Understanding Brain Changes In Chronic Pain

Understanding chronic pain is very challenging for both patients and healthcare providers alike. Many

chronic painful conditions – low back pain, head ache, and fibromyalgia syndrome for example – are not

characterized by any unique markers of disease and patients with these conditions typically have normal

anatomy, physical examinations, and laboratory values. This often leaves both patients and their

providers frustrated that no clear tissue level diagnosis can be made in spite of the patient’s clear

suffering. However, recent findings using functional MRI of the brain are beginning to change this.

Functional MRI (fMRI) is a research technique used to assess and map brain activity. It has long been

known that pain information travels in a very specific part of the spinal cord. However, until recently the

location of pain processing in the brain was a mystery. In 2013 a pain research group in Colorado

discovered the “neurologic pain signature” or NPS in the brain.(1) The NPS is believed to be the circuit

where acute pain is processed in all human brains. The researchers found that when they produced pain

in healthy volunteers virtually all of their brains showed increased activity in precisely the same exact

NPS circuit. Moreover, when they numbed the pain in these same healthy volunteers the NPS circuits

decreased their activity in all volunteers. Many brain researchers feel that the NPS is where acute pain is

housed in all of our brains.

Other researchers have since shown that as pain transitions from being acute - < 3mo - to chronic - >

3mo - it moves from the NPS to a separate and distinct emotion and reward area of the brain. Some

researchers and pain specialists believe that, as the NPS houses pain, so the chronic pain circuitry

houses suffering. The suffering circuitry is not activated by acute pain, it does not overlap with the NPS,

and it remains constant for at least 10yrs. Researchers are now studying techniques to try to predict

who will develop chronic pain, and once they do, how to best treat it by targeting the areas in the brain

where it is housed.

Research has shown that certain predictive instruments can help distinguish where pain is housed in an

individual patient’s brain without resorting to an fMRI. We use some of these instruments in our

practice in order to better match your care to where your unique pain or suffering is housed in your

brain. Unlike acute pain, chronic pain and suffering can respond to behavioral therapies targeted at the

brain’s emotion and reward circuitry. Ask you provider about how behavioral therapies might be a good

choice for managing your chronic pain.

1. N Engl J Med. 2013 Apr 11;368(15):1388-97. doi: 10.1056/NEJMoa1204471. An fMRI-based

neurologic signature of physical pain. Wager TD1, Atlas LY, Lindquist MA, Roy M, Woo

CW, Kross E.

2. Brain. 2013 Sep;136(Pt 9):2751-68. doi: 10.1093/brain/awt211.Shape shifting pain: chronification

of back pain shifts brain representation from nociceptive to emotional circuits . Hashmi JA1, Baliki

MN, Huang L, Baria AT, Torbey S, Hermann KM, Schnitzer TJ, Apkarian AV.