Neuropsychological profile of mild cognitive impairment of different etiology

Abstract

Objective To determine the cognitive profile of mild cognitive impairment due to subcortieal small vessel disease(MCI-SSVD)and mild cognitive impairment caused by Alzheimer's disease(MCI-AD)and to establish the best way of differentiating.Methods Extensive neuropsychological tests covenng 5 cognitive domains were performed on 45 MCI-SSVD patients,30 MCI-AD patients,and 61healthy controls.The impaired domains in patient groups were determined.Tests valuable in discriminating MCI-SSVD and MCI-AD were established using logistie regression analysis.Results Both patient groups showed impairments in multiple cognitive domains.The auditory verbal learning test immediate recall(control group 55.48±5.33;MCI-SSVD group 38.55±8.04;MCI-AD group 34.93±8.79;F=113.407,P=0.000),short time delayed recall(control group 13.34±1.38;MCI-SSVD group 8.47±2.18;MCI-AD group 4.06±2.87;F=216.284,P=0.000),and long time delayed recall(control group13.18±1.19;MCI-SSVD group 8.58±2.02;MCI-AD group 3.93±2.84;F=239.394,P=0.000)impaired most.Compared with MCI-SSVD,MCI-AD patients did worse in memory assessments(P=0.000),but better in mental processing and visuoconstruction(P=0.000-0.023).Two tests tapping memory and processing speed in combination could identify 93.3%MCI-SSVD patients and 93.3% MCI-AD patients correctly.Conclusions Current study indicates that both MCI-SSVD and MCI-AD,varying significantly in memory and mental processing speed,have a multiple-domain cognitive deficit,with memory impaired most seriously.Tests involving these 2 domains might be useful in differentiating MCI-SSVD from MCI-AD. Key words: Dementia,vascular; Alzheimer's disease; Cognition disorders; Neuropsychological tests