Ultrasonography Study Of Extracranial Vertebral Artery And The Relationship With Cell Apoptosis In Brain Stem

IntroductionVertebrobasilar system is also called posterior circulation, which mainly provide blood supply to brain stem and posterior cerebellum. Blood insufficiency in posterior circulation is a common cerebral vessel disease. It makes up about 20% in oblitting of short blood supply. Its clinic presentation are languid limb,dizziness,ataxia,headache and syncope caused by blood insufficiency in posterior circulation. The reason for it is usually the lower perfusion caused by narrowness and occlusion of vertebral artery. Nervous system is much sensitive to blood short supply. Nerve cell die for apoptosis, not by necrosis after blood short supply in brain.Brain stem is an important nervous active position. Cerebral nerve,reticular formation and up-and-down conductive bunches go through in it. Once blood insufficiency happened, there will be some different and overlap clinic presentations because of malfunction in medulla oblongata,pons and some cerebral nerves.Apoptosis and anti-apoptosis are all signal transduction procedure that are diversity,connective and multi-roads. The most powerful evidence to test apoptosis after blood short supply in brain is the study of its molecular mechanism.These years more and more researches have demonstrated that some nervous system disease such as epileptic,parkinsonism,senile dementia and blood insufficiency in brain have close relationship with apoptosis along with the development of apoptosis mechanism.This study is to get normal and abnormal ultrasonographic data from vertebral artery in children. Then building up the rabbit models which have blood insufficiency in posterior circulation. Imitating clinic changes to perform the experiment. Volume and other hemodynamic data are got in color Doppler flow imaging. In comparison with each other to evaluate blood supply in posterior circulation. The slice of brain stem are got to dye to identify the morphology of nerve cell in insufficiency area. Apoptosis index are calculated. The correlation is analyzed between data got from ultrasonography and apoptosis index. Which can provide the tangible theory and experiment gist to diagnose the disease.Materials and Methods1. From November 2007 to November 2008,156 children came to our hospital. The complaints are headache,dizziness and syncope. GE Logic 7 were used to perform the examination. The frequency of probe is 10MHz.42 cases were detected.12 patients had asymmetric underdevelopment of the vertebral artery.15 had tortuosity of the extracranial vertebral artery.5 had bilateral asymmetric underdevelopment of the vertebral artery with tortuosity on the right side.6 had a congenital hypoplastic vertebral artery. And 4 had an abnormality of the path of the vertebral artery.In addition, 86 unaffected children aged 2 to 14 years were included as a control group. By statistical analysis, the results showed no significant variations in the control group. All patients underwent electroencephalography, which yielded negative findings in all cases. The information we got from ultrasnography is diameter,course,pulsating,wave configuration,volume.2. From January 2009 to February 2010,50 rabbits are chosen to be study. Alokaα10 were used to perform the examination.The frequency of probe is 10MHz. Ultrasonographic characteristics about 2-dimensional and CDFI are got after rabbits anesthetized. Building up the animal models whose vertebral artery is narrowness and occlusion. Comparing data discrepancy with each groups. Performing and getting data from models in diffirent time to explain the pathologic basis of clinic changes.3. Executing rabbit models to get brain stem which include the whole basilar artery. The cell morphology are observed after dyed in HE. Apoptosis index are calculated and analysed in statistic ways among different group. Correlation between the hemodynamic data and apoptosis index is studied.Results1.42 cases among 156 children are diagnosed congenital anomaly in vertebral artery. The group of asymmetric underdevelopment of the vertebral artery has 12 patients. The tortuosity of the extracranial vertebral artery has 15cases. The bilateral asymmetric underdevelopment of the vertebral artery with tortuosity has 5 cases. The group of congenital hypoplastic vertebral artery has 6 cases. The abnormality of the path of the vertebral artery has 4 cases. They consist of 5 case groups. In the comparison between the normal control group and the 5 case groups, it showed that bilateral diameters,PSV and volumes of these six groups had variations (p < 0.05). EDV,RI in disease side is significance, p< 0.05.The group of asymmetric development of vertebral artery has 12 cases. The bilateral diameters of vertebral