LONGITUDINAL QUANTITATIVE HIPPOCAMPAL MAGNETIC-RESONANCE-IMAGING STUDY OF ADULTS WITH NEWLY-DIAGNOSED PARTIAL SEIZURES - ONE-YEAR FOLLOW-UPRESULTS

Purpose: We wished to establish whether hippocampal changes occur in 1 year in adults with newly diagnosed partial seizures and, if so, to i dentify possible causes and mechanisms. Methods: Thirty-six adult pati ents with newly diagnosed partial seizures underwent a magnetic resona nce imaging (MRI) scan of the brain including hippocampal volume and T -2 relaxation time (HCT2) measurement and had a follow-up quantitative MRI scan similar to 1 year after the baseline MRI scan. Results: At b aseline, 4 patients (11%) had hippocampal sclerosis (HS), 4 (11%) had abnormalities other than HS, and 28 had a normal MRI scan (78%). Twent y-three patients (64%) had recurrent seizures in the period between th e two MRI scans. One of the 4 patients with HS, who had daily seizures , had significantly increased HCT2 values on follow-up, possibly refle cting progressive hippocampal damage. None of the 32 patients with MRI findings other than HS at baseline progressed to HS on follow-up. How ever, 2 of the 32 patients had significant hippocampal changes, probab ly related to resolution of inflammatory swelling or edema after seizu res were controlled. Conclusions: Subtle changes in hippocampi can occ ur in 1 year in adults with newly diagnosed partial seizures, which co uld be due to resolution of edema after seizure control or to hippocam pal changes associated with frequent and daily seizures. Follow-up of the studied cohort for several years will be required to settle the qu estion of whether progressive hippocampal damage occurs in temporal lo be epilepsy (TLE).