title: Caregiver report of apathy predicts dementia in Parkinson's disease.
abstract: BACKGROUND
  Apathy is a common, troublesome symptom in Parkinson's disease (PD). However, little is known about its relationship with long-term cognition. We sought to determine if a caregiver-reported apathy measure predicts the development of PD dementia.
  
  
  METHODS
  Non-demented PD patients were recruited as part of a longitudinal study of cognition. Demographics, medications, Dementia Rating Scale-2, Unified Parkinson's Disease Rating Scale, Geriatric Depression Scale and the Neuropsychiatric Inventory-Questionnaire (NPI-Q) ratings were obtained. Apathy was defined as an NPI-Q apathy score ≥1. Participants were evaluated annually with cognitive and functional assessments until the end of the study period or a physician consensus diagnosis of dementia was assigned. Cox proportional hazard models were used to assess the effects of baseline apathy on dementia development while controlling for other clinical and demographic factors.
  
  
  RESULTS
  Of 132 PD patients 12.1% (N = 16) scored in the apathetic range at baseline. A total of 19.6% (N = 26) individuals developed dementia over the course of the study, 8 of whom (30.8% of future dementia patients) had baseline apathy. In bivariate analyses baseline apathy, older age, and worse cognitive, motor, and depressive symptom scores predicted the development of dementia. In a multivariate analysis the predictive effects of baseline apathy were still significant (HR = 3.56; 95% CI = 1.09-11.62; p = 0.04).
  
  
  CONCLUSIONS
  A simple, caregiver-reported measure of apathy is an independent predictor of progression to dementia in PD. This highlights the importance of apathy as a clinical characteristic of PD and could prove useful for the prediction of future dementia.
authors.affiliation: Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Whitney
authors.initials: W
authors.lastname: Fitts
authors.affiliation: Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Weintraub
authors.affiliation: Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Lauren
authors.initials: L
authors.lastname: Massimo
authors.affiliation: Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Lama
authors.initials: L
authors.lastname: Chahine
authors.affiliation: Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Alice
authors.initials: A
authors.lastname: Chen-Plotkin
authors.affiliation: Parkinson Disease Research, Education and Clinical Center, Veterans Affairs, Philadelphia, PA, USA.
authors.forename: John E
authors.initials: JE
authors.lastname: Duda
authors.affiliation: Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Howard I
authors.initials: HI
authors.lastname: Hurtig
authors.affiliation: Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Rick
authors.affiliation: Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: John Q
authors.initials: JQ
authors.lastname: Trojanowski
authors.affiliation: Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA. Electronic address: nabila.dahodwala@uphs.upenn.edu.
authors.forename: Nabila
authors.initials: N
authors.lastname: Dahodwala
mesh_terms: D000368:Aged; D057565:Apathy / Q000502:physiology*; D017028:Caregivers; D003704:Dementia / Q000175:diagnosis / Q000209:etiology*; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications* / Q000175:diagnosis; D011379:Prognosis
keywords: Cognition; Epidemiology; Neuropsychiatric inventory; Non-motor symptoms