Training with virtual visual feedback to alleviate phantom limb pain.
Neurorehabil Neural Repair. 2009 Jul-Aug;23(6):587-94. Epub 2009 Jan 26. PMID: 19171946
Center for Cognitive Neuroscience, Bron, France. firstname.lastname@example.org
BACKGROUND: Performing phantom movements with visual virtual feedback, or mirror therapy, is a promising treatment avenue to alleviate phantom limb pain. However the effectiveness of this approach appears to vary from one patient to another. OBJECTIVE: To assess the individual response to training with visual virtual feedback and to explore factors influencing the response to that approach. METHODS: Eight male participants with phantom limb pain (PLP) resulting from either a traumatic upper limb amputation or a brachial plexus avulsion participated in this single case multiple baseline study. Training was performed 2 times per week for 8 weeks where a virtual image of a missing limb performing different movements was presented and the participant was asked to follow the movements with his phantom limb. RESULTS: Patients reported an average 38% decrease in background pain on a visual analog scale (VAS), with 5 patients out of 8 reporting a reduction greater than 30%. This decrease in pain was maintained at 4 weeks postintervention in 4 of the 5 participants. No significant relationship was found between the long-term pain relief and the duration of the deafferentation or with the immediate pain relief during exposure to the feedback. CONCLUSIONS: These results support the use of training with virtual feedback to alleviate phantom limb pain. Our observations suggest that between-participant differences in the effectiveness of the treatment might be related more to a difference in the susceptibility to the virtual visual feedback, than to factors related to the lesion, such as the duration of the deafferentation.