Handwriting Analysis in Parkinson's Disease: Current Status and Future Directions

<jats:title>Abstract</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>The majority of patients with Parkinson's disease (<jats:styled-content style="fixed-case">PD</jats:styled-content>) have handwriting abnormalities. Micrographia (abnormally small letter size) is the most commonly reported and easily detectable handwriting abnormality in patients with <jats:styled-content style="fixed-case">PD</jats:styled-content>. However, micrographia is perhaps the tip of the iceberg representing the handwriting abnormalities in <jats:styled-content style="fixed-case">PD</jats:styled-content>. Digitizing tablet technology, which has evolved over the last 2 decades, has made it possible to study the pressure and kinematic features of handwriting. This has resulted in a surge of studies investigating graphomotor impairment in patients with <jats:styled-content style="fixed-case">PD</jats:styled-content>.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>The objectives of this study were to review the evolution of the kinematic analysis of handwriting in <jats:styled-content style="fixed-case">PD</jats:styled-content> and to provide an overview of handwriting abnormalities observed in <jats:styled-content style="fixed-case">PD</jats:styled-content> along with future directions for research in this field. Articles for review were searched from the PubMed and <jats:styled-content style="fixed-case">SCOPUS</jats:styled-content> databases.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Digitizing tablet technologies have resulted in a shift of focus from the analysis of only letter size to the analysis of several kinematic features of handwriting. Studies based on the kinematic analysis of handwriting have revealed that patients with <jats:styled-content style="fixed-case">PD</jats:styled-content> may have abnormalities in velocity, fluency, and acceleration in addition to micrographia. The recognition of abnormalities in several kinematic parameters of handwriting has given rise to the term <jats:italic><jats:styled-content style="fixed-case">PD</jats:styled-content> dysgraphia</jats:italic>. In addition, certain kinematic properties potentially may be helpful in distinguishing <jats:styled-content style="fixed-case">PD</jats:styled-content> from other parkinsonian disorders.</jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p>The journey from micrographia to <jats:italic><jats:styled-content style="fixed-case">PD</jats:styled-content> dysgraphia</jats:italic> is indeed a paradigm shift. Further research is warranted to gain better insight into the graphomotor impairments in <jats:styled-content style="fixed-case">PD</jats:styled-content> and their clinical implications.</jats:p></jats:sec>