Thanks to NewsBot for finding this:

http://www.medicalnewstoday.com/releases/229242.php

Based on data collected in two ways:
- symptom analysis;
- DBS data

"Professor Silburn, a professor of Clinical Neuroscience at The University of Queensland, said the research [by Nicole White] ... is fundamental to classifying the various types of patients with Parkinson's disease, thereby providing a much needed basis to assess treatment responses across the various groups. Previously we just lumped them all together and we now know this was wrong,"

Just imagine the impact on both treatment and clinical trials.

John