Comparison Of Cognitive Function And Cerebral White Matter Lesions In Middle-aged And Elderly Tibetan And Han People At Middle And High Altitude

Objective:To explore the correlation between multidimensional cognitive dysfunction and white matter lesions in different brain regions among middle-aged and elderly in the Tibetan and Han people at middle and high altitude.Methods: From June 2018 to December 2020,total 104 people of Tibetan and Han middle-aged and elderly(age≥50 years old)with education level≥6 years were recruited in Qinghai Provincial People’s Hospital(mean altitude 2,260m).Collect demographic information,including(age,sex,height,weight,marriage,occupation,education,smoking history,alcohol consumption history,and other disease history);Multiple cognitive functions were were assessed by the Mini Mental State Examination(MMSE),Montreal Cognitive Assessment(Mo CA),Clock Drawing Test(CDT),Auditory Verbal Learning Test(sound-to-verbal learning Test),AVTL),Rey-Osterrieth Complex Figure Test(CFT),Digit Span Task(DST),Trail Making Test(TMT),Stroop Color-Word Test(Stroop Color-Word Test),CWT),Symbol-digit Modalities Test(SDMT),Boston Naming Test(BNT),and Verbal Fluency Test(VFT).There were 32 patients(half Tibetan and half Han)of mild cognitive impairment(MCI)and 20 patients(half Tibetan and half Han)of Alzheimer’s disease(AD).The control group was selected from the same ethnic gruop.The head was scanned by Sky RA 3.0T magnetic resonance instrument(Siemens,Germany).Ventricular voiceover disease(PVL)and deep brain white matter disease(DWML)were scored using the Fazekas scale.Results: 1.General cognitive function: MMSE and Mo CA scores in Tibetan and Han of AD and MCI groups were lower than those in NC group(P < 0.05),while MMSE and Mo CA scores of AD group were lower than those in MCI group(P < 0.05).Mo CA scores in Tibetan of MCI and AD group were lower than those in Han MCI and AD groupt(P <0.05).2.Multi-dimensional cognitive domains: in terms of episodic memory,scores of AVLT-delay and CFT-delay Recall in Tibetan and Han AD and MCI groups were significant lower than those in NC group,meanwhile scores of AVLT-delay and CFT-delay Recall in Tibetan and Han AD groups were significant lower than those in MCI group.In terms of working memory,scores of DST-F and DST-B in Tibetan and Han AD group were significant lower than those in MCI and NC group.Scores of DST-F in Tibetan Han MCI group were significant lower than those in NC group.In terms of attention,scores of SDMT and TMT A time in Tibetan and Han AD and MCI groups were lower than those in NC group,and scores of SDMT and TMT A time in Han AD group were significant lower than those in MCI group.SDMT score of Tibetan MCI group was statistically significant lower than that of Han MCI group.In terms of language,scores of VFT and Boston in Tibetan and Han AD groups were lower than those in MCI and NC group,and scores of Boston in Tibetan MCI group were lower than those in NC group.In terms of visual spatial ability,scores of CFT-copy and CDT in Tibetan and Han AD group were lower than those in MCI and NC group,scores of CFT-copy and CDT in Tibetan AD group were lower than those in MCI group,as well as Han MCI group were lower than those in NC group.In the of executive ability: scores of Stroop-C Time test in Tibetan and Han AD groups were lower than those in MCI group and NC group,and scores of TMT-Btime test in Tibetan and Han AD and MCI groups were lower than those in NC group.Scores of TMT-Btime in Tibetan AD group were statistical significance lower than those in Han AD group.3.Comparison of Fazekas scores for white matter lesions showed that Fazekas score(total score)in Tibetan and Han AD group was statistical significance higher than that in NC group(P <0.05);Fazekas score(DWML)of Tibetan MCI group was statistically significant higher than that of Han MCI group(P<0.05).4.Fazekas score(DWML)of Han nationality was negatively correlated with processing speed and language test scores(P< 0.05).Fazekas score(PVL)was negatively correlated with episodic memory,processing speed and language test scores(P<0.05).Fazekas score(DWML)of Tibetan nationality was correlated with all cognitive domain tests(P < 0.05).Tibetan Fazekas score(PVL)was negatively correlated with episodic memory,processing speed and executive ability tests(P<0.05).Conclusions:Middle-aged and elderly patients with MCI and AD have cognitive impairments in multiple domains,paraventricular and deep cerebral white matter lesions in brain at middle and high altitude.The attention and executive ability of MCI and AD patients of Tibetan are worse than those of Han.The lesions of deep white matter in MCI patients of Tibetan were more serious than those of Han nationality.The episodic memory,attention and language ability of Han group were easily impaired,while the paraventriculoventricular and deep cerebral white matter lesions of Tibetan group were impaired in many cognitive domains.