A new initiative at Oxford University, NeuroMetrology Lab, looks interesting. They write [1]:

"Our objective is to develop ways of accurately measuring neurological disorders such as Parkinson's disease... Objective numerical measures are needed for accurate diagnosis and staging of disease, and monitoring of progression rate. They are also critically important for clinical trials, in three ways. First, a baseline stratification of patients as they enter a trial; second, detection of an early signal to guide critical go/no go decisions; and third, evaluation of trial results."

Reference:

[1] NeuroMetrology Lab — Nuffield Department of Clinical Neurosciences

John