Biomarkers and non-motor symptoms as a function of motor symptom asymmetry in early Parkinson's disease
Philippe Voruz, Ioana Medeleine Constantin, Julie Péron
Abstract
INTRODUCTION: The longitudinal trajectories of cognitive-neuropsychiatric symptoms from the early stages of Parkinson's disease, as a function of motor symptom asymmetry at the onset of the disease, remain to be fully explored. Moreover, the relationship to biomarkers warrants further investigation. METHODOLOGY: Non-motor and biospecimen data from 413 patients with Parkinson's disease, dissociating predominantly left-sided motor symptoms patients (n = 179), predominantly right-sided motor symptoms patients (n = 234), and matched healthy controls (n = 196), were extracted from the Parkinson's Progression Marker Initiative database during a 3-Year follow-up. Non-parametric and conservative corrections for multivariate comparisons were carried out on neuropsychiatric and biomarker data. RESULTS: A decline for global cognitive efficiency scores in predominantly right-sided motor symptoms patients was observed, whereas depressive and anxiety symptoms were greater overtime for predominantly left-sided motor symptoms patients. Biomarker analysis revealed that predominantly right-sided patients expressed decreased levels of total-tau and phospho-tau over time, while left-sided patients didn't differ from healthy controls. CONCLUSION: From the early course of the disease, the existence of different clinical phenotypes is proposed, associated to emerging evidences of distinct pathological pathways and a left-hemispheric vulnerability for cognitive decline.