The Pain Mystery
It’s an incredible thing; Americans spend up to 600 billion (billion with a B) dollars to treat pain. Almost 30% percent of people with pain have low back pain and about 25% of them have chronic low back pain.
You’d think with that many people in pain we’d be pretty far along in understanding low back pain, but it’s just the opposite. The scans don’t line up, the exams don’t lend a clue. It’s a big mystery and it’s a mystery that could have implications for fibromyalgia, chronic fatigue syndrome and other pain disorders.
These mysterious chronic pain sufferers may be the fibro patients of the back.
“Currently we know very little about why some patients suffer chronic low back pain,” said Debra Babcock, M.D., Ph.D., a program director at NINDS.
The same question applies to chronic low back pain that applies to ME/CFS, FM, IBS, post-cancer fatigue, etc.. Why while person makes it through an infection, injury, stressful event, cancer treatment, etc. and moves on with their lives while remain stuck in in pain and fatigue.
These researchers did something very similar to what the Dubbo researchers did with chronic fatigue syndrome years ago; they took a bunch of people with a new case of, in this case tested them early and then tested them later to try and figure out why one group got sick while the others didn’t.
In this case, researchers took people with a recently onset of low back pain scanned their brains with a diffusion tensor imaging machine, followed them for a year and and scanned their brains again.
Different Brains Early on
“The hypothesis (is that)..the propensity to pain chroniﬁcation is an a priori disposition awaiting an inciting event” Authors
The astonishing thing about their findings was not that the brains of the people who developed chronic low back pain were different after a year, but that they were different from day one.
Their brains appeared to be set up to, when the right trigger hit, to start producing chronic pain, perhaps for the rest of their lives. The startling suggestion is that people who are largely symptom free may nevertheless be undergoing changes that cause their systems to become chronically unbalanced at some point.
This kind of internal system set up may not be unusual in chronic illness. The stage appears to be set for autoimmune disorders years before many people become ill. People with ME/CFS often appear to go through a string of infections which they recover from before a last one finally tips the balance. People who later come down with Alzheimer’s appear to have abnormalities that long precede the actual disease.
This study found that the white matter which forms the connections between different parts of the brain was altered from the beginning. An analysis concluded that white matter changes occurring prior to or early in the pain process could predict 80% of those who came down with long term back pain. The high degree of predictability astonished the researchers.
Specifically, the connections between the nucleus accumbens in the back of the brain and the medial prefrontal cortex in the front of the brain were different. If you’re still thinking this is all about low back pain consider that Baraniuk’s recent Gulf War Vets found increased activity in the similar but a bit different tract that ultimately extends to the nucleus accumbens as well. Batraniuk concluded that one part of the PFC connection was ‘intimately associated with the severity of fatigue’. It may be that different parts of this major nervous system circuit determine how much pain and fatigue we feel.
Interestingly, given Dr. Newton’s findings of similar problems with blood pressure regulation in people with ME/CFS and fatigued elderly people this study found evidence of accelerated aging had taken place in the brains of people with chronic low back pain.
One possible clue is that the connectivity in the prefrontal regions of the people who came down with chronic pain was similar to that found in people who were no less than 30-50 years older.
“We were surprised how robust the results were and amazed at how well the brain scans predicted persistence of low back pain. Prediction is the name of the game for treating chronic pain.” Dr. Apkarian
The fact that genetics appears to explain from 75-90% of the differences in white matter in the brain suggests a brain that was hardwired, at some point to produce ongoing pain once the necessary trigger occurred. The high heritability of white matter is intriguing given the high degree of heritability found in ME/CFS and FM relative to other disorders.
White matter abnormalities have been found in other ‘neurodegenerative’ diseases, and the disorders they listed was highly informative; they included chronic regional pain syndrome, fibromyalgia, temporal mandibular disorders, cluster headache and IBS. (Given Baraniuk’s recent results they could have included GWS in there.)
These findings clearly suggest chronic back pain may fit in the same kind of disease spectrum as fibromyalgia, chronic fatigue syndrome, GWS and other disorders. It’s not that the same patterns of connectivity shows up, but that unusual patterns of connectivity consistently show up in these different disorders. They are all, at least in part, brain or ‘neurodegenerative disorders’.
“…brain white matter abnormalities reported in diverse chronic pain conditions should be considered as evidence for structural predisposition for developing these speciﬁc chronic pain conditions.”
Ultimately this study suggests DTI could be used a sort of predictive screen that could highlight people at risk, not just for low back pain but for all sorts of chronic pain conditions.
Rewiring the Brain?
If some parts of the brain are interacting too intensely for the brains own good it may be possible to turn them down using transcranial magnetic stimulation or other therapies. A recent rTMS FM study found therapy was able to significantly enhance FM patients ability to perform daily activities, improve their sleep quality and ‘perceived chronic pain’. More rTMS trials are underway in FM and the technology is improving rapidly.