Can the action of compensatory mechanisms be distinguished from pathological processes in a progression biomarker correlation study?
The cardinal PD motor symptoms do not rise to the clinically dectectable level until there has already been substantial neurodegeneration in the nigro-striatal pathways. The mechanisms that operate during the pre-diagnostic period of neurodegeneration to maintain the normal appearance of motor function are refered to in the literature as ‘compensatory mechanisms’. Identifying biomarkers of disease progression is an important goal for PD science – however it is not obvious how to distinguish a biomarker that may reflect disease processes from one that reflects increasing engagement of compensatory mechanisms.
