The Experiment Study Of The Change Of Pyramidal Tract After Basal Ganglia Hemorrhage And The Intervention Effect Of The Minimally Invasive Hematoma Aspiration

PartⅠChanges of microstructure and ultrastructure of pyramidal tract after basal ganglia hemorrhage in a rat modelObjective To study the change and pathological feature of pyramidal tract after intracerebral hemorrhage in a rat model.Methods Adult male Sprague-Dawley rats were divided into three groups randomly: normal group(n=8), the shame operation group(n=32)and the intracerebral hematoma group(n=32).Both the shame operation group and the intracerebral hematoma group were divided 4 subgroup: group 1d,group3d,group7d and group14d, and each subgroup contain 8 rats. TypeⅣcollagenase and heparin were injected to the caudate nucleus of rats to induce intracerebral hemorrhage. Luxol fast blue stain,neurofilament immunohistochemisty and electron microscope were performed to observe posterior limb of internal capsule.Results Intracerebral hemorrhage model in rats with typical neurological defect was established by injection of TypeⅣcollagenase and heparin successfully.Changes of myelin sheath of pyramidal tract observed by light microscope aggravated at 1 to 3 days post cerebral hemorrhage, and remyelination initiated at 7d.Axons injury was aggravated continuously at 1d to 7d, and improved slightly with optical density value (0.09±0.01) at 14d,which had no statistic difference compared with that(0.10±0.02) at 7d.The results with the utilization of electron microscope showed that the structures of myelin sheath loosed,axons swelled,partial unmyelinated nerve fibers disintegrated and vanished at 1d,myelin sheath loosed and vacuolar degenerated,partial myelin sheath vanished ,axons swelled severely,even disintegrated and vanished at 3d.Conclusion Injury of pyramidal tract aggravated continuously in 1w after intracerebral hemorrhage in a rat model,which prompted that interference and treatment were demanded in early or ultra-early period of intracerebral hemorrhage to reduce the tract's injury and promote the repairation.PartⅡThe intervention effect of the minimally invasive hematoma aspiration on pyramidal tract after basal ganglia hemorrhage in a rat modelObjective To explore the mechanism of repairation of pyramidal tract and neuroprotection after the minimally invasive hematoma aspiration, and find out the best time window of the operation to serve the treatment of medium dose of intracerebral hemorrhage in clinical works.Methods Adult male Sprague-Dawley rats were divided into six groups randomly: normal group, the shame operation group, ICH group with no treatment, ICH group with hematoma aspiration 6 hours after collagenase injection, ICH group with hematoma aspiration 12 hours after collagenase injection and ICH group with hematoma aspiration 24 hours after collagenase injection. ICH was induced by injection ofⅣbacterial collagenase into the caudate nucleus of rats and then the hematoma was lysed by injection of urokinase into the hematoma center, after which the clot was aspirated. The time of injected urokinase is 4 hours,10 hours, 22 hours in the 4th-6th group respectively. Animals were sacrificed after behavioral function evaluation with"stair test"to reflect the change of snatch ability of paralyzed forelimb at 14d after collagenase injection respectively. Neurofilament and growth associated protein-43 immunohistochemisty were performed to observe posterior limb of internal capsule.Results The snatch ability of left forelimb in each hematoma aspiration group was much higher than the ICH group with no treatment on the 14th day after collagenase injection respectively. Within hematoma aspiration groups, the snatch ability in 6h aspiration group was higher than 12h aspiration group and 24h aspiration group, however, there was no difference between the latter ones. The number of neurofilament immunohistochemistry staining positive fibers of the three hematoma aspiration groups was much more than that of the ICH group with no treatment .The number of NF positive fibers of 6h aspiration group was the most among of the three hematoma aspiration groups, and had significant difference compared with 12h and 24h group. The GAP-43 immunoreactivities of the three hematoma aspiration groups was much more than that of the ICH group with no treatment. The GAP-43 immunoreactivities of 24h group was the least among of the three hematoma aspiration groups,and had significant difference compared with 6h and 12h group, however,there was no difference between the latter ones.Conclusion The"stair test"can reflect the change of snatch function of forelimb and pyramidal tract for the rats simply and credibly.The minimally invasive hematoma aspiration performed at 24 hours especially 6 hours after ICH, would reduce pyramidal tract's injury and promote the repairation to improve neurological function.