Lateralizing the affected side of hippocampal sclerosis with quantitative high angular resolution diffusion scalars:...

Area of Science:

• Neuroimaging
• Epileptology
• Diffusion Tensor Imaging

Background:

• Lateralizing seizure onset in mesial temporal lobe epilepsy (MTLE) presents diagnostic challenges during presurgical evaluations.
• Diffusion spectrum imaging (DSI) offers a quantitative approach to assess seizure involvement, but its accuracy requires further elucidation.

Purpose of the Study:

• To determine the lateralizing value of DSI indices in patients with MTLE.
• To investigate the sensitivity of DSI-derived metrics in differentiating affected brain regions.

Main Methods:

• Eleven MTLE patients and 11 healthy controls underwent DSI scans.
• Reconstruction of diffusion scalars including quantitative anisotropy (QA), isotropic (ISO), and track density imaging (TDI).
• Statistical analysis focused on differences between healthy/ipsilateral sides and patients/controls in key brain structures (FORX, PHCR, HP, PHC, AM, EC).

Main Results:

• TDI of the crura of fornix (FORX) and parahippocampal radiation of the cingulum (PHCR) achieved high AUC values (0.95 and 0.93) for lateralization.
• QA, ISO, and TDI of PHCR, along with TDI of FORX, showed significant lateralizing value in MTLE patients.
• Decreased diffusion was observed in the hippocampus (HP), amygdala (AM), and entorhinal cortex (EC) in MTLE patients.

Conclusions:

• Quantitative DSI scalars, especially TDI of FORX and PHCR, are sensitive indicators for defining the ipsilateral side in MTLE.
• Quantitative DSI holds potential to enhance localization and lateralization accuracy, potentially improving seizure outcomes in MTLE patients.