The Clinical Efficiency Of PET In Localization Of Temporal Lobe Epilepsy With Negative Cranial MRI

BackgroundTemporal lobe epilepsy(TLE)is the most common type of adult focal epilepsy in clinical practice,accounting for 70%-80% of refractory epilepsy.The long-term prognosis of surgical treatment is preferable.At present there are still about 30% of TLE patients,of whom it is difficult to find obvious structural abnormalities through cranial magnetic resonance in clinic.It increases the difficulty of assessing the potential epileptogenic focus before surgery,and it is difficult to predict postoperative efficacy.Positron emission tomography(PET)is currently used as a novel non-invasive neurological imaging examination.It is often used in preoperative evaluation of epileptic patients to localize the epileptogenic focus,especially when the skull MRI was negative.Objective(1)To evaluate the accuracy and sensitivity of preoperative application of PET in the localization of epileptogenic focus in cranial MRI-negative TLE patients.(2)To evaluate the feasibility of multiple modality preoperative evaluation system in selecting operative indications and predicting and evaluating surgical outcomes.MethodsRetrospective analysis of 120 patients with TLE who were clinically diagnosed with anterior temporal lobectomy(ATL).All patients had complete cranial MRI,video electroencephalography(VEEG),and PET and other relevant inspection information.ATL was performed after comprehensive multidisciplinary preoperative assessment.Engel's grading method was used to evaluate the efficacy of the surgery.(1)By comparing the postoperative efficacy differences of PET(+)combined with MRI(-)group and PET(+)combined with MRI(+)imaging group,evaluate the accuracy and sensitivity of epileptogenic focus in PET-posited TLE patients with negative cranial MRI;(2)Compared with MRI negative group,the accuracy of PET and VEEG-induced epileptic foci in patients with Engel I surgery reached postoperative efficacy;(3)To evaluate the accuracy of preoperative evaluation of different modality for predicting and evaluating the efficacy of surgery by comparing the surgical efficacy of preoperative PET and VEEG in the MRI negative group.Results(1)With 42 cases of MRI Negative Group and 78 cases of MRI Positive Group,VEEG monitoring all found abnormal epileptic discharge wave and PET brain imaging all had abnormal metabolic change(obviously low metabolic region)during the attack.After the follow-up,30 patients with Engel I were graded,accounting for 71%,and 12 patients with Engel II-IV grade were present,accounting for 29%.A total of 78 TLE patients with PET(+)combined MRI(+)were enrolled.56 patients with Engel I were followed up,accounting for 72%,and 22 patients with Engel II-IV,accounting for 28%.There was no significant difference(P>0.05).(2)Among the 42 MRI-negative patients,30 were Engel I grades after follow-up,accounting for 71% of the total.Comparing PET and VEEG positioning respectively,PET positioning accuracy(90%)is higher than VEEG(56%).There was significant difference(P<0.05).(3)When the cranial MRI is negative,PET and VEEG positioning can significantly improve the surgical efficacy of epilepsy.Conclusions(1)PET localizing the position of the epileptogenic focus has a higher sensitivity and accuracy,especially for the skull MRI-negative TLE patients.It can significantly increase the positive detection rate and improve the efficacy of surgery.(2)PET,VEEG,MRI have a certain value in the localization of epileptic foci,when the head MRI is negative,the operation effect is remarkable when PET and VEEG are in the same position.