Summary: NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.
Kruger L, Light AR, editors. Translational Pain Research: From Mouse to Man. Boca Raton, FL: CRC Press;
Bookshelf ID: NBK57254 PMID: 21882455
Chapter 15 Human Brain Imaging Studies of Chronic Pain
A. Vania Apkarian.
The advent of non-invasive human brain imaging technologies provided the opportunity for direct examination of
the human brain. This occurred about 15 years ago with the related expectation that we were at the threshold of
a revolution in our understanding of chronic pain. This expectation remains largely unfulfilled, although much has
been published in the topic. Here we concentrate mainly on our own work in the topic, arguing in general that the
subject of brain mechanisms of chronic pain remains in its infancy mainly because of a heavy emphasis in the
field on studying nociception rather than chronicity of pain.
The definition of chronic pain, namely, pain sustained beyond the healing process 53, says nothing regarding
underlying mechanisms and perhaps suggests that mechanisms similar to acute pain are maintained for a longer
period. Early brain imaging attempts to characterize chronic pain adopted the same methods used for studying
nociception, where acute painful stimuli of various dimensions were applied to clinical chronic pain conditions
seeking to observe differences in brain activity. The assumption was that the interaction between chronic and
acute pain could be identified at the level of brain activity. Often, such studies were conducted without even
performing simple psychophysical tests to determine whether the procedure gives rise to differences in pain