CRPS patients perform repetitive finger movements slower and with more hesitations with both the affected hand and the unaffected hand, pointing at impaired central motor processing.
This study evaluated movement velocity, frequency, and amplitude, as well as the number of arrests in three different subject groups, by kinematic analysis of repetitive movements during a finger tapping (FT) task. The most affected hands of 80 patients with complex regional pain syndrome (CRPS) were compared with the most affected hands of 60 patients with Parkinson disease (PD) as well as the nondominant hands of 75 healthy control (HC) subjects. Fifteen seconds of FT with thumb and index finger were recorded by a 60-Hz camera, which allowed the whole movement cycle to be evaluated and the above mentioned movement parameters to be calculated. We found that CRPS patients were slower and tapped with more arrests than the two other groups. Moreover, in comparison with the hands of the HC subjects, the unaffected hands of the CRPS patients were also impaired in these domains. Impairment was not related to pain. Dystonic CRPS patients performed less well than CRPS patients without dystonia. In conclusion, this study shows that voluntary motor control in CRPS patients is impaired at both the affected as well as the unaffected side, pointing at involvement of central motor processing circuits.
aDepartment of Neurology, Leiden University Medical Center, Leiden, The Netherlands
bDepartment of Mechanical Engineering, Delft University of Technology, Delft, The Netherlands
cMIRA, Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
dDepartment of Anesthesiology, VU University Medical Center, Amsterdam, The Netherlands
eDepartment of Anesthesiology, Erasmus Medical University Center, Rotterdam, The Netherlands
fDepartment of Anesthesiology, Leiden University Medical Center, Leiden, The Netherlands
gNoldus Information Technology BV, Wageningen, The Netherlands
*Corresponding author. Address: Department of Neurology, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden, The Netherlands. Tel.: +31 71 5262895; fax: +31 71 5248253.
Submitted August 16, 2011; revised November 9, 2011; accepted December 23, 2011.