Characteristics Of Cognitive Impairment And Cerebral Perfusion In Subcortical Ischemic Vascular Dementia

Objective: To analyze the characteristics of cognitive impairment and changes in cerebral blood flow(CBF)measured with arterial spin labeling(ASL)MRI in patients with subcortical ischemic vascular dementia(SIVD).Methods: Twenty-five patients with SIVD from the memory clinic of Tianjin Medical University General Hospital were recruited from October 2017 to February 2019.Meanwhile,20 age-,gender-and education-matched healthy controls(HC)were recruited from the same hospital.All participants underwent a neuropsychological battery,including the Mini-Mental Status Examination(MMSE)and the Montreal Cognitive Assessment(Mo CA),the Digital Span Test(DST),the Auditory Verbal Learning Test(AVLT),the Brief Visuospatial Memory Test(BVMT),the Symbol Digit Modalities Test(SDMT)and Trail Making Test-A,the Trail Making Test-B,the Animal Fluency Test(AFT),the Geriatric Depression Scale(GDS)and Activity of Daily Living(ADL)to assess the overall cognitive function,attention,verbal and spatial learning and memory,information processing speed,verbal learning and memory,visuospatial function,information processing speed,verbal fluency,execution function,emotion and daily life.In addition,a multimodal MRI scan,including 3D-ASL,was conducted to the subjects.Results: 1.Characteristics of cognitive impairment in SIVD Compared with HC group,SIVD patients had lower MMSE and Mo CA scores(P<0.001).The DST,AVLT scores(total learning,30 min delayed recall and recognition scores),BVMT scores(total learning,delayed recall and recognition scores),SDMT and AFT scores were lower than HC group(P<0.001),TMT-A and TMT-B scores were higher(P<0.001).The GDS score was higher in SIVD groups compared with HC group,although the difference did not reach a statistical significance(P=0.18).The ADL score was higher than HC group(P<0.001).2.CBF changes in SIVD Compared with the HC group(37.31±6.72ml/100g/min),global CBF was significantly reduced in the SIVD group(29.09±6.15 ml/100g/min)(P<0.05).The brain areas with reduced CBF included bilateral superior frontal gyrus,left middle frontal gyrus,left precuneus,bilateral parietal lobe,right inferior parietal lobule,bilateral cerebellar lobe and left occipital lobe.The relative values of CBF in these regions were lower in SIVD group than HC group(P<0.05).The brain regions with relatively increased CBF included bilateral lenticular nucleus,left lateral nucleus,right midbrain,right pons and right parietal lobe.However,the differences in relative value of these regions between SIVD patients and HCs were not significant(P>0.05).Conclusion: 1.SIVD was manifested in a deficit of multi-cognitive domains,including learning and memory,language,executive function,attention and information processing speed.2.Patients with SIVD had a decreased CBF in the whole brain and an extensive regional cerebral hypoperfusion.The brain areas with hypoperfusion mainly included bilateral superior frontal gyrus,left middle frontal gyrus,left precuneus,bilateral parietal lobe,right inferior parietal lobule,bilateral cerebellar lobe and left occipital lobe.