Although the pathology of fibromyalgia is poorly understood, a growing body of evidence suggests involvement of the central nervous system. The hippocampus is a brain center that is sensitive to the effects of stress exposure and has been demonstrated to be affected in a variety of disorders whose onset, like fibromyalgia, are associated with stressful experience.
We therefore interrogated the bilateral hippocampus of 16 female fibromyalgia patients in comparison to 8 age- and gender-matched healthy control subjects using single voxel proton magnetic resonance spectroscopy.
• Our results demonstrate a significant reduction in the ratio of N-acetylaspartate to creatine (NAA/Cr) in fibromyalgia patients versus matched control subjects specifically in the right temporal lobe from a voxel centered on the right hippocampus (patient vs control, mean +/- standard deviation: 1.20 +/- 0.13 vs 1.34 +/- 0.10, P = .03).
• Moreover, correlation analysis demonstrated a significant negative correlation between patient scores on the Fibromyalgia Impact Questionnaire and NAA/Cr ratio within the right hippocampus (Spearman rank correlation, rho = -0.681, P = .018).
Our results indicate that fibromyalgia is associated with brain metabolite abnormalities within the right hippocampus that correlate with patient symptoms.
Perspective: We have demonstrated an abnormality in hippocampal brain metabolites in premenopausal female fibromyalgia patients with no psychiatric comorbidity. A significant negative correlation between patient subjective experience of symptoms and a reduced NAA/Cr ratio suggests a role for hippocampal pathology in fibromyalgia.
Source: Journal of Pain, Sep 2, 2008. [Epub ahead of print] PMID: 18771960, by Wood PB, Ledbetter CR, Glabus Deceased MF, Broadwell LK, Patterson JC 2nd. Departments of Family Medicine, Anesthesiology, Psychiatry, Pharmacology, Toxicology, Neuroscience, and Internal Medicine, LSU Health Sciences Center, Shreveport; PET Imaging Cener, Biomedical Research Institute of NW Louisiana, Shreveport, Louisiana, USA. [E-mail: firstname.lastname@example.org ] Note: part of this research was presented previously at the 2004 World Congress on Myofascial Pain and Fibromyalgia (Munich, Germany) and Human Brain Mapping (Budapest, Hungary).