A Study On Correlative Factors Of Cerebral Microbleeds Associated With Idiopathic Normal Pressure Hydrocephalus

Objectives: We investigated pathogenesis,imaging features and diagnostic criteria of idiopathic normal pressure hydrocephalus(iNPH)and cerebral microbleeds(CMBs),detected risk factors and pathogenesis of iNPH with CMBs.At the same time,we analysised the correlation between the number and distribution of cerebral microbleeds and Adams and Hakim's triad provide reference for the diagnosis and treatment of iNPH.Methods: A retrospective analysis was conducted to continuously collect 31 patients diagnosed as iNPH who were admitted to the hospital from June 2013 to October 2019.Exclusion criteria:(1)patients with incomplete clinical data;(2)secondary normal pressure brain edema(s NPH)caused by other factors(such as subarachnoid hemorrhage,brain trauma,meningitis,etc.);(3)clinical diagnosis or suspicion of cerebral amyloid vascular disease;(4)secondary cerebral hemorrhage(such as intracranial aneurysm,arteriovenous malformation,brain trauma,tumor,etc.);(5)previous history of cerebral hemorrhage;(5)patients with severe blood disease,severe heart,liver and renal insufficiency.All enrolled patients signed the informed consent.After enrollment,all patients were routinely examined with Mini-mental State Examination(MMSE),axial and coronal craniocerebral magnetic resonance imaging(MRI)and Susceptibility Weighted Imaging(SWI),and the baseline data and the results of various examinations were recorded in detail.According to the presence or absence of CMBs,they were divided into CMBs(+)and CMBs(-)groups,and iNPH clinical manifestations,severity of dementia(mild,moderate,severe),and imaging characteristics [Evans index,Disproportionately Enlarged Subarachnoid-space Hydrocephalus sign(DESH sign),and Callosal angle(CA)] were recorded.CMBs definition: by the SWI images CMBs,clearly defined boundary,uniform uniform circular or elliptic low signal,about 2 to 5mm in diameter,sometimes also can achieve 10 mm,at the same time pay attention to identify vascular flow empty shadow,calcium,iron deposit,cavernous hemangioma,diffuse axonal injury and other diseases may be similar lesions in the image.There is no high signal performance on conventional T1 WI and T2 WI images.The locations and number of intracranial microhemorrhages were observed in the CMBs(+)group.The locations were divided according to Stark and Bradley,cortex including frontal lobe,parietal lobe,temporal lobe and occipital lobe.The deep areas included basal ganglia,thalamus,internal capsule,external capsule,corpus callosum and periventricular white matter.The infratentorial includes the brain stem and cerebellum.The noncortical group included deep and infratentorial.The number of CMBs was grouped according to the following principles :(1)if CMBs are only located in cortex,they are cortical group;(2)if CMBs are only located in non-cortical group,they are non-cortical group;(3)CMBs are located in both cortical and non-cortical areas,among which half of the group with fewer CMBs is more than half of the group with more CMBs is included in the mixed group;(4)CMBs are located in both cortical and non-cortical areas,among which the group with fewer CMBs is less than half of the group with more CMBs,and the group with more CMBs is included.The gender,age,dyslipidemia,hypertension,diabetes and smoking history of the enrolled patients were also collected.The severity of dementia was determined by the MMSE scale.Statistical analysis was performed using SPSS21.0.The normal distribution of the measurement data was expressed by means±standard deviation(SD).The t-test was used for continuous variables.Relationship between the two group were assessed with the Fisher exact probability test for norminal variables.If the P value was less than 0.05,it was accepted as statistically significant.Results: There were 16 CMBs(+)cases,with a detection rate of 51.6%.A total of 129 CMBs were detected,among which 70(54.3%)occurred in basal ganglia,followed by18(14.0%)brain stem,16(12.4%)occipital lobe and 13(10.1%)temporal lobe.There were 4 cases(25%)of 1 to 2 CMBs,8 cases(50%)of 2 to 9 CMBs,and 4 cases(25%)of more than 9.Univariate analysis showed that a history of type 2 diabetes,and smoking were risk factors for CMBs,and multivariate logistic regression analysis suggested a history of diabetes(OR=9.487,95%CI,1.194-75.354)and Smoking history(OR=10.084,95%CI,1.319 ~ 77.104;P=0.026)were the independent risk factor of CMBs.The number and distribution of CMBs and clinical manifestations of iNPH were compared respectively.There was no statistically significant difference between the two groups(P>0.05).Conclusion:1 The occurrence of CMBs in iNPH patients was independently related to the history of type 2 diabetes and smoking.2 The incidence of CMBs in iNPH patients was significantly higher than that in healthy people of the same age,suggesting that iNPH may increase the risk of CMBs.3 Among the patients with iNPH,CMBs(+)accounted for about half,and the number of CMBs was 2-9,which accounted for a large number.CMBs was mostly distributed in the basal ganglia region,while the distribution of cerebral lobes was relatively small.4 In patients with iNPH,Adams and Hakim's triad was independent of the number and distribution of CMBs.