Fibromyalgia & Chronic Pain LIFE Sep/Oct 2012, Issue 6 - Page 23

the brain plays in individual differences before changing course slightly to discuss the plasticity (the capacity for physical alteration) of the brain, asking, “What happens when pain goes bad, and it fundamentally alters the central nervous system?” He told of one study which compared the changes in structural grey matter between patients with chronic back pain and healthy patients. The findings were telling: apparently, “we’re all losing about a half percent of our grey matter per year after about the age of 30… But,” he continued, “if you’ve got chronic low back pain, the numbers are about 5 and a half percent or so of premature grey matter loss, which works out to about a decade of grey matter loss as a consequence of just having chronic pain.” These losses were heaviest, he said, “in [the] prefrontal cortical regions, regions of the brain involved with executive functioning and working memory; it’s keeping pieces of information in mind and manipulating [them]. And so maybe with many of the patients that we see with cognitive dysfunction, we always attribute it to a mood disorder or the medications. Maybe it’s due to the chronic pain itself.” “So,” he said, “we can look at structure as a way of identifying plasticity within the brain, but are there other ways of doing this? The answer is yes.” The technique he’s referring to is called “resting-state network analysis,” and it involves measuring the brain’s activity while the person isn’t doing anything. One particular finding Dr. Mackey discussed may be important to people with fibromyalgia. “What happens is it turns out that while you’re sitting there not doing any particular task, there’s a very slow alternating set of electrical activity, for the period of about 20 seconds, [which] connects a variety of different regions of your brain together. “There are a number of different resting-state networks that have been identified, each with its own proposed function. One of those is called the default mode network. This default mode network, involved with self-referential thought, is thought to reflect maybe that little internal voice in your head. And so this study that came out a few years ago looked at the differences between healthy volunteers and those with painful diabetic neuropathy. And what they found is that there were alterations in this connectivity reflected in the default mode network in patients with neuropathic pain compared to healthy volunteers. “Napadow and his group followed up with this -looking at patients with fibromyalgia, a condition that afflicts 4 to 6 million Americans, 80 percent of them women, terrible, terrible pain. It takes a huge toll on their life -- and found that if you can compare them against healthy controls, what you find is in looking at networking, network connectivity of this default mode network with some of the sensorimotor areas, you find abnormal connectivity; that there are abnormal connections in these [brain] networks to other regions that are involved with bodily awareness and Sep/Oct 2012 Fibromyalgia & Chronic Pain Life 23