Cortical Abnormalities in Patients with Fibromyalgia: A Pilot Study of Surface-Based Morphometry Analysis

Background: Although neuroanatomical studies correlated to fibromyalgia (FM) are gaining increasing interest, the cortical morphology of patients are largely unknown, and data on cortical gyrification are scarce. The objective of the present study is to assess the cortical morphology in female patients with FM compared with healthy controls (HC) using surface-based morphometry (SBM) analysis of magnetic resonance imaging (MRI).

Methods: T1-MRIs and clinical data of 20 FM patients and 20 HC subjects were obtained from a public data set via OpenNeuro. For each subject, surface parameters including cortical thickness, local gyrification index (LGI), sulcal depth, and fractal dimensionality were estimated using SBM analysis. These data were compared between two groups controlled by age. The correlations between regional SBM parameters showing group differences and clinical profiles were analyzed.

Results: Compared with HC subjects, FM patients showed reduced cortical thickness in right primary motor cortex, lower LGI in right rostral anterior cingulate and higher sulcal depth in right precuneus (P < 0.05 cluster level family- wise error corrected). In FM patients, correlation analysis showed that the cortical thickness in right primary motor cortex were inversely correlated with scores of pain catastrophizing scale (r = -0.498, P = 0.030) and pain self-perception scale (r = -0.527, P = 0.020), and disease duration (r = -0.488, P = 0.034), respectively.

Conclusions: Our findings provide evidence of neuroanatomical aberrations in FM patients, which may provide insight into the neuropathology of FM.