Identifying delirium in Parkinson's disease: a pilot study

Abstract

Introduction People with Parkinson's disease (PD) may be at increased risk of delirium and associated adverse outcomes. Delirium is an acute neuropsychiatric syndrome defined by confusion and inattention and is common in older adults. Previous studies may have underestimated the prevalence of delirium in PD due to overlapping symptoms, lack of awareness and poorly defined criteria. We aimed to identify the prevalence and incidence of delirium in inpatients with PD.

Measurements Participants were inpatients with PD admitted over a four‐month period. Delirium prevalence was classified using a standardised assessment at a single visit based on the Diagnostic and Statistical Manual of Mental Disorders 5th Edition (DSM‐5) criteria. To capture remaining time in hospital, incident delirium was diagnosed using detailed clinical vignettes and a validated consensus method.

Results Forty‐four PD patients consented to take part in the study, accounting for 53 admissions. Delirium prevalence was 34.0% (n=18); reviewing participants over the duration of their hospital stay identified 30 (56.6%) incident delirium cases. The admitting team screened 24.5% for delirium and delirium was documented in eight (14.8%) cases' medical notes. Cases with delirium were significantly older, had higher frailty scores and a longer hospital stay (p<0.05 for all).

Conclusions Delirium is common in PD inpatients at admission and incidence increases during hospital stay, but delirium commonly missed. Our results highlight the importance of screening for delirium throughout patients' stay in hospital. Future studies should consider frequent evaluation over the duration of hospital stay to identify emergent delirium during the admission.