慢性高原暴露脑适应性变化的纵向T1加权成像研究OACHSSCD

Objective To investigate the effects of chronic high-altitude exposure on cognitive function and whole-brain gray matter structure,and to elucidate the association between them.Methods A prospective cohort study design was employed,enrolling 69 healthy adolescents who migrated from lowlands to high altitudes.Neurobehavioral assessments and high-resolution T1-weighted imaging data were collected at baseline(t1),2 years of high-altitude exposure(t2),and 4 years of high-altitude exposure(t3),respectively.Imaging data were processed using voxel-based morphometry(VBM).Repeated-measures analysis of variance and paired t-tests were utilized to longitudinally track the dynamic evolution of neurobehavioral indices and gray matter volume(GMV).Pearson correlation analysis was conducted to reveal the intrinsic link between structural alterations in key brain regions and cognitive impairment.Results(1)Immediate and delayed verbal memory,as well as visual memory,progressively declined with prolonged high-altitude exposure(P<0.05),while reaction times for visual and auditory simple discrimination tasks progressively increased(P<0.05),indicating that chronic high-altitude hypoxia significantly impairs working memory capacity and psychomotor speed.(2)VBM analysis revealed significant differences in the bilateral putamen and precuneus across time points;specifically,GMV in these regions was significantly lower at t3 compared to t1.(3)Compared to t1,changes in GMV of the right precuneus at t3 were significantly correlated with changes in delayed verbal memory and auditory/visual discrimination reaction times.Furthermore,changes in GMV of the left putamen were significantly correlated with changes in auditory discrimination reaction times.Conclusion Chronic high-altitude exposure induces persistent and progressive atrophy of GMV in the bilateral putamen and precuneus,accompanied by significant neurobehavioral functional decline.This suggests that the high-altitude hypoxic environment may mediate cognitive impairment by causing neuronal loss or synaptic remodeling in key cognitive network nodes such as the putamen and precuneus.The structural remodeling of these brain regions constitutes a critical neuroanatomical basis for cognitive disorders associated with chronic mountain sickness.