Neuropsychological Characteristics And P300Deteciton Of Subjecitve Memory Impairment

Objective: Alzheimer’s disease (Alzheimer’s disease, AD) is an age-related, thepotential occurrence of neurodegenerative diseases. The first symptom of Alzheimer’sdisease mostly based on memory disorders, it is a common neurodegenerativediseases of old age. Studies predict thatthe world will have81million patients withAD in2040.Pathogenesis of Alzheimer’s disease has been a century，its pathogenesis is complex.So far, the biological mechanisms for Alzheimer’s disease research is still notachieved a breakthrough in nature. Its treatment and early diagnosis are difficult,therefore, how to effectively identify the early stages of AD has great significance forthe delay and reverse the course of Alzheimer’s disease. Previous studies have shownthat AD exist preclinical phase. Recently, it has been widely recognized that mildcognitive impairment, especially amnestic mild cognitive impairment (amnesia Mildcognitive impairment, aMCI), is the early stages of AD. aMCI refers to: theindividual’s memory or other cognitive dysfunction, the extent of their age andeducation levels than the allowed range, but have not yet reached dementia and theirdaily lives had no significant effect. Numerous neuropsychology, pathology, imaging,molecular genetic and other studies have shown that aMCI is a range between normalaging and Alzheimer’s disease pathological cognitive impairment. Although SM is oris not a precursor stage of aMCI and SMI is or is not the risk of Alzheimer’s disease isa crowd, this view is still controversial at present, but this concept has opened up newareas proposed for Alzheimer’s disease research. To verify these results require furtherlarge sample of clinical research, the study population SMI has great significance, forthe prevention of Alzheimer’s disease and pathogenesis. To investigate the subjective memory impairment(subjective memory impairment,SMI) as the possibility of amnesia Mild cognitive impairment （amnesia Mildcognitive impairment, aMCI）prodromal phase,and the clinical value of event-relatedpotentials (P300) for Alzheimer’s disease in the early diagnosis and evaluation. Inrecent years, for this prevalent in the elderly subjective memory loss (subjectivememory impairment, SMI) of the phenomenon, researchers further proposed:subjective memory impairment (subjective memory impairment, SMI) is amnesticmild cognitive impairment (amnesia Mild cognitive impairment, aMCI) prodromalphase. SMI refers to a cognitive state: it has complained of memory loss, butundetectable objective memory deficits，its overall cognitive function is normal andthe activities of daily living are not affected. It is located between normal aging andaMCI. It has not been reported that neuropsychological characteristics andperformance of the P300event-related potentials for SMI. Based on the sample of thepopulation, the project expects to study the neuropsychological and P300characteristics of SMI group, MCI and normal aging control group, it attempts to findthe differences among the three in neuropsychological assessment performance，tofind the cognitive significance of P300for the three identification. It is possible toexpect that SMI is prodromal stage of MCI. It explores the early diagnosis andevaluation of the clinical value for subjective memory loss (subjective memoryimpairment, SMI) and aMCI by using of neuropsychological testing and cognitiveevent-related potential P300testing.Methods: The first survey conducted demographic, medical history and physicalexamination collected in the crowd. All subjects were enrolled, according to theinclusion criteria and signed informed consent. They were to conduct acomprehensive assessment of cognitive function, which is all20subjects from SMI,aMCI and normal control group, using a simplified Chinese version of thequestionnaire memory, multi-dimensional scale neuropsychological testing, MMSE(mini-mental status examination)， MoCa(Montreal cognitive assessment),ADL (Activities of daily living, ADL)(14), clinical Dementia scale (Clinicaldementia rating, CDR) and so on. Three groups of subjects are detected by cognitiveevent-related potentials ERP-P300. Subjects were twenty-two comparison andanalysis of statistical difference among the three groups in neuropsychologicalindicators and the P300latency and amplitude parameters change.Results: SMI group scores are higher than the aMCI group and the control group inthe AVMT-delay memory recall、AVMT-immediate memory and Clock drawing test（CDT）（P<0.05~P<0.01），but aMCI and control groups showed no significantdifference between（P>0.05）；In VFT（Verbal fluency test reflects the semanticmemory and language functions）, SMI and aMCI group was significantly higher thancontrol group（P<0.01）, the SMI group and the aMCI is no difference between groupsstatistically significant（P>0.05）. In the connection testing, DS （which reflectsexecutive function）and CFT copying score test（Rey-Osterrich Complex Figure Testis a reflection of visual episodic memory）, the differences between the three groupswas not statistically significant (P>0.05). The differences of ERP-P300and P3a’sindexes in three groups had no statistcal significance (P>0.05).Conclusion: This study showed that amnestic mild cognitive impairment haveprodromal stages, namely: subjective memory impairment stage. Neuropsychologicaltesting for early diagnosis of SMI and aMCI have some clinical significance. Thedetection of the P300is not statistically significant, for SMI, aMCI both subclinicaldiagnosis and distinction. It should be noted that the sample used in this study arelimited, so we expect the use of a larger sample and a more extensiveneurophysiological testing methods for SMI and aMCI related research. To explorethe neuropsychological and neurophysiological monitoring techniques are possible, asearly diagnosis of AD biomarkers, which provides help for further Alzheimer’s disease research.