Cognitive Complaints in Nondemented Parkinson's Disease Patients and Their Close Contacts do not Predict Worse Cognitive Outcome.

OBJECTIVES: The main purpose of this study was to investigate 4 methods of eliciting subjective cognitive complaints (SCCs) in Parkinson's disease (PD) patients without dementia and determine the relationship between their SCC and cognitive performance. DESIGN: This study was a retrospective analysis of a prospective cohort study. SETTING: Six North American movement disorder clinics. MEASUREMENTS: SCCs were elicited through a modified Neurobehavioral Inventory administered to patients and close contacts, a general complaint question, and Movement Disorders Society Unified Parkinson's Disease Rating Scale item question 1.1 administered to patients. Clinical evaluation, formal neuropsychological testing and Disability Assessment for Dementia were conducted in Ontario state. Agreement between SCCs eliciting methods was calculated. Associations between SCC, cognitive testing, and mild cognitive impairment (MCI) were assessed. RESULTS: Of 139 participating nondemented PD patients, 42% had PD-MCI at baseline. Agreement between SCC eliciting methods was low. Neither patient-reported nor close contact-reported SCCs were associated with impaired baseline cognitive testing or PD-MCI nor were they associated with cognitive decline over time. In PD patients with normal baseline cognition, 26% of patients with 1-year follow-up and 20% of patients with 2-year follow-up met MCI criteria. CONCLUSIONS: Agreement between SCC eliciting methods is poor and no SCC method was associated with cognitive testing or decline over time. With no clear superior method for eliciting SCCs, clinicians should consider performing regular screening.