What is a Hemispherectomy?

For epileptic patients who do not get satisfactory results with drugs, surgery may become the only recourse. Although there are several types of epileptic surgery available, there are few more radical or surprising than the hemispherectomy. Typically performed on very young children, a hemispherectomy is the removal of one half of the brain to reduce or prevent epileptic seizures. This procedure is relatively rare, and can have surprising rates of success and recovery.

Epileptic seizures can occur due to many different brain disorders. Patients who can be considered for hemispherectomies usually suffer from seizures that occur on one side of the brain only. Hemispherectomies are generally performed on patients who have not responded well to several different drug therapies, although time and age are also major factors in the decision. Most evidence suggests that the younger a child is, the more normal brain function can be recovered post-surgery. For this reason, people over the age of 14 rarely undergo the procedure.

It may seem impossible that a brain could function normally after half of it has been removed, yet the procedure can leave a substantial part of ability intact or even improved. Personality, language and memory are almost never damaged or changed by a hemispherectomy. Particularly in young children, the remaining half of the brain adapts to perform the functions of the removed half. In addition, nearly all who successfully undergo the surgery will have a significant decrease in seizure activity, and some evidence suggests that more than half will stop seizing entirely.

There are naturally risks and side effects to such an extreme surgical procedure. According to many experts, almost all patients will experience partial paralysis on the side of the body that corresponds with the removed hemisphere of the brain. Although walking and use of arms may be possible, hand, finger, and foot movement are usually restricted and may become permanently numb.

As with almost all surgical procedures, there are also risks of complications associated with a hemispherectomy. Swelling or bleeding can occur in the brain during or after the surgery. If performed incorrectly, the remaining side of the brain can experience some damage. Vision may become blurry or affected, and some retardation of mental capabilities is possible. Short-term side effects include weakness, depression, language problems, and exhaustion.

Without complications, recovery from a hemispherectomy can be relatively short. Patients who experience a healthy recovery may leave the hospital within a week, and may return to normal activities within two or three months. Naturally, monitoring is extremely important during this time to measure brain function and possible occurrence of seizures. Patients may need to remain on seizure medication even following the surgery, though seizures will likely be few and far between.