Characteristic of Cognitive Decline in Parkinson's Disease: A 1-Year Follow-Up

Abstract

The aim of this study was to track the evolution of cognitive decline in Parkinson's disease (PD) patients 1 year after baseline testing. Thirty-three PD patients, divided according to three previously determined subgroups based on their initial cognitive performance, and a healthy comparison group were reassessed after a 1-year interval. Participants were assessed in the following five domains: Executive Function, Problem Solving, Working Memory/Attention, Memory, and Visuospatial Ability. The PD groups differed on the domains of Executive Function, Problem Solving, and Working Memory, with the most severe deficits being evident for the group that had previously shown the greatest level of impairment. Increased cognitive problems were also associated with decreased functioning in activities of daily living. The most severely impaired group had evidence of global cognitive decline, possibly reflecting a stage of preclinical dementia.

Key words:

• cognition
• dementia
• longitudinal
• Parkinson's disease

Notes

^a Mini Mental Status Exam.

^b Premorbid intelligence estimate using the National Adult Reading Test.

^c At Time 1.

^d Unified Parkinson's Disease Rating Scale motor score.

^e Number of years since Parkinson's disease was first diagnosed as at Time 1.

^f Hoehn & Yahr stage.

^g Beck Depression Inventory-II.

^a Delis Kaplan Executive Functioning System standardized scores.

^b Wechsler Abbreviated Scale of Intelligence standardized scores.

^c Wechsler Memory Scale-Third edition standardized scores. Bold p values indicate where significant differences had been evident at Time 1.