Magnetoencephalographic Application Of Dynamic Magnetic Source Imaging In Patients With Refractory Temporal Lobe Epilepsy

Objective: Temporal lobe epilepsy(TLE)is a chronic disease of brain dysfunction caused by abnormal synchronous discharge of temporal lobe neurons,which is the most common refractory epilepsy.Surgical treatment significantly increases seizurefree outcomes,but epilepsy surgery is not effective in 30% of the patients.Magnetoencephalography(MEG)can be of great value in improving the efficacy of epilepsy surgery as a noninvasive exam method with high temporal and spatial resolution.Methods: MEG data of intractable temporal lobe epilepsy was analyzed by us to confirm its positive role in the preoperative evaluation and to obtain long-term seizure free periods by increasing the accuracy of identifying epileptogenic focus.Results: The results falls into two parts: topographic spectrogram analysis(TSA)and magnetic source imaging(MSI).TSA found that there is statistically significant differences in consistency between 4-30 Hz and 30-140 Hz frequency bands,the highest of which are 4-8 and 8-13 Hz frequency band,70.7%(29/41),compared to MRI with 62.5%(24/41).Seizure-free rate of 13-30 Hz frequency band is the highest,64.3%(18/28),MRI and EEG are 62.5%(15/24)and 51.4%(18/35).MSI has come up with similar results,which suggested the highest consistency of which is 4-8Hz frequency band with 54%,which is close to MRI with 58%.The highest seizure-free rate of which is 13-30 Hz frequency band with 75%,which is apparently higher than MRI with 63%.Conclusions: MEG is a valuable non-invasive tool which can locate epileptogenic focus before operation and help predict operative prognosis.