Study On Correlation Between Cognitive Function And Electroencephalogram In Patients With Alzheimer Disease

To analysis the cognitive function and electroencephalogram features of AD andexplore the relationship between them, in order to provide objective basis fordiscoveringAD in an early phase and mastering the disease progress.MethodRetrospectively analysis the48patients diagnosed as Alzheimer Disease whovisited the memory clinic of the first hospital of Jilin University from October2013toOctober2014, recording the clinical data, Clinical Dementia Rating, Mini-MentalState Examination, Montreal Cognitive Assessment, Activities of Daily Living and4hvideo-EEG results. According to the grading of Clinical DementiaRating(CDR).According to score of CDR,the patients were divided into threegroups:mild AD group (CDR=1), moderate AD group (CDR=2),severe AD group(CDR=3).Use software SPSS20.0to carry out the statistical analysis.Result(1)There was no significantly difference in age, gender, EEG open-close eyes test,photic stimulus provocation test and hyperventilation provocation test among the mildAD group,moderate AD group and severe AD group(P>0.05),while there wassignificantly difference in disease duration, MMSE score, MoCA score, ADL score,EEG background rhythm, regulation and modulation, epileptiform discharges,patternsof EEG abnormalities and EEG classifications among the three groups(P<0.05).(2)For the score of MMSE items,there was significantly difference in timeorientation, place orientation, attention and calculation, language ability among thethree groups or between two groups(P<0.05); there was no significantly difference in immediate memory between mild AD group and moderate AD group(p>0.05); therewas no significantly difference in delayed memory and visuospatial ability betweenmoderateAD group and severe AD group(P>0.05).(3)For the score of MoCA items, there was significantly difference in visuospatialand execution ability, naming ability and attention among the three groups or betweentwo groups(P<0.05); there was no significantly difference in language ability, delayedmemory and orientation between moderate AD group and severe AD group(P>0.05);there was no significantly difference in abstract ability among the threegroups(P>0.05).(4)The abnomal rate of EEG was87.5%, characterized by the background rhythmof slow wave, different degrees of sharp wave, spike wave, sharp and wave complex,spike and wave complex in the unilateral or bilateral frontal and temporal regions.The mild AD group showed mainly mild abnormal EEG,accounting for53.3%; themoderate AD group and severe AD group showed mainly moderate-severe abnormalEEG,78.9%and85.7%, respectively.(5)The EEGs showed diffuse abnormalities in36patients(75.0%of all EEGs). Themild and moderate AD group showed mainly diffuse abnormalities,60.0%and73.7%,respectively; severe AD group showed mainly with both focal and diffuseabnormalities, accounting for64.3%.(6)Epileptiform discharges, patterns of EEG abnormalities and EEG classificationsall affected cognitive function. The MMSE score(12.38±5.31vs17.62±6.10, P=0.003)and MoCA score(8.19±5.32vs12.22±6.38, P=0.024) of epileptiform discharges groupwere lower than non-epileptiform discharges group.Different patterns of EEGabnormalities were ranked according to the MMSE and MoCA score:normal> onlydiffuse abnormalities> only focal abnormalities> both focal and diffuseabnormalities.This paper indicated a negative correlation between EEG classificationsand the MMSE and MoCA score, that indicated that the more obviously the cognitivedecline,the more severe the EEG abnormalities. Conclusion(1)As the course of the disease prolong,cognitive function and daily living abilitydrop accordingly. Time orientation,delayed memory and visuospatial skill ability havesignificantly impaired in the early stages of dementia.(2)As the degree of dementia aggravating,the EEG changes more severely, thecognitive function declines more obviously. EEG can be used as a reliable indicatorfor reflection of cognitive function and assessment of disease severity for patientswithAD.(3)EEG of patients with AD can be featured by diffuse abnormalities or focalabnormalities, among which diffuse abnormalities is the main form of AD EEGabnormalities.(4)EEG of patients with AD can have epileptiform discharges, characterized bydifferent degrees of sharp wave, spike wave, sharp and wave complex, spike andwave complex in the unilateral or bilateral frontal and temporal regions. Epileptiformdischarges can make cognitive function impair more seriously.