Functional MRI and the Wada test provide complementary information for predicting post-operative seizure control

Area of Science:

• Neurosurgery
• Epileptology
• Neuroradiology

Background:

• Predicting post-surgical seizure relief and cognitive deficits after anterior temporal lobectomy (ATL) is crucial for pre-surgical planning.
• The intracarotid amobarbital test (IAT) predicts seizure outcomes but is invasive; non-invasive methods are needed.
• Functional MRI (fMRI) was previously explored for evaluating mesial temporal lobe adequacy before ATL.

Purpose of the Study:

• To report 1-year follow-up seizure outcome data for temporal lobe epilepsy (TLE) patients who underwent ATL.
• To evaluate the predictive efficacy of pre-surgical functional memory lateralization using fMRI compared to IAT.
• To assess the combined predictive value of fMRI and IAT for post-ATL seizure control.

Main Methods:

• Evaluated eight TLE patients pre-surgically using both IAT and fMRI.
• Assessed functional memory lateralization via fMRI to determine relative mesial temporal lobe functional adequacy.
• Collected 1-year post-operative seizure outcome data for all participants.

Main Results:

• Functional memory lateralization using fMRI predicted post-ATL seizure outcome as effectively as the IAT.
• Hemispheric asymmetry of functional mesial temporal lobe (mTL) activation favoring the non-epileptic side correlated with seizure-free status at 1 year.
• Combining fMRI and IAT data provided complementary information, enhancing the prediction of post-operative seizure control.

Conclusions:

• fMRI is a viable, non-invasive tool for predicting seizure relief after ATL in TLE patients.
• fMRI-based functional memory lateralization shows comparable predictive power to the IAT.
• Integrated use of fMRI and IAT offers superior prediction accuracy for post-surgical seizure outcomes.