Effect Of Hypometabolism In Different Brain Regions On Dementia Outcome In Amyloid β-positive Population

Objective:The most common type of senile dementia is Alzheimer’s disease.As China’s aging population continues to increase,the incidence of dementia also increases.It is very necessary to develop early diagnosis and prevention strategies for dementia.In this study,the ADNI database was used to complete the collection of general clinical information on non-demented subjects with positive Aβ pathology,and the neuro Q quantitative software was used to analyze the degree of metabolism in different brain regions.The effects of different brain regions on the conversion rate of dementia and cognitive indicators such as memory and execution were further evaluated to provide a basis for early identification and clinical intervention of patients with clinical dementia.Methods:This study included 239 non-demented subjects with positive Aβ pathology who completed FDG PET examination at the baseline stage.Considering the sample size and follow-up time,the subjects who completed the follow-up at the baseline stage and the 4th year were selected.including 62 cognitively normal and 177 mild cognitively impaired patients.All subjects come from the ADNI database(Alzheimer’s Disease Neuroimaging Initiative),and the general clinical information collected includes: clinical diagnosis,age,gender,marital status,years of education,APOE4 carrying status,MMSE total score,ADNI-EF,ADNI-MEM,ADAS13,FAQ,NPI.In this study,Neuro Q image quantitative analysis software was used to quantitatively analyze the PET images of the patients’ brains.According to the presence or absence of hypometabolism in brain regions,the patients were divided into groups with hypometabolism in brain regions and groups without hypometabolism in brain regions.Patients were divided into cognitive normal group(CN)and mild cognitive impairment group(MCI)according to cognitive status.First,according to the cognitive status of the subjects,the demographic characteristics and general scale information were compared between the groups at baseline and the fourth year of follow-up;secondly,the conversion rate of dementia in the group with or without hypometabolic brain regions at the fourth year of follow-up was calculated,and The comparison between groups was carried out to further determine the brain regions related to dementia transformation,and the correlation between the specific degree of brain metabolism in the corresponding brain regions and the indicators of the cognitive scale was further analyzed,and SPSS 21 statistical software was used for data processing.Results:1.This article further confirms that APOE4 is closely related to the occurrence of cognitive impairment.Among them,APOE4 carriers are more common in the MCI group,while APOE4 non carriers are more common in the healthy control group.2.In the cognitively normal group,there were significant differences in CDRSB,MMSE total score,and FAQ total score before and after the four-year longitudinal comparison between the baseline and the fourth-year follow-up(p<0.05).In the mild cognitive impairment(MCI)group,ADNI-EF(ADNI Executive Composite Index),ADNI-MEM(ADNI Memory Composite Index)and the four-year longitudinal comparison of each scale were significantly different(p<0.001).3.In the comparison of horizontal group differences between different cognitive status groups at baseline and the fourth year of follow-up,whether at baseline or at the fourth year of follow-up,the CDRSB,ADAS13,FAQ,and NPI scores of the mild cognitive impairment(MCI)group were higher than those of the mild cognitive impairment(MCI)group.The scores of MMSE,Mo CA,ADNI-EF(ADNI Executive Composite Index),ADNI-MEM(ADNI Memory Composite Index)in the mild cognitive impairment(MCI)group were lower than those in the cognitive normal(CN)group(CN)group.4.For non-demented subjects with positive Aβ pathology,the brain regions most associated with dementia transformation at the fourth year of follow-up were left posterior cingulate,left anterior cingulate,left parietotemporal cortex,Posterior part of right cingulate gyrus,posteroinferior part of right lateral temporal lobe,anterior and inferior part of right lateral temporal lobe,right parietotemporal cortex,anterior and inferior part of left lateral temporal lobe,posteroinferior part of left lateral temporal lobe,anterior part of left medial temporal lobe,The right visual association cortex,these are also classic AD hypometabolic brain areas.5.The degree of FDG metabolism in multiple regions was positively correlated with memory,executive composite index,MMSE or Mo CA total score in ADNI,and negatively correlated with APOE4 carrying number,CDRSB score,and FAQ total score.Conclusion:1.This study further confirms that APOE4 is closely related to the occurrence of cognitive impairment.Apo E4 carriers are significantly more common in the more severe MCI group,while Apo E4 non carriers are more common in the healthy control group.2.Early A β Accumulation has had an impact on the cognitive decline of the CN and MCI groups,further confirming that A β May be involved in the occurrence and development of cognitive impairment.3.In Aβ-positive non-dementia subjects,dementia conversion over the next four years was associated with the left anterior cingulate gyrus,Brain regions related to metabolism of left posterior cingulate gyrus,left parietemporal cortex,right posterior cingulate gyrus,right lateral posterior lower temporal lobe,right lateral anterior lower temporal lobe,right parietemporal cortex,left lateral anterior lower temporal lobe,left medial anterior temporal lobe,right visual association cortex.4.By analyzing the difference of dementia conversion rate in different metabolic regions between the normal group and the MCI group with positive Aβ pathology,the combination of Aβ pathological results and imaging results is beneficial to the early diagnosis of AD.