Proton magnetic resonance spectroscopy for the prediction to drug responsiveness of mesial temporal lobe epilepsy according to ILAE definition.

OBJECTIVE

Approximately 30-40% of patients with mesial temporal lobe epilepsy (MTLE) develop drug resistance, yet conventional MRI measures lack sufficient accuracy for early identification of drug-resistant cases. Proton magnetic resonance spectroscopy (1H-MRS), as a non-invasive technique, enables quantitative assessment of neurometabolic alterations in epileptogenic regions. We hypothesized 1H - MRS may assist in distinguish ASM responsiveness of newly diagnosed MTLE patients and aimed to establish clinically neuroimage actionable biomarkers.

METHODS

This prospective study recruited 195 newly diagnosed MTLE patients (aged 15-65 years) meeting inclusion/exclusion criteria. Collected data included demographics, seizure characteristics, interictal epileptiform discharge (IED) distribution, and hippocampal N-acetylaspartate/(Choline+Creatine) [NAA/(Cho+Cr)] ratios. After follow-up, patients were classified as drug-responsive (Group I, n=80), drug-resistant (Group II, n=32), or undefined (Group III, n=30). Variables with univariate significance (p<0.1) - including age, duration of epilepsy, epilepsy frequency, IED distribution, hippocampal asymmetry indices (right-left AI, IED ipsilateral-contralateral AI) and NAA/(Cho+Cr) - underwent binary logistic regression analysis.

RESULTS

Univariate analysis showed significant differences in right-left asymmetry index (-0.09±0.51 vs 0.16±0.34, p=0.02) and IED ipsilateral-contralateral asymmetry index (-0.04±0.32 vs 0.14±0.26, p=0.01) of hippocampal head between group II and group III, and differences in right-left asymmetry index of hippocampal tail between group I and group III(-0.04±0.32 vs 0.14±0.26, p=0.01). In multivariate logistic regression models (adjusting for variables with p < 0.1 in univariate analysis), only the right-left AI of the hippocampal tail remained statistical importance (Group I vs III: OR=6.97, p=0.049). Furthermore, age > 35 years, moderate seizure frequency, longer epilepsy duration, right-sided and bilateral IEDs were identified as significant independent predictors of drug resistance.

CONCLUSION

The study suggested that hippocampal metabolism was more severely and extensively disrupted in drug-resistant MTLE. 1H-MRS may provide prognostic value for drug responsiveness in patients with newly diagnosed MTLE but further investigations are needed to validate these findings.