Conditioned pain modulation, cortical imbalance, and arthrogenic muscle inhibition: an integrative model with...

Conditioned Pain Modulation (CPM), cortical excitability, psychosocial factors, and arthrogenic muscle inhibition (AMI, defined as reflex inhibition of musculature surrounding a damaged joint), proposing a framework linking these domains in chronic pain.

A narrative literature search was conducted in databases, focusing on studies addressing endogenous pain modulation, cortical mechanisms, psychosocial influences, and motor dysfunction in chronic musculoskeletal conditions.

Evidence suggests that impaired CPM is associated with altered cortical function, including compromised prefrontal top-down control and maladaptive motor cortex excitability. In this context, AMI reflects peripheral joint-driven adaptations and centrally mediated alterations in motor output. We propose that CPM and AMI interact through a shared cortical-motor axis, where the dorsolateral prefrontal cortex acts as an executive top-down regulator of brainstem nociceptive pathways, while the primary motor cortex serves as a crucial neurophysiological intersection actively engaged during CPM paradigm, collectively contributing to persistent AMI.

Chronic pain involves complex interactions among pain modulation, cortical mechanisms, and motor control. Consequently, baseline CPM efficiency may help predict AMI severity, offering a novel perspective for early patient identification and stratified, timely multimodal rehabilitation; however, further empirical research is required.