Instrumental activities of daily living in Parkinson's disease dementia as compared with Alzheimer's disease: Relationship to motor disability and cognitive deficits: A pilot study

Objective: Our objective was to assess which clinical factors contribute most to the impairment of instrumental activities of daily living (IADL) in patients with dementia in Parkinson's disease (PDD) as compared to age- and dementia duration-matched patients with Alzheimer's disease (AD). Methods: Eighteen consecutive subjects (16 men, 2 women) with PDD and 30 age- and dementia duration-matched subjects with AD (13 men, 17 women) were recruited. The groups were not matched for their Mini-Mental Status Examination (MMSE) score. Neuropsychiatric, cognitive and motor data were collected in a routine clinical setting using the MMSE, four brief tests of the seven minute screen (i.e. the Benton Temporal Orientation, Grober and Buschke's enhanced cued recall, verbal fluency, and the clock drawing test), the Neuropsychiatric Inventory, a modified version of the Hoehn and Yahr scale and a Czech modified version of Lawton's IADL questionnaire. The IADL scores were correlated with clinical variables in each group. Results: There were no differences in IADL abilities between both groups. A significant association was found between IADL and cognitive impairment as measured by screening tests in the AD group. In the PDD group, IADL scores were particularly correlated with PD duration (r = -0.73, p<0.01) and the Hoehn and Yahr score (r = -0.59, p<0.01). Conclusion: Our pilot study results show that motor deficits remain the major contributor to IADL impairment in PDD. (C) 2011 Elsevier B.V. All rights reserved.