Everybody Hurts Sometimes

EHM asks James Rathmell, Director of Massachusetts General Hospital’s Center for Pain Medicine, about the true nature of pain.

“When pain becomes chronic – persisting more than six months – many experts now argue that it is more like a disease than a symptom”
-James Rathmell

What are the latest technologies being used at the center to diagnose pain and determine a patient’s care needs?
James Rathmell. Diagnostic testing is directed at the suspected underlying cause, and all modern diagnostic modalities are used when appropriate. Among the more common diagnostic tests is magnetic resonance imaging, which can be very helpful in determining structural causes for acute and chronic low back pain. Electrodiagnostic testing (electromyography/peripheral nerve conduction testing) can also be very useful in evaluating patients with suspected nerve injury.

Finally, some tests remain experimental, but are emerging as useful tests; for example, skin biopsy looking at changes in small nerve fiber density may be useful in diagnosing some neuropathies. We also use ‘diagnostic injections’ – placing local anesthetic on or near a structure we think is causing pain and seeing if this relieves the pain. However, there is a big problem with placebo response in using diagnostic nerve blocks, so the response must be carefully coordinated with the rest of the clinical picture when making decisions about treatment.

Chronic pain is sometimes defined as a disease, not a symptom. Can you explain the reasoning behind this definition?
JR. We now know that there are changes in the structure and connections within the nerves that carry pain signals that occur when a patient suffers from a painful injury. In some cases, it seems that these changes in the nervous system are not reversible. Thus, when pain becomes chronic – persisting more than six months – many experts now argue that it is more like a disease than a symptom: a disease of the nervous system.

What interventional treatments are used to ease or eliminate pain?
JR. There are many and they have very specific uses. Among the most common is the epidural steroid injection, which has been shown to speed the resolution of leg pain (sciatica) associated with intervertebral disc herniations (slipped discs). There are many others, but two of the more advanced therapies that can be useful in patients with severe and ongoing pain included spinal cord stimulation and intrathecal drug delivery. Some patients with chronic low back or leg pain, even those with ongoing pain after surgery, can benefit from spinal cord stimulation, a treatment where a small electrode is placed over the spinal cord and a very pleasant sensation is placed to overlap the painful region.

The therapy can be ongoing through the use of a pacemaker-sized battery to provide the ongoing electrical stimulation. Intrathecal drug delivery involves implanting a small programmable pump that delivers pain medication directly in to the spinal fluid surrounding the lower spinal cord, where the medicine can act directly at the spinal cord level without producing systemic side effects like sedation. This is most useful in patients with severe pain associated with cancer that cannot be controlled by other means.

What teaching skills are used to help patients understand and cope with pain easier?
JR. Many, and not my expertise. Specific exercise regimens can be very beneficial. Cognitive behavioral therapy is a structured means that psychologists use to help patients understand the stressors that exacerbate their pain and develop strategies to cope and/or avoid these stressors.

What will be the effects of President Obama’s focus on preventative healthcare for pain management?
JR. We hope that it will stimulate better clinical research as well as basic science research. I can assure you that our research group here at MGH has been very active in submitting new research proposals that aim to examine everything from the genetic basis of pain to new pain therapies.

James Rathmell is Director of the Massachusetts General Hospital Center for Pain Medicine.