The Role Of Amygdala Volume In Mesial Temporal Lobe Epilepsy

AimTo investigate the role of amygdala volume in presurgcial evaluation and surgical outcome prediction in patients with mesial temporal lobe epilepsy(mTLE).MethodsThirty six patients were diagnosed as mTLE after presurgical evaluation including clinical manifestations,video-electroencephalogram(V-EEG)and magnetic resonance imaging(MRI)at The Second Affiliated Hospital of Zhejiang University between March 2013 and March 2016.Bilateral amygdala volume index(AVI)was then calculated from amygdala volumes on MRI,which were measured with region of interest(ROI)analysis.All patients were treated surgically.Etiologies of mTLE were further confirmed by the histopathology of the resected tissue.The surgical outcomes were evaluated with Engel classification and patients were divided into two groups accordingly,seizure-free group(Engel ?)and non-seizure-free group(Engel ??Engel IV).Correlation analysis was performed between AVI and clinical features as well as etiologies.Logistic regression analysis was used to further evaluate predictors of surgical outcome.ResultsAmong the 35 patients,there is a strong correlation between AVI on the lesion side.and age of onset(Pearson correlation analysis r=-0.389;P = 0.019)as well as age of surgery(Pearson correlation analysis r=-0.357;P = 0.032).No obvious relation can be seen between AVI and gender,history of febrile convulsion,duration of epilepsy,secondary generalized seizure,side of lesion,presurgical seizure frequency and electrode implantation.For the etiologies,there are thirteen patients(37.1%)with focal cortical dysplasia(FCD),seven(20.0%)with hippocampal sclerosis(HS),four(11.4%)with cavernous hemangioma and two(5.7%)with nonspecific gliosis.There is no significant difference in AVI among the five etiologies.Atfollow-up,thirty patients(80.5%)reached seizure-free.Long duration of epilepsy is found to be the predictor of surgical failure(P<0.05).ConclusionThere is limited value of amygdala volume in the presurgical evaluation of mTLE.Early surgery is warranted once surgery is indicated for mTLE patients.