The journal of pain : official journal of the American Pain Society
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Randomized Controlled Trial
Focal modulation of the primary motor cortex in fibromyalgia using 4×1-ring high-definition transcranial direct current stimulation (HD-tDCS): immediate and delayed analgesic effects of cathodal and anodal stimulation.
Fibromyalgia is a prevalent chronic pain syndrome characterized by altered pain and sensory processing in the central nervous system, which is often refractory to multiple therapeutic approaches. Given previous evidence supporting analgesic properties of noninvasive brain stimulation techniques in this condition, this study examined the effects of a novel, more focal method of transcranial direct current stimulation (tDCS), using the 4×1-ring configuration of high-definition (HD)-tDCS, on overall perceived pain in fibromyalgia patients. In this patient- and assessor-blind, sham-controlled, crossover trial, 18 patients were randomized to undergo single 20-minute sessions of anodal, cathodal, and sham HD-tDCS at 2.0 mA in a counterbalanced fashion. The center electrode was positioned over the left primary motor cortex. Pain scales and sensory testing were assessed before and after each intervention. A finite element method brain model was generated to predict electric field distribution. We found that both active stimulation conditions led to significant reduction in overall perceived pain as compared to sham. This effect occurred immediately after cathodal HD-tDCS and was evident for both anodal and cathodal HD-tDCS 30 minutes after stimulation. Furthermore, active anodal stimulation induced a significant bilateral increase in mechanical detection thresholds. These interventions proved well tolerated in our patient population. ⋯ 4×1-ring HD-tDCS, a novel noninvasive brain stimulation technique capable of more focal and targeted stimulation, provides significant reduction in overall perceived pain in fibromyalgia patients as compared to sham stimulation, irrespective of current polarity. This technique may have other applications in research and clinical settings, which should be further explored.
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Opiate use for chronic pain is becoming increasingly controversial. There has been a shift away from supporting the use of opiates for treatment of chronic pain. In addition to lack of effectiveness, concerns for adverse clinical outcomes, addiction, and death have provided the impetus for this change. The purpose of this study was to investigate the percent of trauma patients still using opiates, their pain levels, and psychological outcomes 4 months posttrauma. This was a study to evaluate chronic pain at 4 months posttrauma in 101 participants from a single level 1 trauma center. Eighty of the 101 participants developed chronic pain 4 months after their initial traumatic injury (79%). Of those who developed chronic pain, 27 (26%) were still using opiates. Those using narcotics at 4 months posttrauma had significantly more pain, life interference, depression, and anxiety. Posttraumatic stress disorder (PTSD) was not significantly influenced by narcotic use in this analysis. However, the mean associated with those using narcotics was higher and diagnostic for PTSD. Those taking opiates did not have significantly better relief from their pain using treatments or medications than those not using opiates (F = 8, P = .08). These findings bring into question the appropriate use of opiates for chronic pain and the possible exacerbating effects on pain and psychopathology in traumatically injured patients. ⋯ This article identifies data that provide evidence that narcotic pain medication needs to be used carefully in traumatically injured patients with chronic pain, especially in those individuals with comorbid psychological pathology.