Ms Lowe owns stock or stock options in Philips Medical.
Reduced insular γ-aminobutyric acid in fibromyalgia
Version of Record online: 27 JAN 2012
Copyright © 2012 by the American College of Rheumatology
Arthritis & Rheumatism
Volume 64, Issue 2, pages 579–583, February 2012
How to Cite
Foerster, B. R., Petrou, M., Edden, R. A. E., Sundgren, P. C., Schmidt-Wilcke, T., Lowe, S. E., Harte, S. E., Clauw, D. J. and Harris, R. E. (2012), Reduced insular γ-aminobutyric acid in fibromyalgia. Arthritis & Rheumatism, 64: 579–583. doi: 10.1002/art.33339
- Issue online: 27 JAN 2012
- Version of Record online: 27 JAN 2012
- Accepted manuscript online: 12 SEP 2011 11:59PM EST
- Manuscript Accepted: 6 SEP 2011
- Manuscript Received: 15 APR 2011
- US Department of the Army. Grant Number: DAMD-W81XWH-07-2-0050
- Dana Foundation (Award in Brain and Immuno-Imaging)
Recent scientific findings have reinvigorated interest in examining the role of γ-aminobutyric acid (GABA), the major inhibitory central nervous system neurotransmitter, in chronic pain conditions. Decreased inhibitory neurotransmission is a proposed mechanism in the pathophysiology of chronic pain syndromes such as fibromyalgia (FM). The purpose of this study was to test the hypothesis that decreased levels of insular and anterior cingulate GABA would be present in FM patients, and that the concentration of this neurotransmitter would be correlated with pressure–pain thresholds.
Sixteen FM patients and 17 age- and sex-matched healthy controls underwent pressure–pain testing and a 3T proton magnetic resonance spectroscopy session in which the right anterior insula, right posterior insula, anterior cingulate, and occipital cortex were examined in subjects at rest.
GABA levels in the right anterior insula were significantly lower in FM patients compared with healthy controls (mean ± SD 1.17 ± 0.24 arbitrary institutional units versus 1.42 ± 0.32 arbitrary institutional units; P = 0.016). There was a trend toward increased GABA levels in the anterior cingulate of FM patients compared with healthy controls (P = 0.06). No significant differences between groups were detected in the posterior insula or occipital cortex (P > 0.05 for all comparisons). Within the right posterior insula, higher levels of GABA were positively correlated with pressure–pain thresholds in the FM patients (Spearman's rho = 0.63; P = 0.02).
Diminished inhibitory neurotransmission resulting from lower concentrations of GABA within the right anterior insula may play a role in the pathophysiology of FM and other central pain syndromes.