Clinical Trial: Effects of Direct Transcranial Current Stimulation on Central Neural Pain Processing in Fibromyalgia

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Effects of Direct Transcranial Current Stimulation on Central Neural Pain Processing in Fibromyalgia

Brief Summary: The main goal of this Collaborative Proposal is to investigate biochemical, functional, and structural neuroimaging changes following non-invasive brain stimulation in patients with chronic widespread pain: fibromyalgia (FM). The fact that multiple therapeutic modalities which focus on central mechanisms provide modest relief for these patients raises the possibility that the cause for the chronicity of this debilitating disorder may lie within the brain itself. We propose that changes in the cortical milieu may result from prolonged experience of pain and suffering. Our previous results suggest changes in excitatory neurotransmitter levels, connectivity between multiple brain networks, and cortical thickness coincide within central neural loci related to pain perception and modulation in FM. Interestingly, modulation of cortical activity can be achieved noninvasively by a novel tool, transcranial direct current stimulation (tDCS), which has been reported to produce lasting therapeutic effects in chronic pain, especially FM. We propose to study the long-term effects of tDCS application on multiple levels of the central nervous system in FM patients. This project has significant clinical relevance and has the support of collaborators from University of Michigan and Harvard University

Detailed Summary:

  1. BACKGROUND AND SIGNIFICANCE:

    1. Fibromyalgia (FM):

      *Fibromyalgia is the second most common rheumatologic disorder, behind osteoarthritis, afflicting 2-4% of the population of industrialized countries.(Jacobsen and Bredkjaer, 1992; Wolfe et al., 1990) To fulfill the criteria for FM established by the American College of Rheumatology in 1990, an individual must have both chronic widespread pain involving all four quadrants of the body (and the axial skeleton), and the presence of 11 of 18 pre-defined "tender points" on examination. A positive tender point is identified when an individual complains of pain when approximately four kilograms of pressure is applied to one of these points by an examiner. FM is the prototypical "central" or "non-nociceptive" pain syndrome. Research performed within the past decade has clarified a number of important issues regarding this condition. Multiple studies suggest neurological dysfunction as a hallmark of this disease (Clauw and Crofford, 2003), and this is supported by a number of objective functional neuroimaging abnormalities. (Gracely et al., 2002; Harris et al., 2007; Mountz et al., 1995) Overall the data suggest that the primary abnormality in FM is a generalized disturbance in central nervous system pain processing, leading individuals to sense pain throughout the body in the absence of inflammatory or patho-anatomic damage. (Clauw and Chrousos, 1997; Yunus, 1992) Most FM neuroimaging studies to date have examined brain responses to a painful stimulus, as the imaging of endogenous chronic pain is notoriously difficult. (Baliki et al., 2007). However few studies have examined the modulation of specifi
      Sponsor: University of Michigan

      Current Primary Outcome: Glu levels within the insula and thalamus will be reduced following tDCS [ Time Frame: 3rd MRI (week 5 of patient participation) ]

      Determine the effects of tDCS on the excitatory neurotransmitter glutamate (Glu) within the insula (posterior and anterior) and thalamus in individuals with FM. Glu levels within the insula and thalamus will be reduced following tDCS, reflecting a down regulation of excitatory neurotransmission in these pain regions.


      Original Primary Outcome: Same as current

      Current Secondary Outcome: Cortical thickness in FM patients, will return to comparable age- and sex-matched pain-free control participant levels following tDCS [ Time Frame: 3rd MRI (week 5 of patient participation) ]

      Investigate whether long-term therapy with tDCS normalizes gray matter thickness in target and cortical areas associated with pain perception and modulation in FM. Cortical thickness in FM patients, will return to comparable age- and sex-matched pain-free control participant levels following tDCS. These effects will be specifically detected in pain modulatory regions (e.g. dorsal lateral prefrontal cortex) of FM patients


      Original Secondary Outcome: Same as current

      Information By: University of Michigan

      Dates:
      Date Received: December 4, 2012
      Date Started: March 2012
      Date Completion:
      Last Updated: December 1, 2015
      Last Verified: December 2015