fs at cs.tulane.edu (Frank Silbermann) writes:
>A few weeks ago CNN described an operation for babies/todlers
>with uncontrollable epilepsy.
>About 35 of these small children were diagnosed as having abnormalities
>on one side of the brain only. The doctors removed or disconnected
>the abnormal side of the brain. About 80% were then completely
>free of seizures. Children once expected to be profoundly retarded
>began developing fairly normally. The doctors said that in small children
>the healthy half of the brain will take on most of the functions
>of the removed/disconnected half.
>I am curious as to what sort of long-term disabilities associated
>with children who have had this operation. Can they indeed
>become truly normal, or are there certain abilities that
>cannot be transferred to the other side?
These babies are born with a big arterovenous malformation in one cerebral
hemisphere; the neurons get starved for oxygen because of the shunting of
oxygenated blood directly into the veins. For some decades, neurosurgeons
have been removing those blood vessels and the attached cerebral cortex,
leaving the subcortical structures. IF the operation is done early
enough, the kids develop surprisingly normally, i.e., they are not
paralysed on the opposite side of their body as you might expect. The
surviving hemisphere seems to operate both sides of the body.
Kids with a remaining left hemisphere have some spatial-knowledge
deficits but normal language. Kids with only a right hemisphere have
seemingly normal language; there are deficits but they are subtle. See
the article by M. Dennis and Harry Whittaker in BRAIN AND LANGUAGE 3:404
William H. Calvin WCalvin at U.Washington.edu
University of Washington NJ-15
Seattle, Washington 98195 FAX:1-206-720-1989