What does brain imaging tell us about itch?

Abstract

Understanding the mechanism of itch as well as the pathophysiology of chronic itch is important for the development of effective treatments. In the past 25 years, researchers have investigated the cerebral mechanism of itch in healthy subjects and chronic itch patients using functional brain imaging techniques. These studies have demonstrated that a variety of cortical and subcortical areas are associated with itch. In addition, it has been found that there are differences in brain activity and brain anatomy between healthy subjects and chronic itch patients. In this review article, we discuss potential roles of those identified brain regions in itch perception, and associations of the functional and structural changes in the brain with chronic itch. Brain imaging studies of psychological modulations of itch are also discussed.