The Clinical Study Of The Posterior Circulation Ischemic

Part I: The demographic and risk factors of the posterior circulation ischemic patients.Objective To supply some useful information about the screen and prevention of the risk factors in Chinese posterior circulation ischemic patients,according to the profiles of the risk factors in these patients.Methods We studied the 1227 patients with fist-ever ischemic stroke registered in Nanjing Stroke Registry Program from January 2004 to June 2006. A total of 254 consecutive posterior circulation ischemic patients were enrolled in this study. The risk factors and the relationship between sex, age constituent and the risk factors were assessed, then compared with NEMC-PCR study.Results (1) In this study, there were 171 men and 83 women with an average age of 65.0±14.8 years,.Of these 254 patients,24 patients≤45 years of age, 230 patients>45 years of age. (2) Hypertension, Diabetes mellitus , hyperlipemia and smoking were the most common risk factor in the study. Compared with NEMC-PCR study, Hypertension and hyperlipemia were more common in our study, but smoking ,coronary heart disease and heart disease were less common. (3) Men posterior circulation stroke patients were more likely than women patients to have a history of hyperlipemia(36.9% vs 21.9%,P<0.05), smoking(38.5% vs 1.6%,P<0.001)and alcohol overuse(21.3% vs 0%,P<0.001),whereas women patients were more likely than men patients to have coronary heart diseas(e29.7% vs 14.8%,P<0.05).(4) Hypertension(79.4% vs 38.1%,P<0.001)and diabetes mellitus(37.0% vs 4.8%,P<0.05) were more common in posterior circulation stroke patients>45 years of age than in those stroke patients≤45 years of age.Conclusions (1) Compared with results derived from western population, risk factors profiles of the Chinese posterior circulation ischemic patient were different. (2) Risk factors profiles in posterior circulation stroke patients had sex and age differences.Therefore, the screen and prevention of the risk factors may be different according to sex and age. Part II: The distribution of the posterior circulation infarctsObjective To demonstrate the characteristics of the posterior circulation infarcts distribution.Methods Territorial infarcts were present in 186 patients among the 254 posterior circulation ischemic patients. We subdivided the posterior circulation infarcts into proximal, middle, and distal infarcts, refering to NEMC-PCR study.Results (1) The most common location of infarcts was in the distal segment(53.2%), following by middle segment(53.2%) and proximal(23.1%).(2) There were 47 multiple infarcts patients(25.3%), among these, the distal, proximal and middle and distal territories were involved most often. (3) The medullary infarct was often isolated and combination with homonymy proximal cerebellar infarct was uncommon. Among the cerebellar infarcts, the proximal territory infarct was involved most often, following by distal and middle territory infarct. The posterior cerebral artery (PCA) territory infarcts can be subdivided into cortical infarcts, deep infarcts and cortical and deep infarcts. Infarcts that were cortical were most common, following by deep infarcts and cortical and deep infarcts.Conclusions The posterior circulation infarcts distribution in Chinese patients were similar with western patients. Part III: The vascular lesions of the posterior circulation ischemic patients.Objective To evaluate the characteristics of the vascular lesions in Chinese posterior circulation ischemic patients and the differences with western patients.Methods DSA, MRA, CTA, extracranial ultrasound and TCD were used to evaluate the posterior circulation arteries and DSA was predominate. Posterior circulation arteries were divided into extracranial and intracranial arteries. A severe occlusive lesion was defined as greater than 50% stenosis of an artery. The differences of the posterior circulation vascular lesions in sex,age(≤45,>45)and different infarcts location were assessed. The indepent predictive factors of the vascular occlusive lesions were evaluated, according to clinical symptoms, risk factors and MRI.Results (1) The great majority of the vascular lesions(95.7%) were due to atherosclerosis, while no patients had dissections. (2) The most common site of lesions was the extracranial(ECVA), mostly(96.7%) involving the V1 segment. Intracranial lesions disease(32.3%)and extracranial combined with intracranial lesions(16.5%) were also very common .