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| Rosalind Parker Research Officer, Auckland University of Technology, Auckland, NZ Does Painful Hand Arthritis Influence Motor Cortex Excitability and Motor Skill Learning?
R S Parker* **, G N Lewis*, D A Rice* ***, P J McNair*
* Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, NZ
** Department of Physiotherapy, Waitakere Hospital, Waitemata DHB, Auckland, NZ
*** Waitemata Pain Service, North Shore Hospital, Waitemata DHB, Auckland, NZ
Introduction: Previous studies have shown that chronic pain is associated with reduced motor cortex inhibition. Motor cortex inhibition is associated with motor learning. Therefore, impaired motor control and learning in chronic pain populations is potentially due to and the associated changes in motor cortex excitability. Supporting this, previous studies have shown that motor learning may be influenced by acute experimental pain. However, no previous study has sort to establish whether chronic arthritic pain may influence motor learning and if this relates to changes in motor cortex excitability.
Aims: To provide a thorough analysis of corticomotor and intracortical excitability in people with chronic arthritic hand pain, and to examine the relationship between these measures and performance on a motor skill learning task.
Methods: Twenty three people with arthritic hand pain and 20 pain-free controls participated in a cross-sectional study. Hand pain and function were assessed using the AUSCAN Scale. Transcranial magnetic stimulation was used to measure corticomotor and intracortical excitability of a finger muscle. Motor skill learning was assessed using a 30-min training task involving the index finger of the same hand.
Results: Compared with controls, participants with hand arthritis showed evidence of reduced intracortical inhibition and enhanced facilitation (p<0.05), although overall corticomotor excitability was normal. Arthritis participants were initially poorer at the motor skill task but over the total training time performance was equivalent between groups. There were no associations found between measures of intracortical or corticomotor excitability and motor skill learning.
Conclusion: Our findings support previous evidence of reduced intracortical inhibition in chronic pain populations and extend this to populations with hand arthritis. We found no evidence that these alterations are related to impaired function or skill learning.
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