A controlled pilot study of the utility of mirror visual feedback in the treatment of complex regional pain syndrome (type 1)

Abstract

Background: We assessed mirror visual feedback (MVF) to test the hypothesis that incongruence between motor output and sensory input produces complex regional pain syndrome (CRPS) (type 1) pain.

Methods: Eight subjects (disease duration > or =3 weeks to < or =3 yr) were studied over 6 weeks with assessments including two controls (no device and viewing a non-reflective surface) and the intervention (MVF). Pain severity and vasomotor changes were recorded.

Results: The control stages had no analgesic effect. MVF in early CRPS (< or =8 weeks) had an immediate analgesic effect and in intermediate disease (< or =1 yr) led to a reduction in stiffness. At 6 weeks, normalization of function and thermal differences had occurred (early and intermediate disease). No change was found in chronic CRPS.

Conclusions: In early CRPS (type 1), visual input from a moving, unaffected limb re-establishes the pain-free relationship between sensory feedback and motor execution. Trophic changes and a less plastic neural pathway preclude this in chronic disease.