Somatosensory Rehabilitation for Neuropathic Pain in Burn Survivors: A Case Series.

Abstract

Neuropathic pain is an enormous rehabilitation challenge that has a substantial negative effect on patient function and quality of life. Somatosensory rehabilitation is a novel, nonpharmacological intervention described by Spicher based on the neuroplasticity of the somatosensory system. The rationale for somatosensory rehabilitation is that treating hypoesthesia will decrease neuropathic pain. Particularly for those with established neuropathic pain, the hypoesthesia may be masked by mechanical allodynia, which must be treated before treating the underlying hyposensitive zone. This case series describes the outcome of 17 burn survivors treated with somatosensory rehabilitation for their neuropathic pain. Before initiating treatment a modified version of the McGill Pain Questionnaire-short form (Questionnaire de la douleur St. Antoine, QDSA) was completed with the patients. The total score (×/64) was converted to percentage. The mechanical allodynia was assessed with the Rainbow Pain Scale that uses touch with the 15-g Semmes Weinstein Monofilaments (SWMs) and that was rated as painful on the visual analog scale (3/10 or resting pain + 1/10), as the criteria for mechanical allodynia. The severity level was assessed using seven predetermined SWMs to identify the smallest that elicited pain. The treatment consisted of avoiding all touch in the allodynic zone while concurrently providing proximal sensory and vibratory counter stimulation. Once the mechanical allodynia was eliminated, the underlying hypoesthesia was treated. Hypoesthesia was evaluated with the SWMs, and the percent improvement from baseline was calculated. The sensory reeducation treatment for hypoesthesia consisted of touch discrimination, texture perception, and vibratory stimulation. Seventeen patients (71/29% male/female, 21 ± 25% TBSA burned, 486 ± 596 days postburn) were evaluated and treated. Of these 15 initially presented with mechanical allodynia. The SWM scores had improved by 27 ± 21% (n = 14) and 29 ± 26% (n = 12) at 2 and 3 months posttreatment, respectively. The QDSA scores had improved by 9 ± 14% (n = 8) and 23 ± 23% (n = 6) at 2 and 3 months posttreatment, respectively. There were two patients who initially presented with hypoesthesia and six who had their zone of hypoesthesia treated after the mechanical allodynia had resolved. For these eight patients, their ability to perceive light touch improved by 27 ± 17% (n = 8) and 35 ± 25% (n = 6) at 2 and 3 months postsensory reeducation treatment initiation, respectively. The QDSA improved by 9 and 50% for the two patients who initially presented with hypoesthesia. In this case series, the majority of patients (13/17 or 76%) showed substantial improvements after somatosensory rehabilitation suggesting this is a treatment approach that should be considered with burn survivors experiencing neuropathic pain. There is a need, however, for future controlled studies to further investigate this approach and to determine if there is a subpopulation of burn survivors that are more likely than others to benefit from this approach.