to another. It does not remove brain tissue. It may be done in two stages. In the first there is a partial separation. If seizures continue, then the surgeon may perform a complete separation. This surgery can reduce (although not entirely stop) uncontrolled tonic clonic seizures. The procedure has been used in patients with specific syndromes, such as Lennox-Gastaut syndrome. The procedure can have very severe complications, however.

Vagus Nerve Stimulation (VNS) and Other Neurostimulation Procedures

Electrical stimulation of areas in the brain that affect epilepsy is helping many patients with refractory epilepsy. Vagus nerve stimulation (VNS), an electrical stimulation of the vagus nerve, is now an accepted therapy for severe epilepsy that does not respond to AEDs. The two vagus nerves are the longest nerves in the body. They run along each side of the neck, then down the esophagus to the gastrointestinal tract. They affect swallowing, speech, and many other functions. They also appear to connect to parts of the brain that are involved with seizures. The procedure is as follows:

Click the icon to see a depiction of epilepsy treatment.

A battery-powered device similar to a pacemaker is implanted under the skin in the upper left of the chest.
A lead is then attached to the left vagus nerve in the lower part of the neck.
The neurologist programs the device to deliver mild electrical stimulation to the vagus nerve. (Patients may also pass a magnet over the device to give it an extra dose if they sense a seizure coming on. This appears to help about 25% to 30% of patients.)
The batteries wear out after three to five years and need to be removed and replaced by a simple surgical procedure.

An investigatory approach called deep brain stimulation targets the thalamus (which relays pain, temperature, and touch sensations to the brain). Early small studies are promising.

Candidates. The American Academy of Neurology now recommends VNS for the following: