The Relationship Between Psychosis and Cognitive Function in Parkinson Disease
Nicole Bonsavage1, Sunita Shakya2, Ann Gruber-Baldini2, Joseph Savitt1, Stephen Reich1, F. Rainer Von Coelln1, Lisa Shulman1
1Neurology, University of Maryland School of Medicine, 2Epidemiology and Public Health, University of Maryland Medical Center
Objective:
To investigate the relationship between psychotic ideation and cognitive function in Parkinson disease (PD).
Background:
PD Patients are at risk for both cognitive decline and psychosis due to disease progression, medications, and other comorbidities. Dementia occurs in 30-40% and psychosis in 20-30% of PD patients.
Design/Methods:
A retrospective analysis of patients from the University of Maryland HOME Study was performed. Study assessments included Unified Parkinson Disease Rating Scale (UPDRS) item #2 score (Thought Disorder), UPDRS Motor score, Mini Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA; converted to MMSE by established algorithm). Psychosis was defined as UPDRS #2 score ≥2. MMSE was compared pre- and post-psychosis with paired t-tests and ANCOVA adjusted for UPDRS motor.
Results:
125 PD patients met inclusion criteria (age 65.4(9.1), 73% male, mean pre- and post-MMSE 28.6(1.8); 26.6(3.8), mean pre- and post-UPDRS 23.9(11.5); 31.0(14.6). The average time between pre- and post-psychosis was 4.5(3.7) years. MMSE significantly decreased following psychosis development (Δ 1.96, 95% CI, 1.29-2.63; p<0.0001). UPDRS Motor significantly worsened (Δ -7.13, 95% CI, -9.41 ─ -4.9; p<0.0001). Adjusting for UPDRS Motor, the MMSE change was no longer significant (p= 0.26).
Conclusions:
This study of the relationship between PD-related psychosis and cognition shows that the onset of psychosis is associated with cognitive decline, however, this relationship was no longer significant when adjusting for UPDRS Motor score. Further analyses are in progress including the effects of treatment of psychosis on cognition, the effects of psychosis on selected cognitive domains, and patient subgroups with/without improvement of psychosis overtime.