COMMENTARY - HOW HAS NEUROIMAGING IMPROVED PATIENT-CARE

Neuroimaging has significantly altered the management of patients with partial epilepsy. Magnetic resonance imaging (MRI) has been demonstrated to be a reliable and accurate indicator of the common pathologic findings underlying a partial seizure disorder. Intracranial mass lesions have been shown to be highly coherent with the localization of the epileptogenic zone. An MRI-identified epileptogenic lesion affects the selection of patients for epilepsy surgery and alters the diagnostic evaluation and the operative strategy. The results of the MRI preoperatively have prognostic importance in patients undergoing surgical treatment for partial epilepsy. Patients with lesional epileptic syndromes are considered favorable candidates for surgical ablative treatment. Hippocampal volume studies may predict the neurocognitive outcome in patients undergoing temporal lobe surgery. The use of MRI has resulted in a reduction in chronic intracranial EEG monitoring at most epilepsy centers, especially in patients with lesional pathology. MRI may be a reasonable initial ''screening'' procedure in selected patients with intractable partial epilepsy before consideration of a presurgical evaluation. A classification of partial epilepsy is proposed, based on the results of MRI, that may be useful for patients being considered for surgical treatment. Importantly, preoperative MRI must be correlated with the electrophysiologic studies and ictal semiology before decision-making regarding surgical therapy.