Effect Of Brain Atrophy On The Cognition In Patients With Subcortical Ischemic Vascular Disease

Objective To explore the relationship between brain atrophy and cognition in patients with subcortical ischemic vascular disease(SIVD) by using a visual rating scale to rate the severity of frontal, parietal and temporal lobe atrophy.Methods A total of 116 SIVD patients were enrolled from the Depanment of Neurology,First Affliated Hospital,Anhui Medical University between September 2013 and December 2014. Lobar atrophy, leukoaraiosis, lacunar infarcts and vascular risk factors were analyzed in the 116 SIVD patients who were divided into three groups according to the diagnostic criteria : non-cognitive impairment group(SIVD-NCI), mild cognitive impairment group(SIVD-MCI) and dement group(SIVD-Va D). All patients underwent magnetic resonance imaging(MRI) with a 3.0-T system. The cognitive functions were evaluated by mini-metal state examination(MMSE),the Cambridge cognitive examination-Chinese version(CAMCOG-C),etc. A widely used visual rating scale(0 to 3) was adopted to rate the severity of frontal, parietal and temporal lobe atrophy. The degree of leukoaraiosis and the number of lacunar infarcts in 4 brain regions(frontal, parieto-occipital, temporal, and basal ganglia) was evaluated meanwhile. The severity of different lobe atrophy, the degree of leukoaraiosis and the number of lacunar infarcts was compared among the three groups. Moreover, association between cognitive function score(MMSE socre) with atrophy, leukoaraiosis, lacunar infarcts and vascular risk factors were evaluated using a binary logistic regression analysis.Results Firstly, there were no statistically significant differences in sex,age,education year and vascular risk factors among the three groups. On the contrary,there were statistically significant differences in MMSE, CAMCOG-C and subitems of CAMCOG-C. Secondly, both the SIVD-MCI and SIVD-Va D groups showed significantly higher total scores of atrophy, higher frontal lobe atrophy scores, higher leukoaraiosis total scores, higher leukoaraiosis scores of the four different region, and larger total number of lacunar infarcts, larger number of lacunar infarcts of the four different region than SIVD-NCI(H=6.138,P=0.013;H=45.845,P=0.000;H=36.818,P=0.000;H=19.384,P=0.000;H=34.296,P=0.000;H=28.979,P=0.000;H=21.061,P=0.000;H=37.46,P=0.000;H=16.808,P=000;F=13.039,P=0.000;F=6.101,P=0.003;H=32.752,P=0.000). There was no significant difference in temporal lobe atrophy scores between SIVD-NCI group and SIVD-MCI group, parietal lobe atrophy scores as well showed no difference among three groups. Thirdly, total number of lacunar infarcts, total scores of atrophy and leukoaraiosis were negatively correlated with SIVD cognition, especially frontal lobe atrophy scores, parieto-occipital leukoaraiosis scores and the number of basal ganglia lacunar infarcts had a remarkable negative correlation with MMSE scores,CAMCOG-C scores and partial subitems in CAMCOG-C scores(P<0.005). However,there was no significant correlation between the number of temporal lacunar infarcts, MMSE scores,CAMCOG-C scores and partial subitems in CAMCOG-C scores(P>0.005). Fourthly, education year(regression coefficient=-0.240,OR= 0.787), total scores of leukoaraiosis(regression coefficient =0.183,OR= 1.201) and total number of lacunar infarcts(regression coefficient =0.200,OR= 1.221) remained associated with cognition after controlling for sex, age, education year, vascular risk factors,etc. While,after adjusting atrophy scores, total scores of leukoaraiosis had no significant association with cognition, atrophy scores, total number of lacunar infarcts and education still showed significant association, particularly frontal lobe atrophy scores(regression coefficient =2.778,OR= 16.082), but not temporal and parietal lobe atrophy scores.Conclusion Frontal lobe atrophy is obvious in SIVD patients, but parietal lobe atrophy is not. As for the temporal lobe atrophy, it is obvious when the degree of cognitive impairment to dementia. Frontal lobe atrophy is negatively correlated with SIVD cognition, it may be a new and independent predictive index of cognitive impairment in SIVD. Further, the effect of brain atrophy, the number of lacunar infarct and degree of leukoaraiosis on cognitive decline is independent and decreased in turn.