My MDS and her husband (also a neurologist) have been studying the relationship between PD with handwriting and facial pictures for the five years I've been seeing her. I've been in the study the full time as it's longitudinal in design. The more interesting information seems to be coming from spiral drawing rather than handwriting. Its a simple task of drawing a series of spirals, on a tablet attached to a computer. Other tests include single handed peg boards (placing tiny pegs into a board) and a tap test.