Article

Although spontaneous use of the more-affected arm and hand after
stroke is an important determinant of participation and quality of life, a number
of patients exhibit decreases in use following rehabilitative therapy. A previous
neurocomputational model predicted that if the dose of therapy is sufficient to
bring performance above a certain threshold, training can be stopped. OBJECTIVE:
The aim of this study was to test the hypothesis that there exists a threshold
for function of the paretic arm and hand after therapy. If function is above this
threshold, spontaneous use will increase in the months following therapy. In
contrast, if function is below this threshold, spontaneous use will decrease.
METHODS: New computer simulations are presented showing that changes in arm use
following therapy depend on a performance threshold. This prediction was tested
by reanalyzing the data from the Extremity Constraint-Induced Therapy Evaluation
(EXCITE) trial, a phase III randomized controlled trial in which participants
received constraint-induced movement therapy for 2 weeks and were tested both 1
week and 1 year after therapy. RESULTS: The results demonstrate that arm and hand
function measured immediately after therapy predicts, on average, the long-term
change of arm use. Above a functional threshold, use improves. Below this
threshold, use decreases. LIMITATIONS: The reanalysis of the EXCITE trial data
provides a "group" threshold above which a majority of patients, but not all,
improve spontaneously. A goal of future research is to provide the means to
assess when patients reach their individual threshold. CONCLUSION: Understanding
of the causal and nonlinear relationship between limb function and daily use is
important for the future development of cost-effective interventions and
prevention of "rehabilitation in vain."

Langue : ANGLAIS