(3) Isolated occlusive lesions were more common than multiple occlusive lesions(64.7% vs 35.7%)in our study. (4) Hypertension (OR=4.549,P<0.001), male gende(rOR=3.665,P<0.001), TIA or TIA symptom previous of stroke(OR=3.480,P<0.001)were indepent predictive factors for ECVA occlusive disease. Medullary infarct(OR=8.775,P<0.001)and male gender(OR=4.248,P<0.05)were indepent predictive factors for ICVA occlusive disease. Intracranial occlusive disease of the anterior circulation arteries(OR=4.696,P<0.05)and diabetes mellitus(OR=3.771,P<0.05)were indepent predictive factors for BA occlusive disease. The most statistically significant predictive factors for posterior circulation occlusive disease combination with internal carotid arteries origin occlusive disease and renal arteries occlusive disease were ECVA occlusive diseas(OR=6.460,P<0.001)and ECVA occlusive diseas(OR=3.037,P<0.05), hypertension(OR=2.905,P<0.05), respectively. (5) ECVA occlusive diseas(65.3% vs 36.8%, P<0.05), ICVA occlusive diseas(21.4% vs 5.3%,P<0.05) and renal arteries occlusive disease (18.8% vs 7.0%,P<0.05)were more common in men stroke patients than women patients. Stroke patients>45 years of age were more likely than stroke patients≤45 years of age to have ECVA occlusive disease(33.6% vs 10.0%,P<0.05),whereas stroke patients≤45 years of age were more likely than patients>45 years of age to have ICVA occlusive diseas(35.0% vs 13.4%,P<0.05). (6) Medullary infarct patients often had ICVA occlusive disease. Cerebral infarct patients often had ECVA lesions, as for proximal cerebellar infarct patients, ICVA occlusive disease was often involved, in addition to ECVA lesions. ECVA, BA lesions and ECVA , ICVA lesions were often involved in pons infarct patients and PCA infarct patients,respectively. Conclusions (1) The posterior circulation vascular lesions were different between Chinese and western. (2) The distribution of the posterior circulation vascular lesions were different in sex, age and different infarcts location . Part IV: The mechanisms of the posterior circulation strokeObjective To analyze the mechanisms of the posterior circulation stroke, supplying useful information for etiology detection.Methods Fist, refering to TOAST classification, we classified the posterior circulation stroke mechanisms as large-artery atherosclerosis, small-artery occlusion, cardioembolism, other determined etiology and undetermined etiology,included negative evaluation, two or more causes identified and incomplete evaluation. Then, for comparion with NEMC-PCR study and following analysis, we, refering to NEMC-PCR criteria, classified the artery-to-artery embolism subtype and embolism subtype, included cardioembolism, artery-to-artery embolism and cardioembolism + artery-to-artery embolism. The differences of the posterior circulation stroke mechanisms in sex,age(≤45,>45)and different infarcts location were assessed. The indepent predictive factors of the stroke mechanisms were evaluated, according to clinical symptoms, risk factors, vascular lesions and MRI.Results (1) Refering to TOAST classification, large-artery atherosclerosis was the most common stroke mechanism. TIA or TIA symptom previous of stroke(OR=4.748,P<0.05), internal carotid arteries origin occlusive disease(OR=2.990,P <0.05)and male gender (OR=2.763,P<0.05)were indepent predictive factors for large-artery atherosclerosis. Hypertension(OR=4.302,P<0.05),diabetes mellitus(OR=2.092,P<0.05)were indepent predictive factors for small-artery occlusion. Multiple infarcts(OR=4.283,P<0.05)and female gender(OR=4.022,P<0.05)were indepent predictive factors for cardioembolism. The most statistically significant predictive factors for other determined etiology (OR=7.268,P<0.05)and negative evaluation(OR=16.100,P<0.001)were≤45 years of age. (2) Refering to NEMC-PCR criteria,embolism was the most common stroke mechanism accounting for 50% of cases and artery-to-artery embolism was more common than cardioembolism(23.1% vs 21.0%).The ECVA was the most common donor sources of the artery-to-artery embolus accounting for75% of cases. (3) Large-artery atherosclerosis (39.4% vs 18.8%,P<0.05)and artery-to-artery embolism (29.5% vs 10.9%,P<0.05)were more common in men stroke patients than women stroke patients, whereas cardioembolism was less common(13.1% vs 35.9%,P<0.001).(4) Comparied with stroke patients >45 years of age, stroke patients≤45 years of age had more other determined etiology(19.0%vs 2.4%,P<0.05)and negative evaluation(33.3% vs 10.3%,P<0.05). (5) Large-artery atherosclerosis was the most common stroke mechanism in medullary infarct patients. Embolism, especially cardioembolism, was the most common stroke mechanism in cerebellar infarct patients. Patients with pons infarcts had a very high likelihood of embolism or BA and branch artery occlusive disease. Patients with posterior cerebral artery infarcts,except for small-artery occlusion was common in isolated deep infarcts, embolism was the most common stroke mechanism in cortical infarcts, cortical and deep infarcts and deep infarcts combination with other territorial infarcts.Conclusions (1) According to TOAST classification, large-artery atherosclerosis was the most common stroke mechanism. If Refering to NEMC-PCR criteria,the most common stroke mechanism was embolism . (2) The posterior circulation stroke mechanisms were different in sex, age and different infarcts location .(3) As for posterior circulation stroke patients, we should gave complete evaluation, especially echocardiopgraphy. If patients≤45 years of age, we should pay attention to examine uncommon cause.