Does 7 T MRI offer an added value in drug resistant temporal lobe epilepsy?

To evaluate the added value of 7 Tesla (T) magnetic resonance imaging (MRI) in the presurgical assessment of patients with temporal lobe epilepsy (TLE), considering its overall impact on clinical decision-making, including both MRI-positive and MRI-negative cases, and its timing during the evaluation process.

Sixty-one patients with drug-resistant TLE, enrolled in this study underwent both 3 T and 7 T MRI, along with other diagnostic assessments (video electroencephalography, positron emission tomography, stereo electroencephalography). Patients were categorized into three phases of the presurgical evaluation: basic, intermediate, and advanced. The added value of 7 T MRI was assessed based on its ability to confirm, exclude, or detect new epileptogenic lesions, as well as its influence on surgical decision-making.

7 T MRI provided added clinical value in 51 % of cases, improving lesion detection and contributing to clinical decisions, particularly in patients with unclear or ambiguous findings. In some instances, it confirmed previously suspected lesions or revealed previously undetected lesions, leading to surgical interventions. It also helped exclude possible lesions, influencing decisions to avoid unnecessary surgery. Notably, hippocampal malrotation (HIMAL) was identified in several patients, warranting further investigation regarding its potential epileptogenic role.

7 T MRI enhances the presurgical evaluation of TLE by improving lesion detection, clarifying ambiguous findings, and aiding clinical decision-making. Its use should be considered at various stages of the evaluation process, as it offers valuable diagnostic information for both MRI-positive and MRI-negative patients. Further research is needed to explore the possible epileptogenic significance of HIMAL.