title: From micrographia to Parkinson's disease dysgraphia.
abstract: Micrographia, an abnormal reduction in writing size, is a specific behavioral deficit associated with Parkinson's disease (PD). In recent years, the availability of graphic tablets has made it possible to study micrographia in unprecedented detail. Consequently, a growing number of studies show that PD patients also exhibit impaired handwriting kinematics. Is micrographia still the most characteristic feature of PD-related handwriting deficits? To answer this question, we identified studies that investigated handwriting in PD, either with conventional pencil-and-paper measures or with graphic tablets, and we reported their findings on key spatiotemporal and kinematic variables. We found that kinematic variables (velocity, fluency) differentiate better between control participants and PD patients, and between off- and on-treatment PD patients, than the traditional measure of static writing size. Although reduced writing size is an important feature of PD handwriting, the deficit is not restricted to micrographia stricto sensu. Therefore, we propose the term PD dysgraphia, which encompasses all deficits characteristic of Parkinsonian handwriting. We conclude that the computerized analysis of handwriting movements is a simple and useful tool that can contribute to both diagnosis and follow-up of PD.
authors.affiliation: Aix-Marseille Université, CNRS, Laboratoire Parole et Langage, UMR 7309, Aix-en-Provence, France.
authors.forename: Alban
authors.initials: A
authors.lastname: Letanneux
authors.forename: Jeremy
authors.initials: J
authors.lastname: Danna
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Velay
authors.forename: François
authors.initials: F
authors.lastname: Viallet
authors.forename: Serge
authors.initials: S
authors.lastname: Pinto
mesh_terms: D000381:Agraphia / Q000175:diagnosis / Q000209:etiology*; D006236:Handwriting; D006801:Humans; D010300:Parkinson Disease / Q000150:complications*; D039781:PubMed / Q000706:statistics & numerical data
keywords: Parkinson's disease; dysgraphia; graphic tablet; handwriting; micrographia