The Effect of Duloxetine on Brain Neural Activity and Pain Processing in Patients with Knee Osteoarthritis: An fMRI-Based Study

Abstract

Background: This study aimed to evaluate the effect of duloxetine on the pain matrix in the brains of patients with knee osteoarthritis (Osteoarthritis or OA) using functional Magnetic Resonance Imaging (fMRI). Methods: The study was conducted using fMRI on 39 patients with knee osteoarthritis, divided into two groups: one receiving a placebo and the other group treated with duloxetine. Data analysis involved Independent Component Analysis (ICA) to identify brain networks and Graph Theory to assess functional connectivity within the pain matrix. All analyses were performed using the Statistical Parametric Mapping (SPM) toolbox and the functional connectivity toolbox (CONN) in MATLAB software. Findings: Results: In the Independent Component Analysis (ICA) method, various brain regions such as the anterior cingulate cortex (ACC), thalamus (THL), insular cortex (IC), parietal cortex (PO), and frontal pole (FP) exhibited higher numbers of active voxels in both the placebo and duloxetine groups. Graph theory analysis revealed that in the placebo group, the left thalamus (THL-left) was functionally connected with the right parietal cortex (PO-right), and the left parietal cortex (PO-left) showed functional connections with the frontal pole (FP) and insular cortex (IC). In the duloxetine group, the left parietal cortex (PO-left) demonstrated functional connectivity with the frontal pole (FP). Conclusion: The findings of this study demonstrate that duloxetine has a significant impact on the neural architecture and pain-related functional dynamics in patients with knee osteoarthritis. These results provide a foundation for future research in the fields of cognitive neuroscience and pharmacology. © 2025, Isfahan University of Medical Sciences(IUMS). All rights reserved.