Clinical Analysis Of Midbrain Infarction In 97 Consecutive Patients

Background and Objective: Midbrian infarction is uncommon,accounting for 1%-2% of all cerebral ischemic stroke,3%-8% of posterior circulation ischemia.We studied 97 consecutivepatients with acute infarction involving mesencephalon.The purpose of this study was to review and study the risk factors,clinical features,imaging features and prognosis of these 97 patients.Methods: We collected 97 consecutive patients with acute infarct involving mesencephalon proven by MRI who were admitted to the General Hospital of Shenyang Military Command from December 2013 to January 2017,analyzed their fundamental factors,clinical manifestations,neuroimaging findings and prognosis.Midbrain infarction was further categorized into two groups: isolated midbrain infarction(IMI)and associated extended infarcts in the posterior circulation.According to arterial supply territories of midbrain,all patients were divided into four groups: anteromedial(AM),anterolateral(AL),lateral(L)and dorsal(D).According to the modified Rankin Scale(m RS),all patients were divided into favorable prognosis(m RS≤2)and poor prognosis(m RS≥3)based on discharging status.Analyzing the differences of the clinical features,imaging features and prognosis between different groups.Results: 1.Fundamental factors: Among 97 cases,66(68.0%)were male and 31(32.0%)were female.There were 68 patients(70.1%)with hypertension,46(47.4%)with hyperlipidemia,39(40.2%)with diabetes mellitus,35(36.1%)with history of stroke,18(18.6%)with coronary heart disease,7(7.2%)with atrial fibrillation,2(2.1%)with cardiac valve disease,also 44(45.4%)with history of alcohol intake,39(40.2%) with smoking history.There were no differences at the baseline information including age,sex and risk factors between the IMI group and the associated extended infarcts group(P>0.05).There were significant differences at the rate of complication between the two groups(P<0.001).2.Imaging features: 68 patients’(70.1%)infarction was limited to unilateral midbrain,and 29(29.9%)was bilateral involved.The basal region(50 patients,51.5%)and the tegmentum(42 patients,43.3%)of midbrain was most frequently involved.According to arterial supply territories of midbrain,the lesion involvement was frequently including the AM(51.5%)and AL(41.2%)area.There were significant differences at lesion distribution(P<0.001)between the IMI group and the associated extended infarcts group.Lesion was frequently involved in the AM area in the former group,while in the AL area in the latter group.Also,the infarction in the IMI group was often limited to unilateral midbrain,and the associated extended infarcts group was often bilateral involved(P=0.002).3.Clinical features: There was no difference at baseline data between the group of AM and AL in IMI(P>0.05).There were differences at the rate of supranuclear facial paralysis between the two groups(P<0.05).There were significant differences at the rate of ocular movement disorders and the etiology between the two groups(P<0.001).There were differences at baseline GCS Score between the IMI group and the group of associated extended infarcts(P=0.001).There were significant differences at the rate of limb weakness,disturbance of consciousness and baseline NIHSS Score between the two groups(P<0.001).There were differences at the rate of ataxia,limb weakness and dysarthria between the group of unilateral midbrain infarction and bilateral midbrain infarction(P<0.05).There were significant differences at the rate of disturbance of consciousness,complication and baseline NIHSS Score,baseline GCS Score between the two groups(P<0.001).4.Prognosis: The clinical outcomes at discharge were favorable in 61 patients(62.9%),and poor in 36 patients(37.1%).There were significant differences at imaging subgroup,lesion region and arterial supply territories(P<0.001).Conclusion:1.Patients with midbrain infarction often had basal and tegmentum lesions(particularly in the anteromedial area).2.Patients with bilateral midbrain infarction had more severe clinical symptoms,more common complications and prognosis is poor.3.The common etiology was large-artery atherosclerosis in the patients of with midbrain infarction.4.Small-artery occlusion usually led to isolated midbrain anteromedial legions.