arteries could vary by more than lmm, in which 4 were on left side and 8 were on right side. The bilateral diameters and volumes of vertebral arteries were compared to the normal control group is significant (p< 0.05). EDV in healthy side is significant in comparison with the control group. While PI,RI in disease side comparing with control has variations (p<0.05).The group of tortuosity of vertebral artery at intervertebral foramen has 15 cases, in which 5 had it on both sides,5 had it on left side, and 5 had it on right side. The PSV,EDV,volume in healthy side, in comparison to the control group, was significantly increased (p< 0.05).The group of bilateral congenital asymmetry with tortuosity has 5 cases, tortuosity was reported all on right side, while 3 had asymmetry on right side and 2 had asymmetry on left side. The internal diameters in disease sides, when compared to normal control group, showed narrow and p< 0.05. The volume in healthy side showed higher and p<0.05.The group of congenital hypoplastic vertebral artery has 6 cases. Internal diameter was less than 2mm, with thickening wall and inadequate blood flow. It was shown as blurry darkness and weakened pulse in vascular wall.5 had it on left side and 1 had it on right side. The comparison of internal diameter,PSV,EDV of diseased side and its volume to the normal control group revealed p-value of less than 0.05.The group of merely abnormal original and path of vertebral arteryhas 4 patients. One had direct origin from aortic arch for the start point of vertebral artery. Two had the crossing of vertebral artery from the fifth and the sixth intervertebral foramens before entering the fourth foramen for upward traveling. One had the crossing of vertebral artery from the sixth intervertebral foramen before entering the fifth one for upward traveling. In comparison with control, internal diameter,PSV in disease side has variation (p<0.05).While internal diameter,EDV,PI,RI in healthy side has variations comparing with the control to compensate blood supply.2. Building up rabbits models which have insufficiency blood supply in posterior circulation. One group is the control. The second group is 100% occlusion at one side of vertebral artery. The third group is 70%-100% narrowness at one side of vertebral artery. Performing ultrasonography and getting data from it at different time to get hemodynamic data.In the comparison between the normal control group and the 2 case groups, it showed that PSV,EDV,volume,PI,RI is significance (p＜0.05)The second group showed high speed PSV and much volume in healthy side than control (p<0.05). PSV,EDV have the increasing tendency after operation day by day.The third group, PSV,EDV,PI,RI in healthy side, has variations in comparing with control. While PI,RI,volume in occlusion side decreased and showed significance too (p<0.05).3. Getting brain stem of rabbits covering the whole basilar artery and fixation over 4 hours in 10% neutral formalin. In the middle of brain stem taking out the material. The slice is 3μm.Dying by HE and observing the structure changes of insufficiency area. The determinant guideline of blood insufficiency area is the changes of morphology of nerve cell. Apoptosis cell is observed under microscope and apoptosis index is calculated.4. Comparing apoptosis index between control and case groups is no significance in the method of One-way ANOVA (p>0.05). Apoptosis index showed increased tendency within second group which is significance at different time of taking out material, p<0.05. While within third group, it is no significance, p>0.05.The hemodynamic data from case groups is positive correlated with apoptosis index in the way of pearson analysis. Apoptosis index is positive correlation with model living time,PSV,volume, p<0.05. Conclusion1. Ultrasonography can reveal the morphology and course changes of extracranial vertebral artery correctly in congenital vertebral artery anomaly of children.2. Morphology changes of vertebral artery got by ultrasonography combine with hemodynamic data to evaluate posterior circulation blood supply in congenital vertebral artery anomaly in children have the high appilicative value.3. Studing posterior circulation insufficiency through building up animal model, which is close to vertebrobasilar insufficiency, has the significance both in theory and clinical practise.4. The correlation between apoptosis index and hemodynamic data shows the narrowness and occlusion of vertebral artery are related to apoptosis cell in brain stem, attesting the close relationship for short supply time and cell apoptosis. On the other hand, showing the body's instinction to keep body natural condition in the way of increasing blood flow velocity and volume to compensate the short supply as models' living time longer.