Localized 1H-NMR spectroscopy in patients with fibromyalgia: a controlled study of changes in cerebral glutamate/glutamine, inositol, choline, and N-acetylaspartate
1 Department of Radiology, Hospital Quirón, Paseo de Mariano Renovales, 50006, Zaragoza, Spain
2 Instituto Aragonés de Ciencias de la Salud, Department of Psychiatry, Hospital Miguel Servet, Avda Isabel La Católica 1, 50009, Zaragoza, Spain
3 REDIAPP "Red de Investigación en Actividades Preventivas y Promoción de la Salud" (RD06/0018/0017), Av. Gran Via de les Corts Catalanes, 587 Ático, 08007 Barcelona, Spain
4 Instituto Aragonés de Ciencias de la Salud, Arrabal Health Centre, Calle Andador Aragües del Puerto 2-4, 50015, Zaragoza, Spain
5 Sant Joan de Déu-SSM, Fundación Sant Joan de Déu, c/Dr Antoni Pujadas 4, 08830, Sant Boi de Llobregat, Barcelona, Spain
6 CIBER Epidemiología y Salud Pública, Unidad Epidemiología Clínica, Hospital 12 de Octubre, Avda de Córdoba s/n, 28041, Madrid, Spain
Arthritis Research & Therapy 2010, 12:R134 doi:10.1186/ar3072
See related editorial by Harris, http://arthritis-research.com/content/12/5/141Published: 7 July 2010
The purpose of this study was to investigate whether single-voxel (SV) proton magnetic resonance spectroscopy (MRS), diffusion-weighted imaging (DWI), and diffusion tensor imaging (DTI) detected differences between fibromyalgia (FM) patients and healthy controls. We also searched for correlations between neuroimaging abnormalities and neuropsychological variables.
Ten patients with FM and 10 gender- and age-matched control subjects were studied. A neuropsychological examination, DWI, DTI, and proton MRS were performed on the brain areas known to be associated with pain processing.
Compared with healthy controls, FM patients had significantly higher levels of glutamate + glutamine (Glx) (mean ± SD, 10.71 ± 0.50 arbitrary institutional units versus 9.89 ± 1.04; P = 0.049) and higher glutamate + glutamine/creatine (Glx/Cr) ratios (1.90 ± 0.12 versus 1.72 ± 0.23; P = 0.034) in the posterior gyrus. Myoinositol (Ins) levels of the right and left hippocampi were significantly lower in FM patients (4.49 ± 0.74 versus 5.17 ± 0.62; P = 0.008 and 4.91 ± 0.85 versus 6.09 ± 0.78; P = 0.004, respectively). In FM patients, decreased myoinositol/creatine (Ins/Cr) ratios were found in the left sensorimotor area (P = 0.05) and the left hippocampus (P = 0.002) and lower levels of choline (P = 0.019) and N-acetyl aspartate + N-acetyl aspartyl glutamate (NAA + NAG) (P = 0.034) in the left hippocampus. Significant correlations between depression, pain, and global function and the posterior gyrus Glx levels and Glx/Cr ratios were observed.
Glx within the posterior gyrus could be a pathologic factor in FM. Hippocampal dysfunction may be partially responsible for the depressive symptoms of FM. Additional studies with larger samples are required to confirm these preliminary data.