Hippocampal activations obtained during language fMRI tasks: A complementary tool for predicting postoperative memory...

Area of Science:

• Neurology
• Neurosurgery
• Radiology

Background:

• Medial temporal lobe epilepsy (MTLE) surgery carries a risk of post-operative memory decline.
• Predicting surgical outcomes using functional magnetic resonance imaging (fMRI) is valuable but requires refinement.

Purpose of the Study:

• To evaluate if fMRI language tasks can enhance memory fMRI predictions in MTLE patients.
• To assess the predictive value of hippocampal activations from fMRI tasks for memory outcomes.

Main Methods:

• Retrospective study of 46 MTLE patients (30 right, 16 left) with hippocampal sclerosis.
• Preoperative assessment included neuropsychological tests and fMRI (language and memory tasks).
• Postoperative memory was evaluated one year after surgery, defining worsening as >10% decline.

Main Results:

• Memory fMRI showed higher sensitivity (95%) for hippocampal activations than language fMRI (65%).
• When hippocampal activation occurred, language fMRI predicted memory outcomes more accurately (80% global, 65% verbal, 85% non-verbal) than memory fMRI (71%, 64%, 68%).
• Both fMRI tasks outperformed neuropsychological tests in prediction accuracy.

Conclusions:

• Language fMRI, while less sensitive for hippocampal activation, offers superior memory prediction when activation is present.
• Combining memory and language fMRI tasks is recommended for predicting post-operative memory outcomes in MTLE patients.
• Language fMRI is an independent predictive factor for memory outcomes, irrespective of the epileptic focus side.