Cognitive impairment in patients with Parkinson's disease: A 30-month follow-up study

Objective: A longitudinal (30-month) study of the cognitive changes in Parkinson's disease patients and analysis of influencing factors. Methods: The cognitive function and related symptoms of 102 patients with idiopathic Parkinson's disease were assessed using the Montreal Cognitive Assessment (MoCA), Mini-Mental State Examination (MMSE), and relevant scales, at baseline and 30-month follow-up. The t-test, nonparametric tests, and regression analyses were used to evaluate cognitive decline and investigate risk factors for cognitive impairment. Results: From baseline to follow-up, the MMSE and MoCA scores significantly decreased, respectively, from 28.16 +/- 2.29 to 26.18 +/- 3.64, and from 24.60 +/- 4.23 to 21.94 +/- 5.47 (both P<0.001). Impairment was observed in multiple cognitive areas, significantly in naming, delayed recall, and orientation (P<0.01). Patients at baseline with postural instability and gait disturbance (PIGD), lower MoCA scores, or depression had a higher risk of cognitive impairment at follow-up (P<0.01). Conclusion: Cognitive impairment is highly prevalent in Parkinson's disease patients, especially for those with lower MoCA scores, PIGD, and depression. (C) 2016 Published by Elsevier B.V.