When the onset of seizures is correlated to an obvious lesion on imaging, controversy exists as to whether simple lesionectomy of the anatomic abnormality is a sufficient method for seizure-control.

While recent-onset seizures secondary to a rapidly growing neoplasm may respond well to lesion excision, a chronically active focus may not. The authors have in these instances have found that the seizure focus may be residing directly contiguous to the lesion or it may be remote from the lesion and the planned resection.

In new onset seizure group (< 1 year from onset), excision of the focus is recommended for diagnosis and treatment. Chronic seizures may occur but is not the thrust of treatment at the outset in these patients.

For chronic epilepsy, (seizures > 1 year), in general, the lesions themselves are often not producing the seizures, rather, the associated "irritated" cortex is. In these instances, there may not be an anatomical continuity of the lesion to the epileptogenic zone, but rather a functional one. It is therefore recommended that these patients undergo mapping of a definitive epileptogenic area through the recording of multiple ictal events invasively prior to resection particularly if anatomical and functional data do not adequately define the seizure focus with relationship to the lesion.