Microstructural Evidence of Neuroinflammation for Psychological Symptoms and Pain in Patients With Fibromyalgia.

Objective: In patients with fibromyalgia (FM), the brain shows altered structure and functional connectivity, but the mechanisms underlying these changes remain unclear. This study investigated the associated changes in brain microstructures and neuroinflammation of patients with FM.

Methods: We recruited 14 patients with FM and 14 healthy controls (HCs). Visual analog scale (VAS), Beck Anxiety Inventory (BAI), and Beck Depression Inventory-II (BDI-II) were used for assessing their pain, anxiety, and depression levels, respectively. Diffusion kurtosis imaging (DKI) was used to visualize microstructural alterations associated with neuroinflammation in specific brain regions. The biomarkers for neuron damage, including serum tau and amyloid β protein fragment 1-42 (Aβ1-42) levels, were assessed. Spearman correlation of DKI parameters with VAS, BAI, and BDI-II scores as well as tau and Aβ1-42 levels were assessed.

Results: The patients with FM had significantly higher levels of Aβ1-42 levels than HCs. Compared with HCs, the patients with FM showed significantly lower DKI parameters in the bilateral dorsolateral prefrontal cortex and orbitofrontal cortex. Patients with FM showed a significant correlation between the axial kurtosis values of the amygdala and VAS scores (left: ρ = -0.60, = 0.02; right: ρ = -7.04, = 0.005).

Conclusion: To the best of our knowledge, this is the first study to use DKI to examine the brains of patients with FM. We noted significant DKI changes associated with neuroinflammation at specific areas in patients with FM. Our results provide valuable information on brain neuroinflammation and pathophysiological changes in patients with FM.