Neuroimaging of Pain: Human Evidence and Clinical Relevance of Central Nervous System Processes and Modulation

Abstract

Neuroimaging research has demonstrated definitive involvement of the central nervous system in the development, maintenance, and experience of chronic pain. Structural and functional neuroimaging has helped elucidate central nervous system contributors to chronic pain in humans. Neuroimaging of pain has provided a tool for increasing our understanding of how pharmacologic and psychologic therapies improve chronic pain. To date, findings from neuroimaging pain research have benefitted clinical practice by providing clinicians with an educational framework to discuss the biopsychosocial nature of pain with patients. Future advances in neuroimaging-based therapeutics (e.g., transcranial magnetic stimulation, real-time functional magnetic resonance imaging neurofeedback) may provide additional benefits for clinical practice. In the future, with standardization and validation, brain imaging could provide objective biomarkers of chronic pain, and guide treatment for personalized pain management. Similarly, brain-based biomarkers may provide an additional predictor of perioperative prognoses.

Figure 1

Summary of the main supraspinal regions and their roles in pain processing. Multiple cortical and subcortical structures are involved in various primary roles and aspects of the pain experience (as color coded). Additional brain regions and networks not shown in the figure are involved in the pain experience - see text for details. Abbreviations: ACC - anterior cingulate cortex, Amg - amygdala, Cd - caudate, Hi - hippocampus, Ins - insular cortex, LC - locus coeruleus, M1 - primary motor cortex, NAc - nucleus accumbens, PAG - periacqueductal gray, PFC - prefrontal cortex, Pu - putamen, RVM - rostral ventral medulla, SMA - supplementary motor area, S1 - primary somatosensory cortex, S2 - secondary somatosensory cortex, Th - thalamus, TPJ – temporal-parietal junction.