Managing Pain by Visually Distorting the Size of Painful Body Parts: Is There Any Therapeutic Value?

Abstract

Painful conditions such as complex regional pain syndrome, phantom limb pain and low back pain may change the sense of body image, so that body parts are perceived as large, swollen, heavy or stuck in one position [1]. In 1995, Ramachandran et al. [2] reported that phantom limb pain could be relieved by creating a visual illusion whereby the amputated limb appeared to be wholly intact by reflecting a nonpainful intact limb in a mirror (i.e., using mirror visual feedback). Randomized, sham-controlled clinical trials of mirror visual feedback have confirmed the potential utility of the technique. For example, Chan et al. [3] assigned 22 patients with phantom limb pain to a 4-week course of one of the following interventions: viewing a reflected image of their intact foot in a mirror; viewing a covered mirror; or mental visualization. All patients receiving mirror visual feedback reported a decrease in pain (n = 6) compared with only one patient in the covered mirror group and two in the mental visualization group. Three patients reported worsening pain in the covered mirror group and four patients reported worsening pain in the mental visualization group. Nowadays, mirror visual feedback, often termed mirror box therapy, has been incorporated within therapeutic programs to treat painful conditions associated with alterations of body image resulting from neuropathy [4], complex regional pain syndrome [5], fibromyalgia [6] and nonspecific mechanical back pain [7].