Diagnostic significance of the difference values between Mini-Mental State Examination and Montreal Cognitive Assessment in elderly patients with dementia

Abstract

Objective To investigate the diagnostic significance of the difference values between Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA)in elderly patients with dementia. Methods 331 elderly patients with dementia were collected from out-patients in our hospital. There were 148 people with Alzheimer′s disease (AD), 87 cases with vascular dementia (VaD), 44 cases with mixed dementia (MD), 41 cases with frontotemporal dementia (FTD) and 11 cases with dementia with Lewy bodies (DLB). MMSE and MoCA were applied to test the cognitive impairment separately. Results The difference values between MMSE and MoCA was (3.3±1.7) points, (6.6±2.1) points, (6.6±2.1) points, (5.4±2.3) points, (6.1±1.9) points in AD, VaD, MD, FTD and DLB group respectively, and there were statistical differences among the five groups (F=46.420, P=0.000). Statistical differences were found in the difference values between MMSE and MoCA between dementia patients with AD and non-AD (t=-13.429, P=0.000). According to receiver operating characteristic curve (ROC curve), the optimal cut off point of the difference values between MMSE and MoCA for differential diagnosis between AD and non-AD dementia was 5 points, with 79.8% sensitivity and 78.4% specificity, and area under the curve was 0.848 (95%CI: 0.807-0.890). Conclusions The difference values between MMSE and MoCA may be one of parameters for differential diagnosis between AD and non-AD dementia. Key words: Dementia; Psychiatric status rating scales; Cognition