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 sy ndromes that occur in persons with HIV, distal symmetrical polyneuropathy ( DSPN) is particularly devastating. Because DSPN often responds, at best, on ly partially to available pharmacologic interventions, non-pharmacologic in terventions need to be investigated. Vibration has:been suggested to be eff ective for reducing pain in other populations with chronic pain. This rando mized, 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 vibrat or 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 contro l box lit up during treatment, but only patients randomized to active treat ment received vibration. Pain intensity (0-10) was measured immediately pri or to and after treatment. Subjects were also questioned regarding pain rel ief (0-100%) immediately after the treatment. The mean percentage pain reli ef 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 significan t 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 po st-treatment current-pain difference (Mann-Whitney test; P = 0.92). These r esults underscore the necessity for control groups in studies of non-pharma cologic therapies for pain. (C) 2000 International Association for the Stud y of Pain. Published by Elsevier Science B.V.