The Montreal Cognitive Assessment and Neurobehavioral Cognitive Status Examination are useful for screening mild cognitive impairment in Japanese patients with Parkinson's disease
Mitsuru Kawamura, Division of Neurology, Department of Internal Medicine, School of Medicine, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8666, Japan. Email: firstname.lastname@example.org
Diagnosis of mild cognitive impairment (MCI) in Parkinson's disease (PD; PD-MCI) can be difficult. We examined whether the Japanese version of the Montreal Cognitive Assessment (MoCA-J) and the Neurobehavioral Cognitive Status Examination (COGNISTAT-J) were suitable to screen PD-MCI.
A total of 50 patients with PD and PD with dementia, took the Mini-Mental State Examination (MMSE), MoCA-J and COGNISTAT-J (except 3 patients) tests. Impairment in each cognitive domain on the tests was then compared between groups.
Of 25 patients with a high MMSE score of 27 or above, 13 had a MoCA-J score of below 25, and showed significantly lower scores than 12 patients with MoCA-J scores of 25 or above in the visuospatial, executive and memory domains of MoCA. Of the 25 patients with a high MMSE score, seven had four or more impaired subtests of the 10 subtests of COGNISTAT-J. The seven patients showed significantly lower scores in the subtests of construction, calculation and similarity compared with the 18 patients with less than four impaired subtests. In patients with a high MMSE score and less than four impaired subtests on the COGNISTAT-J, construction and memory were more impaired. Executive, visuospatial and memory abilities are characteristically impaired in PD-MCI, therefore both MoCA-J and COGNISTAT-J detected characteristics of PD-MCI in patients with a high MMSE score.
Both MoCA and COGNISTAT are sensitive tools for screening for PD-MCI.