Objective: To use a combination of magnetic resonance diffusion-tensor imaging (MR-DTI) and MR imaging of voxel-based morphometry (MR-VBM) in patients with fibromyalgia syndrome (FMS) to determine microstructural and volume changes in the central neuronal networks involved in the sensory-discriminative and affective-motivational characteristics of pain, anxiety, memory, and regulation of the stress response.
Methods: Thirty female patients with FMS and 30 healthy female control subjects were studied. Predefined areas of the brain were measured for volume of gray matter by MR-VBM and for diffusivity and fractional anisotropy (FA) by MR-DTI. Higher FA values and reduced diffusivity are thought to reflect increased complexity of brain-tissue microstructure.
Results: MR-VBM and MR-DTI demonstrated a striking pattern of changes in brain morphology in patients with FMS.
• Both thalami, the thalamocortical tracts, and both insular regions showed significant decreases in FA.
• In contrast, increases in FA and decreases in gray matter volume were seen in the postcentral gyri, amygdalae, hippocampi, superior frontal gyri, and anterior cingulate gyri.
• Increased pain intensity scores were correlated with changes in MR-DTI measurements in the right superior frontal gyrus.
• Increased fatigue was correlated with changes in the left superior frontal and left anterior cingulate gyrus,
• And self-perceived physical impairment was correlated with changes in the left postcentral gyrus.
• Higher intensity scores for stress symptoms were correlated negatively with diffusivity in the thalamus and FA in the left insular cortex.
• No relationship was found between MR-VBM measurements and symptom intensity scores.
Conclusion: MR-DTI allows the visualization of microstructural changes in the brain of patients with FMS, appears to be more sensitive than MR-VBM, and may serve as an additional diagnostic technique in FMS and probably other dysfunctional pain syndromes.
Source: Arthritis & Rheumatism, Nov 26, 2008;58(12):3960-3969. PMID: 19035484, by Lutz J, Jager L, de Quervain D, Krauseneck T, Padberg F, Wichnalek M, Beyer A, Stahl R, Zirngibl B, Morhard D, Reiser M, Schelling G. Campus Grosshadern, Ludwig-Maximilians University, Munich, Germany. [E-mail: firstname.lastname@example.org]