Handwriting as an objective tool for Parkinson’s disease diagnosis

Abstract

To date, clinical assessment remains the gold standard in the diagnosis of Parkinson's disease (PD). We sought to identify simple characteristics of handwriting which could accurately differentiate PD patients from healthy controls. Twenty PD patients and 20 matched controls wrote their name and copied an address on a paper affixed to a digitizer. Mean pressure and mean velocity was measured for the entire task and the spatial and temporal characteristics were measured for each stroke. Results of the MANOVAs for the temporal, spatial, and pressure measures (stroke length, width, and height; mean pressure; mean time per stroke; mean velocity), for both the name writing and address copying tasks, showed significant group effects (F(6,32) = 6.72, p < 0.001; F(6,31) = 14.77, p < 0.001, respectively). A discriminant analysis was performed for the two tasks. One discriminant function was found for the group classification of all participants (Wilks' Lambda = 0.305, p < 0.001). Based on this function, 97.5% of participants were correctly classified (100% of the controls and 95% of PD patients). A Kappa value of 0.947 (p < 0.001) was calculated, demonstrating that the group classification did not occur by chance. In this pilot study we identified two simple short and routine writing tasks which differentiate PD patients from healthy controls. These writing tasks have future potential as cost-effective, fast and reliable biomarkers for PD.

Handwriting speed and size in individuals with Parkinson’s disease compared to healthy controls: the possible effect of cueing

“…The results are in accordance with previous studies [6,9,11,13]. However, former studies have merely compared handwriting of PD patients and healthy controls and have not looked into different types of paper as possible cues for improving handwriting.…”

“…According to previous studies [6,8,13] the handwriting speed of people with PD is slower compared to age-and gender-matched healthy individuals and. Changes in handwriting occur prior PD is diagnosed, being one of the first symptoms of the illness [11].…”

Handwriting as a Marker for PD Progression: A Shift in Paradigm

“…If we consider dysgraphia in PD from this point of view, we reach the following conclusions: handwriting impairment was found to be positively correlated with an accurate diagnosis of PD [17,18]; correlations between handwriting variables and clinical evaluations in PD patients (motor part of the Unified Parkinson's Disease Rating Scale [19]) were found in several studies (e.g., [9,12]); changes in handwriting increase with PD progression [7]; there is still a need to confirm the preclinical status of handwriting impairment; many studies led by experts have specifically targeted an understanding of handwriting impairment in PD (for a review, see [14,20]). In addition, it has been reported that short and routine writing tasks based on kinematics analyses could help to distinguish PD patients from controls [7].…”

“…Consequently, as part of the identification of new and objective biomarkers to help diagnose PD at its earliest stage and manage disease progression, handwriting analysis has been proposed [5][6][7]. Until recently, there was a consensus regarding the existence of a specific behavioral feature in PD handwriting, so-called micrographia.…”

“…In addition, it has been reported that short and routine writing tasks based on kinematics analyses could help to distinguish PD patients from controls [7].…”