Motor Function Evaluation By Using TMS-MEP And Its Safety Study After Rats Getting Brain And Spinal Cord Injury

【Background】With the rapid development of economic construction and the transportation industry, thereare more and more craniocerebral traumas occurring during the past several years. After thespinal cord injury caused by preliminary magnetic stimulation, experiments on this aspecthave been held and discussed. However, as for cerebral trauma, there are no specificmodels and experiments. Transcranial magnetic stimulation is clinically applied to treatingmental diseases and nerve dysfunction, which has made certain achievements. In clinicalforensic medicine, preliminary experiments proved that there is significant correlationbetween the amplitude of motor evoked potential and the BBB scores. Meanwhile, thesafety issues concerning TMS, inclusing TMS experimental animals and the applicationsafety, need to be re-assessed. From two aspects, namely the assessments of TMS on animalsafety and related effects and the assessments of unexpected effects, this thesis makesdetailed elaborations. And proposals about TMS application have been raised. This thesisaims at applying TMS-MEP to assessing human motion function and providing safetyconfirmation for objective strength determination in forensic medicine.【Objective】Observe the variation characteristics of TMS-MEP wave pattern, incubation period,amplitude and motion function after rats getting brain injury and spinal cord injury. Observe different indexes of rats and assess its application safety.【Materials and methods】(1) Select60healthy adult SD rats with weight of200-300grams. Randomly divide theminto normal control group (10rats in total and conduct pathological observation on1rat), brain injury group A (heavy hit group,10rats in total and conduct pathologicalobservation on1rat), brain injury group B (TMS group,20rats in total and conductpathological observation on5rats) and both brain and spinal cord injury group (20ratsin total and conduct pathological observation on1rat).(2) Every day, each group records TMS-MEP of gastrocnemius muscle under thetranscranial magnetic stimulation of50%,70%and90%. Observe general behaviors ofrats during the experiments and the overall health and general health of rats after theexperiments. Each group takes5rats to examine the blood biochemical indexes. After3or4weeks, conduct statistical analysis on TMS-MEP results of left lower limbgastrocnemius muscle in rats and figure out the relationship between TMS-MEP andmotion functions after rats having brain injuries.【Results】(1) After rats having brain injuries, MEP incubation periods and amplitude of group B doesnot have significant changes compared with normal control group (p>0.05).(2) It is difficult to draw MEP wave pattern of rats in both brain and spinal cord injurygroup.(3) Under the stimulation of50%,70%and90%, MEP incubation period of all groupsshortens and amplitude increases.(4) Brain injury group A and brain injury group B do not have significant changes in bloodbiochemical indexes.(5) As for the brain injury group B, there is no hemorrhage and obvious edema under HE staining light microscope【Conclusion】(1) TMS-MEP can be used objectively evaluate the muscle of the central movementdysfunction.(2) Under certain conditions and within safety ranges, transcranial magnetic stimulation isa safe, painless, simple and convenient test method.