Background: Chronic pain is a major public health problem resulting in physical and
emotional pain for individuals and families, loss of productivity, and an annual cost of billions
of dollars. The lack of objective measures available to aid in diagnosis and evaluation of
therapies for chronic pain continues to be a challenge for the clinician.
Objectives: Functional magnetic resonance imaging (fMRI) is an imaging technique that can
establish regional areas of interest and examine synchronous neuronal activity in functionally
related but anatomically distinct regions of the brain, known as functional connectivity.
Study Design: The present investigation examines changes in functional connectivity in 4
common pain syndromes: chronic back pain (CBP), fibromyalgia, diabetic neuropathy, and
complex regional pain syndrome (CRPS).
Setting: This is a review of the current understanding of functional connectivity.
Methods: Utilizing functional imaging, patients with these conditions have been shown
to have significant structural and functional differences when compared to healthy controls.
Results: Functional connectivity, therefore, has the potential to assist in diagnostic
classification of different pain conditions, predict individual responses to specific therapeutic
interventions, and serve as a gateway for personalized medicine. Indirect activation of brain
activity can be seen by the blood flow to the brain at specific sites, with chronic pain patients
having increased brain activity.
Limitations: The present investigation is limited in that few studies have examined this
relatively new modality.
Conclusions: Knowing and observing the brain’s activity as related to pain gives pain
patients an opportunity to decrease pain-related brain activity and decrease severe chronic
pain. This modality can be used along with interventional pain management techniques in
order to provide optimum pain relief.
Key words: Functional connectivity, fMRI, chronic pain, chronic back pain, fibromyalgia,
diabetic neuropathy, chronic regional pain syndrome