Patients considering epilepsy surgery should meet the following requirements:
- Medically intractable seizures: an established diagnosis of epilepsy with failure to achieve control using two to four major anti-epileptic drugs (AEDs) and repeated disabling seizures.
- Partial seizure disorder: diagnosed with a localized or partial seizure disorder based on continuous video EEG monitoring and characterization of the seizures. The signs and symptoms are localized to an area of the brain. These patients make ideal surgical candidates and have a high probability of a seizure-free outcome, especially if all the seizures come from one temporal lobe.
- Space-occupying lesions: Surgical treatment is usually determined by the location and size of the lesion, rather than by the epilepsy's symptoms.
- Cognitive impairment or psychosis.
- Lack of serious medical illness or neurological degenerative disease.
The surgical resection of brain tissue is based on findings that are made during an invasive, phase II investigation. Surgery is an option when the epileptic zone is well defined and no eloquent or vital cortex (areas that control motor function or language) are involved. Electrocorticography (ECOG) may be performed during the resection to avoid vital areas of the brain and localize the seizure origin.