The Differences Of Cognition, Cerebral Perfusion And Cerebral Metabolism Between Pib(+) Dementia Patients And Pib (-) Dementia Patients

Objectives:1.To compare the difference of cerebral perfusion and cerebral hemodynamic changes between Alzheimer's disease(AD)patients and healthy control(HC).2.To compare the characteristics of cognitive impairment in PiB PET(+)AD patents and PiB PET(-)AD patients.3.To study the relationship of metabolic levels in different brain regions of PiB PET(+)AD patients and PiB PET(-)patients.4.To compare the differences between PiB(+)group and PiB(-)group.Methods:1.Continuously enrolled 37 patients who met the diagnosis of NINCDS-ADRDA probable AD of Tianjin Medical University General Hospital cognitive disorder outpatients,and 20 of normal control,aged persons with sex and age matched as control group.Doppler ultrasonography and transcranial doppler examination were performed on the cervical vessels,the changes of cerebral hemodynamics in AD patients were investigated by analyzing the peak systolic velocity(PSV)of the common carotid artery,internal carotid artery,vertebral artery and basilar artery,as well as anterior circulation and posterior circulation perfusion,to study the hemodynamic changes of AD patients.2.Among the participants in the first part of the study,the memory was evaluated by auditory word learning test(AVLT),the executive function was evaluated by Stroop color – word association test(SCWAT),the language function was evaluated by Boston naming test(BNT),evaluates the attention and digital processing function through WAIS – III digital span(DS),and the visual space function is judged by line direction(JLO).PiB PET(+)group and PiB PET(-)group were separated by PiB PET examination.SUVR were calculated by FDG PET of each region of interest,to analysis the relationship among lobes.To investigate the characteristics of cognitive impairment in patients with PiB PET(+)AD group and PiB PET(-)AD group,and the correlation of metabolism among brain lobes,to study the hemodynamic changes between the two groups,and cognitive impairment in patients with AD.Results:1.Brain perfusion and hemodynamic changes between AD patients and HCThere were no significant difference in sex,age and years of education of the two groups(P>0.05),and they are all right-handed.The PSV of the left common carotid artery(LCCA)was higher in AD group than in HC group(P<0.05).There was no significant difference in PSV of right common carotid artery(RCCA),left internal carotid artery(LICA),right internal carotid artery(RICA),left vertebral artery(LVA)and right vertebral artery(RVA).The left anterior cerebral perfusion pressure(LCPP),right cerebral perfusion pressure(RCPP),anterior cerebral perfusion pressure(ACPP)and posterior cerebral perfusion pressure(PCPP)have no significant change in AD group and NC group.2.Comparison of cognitive function between PiB PET(+)group and PiB PET(-)group.According to the region of interest mean SUVR>1.11 of PiB PET,defined as PiB(+),a total of 23 people,SUVR?1.11,defined as PIB(-)group,a total of 14 people.There were no significant differences in sex,age and years of education of the two groups(P>0.05).Compared with PiB PET(-)group,the auditory word learning test(AVLT)was reduced in PiB PET(+)group,especially total learning,short time delay,long time delay and long delay recognition(P<0.01).Total Stroop and DS backward decreased significantly in PiB PET(+)group than that in PiB PET(-)group.There was no significant difference in JLO and BNT.3.Correlation of FDG PET metabolism in different lobes of PiB PET(+)group and PiB PET(-)group.The metabolism of frontal lobe,temporal lobe,parietal lobe(including precuneus)in PiB(+)patients were decreased,and extensive metabolic correlation deficiency;the metabolic correlation of PiB PET(-)patients in the parietal lobe(including precuneus)is deficient.4.The differences of hemodynamic between PiB(+)group and PiB(-)groupThe PSV of LVA in PiB PET(+)group has significantly increased,there was no significantly change in PSV and CPP in other vessels.Conclusions:1.The intracranial perfusion in AD patients has changed,especially the vessels in the dominant lateral hemisphere,blood perfusion is relatively insufficient.2.In patients with clinically diagnosed AD,patients with PiB PET(+)had poorer learning and memory,executive function,attention and digital processing capabilities,which suggested cognitive domains such as memory and executive function were more correlated with amyloid ? deposition,which was more consistent with pathological changes of AD.3.The relative decrease of the metabolism of frontal lobe and temporal lobe in patients with PiB PET(+)may be related to the reduction of memory and affective function.PiB(+)patients have a wide range of metabolic links missing,which suggest that the brain network has changed caused by AD pathology,especially in the frontal lobe,temporal lobe and parietal lobe.4.There's no cerebral dynamic difference between PiB(+)dementia patients and PiB(-)dementia patients.