Brain Mechanism Of Cognitive Impairments In Asthma

Objective: Cognitive impairments are common in patients with asthma.We explore the differences between cognitive functions and white matter(WM)integrity of asthma and control group.The correlation between cognitive functions and WM integrity in asthma was analysised to investigate the neuromechanism underlying cognitive impairments of asthma.Methods: Thirty-seven asthma patients and 31 well-matched healthy controls were recruited in the study.All participants received general information collection,asthma control test(ACT)assessment,a set of neuropsychological test assessment and diffusion tensor imaging(DTI)scanning.A set of neuropsychological test assessment was used to assess the cognitive functions of participants,including episodic memory,attention,language ability,executive fuction and visual-spatial ability.Two independent sample t-test or Mann-Whitney rank test were used to compare the differences between cognitive fuctions in asthma and control group.Tract-based spatial statistics(TBSS)approach was used to investigate the whole-brain differences in the WM fractional anisotropy(FA)values between two groups.Correlation analyses of WM region and cognitive functions differences between two groups were performed to explore the relationship between cognitive impairments and WM abnormalities.Correlation analyses of ACT,duration of asthma and WM region,cognitive functions differences between two groups were performed to explore the the impact of clinical variables on cognitive impairments and WM abnormalities.Results: Significant differences of the scores of boston naming test(BNT),semantic similarity test and auditory verbal learning test(AVLT)between asthma and controlgroup were found in the study,implying the impairments of language ability,executive function and visual-spatial processing in asthma.Compared with control group,asthma patients exist widespread FA reduction,especially in forceps minor,superior frontal gyrus part of superior longitudinal fasciculus(SLF-SFG),inferior frontal gyrus part of superior longitudinal fasciculus(SLF-IFG),inferior temporal gyrus part of superior longitudinal fasciculus(SLF-ITG),parietal lobe part of superior longitudinal fasciculus(SLG-PL),middle part of inferior fronto-occipital fasciculus(IFOF-M),posterior and inferior cingulum,suggesting widespread WM disruptions of brain regions of asthma patients.The executive function was related to FA of left forceps major,cingulum and right uncinate fasciculus,ILF(inferior longitudinal fasciculus)positively(r = 0.386,P = 0.015;r = 0.393,P = 0.016;r = 0.471,P = 0.003;r = 0.351,P = 0.033).Mean FA of brain regions with significant differences between two groups were positively correlated with duration of asthma and asthma control test(ACT)scores(r = 0.826,P < 0.001;r = 0.787,P < 0.001).Conclusions: Asthma patients show various cognitive impairments and widespread WM integrity disruptions,among which executive dysfunction closely correlates with WM abnormalities.