Introduction: Chronic neuropathic pain remains challenging to treat and is often associated with poor outcomes, including addiction and suicide. While neuromodulation of the primary motor cortex and dorsolateral prefrontal cortex (dlPFC) can alleviate neuropathic pain in some cases, the underlying mechanisms are not fully understood. Advances in functional MRI have identified the Somato-Cognitive Action Network (SCAN) within the primary motor cortex and the Action Mode Network (AMN) in the dlPFC, which are both implicated in pain perception and endogenous analgesia. These findings suggest that the analgesic effects of motor cortex stimulation may be due to the modulation of action-relevant pain signals within these networks. Individual differences in SCAN and AMN may explain the variability in neuromodulation effectiveness for chronic pain.
Methods: This study synthesizes findings from functional MRI and clinical neuromodulation trials, focusing on the role of the SCAN and AMN in chronic pain. A retrospective analysis was performed on two previous patients with central neuropathic pain who underwent cortical stimulation.
Results: Neuromodulation targeting both SCAN and AMN yielded the highest pain relief, with variability in outcomes tied to the precision of SCAN/AMN modulation. When stimulation engaged both networks, patients experienced significantly greater pain reduction compared to stimulation that missed these regions. Functional connectivity analysis revealed SCAN and AMN are interconnected, influencing both sensory and cognitive pain processes.
Conclusion : This study proposes an action feedback-loop model of pain control, where SCAN and AMN form core circuits for modulating pain. Precision targeting of these networks may enhance neuromodulatory effectiveness, suggesting a path forward for individualized chronic pain treatment. Future research should focus on refining targeting techniques to reliably engage these networks, potentially improving treatment outcomes for patients with intractable pain.
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