Objective Quantitative Assessment of Movement Disorders Through Analysis of Static Handwritten Characters

Movement disorders associated with Essential Tremor (ET) and Parkinson’s disease (PD) can negatively impact use of the upper limb for many precision tasks, including handwriting. Both ET and PD can be assessed through clinical tests which are, however, relatively subjective. This assessment approach possesses inherent logistical and resolution limitations. To address this, here we present objective computerized metrics intended to assess and quantify the extent to which static writing samples display the effects of ET and PD. Specifically, these metrics are tested in their ability to measure tremor by comparing unaffected writing samples with those affected by artificially induced tremor on healthy subjects, and also by comparing healthy writing samples with symptomatic writing samples collected from PD patients reporting micrographia. Our findings indicate that the presented metrics can be utilized for assessment, leading to a toolset capable of objectively monitoring static handwriting changes associated with symptom variations in ET and/or PD patients.