The Study On The Model Building Of Intracerebral Internal Capsule Hemorrhage And The Significance On The Evaluation Of The Nervous Functional Changes Through Somatosensory Evoked Potentials

Objective1. To establish the model of intracerebral internal capsule hemorrhage of rabbits.2. To evaluate the model of intracerebral internal capsule hemorrhage of rabbits.3. To evaluate the changes of nervous function through exploring the changes of SEP before and after internal capsule hemorrhage and make an important reference for the early diagnosis and clinical treatment of internal capsulehemorrhage. Methods:1. Preparation of intracerebral internal capsule hemorrhagic animal model:Anesthetized rabbits with 25% Urethane,fixed it on the stereotaxis instrument. According to the brain stereotaxic atlas, located the hind limb of internal capsule through stereotaxis instrument. An operation was made to open the skull by auger, 0.5 ml autologous arterial blood was injected into the hind limb of internal capsule through microinjector, then we made the acute internal capsule hemorrhage animal model.2. Measurement of SEP: Located the recording point of SEP in cerebral cortex, which was the projection of sensation of rabbit's left leg, through stereotaxis instrument. Separated the posterior tibial nerve of rabbit's left leg. Connected recording electrode, reference electrode, ground electrode, exciting electrode with RM-6240B biological signal collecting and processing system, measured rabbit's SEP before and after internal capsule hemorrhage.3. Measurement of SEAB: Fixed recording electrode in the position of cerebralcortex, which was the projection of sensation of rabbit's leg, made it contact with meninges tightly, connected recording electrode, reference electrode, ground eiectrode with RM-6240B biological signal collecting and processing system, measured rabbit's SEAB before and after internal capsule hemorrhage.4. Measurement and analysis of the relationship between latency of SEP and the distance, which is between recording point and exciting point: Measured the distance between recording point and exciting point with tape rule when the rabbit were relaxed after anesthesia. Measured the latency of SEP with some certain software.5. Preparation of pathological specimen of rabbit's brain tissue and pathomorphological observation of rabbit's brain tissue: After finishing the preparation of internal capsule hemorrhage animal model, took the brain tissue, fix them with 10% formaldehyde solution. Through HE stain, observed their pathomorphological changes under the light microscope.6. Statistical analysis: Statistical software SPSS 11.0 was used. The total significant differences of SEP, SEAB before and after internal capsule hemorrhage were compared by analysis of variance (ANOVA) of reduplicative metered data, and multiple comparison between multiple sample mean. Relationship between latency of SEP and the distance, which is between recording point and excitingpoint, it was analyzed by linear regression. Results: 1. We can copy the model of intracerebral internal capsule hemorrhage of rabbitsthrough injecting its autologus arterial blood, and we confirmed that the hematoma were in the hind limb of internal capsule accurately through specimens and pathological section.We observed through light microscope afterinternal capsule hemorrhage,the position of hematoma were full of red blood cells. 72h after internal capsule hemorrhage, there were lots of inflammatory cells and dropsical blood capillary in the perienchyma of the hematoma.2. Peak latency and onset latency of Nl, PI and N2 of SEP were prolonged 3min, 30min, and 60min after internal capsule hemorrhage than before hemorrhage (P <0.05) . Amplitudes of Nl, PI and N2 of SEP were decreased in 3min, 30min, and 60min after internal capsule hemorrhage than before hemorrhage (P<0.05).3. The frequency of occurrence of slow wave of SEAB were increased in lmin, 25min, and 55min after internal capsule hemorrhage than before hemorrhage (P <0.05) .4. We got a linear regressive equation through the distance between recording point and exciting point with peak latency of PI and N2 of SEP. The equation were Y=0.900X-5.706, Y=1.799X-25.275 , Xe (42,56) ,the unit is cm. Conclusions:1. We can copy the accurate model of intracerebral internal capsule hemorrhage ofrabbits by means of stereotactic method successfully.2. SEP and SEAB are objective index to evaluate the impaired degree of nervous function before and after internal capsule hemorrhage. They can offer an important reference to the diagnosis and the cure of internal capsule hemorrhage.3. The normal latency of SEP has a linear regressive relationship with the distance, which is between recording point and exciting point. The equation can provide an important reference to the evaluation of normal rabbits's SEP latency andfuture research.