Effects of Pain Scrambler Therapy for the Alterations of Cerebral Blood

Overview

Prevalence of chronic pain has been shown to be high after thermal injury. Post-burn neuropathic pain causes chronic disabilities that is often difficult to treat effectively. Pain Scrambler therapy is a patient-specific electrocutaneous nerve stimulation device. To study changes in the pain network associated with neuropathic pain, magnetic resonance imaging(MRI) was used to evaluate cerebral blood volume(CBV) in patients who had been injuried by burn. Participants (N=40, experimental 20 and control group 20) comprised patients with neuropathic pain after thermal injury. The subjects complained of severe neuropathic pain that was rated at least 5 on the visual analogue scale (VAS), despite treatments with gabapentin medication and other physical modalities. Each Scrambler therapy with the MC5-A Calmare® therapy device (Competitive Technologies, Inc. Fairfield, USA ) was performed for 40 min daily (Monday through Friday) for 10 consecutive days. The stimulus was increased to the maximum intensity bearable by the individual patient without causing any additional pain or discomfort. The intensity of neuropathic pain was measured using the visual analogue scale(VAS). Depressive mood was assessed using the Beck Depression Scale. Voxel-wise comparisons of relative CBV maps were made between before scrambler therapy and after 10 scrambler therapy sessions over the entire brain volume. The relationship between individual participant CBV(measured in voxels), BDS and VAS score was also examined. We observed decreased in the cerebral pain network of patients with burn injury. Scrambler therapy is a non-invasive, non-medicinal modality that significantly reduced burn-associated neuropathic pain. Scrambler therapy should be considered as a treatment option for burn survivors with severe neuropathic pain.

The groups (scrambler therapy and sham therapy) were randomly assigned. All subjects were recruited in scrambler thrapy and sham stimulation. Main study outcomes included group differences in CBV changed and the the relationship between CBV changes and neuropathic pain intensity. These analyses were performed using the same framework of the general linear model, which was repeatedly applied to each voxel with the same coordinates.