Quantitative characterization of brain microstructure in Temporal Lobe Epilepsy: comparison with normative T1 atlas

Motivation: Quantification of microstructural T1 relaxometry alterations in mesial temporal lobe epilepsy (MTLE). Goal(s): To compare spatial patterns of deviation from normative ranges, accounting for age and sex, in patients with different clinical characteristics, potentially identifying quantitative correlates of drug-resistance in MTLE. Approach: Z-score maps of T1 relaxometry values were estimated using normative atlases accounting for age and sex. Distributions were compared after stratification of patients by response to treatment and presence of hippocampal sclerosis. Results: Large clusters of deviated z-scores were identified in drug-resistant patients, as well as in the hippocampus affected by hippocampal sclerosis. Impact: This study provides first evidence in support of using qMRI alterations as markers of drug-resistance in MTLE. Analysis using normative atlases accounting for age and sex allowed the identification of specific changes both at population and individual level.