Efficacy of a vibratory stimulus for the relief of HIV-associated neuropathic pain

Pain related to HIV disease is frequently debilitating. Of the many pain syndromes that occur in persons with HIV, distal symmetrical polyneuropathy (DSPN) is particularly devastating. Because DSPN often responds, at best, only partially to available pharmacologic interventions, non-pharmacologic interventions need to be investigated. Vibration has been suggested to be effective for reducing pain in other populations with chronic pain. This randomized, sham-controlled, double-masked study tested the short-term efficacy of a 45-min vibration treatment for DSPN foot pain in persons infected with HIV. Vibration therapy was delivered using a portable platform foot vibrator that provided stimulation at a frequency of 60 Hz. For all patients, the control box for the vibrator emitted an audible hum and part of the control box lit up during treatment, but only patients randomized to active treatment received vibration. Pain intensity (0-10) was measured immediately prior to and after treatment. Subjects were also questioned regarding pain relief (0-100%) immediately after the treatment. The mean percentage pain relief was 61.0+/-33.1% (median 70.0; range 0-100) for all patients, 67.3+/-34.0% (median 80.0; range 0-100) for vibration patients, and 55.0+/-32.0% (median 60.0; range 0-100) for sham patients. No statistically significant differences were found between the vibration and sham groups with respect to percentage pain relief (Mann-Whitney test; P=0.19) or the pre- and post-treatment current-pain difference (Mann-Whitney test; P=0.92). These results underscore the necessity for control groups in studies of non-pharmacologic therapies for pain.