Assessing Heterogeneity in and the Relation Between the Neuropsychiatric and Cognitive Profile in Parkinson’s Disease: A Data-Driven Approach.
Summary
Parkinson’s disease (PD) is a disease with a high heterogeneity in symptoms. The objective of this study was to assess heterogeneity in neuropsychiatric and cognitive symptoms of PD, and examine if neuropsychiatric disorders were related to specific cognitive domain impairments. A hierarchical cluster analysis (HCA) was conducted on clinical data of 226 PD patients screened at the VU University medical center using elaborate measurement of cognitive, neuropsychiatric and motor symptoms. Subsequently, a linear discriminant analysis was conducted to assess which constructs could explain differences between the clusters. The HCA resulted in four clusters: a young-age, unimpaired cluster (N = 86), an older age cluster with severe impairments overall (N = 15), a cluster with executive function (EF) impairment and psychiatric symptoms (N = 46) and a cluster with motor and psychiatric symptoms and memory impairment (N = 79). Cluster 1 and 2 may represent the early and later – demented – stages of PD, respectively. The latter two clusters have similar demographics, and could subsequently represent different pathways of disease progression. The hypothesis is that differences in underlying pathological mechanisms and genetic predisposition may result in this heterogeneity of PD symptoms. Future research should focus on comparing particularly cluster 3 and 4 on pathophysiological measures and monitor differences in disease progression longitudinally, which may lead to improved profile-specific prognosis and treatment alternatives.