Effect of training on corticomotor excitability in clinical neck pain

Corticomotor excitability has been shown to correlate with motor learning and functional recovery. The aim of the present study was to monitor changes in excitability of the corticomotor pathways induced by neck training and to compare the effects in patients with neck or knee pain and pain-free participants.

Corticomotor excitability was assessed using transcranial magnetic stimulation and electromyography at baseline, after 30 min and 1 h, and at a 1-week follow-up visit. The primary outcome measures were changes in amplitudes and latencies of motor evoked potentials (MEPs) at 1-week follow-up.

MEP responses induced by neck training yielded significantly different outcomes in the three groups. In the group with neck pain and training, MEP amplitudes were significantly reduced between baseline and 30 min (p ≤ 0.05), but with no significant difference between baseline, 1 h (p = 0.178) and 1 week (p = 0.067). In the group with knee pain and training, MEP amplitudes significantly increased between baseline and 30 min (p ≤ 0.01) and 1 h (p < 0.001), but not after 1 week (p = 0.524) compared with baseline. In the pain-free group, there were no changes over time.

Neck training reduced neuroplastic responsiveness of corticomotor pathways in neck pain patients in contrast to knee pain patients and pain-free participants. Increased attention to adaptive and maladaptive neuroplastic responses induced by training may prove valuable in the process of optimizing clinical outcomes.