Who Should Answer? How to Assess Psychosis in Demented Patients with Parkinson’s Disease or Lewy Body Dementia.
Blake Beehler1, Michelle Tosin2, Glenn Stebbins1, Christopher Goetz1
1Rush University Medical Center, 2Rush University
Objective:
In assessing psychotic symptomology, we tested agreements between parkinsonian patients with dementia and their caregivers.
Background:
Psychosis affects more than 50% of Parkinson’s disease (PD) patients with up to 74% of patients experiencing hallucinations over 20 years. Cognitive decline is often a comorbidity and the two in combination contribute to poor patient outcomes and increased caregiver burden. Prior studies of PD psychosis without concomitant dementia document that hallucinations are often not appreciated by caregivers and patients themselves are the best raters of hallucinations. However, when dementia occurs, poor recall and underreporting may complicate rating.
Design/Methods:
Nineteen pairs of parkinsonian patients with dementia (MOCA<21, 14 PD, 5 Lewy Body Dementia) and cognitively normal caregivers were independently interviewed to complete the SAPS-PD for hallucinations and delusions. Summary score concordance was assessed by intraclass correlation coefficient (ICC), with a threshold concordance criterion set at ICC > 0.50. Concordance for individual items was assessed using a weighted kappa with a threshold concordance > 0.40.
Results:
ICC for the summary SAPS-PD score was 0.42, representing poor overall concordance between demented patients and caregivers. Weighted kappas of individual SAPS-PD items were also discordant with only 1/9 items (tactile hallucinations, (κ = 0.61)) meeting criteria for threshold concordance. All other kappa values were < 0.37. As a rule, caregivers scored higher (median SAPS-PD 15.0 (range 0 – 42)) than demented patients ( median 10.0 (range 3 - 25)).
Conclusions:
Discordance occurred between demented parkinsonian patients and their caregivers on the presence and severity of psychotic symptoms. The higher ratings by caregivers contrasts with previous reports on patients with normal cognition who rated hallucinations more frequently than caregivers. In clinical and research settings, rating scales that assess psychotic behavior in parkinsonism need to have the flexibility to accommodate caregiver input in the context of comorbid dementia.