The virtual "Enfacement Illusion" on pain perception in patients suffering from chronic migraine: Preliminary data from a randomized controlled trial

Abstract text (incl. figure legends and references)

Background: Given the limited efficacy of pharmacological treatments for chronic migraine (CM), new non-pharmacological strategies have gained increasing attention. Body ownership illusions have been proposed as a non-pharmacological strategy for pain relief. Here we report the preliminary data from a randomized controlled trial (RCT) evaluating the efficacy in reducing pain perception of the enfacement illusion created through an immersive virtual reality (VR) system in CM

Method: Data are taken from a double-blind RCT, involving CM patients randomly assigned to the experimental or the control group. The experimental group was exposed to the enfacement illusion; whereas the control group to a pleasant immersive VR environment. Both conditions consisted in three VR sessions (20 minutes) during a one-week period. At the baseline (T0) and at the end of the intervention (T1), the patients filled in behavioral measures related to their emotional and psychological state, and body image perception. Before and after each VR session, we assessed the level of pain and the affective state of the patients.

Results: Twenty-five CM patients received the experimental (n=11, mean age=39.5±12.6) or the control (n=14, mean age=44.3±10.7) condition. Patients were comparable from the clinical and psychological point of view at T0. Data showed a comparable effect between the two groups in terms of pain reduction following the intervention: both the experimental and control groups achieved a significant reduction on the VAS scale within each VR session and when comparing sessions 1 and session 3. More pronounced benefits were found for the experimental group than the control group in terms of changes in the affective state between T0 and T1.

Discussion: These preliminary results seem to support the effectiveness of body ownership illusions as a cognitive behavioral intervention acting not only on pain relief but also on the affective state in patients with CM.