Hemodynamic Study Of Double Epileptic Foci In Cerebral Cortex Of Anesthetized Rabbits

Background and objectives: Intractable epilepsy drugs can not be relieved,surgical treatment is the only solution to some intractable epilepsy.The operation of multifocal epilepsy is often difficult because it is difficult to determine the number and location of epileptic foci.In clinical practice,electrophysiological records and brain functional imaging are the decisive basis for the localization of epileptogenic foci.Brain functional imaging is based on the mechanism of neurovascular coupling,through the changes of hemodynamic parameters to locate the epileptogenic focus..In this experiment,we simulated the clinical multiple epileptic foci,used the endogenous signal optical imaging technology to detect the hemodynamic changes of neocortex under the status of epilepsy in different distance of dual epileptic foci,and observed the differentiation of multiple epileptic foci in small distance.Optical imaging technology has micron spatial resolution and high time resolution.This data can be used for reference in the interpretation of functional imaging data of epilepsy,and for reference in intraoperative positioning.Methods:In urethane anesthetized rabbits,4-aminopyridine(4-AP,15mm)was used to induce epileptogenic seizures at different locations,and local field potentials(LFP)were recorded by Microglass electrode,while the time-space changes of cerebral blood volume(CBV)were recorded by endogenous optical imaging.The program compiled by Matlab was used for image analysis,and spss20.0 was used for statistical analysis.Results: 1.In the early epileptic seizures,the time of the two epileptic foci with a distance of 4 mm is significantly different,which can distinguish the two epileptic foci.It is difficult to distinguish the late epileptic foci.In the early stage of epilepsy,most of the double epileptogenic foci with a distance of 6 mm and 8 mm can be distinguished from each other.2.In the late stage of epileptic attack,the change range of blood volume of the two epileptic foci increased and gradually merged into one,so it is impossible to distinguish the two epileptic foci from the blood volume imaging.3.In the case of distinguishing two epileptogenic foci,the onset time interval of epileptiform attack is shorter in the two epileptogenic foci with a distance of 4mm than in the two epileptogenic foci with a distance of 6mm and 8mm.Conclusion:In the model of double epileptogenic foci,two epileptogenic foci in the early stage are relatively independent,and two independent epileptogenic foci can be distinguished from the change of blood volume dynamics.The ability to distinguish early epileptic seizures is related to the location of two epileptogenic foci.The greater the distance,the greater the possibility of differentiation.In late epilepsy,two epileptogenic foci seem to merge into one,and it is impossible to distinguish two epileptogenic foci from the change of blood volume.In the distinguishable case,the greater the distance,the greater the difference of the starting time of blood volume between the two epileptic foci.Therefore,it can better guide the interpretation of double or multiple epileptogenic focus in function magnetic resonance imaging(f MRI)and further application in intraoperative localization.