Neuroimaging of pain: what does it tell us?

To present an overview of insights into brain mechanisms of pain perception and analgesia based on human brain imaging.

The technical advancement made in both functional and structural MRI can be used to delineate the cerebral signature of pain and analgesia, specifically, the brain responses to noxious stimuli and specific pain-related forebrain responses, as well as pain modulatory effects. Neuroimaging has revealed that the brain response to noxious stimuli shares neural resources with other systems that subserve salience detection and reward functions. Recent findings indicate that there is a wide range of individual differences in pain-related brain function and structure due to both pre-existing vulnerabilities and disease-driven factors. Furthermore, several studies now illustrate that the brain is capable of tremendous plasticity both in function and structure due to repeated and ongoing pain. However, emerging data suggest that this plasticity can be reversible after successful pain treatment.

Neuroimaging of pain and plasticity can provide a framework to understand the basic mechanisms of pain regarding function, gray and white matter structure and connectivity. This information may also guide future clinical practice. For instance, the time-course of disease-driven brain plasticity and capacity for reversibility may help decide the optimal time frame for chronic pain treatment. Furthermore, findings from functional and structural connectivity studies may indicate potential side effects of targeting specific brain areas in treating chronic pain. Lastly, the correlation between individual factors and functional/structural MRI data may direct individualized treatment plans.