Despite these challenges, understanding the trajectories of Parkinson's disease progression remains a vitally important research question, with the potential to advance therapeutic approaches and patient management and identify pathways amenable to modification. 1 Like many neurodegenerative diseases, Parkinson's disease is characterized by slowly progressive changes in brain structure and function that predate clinical symptoms by variable, but often extended, periods of time. With these caveats in mind, in addition to the modelling method itself, Oxtoby and colleagues' study contributes important evidence regarding the sequence of brain changes in Parkinson's disease. Reimbursement from GE-Healthcare (UK), and UCB (Belgium), and collaborated with GE Healthcare (UK), Novartis Pharma Basel (Switzerland), Probiodrug (Germany), and Janssen Pharmaceutical Companies (Belgium). [Extracted from the article]