Abstract
Chronic itch is multidimensional phenomenon associated with emotional and cognitive aspects of suffering that causes the urge to scratch. The brain is the final terminal to receive itch-related neural signals from the body and to process them. Thus, it is important to better understand the mechanism of itch and its behavioral response of scratching in the brain. Brain imaging studies using positron emission tomography, functional MRI, electroencephalography, and magnetoencephalography have been conducted to understand the cerebral mechanism of itch mainly in healthy subjects using experimental itch models. Several brain imaging studies have investigated this mechanism in chronic itch patients to better understand the pathophysiology of chronic itch in the central nervous system. Pharmacological functional MRI studies add to our understanding of drug-effects on brain systems. Recently, this technique was used to investigate how a kappa opioid drug butoprhanol, modulates the processing of itch in the brain. Other promising treatments targeting the brain such as non-invasive transcranial Direct Current Stimulation that has been used for treatments of chronic pain has been reported for itch relief. In this chapter, we review the current progress in neuroimaging research of itch and scratch and its treatments.