Epilepsy and brain tumors: implications for treatment.

Primary intraparenchymal tumors of the brain are important etiologic factors in partial or focal epilepsy. Indolent low-grade gliomas may be associated with a long-standing seizure disorder refractory to medical treatment. Surgical resection of the neoplasm and the epileptogenic area may render patients seizure-free. Removal of the tumor alone may also be associated with an excellent survival rate and surgical outcome. Conventional neurosurgical procedures are restricted in patients with tumors that are deep-seated lesions or involve functional cerebral cortex. Computer-assisted stereotactic surgical procedures have been developed for biopsy and resection of intra-axial brain-mass lesions. Stereotactic tumor resection may allow pathological determination of intracranial lesions and produce a worthwhile reduction in seizure activity in some patients with intractable partial epilepsy.