Local morphologic alterations of the brain in areas ascribable to the transmission of pain were recently detected in patients suffering from phantom pain, chronic back pain, irritable bowl syndrome, fibromyalgia and frequent headaches. These alterations were different for each pain syndrome, but overlapped in the cingulate cortex, the orbit frontal cortex, the insula and dorsal pons. As it seems that chronic pain patients have a common "brain signature" in areas known to be involved in pain regulation, the question arises whether these changes are the cause or the consequence of chronic pain. The in vivo demonstration of a loss of brain gray matter in patients suffering from chronic pain compared to age and sex-matched healthy controls could represent the heavily discussed neuroanatomical substrate for pain memory.
