Surgery was once an option only for adults with a long history of intractable seizures. Today, surgery is a widely accepted treatment for children with severe seizures. In fact, the ability of a child's brain to re-organize function following surgery makes younger people particularly good candidates for surgery. The side effects of antiepileptic drugs (AEDs) and the well-documented risk of developmental dysfunction among children who are given AEDs at an early age and for a long period of time are two other reasons why surgery may be considered.
There are several surgical procedures available to control the severity and/or frequency of seizures. The type of seizures a patient has and their location within the brain are important factors in determining which surgery is performed.
Vagal Nerve Stimulation
Vagal nerve stimulation is a possibility for some children with epilepsy. The body has two vagus nerves, one that travels up the left side of the neck and one on the right. One of the left nerve's jobs is to relay information to areas of the brain that are believed to produce seizures. When this nerve is stimulated by a low level of electrical current, some people find that their seizures are less frequent or less severe. Vagal nerve stimulation has most commonly been used for patients with partial seizures.
A small, battery-operated device called a vagal nerve stimulator can be surgically implanted in a person's body. It can be programmed to deliver stimulation at regular intervals, or it can be activated with a magnet when a patient anticipates a seizure. The surgery involves implanting the device's generator under the skin in the patient's upper left chest. A connecting wire is guided under the skin and attached to the vagus nerve, which is located on the left side of the neck. The operation lasts about two hours, and a common temporary side effect of the surgery is hoarseness, as the vagus nerve is located near the voice box. Sometimes people experience coughing or a tingling in their throat when the stimulator is activated; adjusting the amount of current can remedy this side effect.
The vagal nerve stimulator's effectiveness varies. Most patients can expect a 50 percent reduction in seizures, with others experience better or worse results. The device is not considered to be a cure, so patients generally continue taking anti-epileptic medication. In cases where the stimulator has proven highly effective, the doctor may decide that a patient's medications can be reduced.
Other Surgical Options
A temporal lobe resection, where part of the brain from which the seizure originates is removed, is commonly performed on adults and children alike.
Two procedures that are almost exclusively done on younger patients are corpus callosotomy (to relieve severe generalized seizures) and hemispherectomy. When seizures originate in one half of the brain and spread to the other, a corpus callosotomy can be performed to sever the neural connections between the brain's two hemispheres. This "disconnection" is not a cure, but it can reduce the severity of the seizures. Corpus callosotomy can also keep seizures from spreading to other areas of the brain. However, partial seizures may increase after surgery.
Hemispherectomy, the removal of about one-half of the brain, is reserved for children with severe, frequent, and often life-threatening epilepsy that cannot be controlled by medication. The seizures originate from one side of the brain, and typically, the child has some degree of paralysis on the opposite side of the body.
Removing half of someone's brain is a radical concept, and there could be some very serious complications, including fluid build-up in the brain, infection, and coma. There is permanent loss of hand mobility on the side opposite of the removed hemisphere and vision may also be affected. For many of these children, hemispherectomy significantly or completely controls seizures and enables the youngsters to function well with improved behavior and intelligence. Especially in younger children, the remaining half of the brain compensates for the missing half.