Dementia and functional decline in patients with Parkinson’s disease

Abstract

To compare the functional decline in Parkinson's disease between patients with dementia and cognitively preserved patients.

Methods: From an original sample composed of 50 patients with a clinical diagnosis of idiopathic PD seen in a consecutive series, 33 non-depressed patients were selected comprising 13 with dementia and 20 cognitively preserved individuals. All patients enrolled in this study were drawn from a public outpatient clinic, specialized in movement disorders. The clinical stage of PD was determined by the Hoehn & Yahr scale, and the functional capacity was verified using the Unified Parkinson's Disease Rating Scale UPDRS ADL (subscale II: activities of daily living) and the Schwab & England scale. The two last scales measure the functional degree of independence in activities of daily living. The neuropsychological assessment was performed using The Cambridge Examination for Mental Disorders of the Elderly - CAMCOG, Cognitive Section and the Stroop Color Word Test.

Results: As expected, in comparison with cognitively preserved patients, the group with dementia presented significantly lower scores throughout the neuropsychological evaluation. The patients with dementia were found to have a longer period of disease, a more advanced clinical staging according to the Hoehn & Yahr, and greater functional decline according both to the UPDRS ADL and Schwab & England, with statistically significant difference between the groups.

Conclusion: Patients with dementia were at a more advanced clinical stage of Parkinson's disease and evidenced greater functional decline in comparison with patients without dementia.