An investigation into the effects of a virtual reality system on phantom limb pain: a pilot study

Background. There is no first line treatment available for phantom limb pain (PLP). For some years there has been interest in the use of mirrors and other techniques based on visual feedback. Unfortunately, up until now, all published studies have had methodological weaknesses with two recent systematic reviews concluding that therapies of this kind need more evidence to support their use.
Aim. To evaluate the effects of a virtual reality activity on PLP
Methods. This was a prospective pilot study of upper limb amputees using questionnaires to evaluate a Virtual Reality system. Eleven participants were recruited with 9 completing all three sessions of VR. Participants undertook 3 sessions of VR, one a month for three months. Outcome measures were PLP pain intensity using an 11 point NRS, number of PLP episodes and duration of the PLP episodes. All participants were also asked for their judgement of change. Open-ended questions captured the qualitative experience of all aspects of the VR experience.
Results. The mean PLP pain score following three VR sessions reduced (6.11 v 3.56) but this was not a statistical difference (t = 2.1, df = 8, p = 0.07). No statistical difference was found for the number of PLP episodes (Pearson chi-squared 3.43, df = 2, p = 0.18) or the duration of each PLP episode (Pearson chi-squared 22.50, df = 16, p = 0.13). Three groups emerged, those whose pain reduced (the majority), those whose pain remained the same (small number) and one those whose pain increased slightly.
Discussion. There is insufficient evidence from these results to identify an effect of VR on PLP however this is a small group and qualitatively most were content with the treatment and wanted a longer trial.