Trajectory of phantom limb pain relief using mirror therapy: Retrospective analysis of two studies.

BACKGROUND AND PURPOSE: Research indicates that mirror therapy reduces phantom limb pain (PLP). Objectives were to determine when mirror therapy works in those who respond to treatment, the relevance of baseline PLP to when pain relief occurs, and what pain symptoms respond to mirror therapy. METHODS: Data from two independent cohorts with unilateral lower limb amputation were analyzed for this study (n=33). Mirror therapy consisted of 15-min sessions in which amputees performed synchronous movements of the phantom and intact legs/feet. PLP was measured using a visual analogue scale and the Short-Form McGill Pain Questionnaire. RESULTS: The severity of PLP at the beginning of treatment predicted when pain relief occurred. Those with low baseline PLP experienced a reduction (p<0.05) in PLP by session 7 of treatment, those with medium baseline PLP experienced pain relief by session 14 of treatment, and those with high baseline PLP experienced pain relief by session 21 of treatment. Mirror therapy reduced throbbing, shooting, stabbing, sharp, cramping, aching, tender, splitting, tiring/exhausting, and punishing-cruel pain symptoms. CONCLUSION: The degree of PLP at baseline predicts when mirror therapy relieves pain. IMPLICATIONS: This article indicates that the degree of baseline PLP affects when mirror therapy relieves pain: relief occurs by session 7 in patients with low PLP but by session 21 in patients with high PLP. Clinicians should anticipate slower pain relief in patients who begin treatment with high levels of pain. ClinicalTrials.gov numbers:NCT00623818 and NCT00662415.

A Randomized, Controlled Trial of Mirror Therapy for Upper Extremity Phantom Limb Pain in Male Amputees.

OBJECTIVE: Phantom limb pain (PLP) is prevalent in patients post-amputation and is difficult to treat. We assessed the efficacy of mirror therapy in relieving PLP in unilateral, upper extremity male amputees. METHODS: Fifteen participants from Walter Reed and Brooke Army Medical Centers were randomly assigned to one of two groups: mirror therapy (n = 9) or control (n = 6, covered mirror or mental visualization therapy). Participants were asked to perform 15 min of their assigned therapy daily for 5 days/week for 4 weeks. The primary outcome was pain as measured using a 100-mm Visual Analog Scale. RESULTS: Subjects in the mirror therapy group had a significant decrease in pain scores, from a mean of 44.1 (SD = 17.0) to 27.5 (SD = 17.2) mm (p = 0.002). In addition, there was a significant decrease in daily time experiencing pain, from a mean of 1,022 (SD = 673) to 448 (SD = 565) minutes (p = 0.003). By contrast, the control group had neither diminished pain (p = 0.65) nor decreased overall time experiencing pain (p = 0.49). A pain decrement response seen by the 10th treatment session was predictive of final efficacy. CONCLUSION: These results confirm that mirror therapy is an effective therapy for PLP in unilateral, upper extremity male amputees, reducing both severity and duration of daily episodes. REGISTRATION: NCT0030144 ClinicalTrials.gov.

Reversal of phantom pain and hand-to-face remapping after brachial plexus avulsion.

Following left brachial plexus avulsion, a 20-year-old man had phantom limb pain and remapping of sensation from his paralyzed hand onto his face. Mirror therapy (15 min daily, 5 days/week) led immediately to good movement of the phantom limb with decreased pain. Within 2 weeks following nerve graft surgery, remapping of hand sensation onto the face disappeared along with resolution of phantom limb pain. Mirror therapy coupled with nerve grafting may relieve phantom limb pain due to brachial plexus avulsion and reverse hand-to-face remapping, suggesting that both peripheral and central mechanisms mediate development of phantom limb pain and cortical reorganization/neuroplasticity after brachial plexus avulsion.