Memory dysfunction represents the most significant neurocognitive morbidity in patients with temporal lobe epilepsy (TLE) in the pre-operative and post-operative states. Present methods of pre-surgical evaluation are limited, because the intracarotid amobarbitol test (considered the gold standard of diagnostic tests) does not always correlate with the side of the temporal lobe lesion and hence, does not accurately predict whether patients will experience further neurocognitive decline in memory post-operatively. Patients with long-standing epilepsy may have variable anatomic localization of memory function because of cerebral reorganization induced by the disease process. Functional MRI (fMRI) has the unique potential to provide an accurate noninvasive means of assessing the integrity of memory related brain structures and elucidate reorganization of memory functions post-operatively. Broad, long term objectives: To utilize fMRI to improve the understanding of brain reorganization with respect to memory encoding in patients with temporal lobe epilepsy.
Specific Aims : 1) To use fMRI to determine the preoperative functional verbal and nonverbal memory encoding status in patients with temporal lobe epilepsy as compared to normal controls. 2)To compare the pre-operative and post-operative functional verbal and nonverbal memory encoding status of the brain in patients with temporal lobe epilepsy after a 1 year period post-operatively using fMRI metrics. 3) To investigate the relationship between functional activation and volumetric changes in the temporal lobes in patients with TLE pre- and postoperatively. At its conclusion, this data could have a real clinical impact on the preoperative decision-making in patients with TLE by predicting contralateral compensatory function, as well as tailoring the extent of the surgical resection itself.
