Beth Benoit asks: |One thing that I haven't been able to find the answer to - but I'll bet |someone on TIPS knows - is why, in severe epilepsy or seizure disorders, |sometimes the corpus callosum is cut and sometimes - in the cases I've seen |it was in children - a hemispherectomy is done. Cutting the corpus callosum |seems so much less radical than removing some or all of one of the |hemispheres of the brain. Obviously, neither is wonderful, but what are |indications for one over the other?
My recollection for this choice is that in some cases, seizure activity that is initiated in one hemisphere is transmitted to mirror sites in the opposite hemisphere. By severing the corpus callosum, the seizure activity is limited to one hemisphere, thereby limiting the severity of the overall seizure. This recruitment of seizure activity in the opposite hemisphere doesn't happen in all cases of seizure activity, which would influence the decision. The decision to remove the tissue in which the seizure activity originates sometimes depends on what that tissue normally does. If it is an important function, the trade-off between loss of function and reduction of seizure activity must be weighed. With children, there is the potential for the remaining hemisphere to take over functions lost. I recall a case of a complete left hemispherectomy (with only the cerebellum left on one side). As an adult, the woman had fairly normal cognitive function, including language, although she was said to have difficulty with mathematics, I think. I don't recall the pattern of functionality for motor control. Claudia J. Stanny, Ph.D. Director, Center for University Teaching, Learning, and Assessment Associate Professor, Psychology University of West Florida Pensacola, FL 32514 - 5751 --- To make changes to your subscription contact: Bill Southerly ([EMAIL PROTECTED])
