Cognitive decline and white matter changes in mesial temporal lobe epilepsy

Area of Science:

• Neuroimaging
• Epilepsy Research
• Cognitive Neuroscience

Background:

• Noninvasive imaging is crucial for assessing brain changes in presurgical mesial temporal lobe epilepsy (MTLE).
• Understanding the relationship between white matter (WM) alterations and cognitive function in MTLE is vital for patient management.

Purpose of the Study:

• To investigate the association between cerebral white matter (WM) changes and cognitive functions in MTLE patients.
• To explore the utility of MRI-based metrics for lateralizing seizure foci and understanding cognitive deficits.

Main Methods:

• Voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS) MRI were used on 24 MTLE patients and 12 controls.
• Gray matter, white matter, and whole brain volumes were measured using VBM.
• Diffusion tensor imaging (DTI) parameters (FA, MD, AD, RD) and cognitive function (MoCA) were assessed.

Main Results:

• MTLE patients showed significantly lower WM volume and WM/WB ratio compared to controls.
• Reduced WM volume positively correlated with MoCA scores and negatively with epilepsy duration.
• Decreased fractional anisotropy (FA) and increased mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were observed in MTLE patients, with more bilateral changes in left MTLE and ipsilateral in right MTLE.

Conclusions:

• Cerebral white matter (WM) volume and diffusion parameters are altered in MTLE patients, correlating with cognitive function.
• MRI findings provide insights into lateralization of the seizure focus and the physiological basis of cognitive disorders in MTLE.