Resting-state functional MRI distinguishes temporal lobe epilepsy subtypes

Area of Science:

• Neuroimaging
• Epilepsy Research
• Functional MRI

Background:

• Distinguishing between temporal lobe epilepsy with (TLE-MTS) and without (TLE-noMTS) mesial temporal sclerosis is crucial for presurgical planning.
• Presurgical evaluation often relies on structural MRI, but functional imaging may offer additional diagnostic value.

Purpose of the Study:

• To determine if presurgical resting-state functional magnetic resonance imaging (fMRI) can differentiate TLE-MTS from TLE-noMTS.
• To assess the utility of fractional amplitude of low-frequency fluctuations (fALFF) as a marker of regional brain integrity in TLE.

Main Methods:

• Resting-state fMRI was performed on 34 TLE patients and 34 controls.
• fALFF, BOLD signal, volume, and cortical thickness were measured in five regions of interest.
• MTS status was histologically confirmed, and fALFF and hippocampal volume were regressed against MTS status.

Main Results:

• The TLE-MTS group showed reduced ipsilateral hippocampal and amygdala fALFF compared to controls.
• Ipsilateral hippocampal volume explained 37% of MTS status variance, while fALFF contributed an additional 10%.
• fALFF provided unique classification information for some MTS cases not captured by volume alone.

Conclusions:

• Resting-state fMRI, specifically fALFF, provides complementary functional information for classifying MTS in TLE.
• fALFF is a valid measure of regional brain integrity in TLE.
• Multi-modal imaging, combining structural and functional data, enhances presurgical epilepsy evaluation.