Metabolic differences in the contralateral hippocampus of concordant and discordant mesial temporal sclerosis (MTS) patients: evaluation with proton magnetic resonance spectroscopy (1H-MRS)

Abstract

PURPOSE: Patients with mesial temporal sclerosis (MTS) are clinically classified as concordant or discordant according to the extent of epileptogenic activity. The aim of this study is to determine whether the metabolic changes in the hippocampus are different in the two groups. MATERIALS AND METHODS: 33 patients diagnosed with MTS, 23 concordant (33±9 years old) and 10 discordant (33±10 years old) and 28 controls (33±10 years old) were evaluated. We obtained magnetic resonance spectroscopy of both hippocampi (ipsilateral and contralateral) on a 3T scanner with single voxel PRESS sequence with TE/TR=135/1500ms. The main metabolites were quantified with LC Model. For comparison between groups statistical tests were performed with a significance level of 0.05. RESULTS: In all patients a reduction of NAAipsi and Cr ipsi was observed, when compared to the contralateral side, but this difference was only significant for the group of concordant patients. In comparison with controls a significant reduction of Cr ipsi and NAAipsi was observed for both groups and for Naa/Cr ipsi in the group of concordant patients while NAA/Cr contra was reduced only in the group of discordant patients. CONCLUSION: Our findings suggest a stronger decline of NAA/Cr ipsi in the group of concordant patients and of NAA/Cr contra in discordant patients, suggesting a slightly different metabolic pattern for both groups. However, we need to increase the sample size to confirm these findings.