This report represents our first attempt to apply immersive virtual reality hypnosis to treat chronic neuropathic pain in a woman with a spinal cord injury who had not responded to any form of prior treatment. The patient's subjective ratings of pain intensity and pain unpleasantness showed an immediate reduction that averaged 36% and 33%, respectively, from pre- to post-VRH treatment. In addition, the amount of time that this patient experienced no pain or a reduction of pain over the course of the 33 VRH-treatment sessions averaged 3.86 and 12.21 hours, respectively. Furthermore, when compared to hypnosis alone (non-VR), this patient experienced a greater reduction in pain intensity and pain unpleasantness as well as longer lasting freedom from pain throughout the course of treatment with VRH.
The fact that this patient's pretreatment ratings of pain intensity and pain unpleasantness were not significantly different from her posttreatment and 1-month follow-up ratings of pain intensity and pain unpleasantness suggests that VRH treatment was helpful for her on a time-limited basis, that is, on average, 12.1 hours. The relatively short-lived effect of VRH in this patient's case is consistent with recent research suggesting that although hypnosis may not “cure” a person's chronic pain, it can be an important part of a person's plan to manage chronic pain on a daily basis (Jensen et al., 2008
). In other words, hypnosis can provide many patients with a means of coping with pain, much like they might use medications (that also provide only short-term relief), but without the negative side-effects of those medications. In fact, research suggests that hypnosis can provide many beneficial “side effects” (e.g., improved well-being, improved sense of control over pain, improved sleep, etc.) that can contribute to a patient's quality of life over and above its effects on pain (Jensen et al., 2006
Thus, even though some patients (about between 20%–30%, cf. Jensen et al., 2008
) with chronic pain can experience substantial and long-term reductions in average daily pain following hypnosis treatment, many more patients than this report some relief of pain via hypnosis, view it as helpful and continue to use it up to 12 months following treatment. Therefore, although the patient in this case report was not “cured” of her pain, which would have been surprising given the refractory nature of it, she did achieve meaningful benefits through the use of VRH that lasted for many hours. Furthermore, while overall pain measurements did not change substantially, observation of means suggests that the directions of changes were in the direction anticipated. Specifically, overall ratings went down during the treatment period rather than baseline and then increased again during the month with no treatment.
The findings that this patient, who has suffered from severe and chronic neuropathic pain for over 5 years and has tried a myriad of other interventions, including over 15 medication trials, achieved a significant and lasting reduction in her pain throughout the course of VRH treatment is extremely promising. It was interesting that the patient went through the efforts to come to the hospital for months; given her spinal cord injury this was logistically difficult for her. It was also noteworthy that she reported that she benefited more from the induction when it was paired to the visual stimuli, rather than presented simply through audiotape. She also chose to resume treatment after a 1-month no-treatment period requested by the investigators. During one of the final VRH sessions before the treatment hiatus, this patient indicated that over time she was learning how to control her pain better, largely due to the experience that she has received through virtual reality hypnosis.
It was also noteworthy that the patient scored low on a scale measuring hypnotizability. Although the Stanford Hypnotic Clinical Scale is a screening measure, it has been reported to have good correlations with the Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C; Bryant, Guthrie, Moulds, Nixon, & Felmingham, 2003
). The fact that the patient had a good response to the virtual reality hypnosis with a relatively low hypnotizability score is encouraging to us. Our hope is that this technology will be most useful to patients that do not have a high level of hypnotizability. Specifically, it may be that providing attention-grabbing stimuli that matches the suggestions may help patients become more absorbed in the process when this does not come naturally.
We maintain that this patient's chronic neuropathic pain is a challenging clinical problem with no easy solution. This report is provided after 6-months of treatment, with an empirical hiatus of no treatment. Our hope is that with repeated treatment, the pain relief experienced by the patient will last for greater, and hopefully more extensive, periods of time.
There are several limitations to this case report. As with a study of this design, we are not controlling for historical factors that might have influenced the patient's pain perception; randomized controlled studies are necessary to control such extraneous variables. One of the biggest threats to validity is not knowing if the patient reported pain reductions simply to please the investigators. However, we should note that she was willing to report no reductions in pain over several periods during the study. Further, although historical confounds are always a consideration, it is difficult to argue that the drops in pain that occurred over almost all of the 33 treatments were attributable to anything other than the intervention. The activity required to travel to the hospital was more likely to exacerbate than to reduce pain in itself. Finally, this technology used in the intervention was novel and has not yet been refined for use. In spite of these drawbacks, however, we view the pain reductions that occurred with VRH, especially in light of previous poor response to other treatments, as promising and indicate that additional investigation of virtual reality hypnosis for chronic pain is warranted.