Clinical Analysis Of Medial Medullary Infarction In 45 Consecutive Patients

Background and Objective: Medullary infarction includes medial medullary infarction(MMI)and lateral medullary infarction(LMI),and MMI is relatively uncommon,accounting for 19%-25% of medullary infarction,1%-5% of posterior circulation ischemia,and 0.5%-1.5% of all strokes.In addition,the bilateral medial medullary infarction(BMMI)is rare,which are published in only few reports now.Here we report 45 MMI patients,and discuss their risk factors,clinical manifestations,imaging features and prognosis.Methods: We collected 45 MMI patients who were in hospital from January 2012 to November 2015 in department of neurology,General Hospital of Shenyang Military Command,analyzed their fundamental factors,clinical manifestations,neuroimaging findings and prognosis.MMI were further categorized into two groups: anteromedial(AM)and anterolateral(AL),based on arterial supply territories.According to the anatomical structures,the lesions were rostro-caudally categorized into those involving the upper(U),middle(M)and lower(L)medulla oblongata,and ventro-dorsally categorized into ventral(V),middle(M),and dorsal(D)medulla oblongata.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 risk factors which influence short-term prognosis by multivariate Logistic regression.Results: 1.Fundamental factors: Among 45 cases,38(84.4%)were male and 7(15.6%)were female.There were 38 patients(84.4%)with the presence of old infarction(s)on the image,35(77.8%)with hypertension,29(64.4%)with smoking history,24(55.3%)with alcohol use,18(40%)with diabetes mellitus,16(35.6%)with stroke progression,13(28.9%)with complications,12(26.7%)with coronary heart disease,6(13.3%)with hyperlipidemia.2.Clinical manifestations: there were motor dysfunction in 43 cases(95.6%),dysarthria in 32 cases(71.1%)and dizziness in 31 cases(68.9%),followed by facial paralysis in 23 cases(51.1%),sensory dysfunction,nausea or vomiting,dysphagia respectively in 20 cases(44.4%),diminished pharyngeal reflex in 15 cases(33.3%),tongue paralysis in 12 cases(26.7%),ataxia in 11 cases(24.4%),consciousness disturbance in 9 cases(20.0%),dyspnea in 7 cases(15.6%).3.Imaging features: Of all the 45 patients,20(48.6%)patients suffered from anteromedial infarction,25(51.4%)patients suffered from anteromedial and anterolateral infarction,and there were 30(66.7%)patients of unilateral MMI and 15(33.3%)of bilateral MMI.Rostro-caudally,there were 32(71.1%)in upper medulla oblongata,7(15.6%)in middle medulla oblongata,5(11.1%)in UM,and 1(2.2%)in UML;Ventro-dorsally,there were 13(28.9%)in ventral medulla oblongata,12(26.7%)in VM,20(44.4%)in VMD.Magnetic resonance angiography(MRA): In 45 patients,only 2(4.4%)cases did not undergo MRA examination,10(22.2%)cases were normal,33 with abnormal vessels,including 10(22.2%)vertebral artery stenosis,7(15.6%)vertebral-basilar artery stenosis,5(11.2%)vertebral artery occlusion,2(4.4%)vertebral-basilar artery occlusion,2(4.4%)basilar artery stenosis,and 7(15.6%)vertebral artery variation.4.Possible TOAST type: there were large artery atherosclerosis in 34 cases(75.6%),small artery occlusion in 8 cases(17.8%),cardiogenic embolism in 1 case(2.2%),undetermined cause in 2 cases(4.4%),no other determined causes(0.0%).5.Prognosis: The clinical outcomes at discharge were favorable in 18 patients(40%),and poor in 27 patients(60%),including endotracheal intubation or incision in 5 patients(11.1%).In the univariate analysis,variables associated with poor prognosis were: baseline NIHSS,GCS score,infarct layers,drinking history,complications,stroke progression.Multivariate analysis showed that baseline NIHSS score,complications,stroke progression were probably independent risk factors for prognosis.Conclusion: The main clinical manifestations of MMI are motor dysfunction,dysarthria and dizziness,and the main signs are facial paralysis,limb paralysis,positive Babinski sign.The lesion of MMI occurred in unilateral,upper ventral medulla oblongata,and the most common cause is vertebral artery atherosclerosis.There were 60% patients with poor prognosis,and drinking history,complications,stroke progression,infarct layers,baseline NIHSS,GCS score were risk factors.Multivariate analysis showed that NIHSS,complications,stroke progression were significantly associated with clinical short-term prognosis.