The Epilepsy Surgery Program at the Georgia Health Sciences University is a major southeastern referral center that offers complete evaluation and surgical treatment for appropriate patients whose seizures remain poorly controlled, despite use of anti-seizure medications. The program was established in 1981 under the guidance of Dr. Herman F. Flanigin, one of Wilder Penfield's students at the Montreal Neurological Institute, with whom he published the landmark paper on temporal lobectomy [Penfield, W. & Flanigin, H. (1950). Surgical treatment of temporal-lobe seizures. Archives of Neurology and Psychiatry]. More than 1,000 operations for seizure control, and over 400 recording electrode implants, have been performed at GHSU since the program's inception in 1981, making it one of the most experienced programs in the country.
A number of different pathologic circumstances can result in seizures, including brain tumors, vascular malformation, hemorrhages, strokes, abscesses, trauma (bullet and missile-type wounds, blunt trauma), scarring (mesial temporal sclerosis, previous stroke or hemorrhage, for example), and abnormally formed brain tissue (cerebral dysgenesis).
Epilepsy evaluations are typically geared toward corrective surgery for patients with presumed mesial temporal sclerosis, benign brain tumors, and other lesions.
Surgical Procedures and Outcomes
Surgical success depends on the type of surgery, but most patients experience a substantial improvement with regard to seizure intensity, seizure frequency, and seizure duration. Surgery generally requires a variable hospital stay, including a period in the neuro-intensive care unit immediately following the procedure. Patients return to GHSU for initial follow-up after their release from the hospital. Patients are referred back to their primary care or referring physician for long-term care.
Terminology and Definitions
Anterior temporal lobectomy -- removal of the anterior temporal lobe including the medial temporal structures; Approximately 80 percent of patients who have an anterior temporal lobectomy are seizure-free, or nearly so, one year following surgery, and 90 percent show marked improvement.
Extratemporal resection -- removal of epileptogenic cerebral cortex outside the anterior temporal lobe. Fifty percent are seizure-free one year following extratemporal resections.
Functional hemispherectomy -- removal of the majority of one cerebral hemisphere and functional disconnection of the remainder of the hemisphere in patients with severe unilateral damage and intractable epilepsy.
Hemispherotomy -- a recent modification of hemispherectomy in which the damaged, epileptogenic hemisphere is disconnected rather than removed. It is a much shorter operation than hemispherectomy, and is ideally suited for patients with significant atrophy of the damaged hemisphere. A large percentage of patients, previously thought to be candidates for hemispherectomy may undergo this procedure. Seventy percent of patients who undergo hemispherectomy are seizure-free postoperatively, and nearly all are improved.
Corpus callosotomy -- sectioning of the corpus callosum to disconnect the two hemispheres and prevent the spread of seizures from one hemisphere to the other. More than 50 percent of patients who have a corpus callosotomy are substantially improved.
Multiple subpial transection - transection of the cortex without removal when the epileptogenic zone is in a functionally important or eloquent brain region. The technique of multiple subpial transection is effective in decreasing seizures without causing a neurological deficit.
Vagal nerve stimulation -- involves implantation of a stimulating electrode around the left vagal nerve and attaching it to a pulse generator which is implanted under the skin just below the collar bone. The pulse generator is programmed so that it may be turned on or off at specified times and so that the amplitude and frequency of stimulation can be modified as indicated. Certain patients with partial or generalized seizure disorders benefit significantly from vagal nerve stimulation (VNS) -- approximately 40-45% of patients experience a 50% reduction in seizure frequency.
Gamma Knife -- for selected brain tumor patients with epilepsy.