Epilepsy and Functional Hemispherectomy
What Happens During a Functional Hemispherectomy?
A functional hemispherectomy requires exposing the brain using a procedure called a craniotomy. "Crani" refers to the skull and "otomy" means "to cut into." After the patient is put to sleep (general anesthesia), the surgeon makes an incision (cut) in the scalp, removes a piece of bone and pulls back a section of the dura, the tough membrane that covers the brain. This creates a "window" in which the surgeon inserts special instruments for removing brain tissue. Surgical microscopes are utilized to give the surgeon a magnified view of the brain structures. During the procedure, the surgeon removes portions of the affected hemisphere, often taking all of the temporal lobe but leaving the frontal and parietal lobes. The surgeon also gently separates the hemispheres to access and cut the corpus callosum. After the tissue is removed, the dura and bone are fixed back into place, and the scalp is closed using stitches or staples.
What Happens After a Functional Hemispherectomy?
The patient generally stays in an intensive care unit for 24 to 48 hours and then stays in a regular hospital room for three to four days. Most people who have a functional hemispherectomy will be able to return to their normal activities, including work or school in six to eight weeks after surgery. Most patients will need to continue taking anti-seizure medication, although some may eventually be able to stop taking medication or have their dosages reduced.
How Effective Is Functional Hemispherectomy?
About 85% of people who have a functional hemispherectomy will experience significant improvement in their seizures, and about 60% will become seizure-free. In many cases, especially in children, the remaining side of the brain takes over the tasks that were controlled by the section that was removed. This often improves a child's functioning and quality of life, as well as reduces or eliminates the seizures.
What Are the Side Effects of a Functional Hemispherectomy?
The following symptoms may occur after a functional hemispherectomy, although they generally go away over time and with therapy:
- Scalp numbness.
- Muscle weakness on the affected side of the body.
- Puffy eyes.
- Feeling tired or depressed.
- Difficulty speaking, remembering, or finding words.