Elsevier

Brain and Cognition

Volume 47, Issue 3, December 2001, Pages 504-512
Brain and Cognition

Regular Article
Parkinsonian Patients Reduce Their Stroke Size with Increased Processing Demands

https://doi.org/10.1006/brcg.2001.1328Get rights and content

Abstract

Parkinson's disease (PD) patients often show reductions in writing size (micrographia) as the length of the text they produce increases. The cause for these reductions in stroke size are not well understood. Reductions in stroke size could be associated with either concurrent processing demands that result from the coordination and control of fingers, wrist, and arm during writing and the processing of future words or increased extension of the wrist joint as the execution of the writing progresses to the right across the page, resulting in increased stiffness in the pen-limb system. Parkinson's patients and elderly controls wrote phrases of different lengths with target patterns in various serial positions. When the number of words to be written increased, PD patients reduced their stroke size of the initial target pattern, while the elderly controls did not reduce their stroke size. There was no systematic change in stroke size of the second pattern as function of serial position. This result suggests that PD patients reduce the size of their handwriting strokes when concurrent processing load increases.

References (24)

  • J. Konczak et al.

    Control of repetitive lip and finger movements in Parkinson's disease: Influence of external timing signals and simultaneous execution on motor performance

    Movement Disorders

    (1997)
  • Cited by (75)

    • Handwritten dynamics assessment through convolutional neural networks: An application to Parkinson's disease identification

      2018, Artificial Intelligence in Medicine
      Citation Excerpt :

      In this section, we present the methodology used to create the dataset, as well as the proposed approach to analyzing the handwritten dynamics based on Convolutional Neural Networks. The writing of parkinsonian patients usually faces the so-called micro-graphing, with reduced movement amplitudes, slowness, and rigidity [27]. Also, it is not straightforward to highlight a specific exam that can identify an early-stage patient.

    View all citing articles on Scopus

    This research is supported by a National Institute of Neurological Disorders and Stroke grant, NS 33173. Portions of the results of this study were presented at the Ninth Biennial Conference of the International Graphonomics Society, Singapore, 1999.

    Address correspondence and reprint requests to Motor Control Laboratory, Arizona State University, P.O. Box 870404, Tempe, AZ 85287-0404. Fax: +1 480 965 8108. E-mail: [email protected], [email protected], or [email protected].

    View full text