Widespread white matter DTI alterations in mesial temporal sclerosis independent of disease side

Area of Science:

• Neuroimaging
• Neurology
• Medical Physics

Background:

• Mesial temporal sclerosis (MTS) is a common cause of epilepsy.
• Understanding white matter (WM) integrity in MTS is crucial for diagnosis and treatment.
• In vivo evaluation of WM in MTS patients is essential.

Purpose of the Study:

• To evaluate white matter (WM) integrity in vivo in patients with unilateral mesial temporal sclerosis (MTS).
• To compare diffusion tensor imaging (DTI) findings between patients with left-sided MTS (L-MTS) and right-sided MTS (R-MTS) and controls.

Main Methods:

• Diffusion tensor imaging (DTI) was performed on 14 L-MTS patients, 13 R-MTS patients, and age/gender-matched controls using a 1.5-T scanner.
• Tract-based spatial statistics (TBSS) analysis was used to identify fractional anisotropy (FA) abnormalities.
• Mean (MD), radial (RD), and axial diffusivities (AD) were projected onto the FA skeleton.

Main Results:

• Patients with MTS exhibited decreased FA in widespread WM tracts compared to controls.
• Extensive areas of increased RD were observed bilaterally in MTS patients, independent of disease side.
• Significant overlap was found between areas of decreased FA and increased RD.

Conclusions:

• Diffusion tensor imaging (DTI) reveals abnormalities in white matter (WM) tracts within and beyond the temporal lobe in patients with MTS.
• Both L-MTS and R-MTS patients present extensive bilateral WM abnormalities compared to controls.
• MTS pathology appears to involve diffuse WM tract dysfunction, even in regions not directly connected to the hippocampus.