The Fantastic and Bizarre in Neuroscience Annals

The operation known as hemispherectomy—where half the brain is removed—sounds too radical to ever consider, much less perform. In the last century, however, surgeons have performed it hundreds of times for disorders uncontrollable in any other way. Unbelievably, the surgery has no apparent effect on personality or memory.

The first known hemispherectomy was performed on a dog in 1888 by German physiologist Friedrich Goltz. In humans, neurosurgeon Walter Dandy pioneered the operation at Johns Hopkins University in 1923 on a brain tumor patient. (That man lived for more than three years before ultimately succumbing to cancer.) The procedure is among the most drastic kinds of brain surgery—"You can't take more than half. If you take the whole thing, you've got a problem," Johns Hopkins neurologist John Freeman quips.

This video addresses a different type of brain surgery.