Prevalence Of Cerebral Microbleeds, Related Risk Factors, And Pathological Studies

Background and Purpose-Cerebral microbleeds(CMBs)is one of the common forms of cerebral small vessel disease.Lipohyalinosis and ?-amyloid protein deposition in blood vessel wall which respectively presents in hypertension and cerebral amyloid angiopathy may be the related vascular changes of CMBs.CMBs doesn't share similar manifestations with other cerebral hemorrhage such as stroke.Cognitive impairment,instead,may be one of its consequences.Besides,CMBs is significantly associated with higher risk of stroke in the future.Researches on CMBs can help to predict stroke events and provide valuable information on medication guidance.The existing large-scale epidemiological studies on CMBs are mainly based on the European and American population,and the epidemiological data for Chinese people need to be supplemented.The purpose of this study was to investigate the prevalence of CMBs and risk factors in a Chinese cadaver donor cohort.Methods-A total of 609 participants with CMBs were included in this study.Their age,gender,history of hypertension,diabetes,smoking,drinking and medication were collected.Their height,weight,blood pressure,fasting blood glucose and blood lipid level were measured.MMSE and MoCA assessment were performed to evaluate participants'cognition.Susceptibility weighted imaging(SWI)sequence was applied to evaluate the number and distribution of CMBs.Fluid attenuated inversion(FLAIR)sequence was used to assess white matter hyperintensity(WMH).Logistic regression model was used to analyze the correlation between CMBs and potential risk factors.Results-267 CMBs were found in 147(24.1%)of 609 participants.Most of them were located in cortex(38.2%)and basal ganglia(15.4%).Male(OR=1.854,95%CI(1.275,2.696))and aging(OR=1.370,95%CI(1.090,1.721))were risk factors of CMBs.After adjusting age and gender,high levels of diastolic blood pressure still increased the risk of CMBs(OR=1.378,95%CI(1.133,1.676)).History of anticoagulants use was also a risk factor of CMBs(OR=5.5 76,95%CI(1.581,19.666)).The increase of total cholesterol(OR=0.776,95%CI(0.629,0.957)and low density lipoprotein(LDL)(OR=0.748,95%CI(0.608,0.921)),however.would reduce the risk of CMBs.Severe periventricular white matter hyperintensity(OR=2.355,95%CI(1.558,3.559))and deep white matter hyperintensity(OR=2.543,95%CI(1.678,3.854))increased the risk of CMBs.After adjusting age,gender,duration of education,hypertension and Fazekas score of white matter lesions,lower MoCA score was still significantly associated with the presence of CMBs(OR=0.770,95%CI(0.617,0.960)).Conclusion-Aging,male,high diastolic blood pressure level,hypertension and anticoagulant use increase the risk of CMBs;The increase of total cholesterol and LDL reduce the risk of CMBs.CMBs were associated with the decrease of MoCA score,suggesting that CMBs may be related to cognitive impairment.Background and Purpose-Hemosiderin is an insoluble complex polymer containing iron,protein and lipid.Hemosiderin deposition in the central nervous system is usually considered as the histological basis of cerebral microbleeds(CMBs).The exploration of the formation mechanism of hemosiderin can help to reveal the pathological mechanism of CMBs.The study aims to explore the staining method and evaluation of hemosiderin depositions in brain tissue,and to find the correlation between hemosiderin deposition and other small vessel pathological changes in human brain.Methods-The pathological sections of basal ganglia of 20 donors from Chinese brain tissue bank were collected and stained with Perls' Prussian Blue(PB stain)and Hematoxylin-Eosin(HE stain).Age,gender,E-Cog score and other information were collected.Hemosiderin deposition was assessed with semi-quantitative and quantitative ways on PB stained sections.Other small vessel changes were assessed on HE stained sections.Results-There was a significant difference of age between the low perivascular hemosiderin deposition group(72.0,(54.0,79.0))and the high perivascular hemosiderin deposition group(87.0,(75.0,90.0))(p=0.031).There was also a significant difference of hemosiderin score(evaluated by quantitative method)in brain parenchyma between the patients with and without microinfarcts(p=0.042).A moderate correlation was found between age and the rating of perivascular hemosiderin(p=0.452,p=0.046),and there was a moderate correlation between age and the hemosiderin score in brain parenchyma(p=0.566,p=0.009).We also found a moderate correlation between the rating of arteriolosclerosis and the hemosiderin score in brain parenchyma(p=0.522,p=0.018).Conclusion-The pathological changes of small vessels in brain,such as hemosiderin deposition,arteriolosclerosis,perivascular space enlargement,microinfarcts and metal deposition in blood vessel wall,are widespread in the brain tissue.Hemosiderin deposition in brain tissue may be related to hemorrhage of arterioles and capillaries,as well as ischemic injury.