In vivo γ-aminobutyric acid alterations as a biomarker of the therapeutic effect of MRI-negative temporal lobe epilepsy

Current diagnosis of MRI-negative TLE relies on clinical history and EEG or IEEG. However, IEEG is invasive and fails to monitor therapeutic effects dynamically. It is necessary to screen for effective biomarkers. We used MEGA-PRESS technique to investigate role of GABA and other metabolic alterations in TLE. We demonstrated that GABA, NAA, NAA+NAAG, and Glu levels in MTL were significantly different between epileptic and contralateral sides, and increasing index of GABA values is associated with increasing index of seizure frequency. These findings suggested that GABA is an effective biomarker for lateralization and therapeutic effect monitoring in patients with MRI-negative TLE.