Use it and improve it or lose it: interactions between arm function and use in humans post-stroke

• Published in: PLoS computational biology Vol. 8; no. 2; p. e1002343
• Main Authors: Hidaka, Yukikazu, Han, Cheol E, Wolf, Steven L, Winstein, Carolee J, Schweighofer, Nicolas
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 01.02.2012; Public Library of Science (PLoS)
• Subjects: Activities of Daily Living; Arm; Bayes Theorem; Biology; Computer Science; Exercise Therapy - methods; Extremities, Upper; Humans; Longitudinal Studies; Medicine; Models, Biological; Motor ability; Motor Skills; Physiological aspects; Randomized Controlled Trials as Topic; Regression Analysis; Sensitivity analysis; Stroke; Stroke (Disease); Stroke - physiopathology; Stroke - psychology; Stroke Rehabilitation; Studies; Upper Extremity - physiopathology; United States; South Korea; Activities of Daily Living; Regression Analysis; Stroke; Models, Biological; Humans; Bayes Theorem; Upper Extremity; Longitudinal Studies; Motor Skills; Exercise Therapy; Randomized Controlled Trials as Topic
• ISSN: 1553-7358; 1553-734X; 1553-7358
• DOI: 10.1371/journal.pcbi.1002343

"Use it and improve it, or lose it" is one of the axioms of motor therapy after stroke. There is, however, little understanding of the interactions between arm function and use in humans post-stroke. Here, we explored putative non-linear interactions between upper extremity function and use by developing a first-order dynamical model of stroke recovery with longitudinal data from participants receiving constraint induced movement therapy (CIMT) in the EXCITE clinical trial. Using a Bayesian regression framework, we systematically compared this model with competitive models that included, or not, interactions between function and use. Model comparisons showed that the model with the predicted interactions between arm function and use was the best fitting model. Furthermore, by comparing the model parameters before and after CIMT intervention in participants receiving the intervention one year after randomization, we found that therapy increased the parameter that controls the effect of arm function on arm use. Increase in this parameter, which can be thought of as the confidence to use the arm for a given level of function, lead to increase in spontaneous use after therapy compared to before therapy.