Epilepsy surgery is not considered unless seizures are not controlled with medications. The surgery has a likelihood of completely controlling the seizures from 50% to 95% of the time depending on the epilepsy syndrome treated and the operation performed. The benefit of epilepsy surgery is always much better than the circumstance of not pursuing the surgical management. So the decision to have epilepsy surgery usually is based upon consideration of the risks and complications associated with the surgery compared to the risks and complications and quality of life associated with continual uncontrolled seizures. The most important risk of epilepsy surgery is nonreversible injury to the brain due to intracranial hemorrhage (bleeding) or stroke. We discussed infection, which is also one of the most common complications above. But unlike infection, stroke or hemorrhage most often leaves the patient with a neurological deficit that may be disabling. This complication occurs in about 1% of the craniotomies performed. In two stage procedures, where two craniotomies are performed, the risk is therefore doubled, since each craniotomy is a separate risk. So two-stage procedures have a 2% risk for stroke or hemorrhage. In some cases, such as patients with previous brain surgery, patients with important associated medical problems, older patients (above 55 years old), or patients with a history of complications, the risk for stroke or hemorrhage or any other complication may be higher. A stroke or hemorrhage may result in a minimal problem or a severe permanent disability. Death is rare, not usually occurring as a direct consequence of the operation, but as a result of a surgical complication like pulmonary embolism (blood clot to the lung).
Though an individual seizure by itself is not very dangerous recurrent seizures do represent important accumulated risks over time. If the summed risk of recurrent seizures over 5 or 10 years is considered, then the risk to serious injury resulting in permanent disability is probably well over 1% or 2%, and for some people with epilepsy this is even higher. Therefore, the accumulated risk of refractory epilepsy can be comparable to, if not worse than, the acute risk of epilepsy surgery. The increased risk of sudden death, decreased life expectancy, the adverse effects of high anticonvulsant doses on body organs and the brain, which are all associated with refractory epilepsy is also considered in the accumulated risk of refractory epilepsy. But most often the poor quality of life associated with recurrent uncontrolled seizures is what most patients consider when they compare the adverse effects of seizures to the risks of epilepsy surgery. Since epilepsy surgery is usually considered only if there is no other viable treatment to control refractory epilepsy, the benefit of epilepsy surgery, that is, the complete control of seizures, is always better than not performing epilepsy surgery.