Structural MRI findings and postoperative prognosis in patients with temporal lobe epilepsy: a retrospective cohort study

Abstract

The association between preoperative structural magnetic resonance imaging (MRI) and seizure freedom in Mexican patients with refractory temporal lobe epilepsy (TLE) undergoing surgery has not been reported. This study describes the hippocampal findings in preoperative structural MRI and their relationship with postoperative prognosis in Mexican patients with refractory TLE. This retrospective cohort study included patients older than 18 years with refractory TLE who underwent epilepsy surgery. The Harmonized Neuroimaging of Epilepsy Structural Sequences (HARNESS-MRI) protocol was used. Patients were followed for 24 months, and seizure freedom was determined based on the Engel classification. Forty-four patients with refractory TLE who underwent epilepsy surgery, 22 men and 22 women with a mean age of 35.2 ± 10.6 years (range 20 to 61), were assessed. Abnormal findings on preoperative structural MRI were identified in 36 patients. Hippocampal atrophy and increased signal on T2/FLAIR were the most common (n = 17, 47.2%). Seizure freedom was achieved in 30 (83.3%) of 36 patients. In contrast, only 4 (50%) of 8 patients with a normal preoperative structural MRI achieved seizure freedom (p = 0.042). This study is the first in Mexico that demonstrates the association between abnormal preoperative structural MRI findings and seizure freedom in patients with TLE undergoing epilepsy surgery.

Keywords

• Refractory temporal lobe epilepsy. Hippocampal sclerosis. Magnetic resonance imaging. Postoperative prognosis.