Safety and efficacy of a novel responsive neurostimulation system in China for drug-refractory focal epilepsy:The first-in-man study

To the Editor:Recent studies have characterized drugresistant epilepsy(DRE)as essentially a neural network disease.[1]Detection and disconnection of this pathological epileptic connectome or network can greatly improve seizure outcomes.Our team also proposes the development of the newly emerging branch of epileptic networks neurosurgery(ENN).Responsive neurostimulation(RNS)is an ENN-oriented emerging treatment option without the resection of the seizure-onset zone or epileptic focus and aims to control the seizure or other epileptic manifestations by modulating or disrupting the network’s key nodes(epileptic hubs)in a self-responsive way.

Critical thinking of Alzheimer's transgenic mouse model:current research and future perspective

Transgenic models are useful tools for studying the pathogenesis of and drug development for Alzheimer's Disease(AD).AD models are constructed usually using overexpression or knock-in of multiple pathogenic gene mutations from familial AD.Each transgenic model has its unique behavioral and pathological features.This review summarizes the research progress of transgenic mouse models,and their progress in the unique mechanism of amyloid-βoligomers,including the first transgenic mouse model built in China based on a single gene mutation(PSEN1 V97L)found in Chinese familial AD.We further summarized the preclinical findings of drugs using the models,and their future application in exploring the upstream mechanisms and multi-target drug development in AD.

Assessing structural integrity of the pyramidal tracts with difusion spectrum imaging to predict postoperative motor function in pediatric epilepsy patients with hemispherectomy

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.