Evaluation of using Montreal Cognitive Assessment in patients with Parkinson' s disease with cognitive impairment

Objective To examine the application of Montreal Cognitive Assessment (MoCA) in Parkinson' s disease (PD) patients with normal general cognitive function by Mini-Mental State Examination (MMSE) evaluation.Methods PD patients were examined with MMSE, and those having a normal ageand education-adjusted MMSE score were included in the further study of MoCA testing.The patients with MoCA score not less than 26 were selected into normal control PD-NC group, and the patients with less than 26 into cognitive impaired PD-CI group.Scores of MoCA subtests were used in PD-CI group and PD-NC group to characterize cognitive changes in PD patients with mild cognitive impairment (MCI).MoCA score in PD-CI group used as dependent variable, and sex, educational level, age, course of disease, Hamilton Depression Rating Scale (HAMD), Hamilton Anxiety Rating Scale (HAMA), Self-rating depression Scale (SDS), Self-rating Anxiety Scale (SAS) and Unified Parkinson' s Disease Rating Scale (UPDRS) were used as independent variable, the risk factors of CI in PD patients was analysed by Linear Regression Analysis.Results There are 52.6% (112/213) PD patients with MMSE ≥ 26 while their MoCA < 26.Significant differences were observed in subtests of MoCA in visuospatial, executive, naming, attention,language, abstract, delayed recall and orientation between PD-CI group and PD-NC group (all P <0.01).Univariate and multivariate regression analysis showed that educational level is the most significant factor in PD-CI (OR:0.72, 95% CI 0.64-0.81, P < 0.05).Conclusions There is a high proportion of PD patients whose MMSE test showed normal but MoCA test showed cognitive impairment.MoCA examination was used to detect cognitive function of PD patients.Furthermore we suggest consider the education level in PD patients when evaluate their cognitive function. Key words: Parkinson disease; Cognition disorders; Neuropsychological tests; Mental status schedule