Application Of Olfactory Assessment In Alzheimer’s Disease

Purpose:To explore the role of olfactory function in evaluating early AD and find feasible methods for clinical operation.Methods:The 29 AD patients who met the admission criteria in September 2019 to January 2021,31 MCI and 29 control patients were selected as the NC group.Collect general clinical data for the patients,UPSIT,APOE genotyping,head MRI,and neuropsychological assessments include a simple mental state examination(Mini-Mental State Examination,MMSE),Montreal Cognitive Assessment Form(Montreal Cognitive Assessment,MoCA),Hearing Word Learning Test(Auditory Verbal Learning Test,AVLT),Memory and Execution Screening Scale(Memory and Executive Screening,)MES).The ITK-SNAP 3.8 software automatically calculated the area of interest(region of interest,ROI)of the bilateral EC,hippocampus in the s MRI sequence.Analysed the differences between groups and the effectiveness of early identification of AD,using SPSS 20.0 statistics and analysis of software.Result:(1)The UPSIT score of NC,MCI,AD group is decreasing,namely> AD group of> MCI group and UPSIT score,the difference is statistically significant(P <0.05)(2)The UPSIT score between three groups was associated with MMSE,MoCA,MES memory and execution,AVLT instant memory and delayed memory score,and showed a positive correlation(P <0.05),the lower the neuropsychological scale score assessed,the lower the UPSIT score.(3)The EC volume is decreasing,namely the EC volume is the> MCI group> AD group,and the EC volume is compared between the three groups,statistically significant(P <0.05).(4)The three groups of EC volumes were associated with UPSIT score,MMSE,MES memory and execution,AVLT instant memory and delayed recall score,and showed positive correlation(P <0.05),i.e.EC volume decreases with reduced UPSIT score and assessed neuropsychological scale score;(5)The hippocampus volume of the NC,MCI,AD group is decreasing,namely the> AD group of the> MCI group of the NC group,and the EC volume compares significantly between the three groups(P <0.05).(6)The three groups of the hippocampus volume are associated with EC volume,UPSIT score,MMSE,MOCA,MES memory and execution,AVLT instant memory and delayed memory score,and show positive correlation(P <0.05),namely the hippocampus volume increases with increased EC volume,UPSIT score and assessed neuropsychological scale score;(7)Under the curves between NC and AD,NC and AD,0.647,0.889,0.972,and sensitivity and specificity were 32.3% and 93.1%,75.9% and 87.1%,86.2% and 93.1%,respectively.NC and MCI,MCI and AD,NC were 0.584,0.960 and AD groups,respectively;sensitivity and specificity were 74.2% and 55.2%,96.6% and 83.9%,89.7% and 89.7%,respectively.The curves between NC and AD,NC and AD groups of EC.were 0.58,0.759 and 0.817,respectively;sensitivity and specificity were: 100% and 20.7%,75.9% and 67.7%,75.9% and 75.9%,respectively.NC scores were 0.641 and 0.875,0.656 and 0.875 between AD,NC and AD groups;sensitivity: 35.5% and 89.7%,69.0% and 77.4%,69.0% and 93.1%,respectively.The UPSIT and EC volumes were 0.660,0.808,0.924,respectively;the sensitivity was 64.5% and 69.0%,62.1% and 90.3%,79.3% and 93.1%,respectively.The area of UPSIT joint EC volume and MoCA score pairs distinguish between NC and MCI,MCI and AD groups are 0.710,0.918 and 0.987,respectively;Sensitivity and specificity are: 67.7%,and 79.3%,93.1%,and 74.2%,96.6%,and 89.7%,respectively,UPSIT combined EC volume,hippocampus volume and MoCA score are 0.753,1 and 1 respectively for NC,MCI,MCI and AD,NC and AD groups(> 0.8 is meaningful);Sensitivity and specificity are: 68.0% and 79.3%,100% and 100%,100% and 100%,respectively;Joint application of a single detection means to improve the diagnostic efficiency,The distinction between both NC and AD groups showed good sensitivity and specificity.(8)According to APOE genotypes into ε 2/ε 2;ε 2/ε 3;ε 2/ε 4;ε 3/ε 3;ε 3/ε 4;ε 4/ε 4;for three APOE genotypes,we found that ε 4 carriers were most widely distributed in the AD group.(9)The UPSIT score was associated with APOE ε 4 carrying,lower than non-ε 4,with statistical differences(P <0.05).(10)APOEε4.air distinction The curves of NC and MCI,MCI and AD,NC and AD groups were 0.597,0.621 and 0.719,respectively;sensitivity and specificity are: 35.5% and 82.8%,58.6% and 64.5%,58.6% and 82.8%,respectively.Age-binding APOE gene to carry theε4.898 The areas under the curves distinguishing between NC,MCI,MCI and AD,NC and AD were 0,0.660,0.774 and AD groups,respectively;the sensitivity and specificity was: 67.7% and 96.6%,37.9% and 87.1%,82.8% and 58.6%,respectively.UPSIT binding age and APOE gene carryingε4The curves divided between NC,MCI,MCI and AD,NC and AD were 0.908,0.761 and 0.893 respectively;sensitivity and specificity were 77.4% and 93.1%,72.4%,77.4% and 77.4%,89.7% and 75.9%,namely,age and APOE gene phenotype combined UPSIT and improved diagnostic efficiency.Conclusion:(1)UPSIT has a decline in scoring early in cognitive impairment and decreases with decreased cognitive function.(2)UPSIT combined with EC volume,hippocampus volume,and neuropsychological evaluation can be better used for AD diagnosis.(3)A decrease in olfactory recognition in seniors with the APOE ε4 gene suggests high AD risk.