Hemispherectomy

Hemispherectomy is a surgical procedure where one cerebral hemisphere (half of the brain) is removed or disabled. This procedure is used to treat a variety of seizure disorders where the source of the epilepsy is localized to a broad area of a single hemisphere of the brain. It is reserved for cases which can't be managed with medication alone.

History and changes
Hemispherectomy was first tried on a dog in 1888 by Friedrich Goltz. The first such operation on humans was done by Walter Dandy in 1923. In the 1960s and early 1970s, hemispherectomy involved removing half of the brain, but this resulted in unacceptable complications and side effects in many cases, like filling of excessive body fluids in the skull and pressuring the remaining lobe (known as hydrocephalus). Today, the functional hemispherectomy has largely replaced this procedure, in which only the temporal lobe is removed; a procedure known as corpus callosotomy is performed; and the frontal and occipital lobes disconnected.

Results
All hemispherectomy patients suffer at least partial hemiplegia on the side of the body opposite the removed or disabled portion, and may suffer problems with their vision as well.

Most patients who have undergone this procedure will have neurons from the remaining hemisphere take over the tasks from the lost hemisphere by making new neural connections. One case, demonstrated by Smith & Sugar, 1975; A. Smith 1987, showed that one patient with this procedure had completed college, had attended graduate school, scored above average on intelligence tests. Another study done by Johns Hopkins University medical team, reflecting on 58 child hemispherectomies they performed, all the reports showed that most children continued on with little or no change to their memory, personality, and humor after removal of either brain hemisphere. (Vining & Others, 1997)