Psychophysical and brain imaging approaches to the study of clinical pain syndromes

Abstract

Results of quantitative sensory testing and functional brain imaging studies in humans experiencing pain indicate that there is a network of cortical and subcortical structures that subserve this experience, whether the pain originates from peripheral tissue damage or from CNS abnormalities. The sensory and emotional experience associated with pain varies widely among individuals, as well as within the same individual at different times and in different contexts, thus highlighting the importance of combining rigorous sensory testing and brain imaging. The experiential dissimilarities are reflected in varying patterns of neural activation observed in different experimental studies. However, despite the dissimilarities among studies, many commonalities emerge, including the activation of sensory regions such as S1 and S2 and limbic areas such as ACC and IC. The degree of activation of these regions is dependent on cognitive factors, such as attentional state, that alter our perception of pain. Thus, when a patient experiences pain, independent of its origin, at least some components of this cortical network are likely to be activated.