A Primary Study On The Clinical Characteristics And Mechanisms Of Inferential Impairment Caused By Ischemic Cerebrovascular Diseases

Background:Many patients with cerebrovascular diseases have variable degrees of cognitive impairment,even though most of them are not dementia by the traditional diagnostic criteria.The criteria for vascular dementia(VaD) have been developed mainly based on the clinical study on Alzheimer's disease(AD),so they are inappropriate to assess the severity of vascular cognitive impairment(VCI).It is imperative to explore further the characteristics of VCI and propose the criteria of VCI for instructing the clinical work.Inference is one of the most important aspects of the advanced cognitive function.So the deficits of inference may directly affect the patients' working and daily living.Up till now the research on the inferential impairment of CVD has rarely been reported.Ischemic cerebrovascular diseases(ICVD) is a common etiology of VCI.It has practical value that the further clinical research on the inferential impairment of ICVD is made.Part 1 A Study On the Damage of Inferential Ability of Isehemie Cerebrovaseular diseaseObjective:Observing the damage of inferential ability in ischemic cerebrovascular disease,and analyze the clinical characteristics of vascular cognitive impairment in order to provide clues for the highlight of early diagnosis of VCI.Methods:75 cases of ischemic cerebrovascular disease and 30 controls without it were investigated in this study.First,all the cases were detected by neuropsychological tests with Mini Mental State Examination(MMSE),Combined Raven's Test(CRT),Hamilton Depression Rating Scale(HAMD),and then evaluate the neurologic impairment of patients by using the National Institutes of Health Stroke Scale(NIHSS)and the basic activities of daily living(ADL) with Barthel index.The difference of thesej neuropsychological variables were compared between ICVD and control group through t-test and variance analysis(ANOVA).Second,the patients of ICVD were divided into nine subgroups on the basis of different etiopathogenisis or different areas of infarction and then the cognitive inferential impairment characteristics were compared.Finally,the relationship between cognitive,inferential impairment and the basic activities of daily living(ADL) of the ICVD patients were analyzed.Results:The ischemic cerebrovascular disease subjects performs significantly low in the total score of MMSE and intelligence quotient(IQ) of the test CRT compared with those controls(P＜0.01).According to the score of CRT-IQ,the incidence of inferential impairment is 72%in ICVD group.The patient of ICVD group shows significantly lower than the control group(P＜0.01)in almost all the items' scores of the Mini Mental State Examination(MMSE) except Immediate memory,ability of naming and reading.To analyze the characteristic of cognitive inferential imparement caused by various types,the patients of TIA and VBI are found significantly better than other subgroups of ICVD in both the total scores of MMSE and CRT-IQ(p＜0.01).The patients of Binswanger disease are found markedly lower than the other subgroups ICVD in all of the items of these neuropsychology tests,especially in the items of memroy and CRT-IQ(p＜0.01).According to different areas of infarct,the ICVD cases are divided into three subgroups(cortex infarct, subcortical infarct and infratentorial infarct).Comparing the scores of MMSE,CRT-IQ in these three subgroups,the scores in infratentorial infarct subgroup are higher than the others.The difference of the incidence of in mild inferential impairment and serious inferential impairment are found among these three subgroups(p＜0.01).There are significantly relationship between the cognitive inferential imparement and the basic activities of daily living(ADL)(p＜0.01).There is obvious relativity between the scores of MMSE,CRT-IQ in ICVD patients and the scores of Barthel index.Conclusions:1.The inferential impairment which occurs in patients with ICVD is one of the most important characteristics.It should not be ignored in clinal work.2.In inferential impairment caused by different types of ICVD,the damage in Binswanger disease is more,serious.3.In inferential impairment caused by ICVD with different areas of infarction,the damage in the infarction of subcortex is more serious.4.The decline of ADL in ICVD patients has obvious positive correlation with the severity of the inferential impairment.Part 2 Study of the Relationship between Inflammatory Cytokine and Inferential Impairment in Patients with ICVDObjective:The action,mechanism and clinical significance of serum inflammatory cytokine change in inferential impairment were Studied on the patients with ischemic cerebrovascular disease.It will provide clues for diagnosis and therapy of cognitive impairment and dementia in ICVD.Methods:In this study,50 ICVD patients and 20 healthy people are choosed to compare the level of serum cytokine interleukin-1β(IL-1β),interleukin-6(IL-6),interleukin-8(IL-8) by radioimmunoassay for all the cases.The t-test and analysis of variance(ANOVA) is applied as basic statistical methods.First,the differences of serum IL-1β,IL-6,IL-8 were compared between ICVD group and the control group.Second,ICVD cases were divided into three subgroups according to the degree of inferential impairment.Then the level of serum IL-1β,IL-6,IL-8 were compared among these subgroups.Last,ICVD cases were divided into several subgroups according to different etiopathogenisis or different areas of infarction.Then the level of serum IL-1β,IL-6,IL-8 were compared among these subgroups.Results:The level of serum IL-1β,IL-6,IL-8 in the ischemic cerebrovascular disease subjects increased significantly comparing with those of the controls(p＜0.01,p＜0.01,p＜0.05). There are obvious difference among these different type subgroups in the level of serum IL-1β,IL-6,IL-8.In vertebro-basilar artery insufficiency(VBI) and transient ischemic attack(TIA) patients are lower(p＜0.05).According to the scores of the CRT-IQ,the ICVD group is classified into three subgroups(no inferential impairment,mild inferential impairment,serious inferential impairment).The serum IL-1β,IL-6,IL-8 in these three subgroups were analyzed.There is markedly discriminate in IL-6 among these three subgroups.Conclusion:1.The levels of serum IL-1βand IL-6 are still higher during the convalescent period of ischemic cerebrovascular disease.Serum IL-1βand IL-6 maybe work on delayed ischemic brain injure.2.The levels of serum IL-1βand IL-6 are related to the degrees of inferential impairment in IVCD.3.The levels of serum IL-6 is of most distinct difference in those patients with no inferential impairment;mild inferential impairment;serious inferential impairment.IL-6 maybe act as the biochemical marker to predict inferential impairment.