摘要
Background:Hemispherectomy is an efective treatment option for patients with drug-resistant epilepsy caused by hemispheric lesions.However,patients often have deterioration of their motor functions postoperatively.Difusion spectrum imaging(DSI)was reliable in presenting the natural shape of the white matter fbers.At the same time,the natural sprawl pyramid tract(PT)might be more intuitive for predicting postoperative motor functions.Therefore,we assessed the motor functions by the natural shape revealed by DSI tractography.Methods:Ten children with drug-resistant epilepsy who were candidates for hemispherectomy performed DSI PTs tractography and transcranial magnetic stimulation(TMS)for motor mapping.The motor function was evaluated with muscle strength and hand grasping capability.Pyramidal tract(PT)structural integrity and TMS mapping results were compared between patients who remained stable and those with deteriorated motor functions.Receiver operating characteristic(ROC)curves with PTs asymmetric ratio were analyzed to evaluate DSI tractography diagnostic value.Results:All patients underwent DSI acquisition,while four patients successfully performed TMS.One patient had no response to TMS until the maximal machine output was reached.Four patients failed to perform TMS due to lacking cooperation.One patient was contraindicated to TMS.DSI successfully reconstructed the sharp angle fan-shaped PTs within the hemisphere.The accurate fber distribution with fber termination and thickness within the lesioned hemisphere was replicated with DSI tractography.No signifcance was found in patients’age,sex,seizure frequency,or medication between patients with stable or deteriorated postoperative motor functions.DSI efectively predicted postoperative motor function as stable with damaged PTs,mild deterioration with atrophied PTs,and intact PTs with contralateral innervation confrmed by intracranial stimulation.The area under the curve(AUC)of DSI tractography was 0.84.According to ROC,the cut-of value of PTs asymmetric ratio was 11.5%with 100%sensitivity and 75%specifcity.The sensitivity and specifcity of TMS were 2/3 and 1/2,respectively.Conclusions:The anatomic integrity of PTs with DSI tractography could efectively predict postoperative motor function after hemispherectomy.This enables neurosurgeons to inform patients and relatives about postoperative motor functions with direct morphological evidence of PTs to help them with their surgical decisions.
基金
This work was supported by the National Natural Science Foundation of China(81871009,81801288)
the National Key R&D Program of China(2016YFC0103909)
the Translational and Application Project of Braininspired and Network Neuroscience on Brain Disorders,Beijing Municipal Health Commission(11000022T000000444685).
