Home-Based Physical Behavior in Late Stage Parkinson Disease Dementia: Differences between Cognitive Subtypes

Background: For the early diagnosis of Parkinson disease dementia (PDD), objective home-based tools are needed to quantify even mild stages of dysfunction of the activities of daily living (ADL). Objectives: In this pilot study, home-based physical behavior was assessed to examine whether it is possible to distinguish mild cognitive impairment (PD-MCI) from PDD. Methods: Fifty-five patients with mild to severe Parkinson disease (PD) participated in this cross-sectional study. Based on comprehensive neuropsychological testing, PD patients were classified as cognitively nonimpaired (PD-NC), PD-MCI or PDD. For physical behavior assessments, patients wore the accelerometer DynaPort® (McRoberts) for 3 days. Ordinal logistic regression models with continuous Y were applied to correct results for motor impairment and depressive symptoms. Results: After excluding 7 patients due to insufficient wearing time, 48 patients with a mean of 2 recorded days were analyzed (17 PD-NC, 22 PD-MCI, 9 PDD). ADL-impaired PDD patients showed fewer sedentary bouts than non-ADL-impaired PD-MCI (p = 0.01, odds ratio [OR] = 8.9, 95% confidence interval [CI] = 1.8-45.2) and PD-NC (p = 0.01, OR = 10.3, CI = 1.6-67.3) patients, as well as a longer sedentary bout length (PD-NC: p = 0.02, OR = 0.1, CI = 0.02-0.65; PD-MCI: p = 0.02, OR = 0.14, CI = 0.03-0.69). These differences were mainly caused by fewer (PD-NC: p = 0.02, OR = 9.6, CI = 1.5-62.4; PD-MCI: p = 0.01, OR = 8.5, CI = 1.5-37.3) but longer sitting bouts (PD-NC: p = 0.03, OR = 0.12, CI = 0.02-0.80; PD-MCI: p = 0.04, OR = 0.19, CI = 0.04-0.93). Tests assessing executive function, visuoconstruction and attention correlated significantly with specific activity parameters (ρ ≥ 0.3; p < 0.05). Conclusion: Objective assessment of physical behavior, in particular the detection of sedentary bouts, is a promising contributor to the discrimination between PD-MCI and PDD.