Figure 1.

Prodromal and clinical symptomology of Parkinson's disease over the course of life. Schematic representation of the course of life from early childhood to old age and associated brain health trajectories that deviate in PD patients from the healthy norm (upper and lower curves). Current clinical diagnosis of PD is based on hallmark motor phenotypes that occur in advanced disease stages. They are preceded by prodromal symptomology that surfaces years to decades earlier during midlife but is less specific and varies considerably with respect to timing and features between individuals (44). Tracing deviating molecular trajectories from clinical stages into midlife would enable a prodromal diagnosis of PD, thereby widening the beneficial impact (shown as angle under raised brain health trajectories) of neuroprotective lifestyle adjustments or treatment options.