The Future of Pain Relief in Fibromyalgia (and ME/CFS)?
Mol Pain. 2013 Jul 2;9(1):33. [Shaped magnetic field pulses by multi-coil repetitive transcranial magnetic stimulation (rTMS) differentially modulate anterior cingulate cortex responses and pain in volunteers and fibromyalgiapatients. Tzabazis A, Aparici CM, Rowbotham MC, Schneider MB, Etkin A, Yeomans DC.
Someone sits in a chair with a coil pressed against the side of their head. Aside from odd tapping sounds they feel nothing. Sometimes they fall asleep. After about 30 minutes, they get up and resume their day; their pain much diminished. No drugs are needed. Could this be the future of pain relief in fibromyalgia?
A powerful magnetic field has been changing the electrical currents in their brain. If everything has gone as planned, the activity in parts of their brains that have been causing pain have been turned down (or parts of the brain that reduce pain have been turned on).
That is the idea behind the use of repetitive transcranial magnetic stimulation (rTMS), a magnetic therapy being pursued in disorders ranging from fibromyalgia to Alzheimer’s to multiple sclerosis to schizophrenia.
Prior fibromyalgia rTMS studies have had some success, but this one is different. Earlier rTMS studies affected the superficial parts of the brain, but this one – using new equipment able to reach deeper in the brain – attempted to increase the activity of a part of the deep brain (anterior cingulate cortex) that has been implicated in fibromyalgia (and chronic fatigue syndrome). Reduced activity in the anterior cingulate cortex correlates with reduced activity in the nervous system circuits that inhibit the production of pain.
Working out of their ‘Brain Stimulation Laboratory’, these South Carolina researchers tried to turn those pain inhibiting circuits back on.
First healthy volunteers and fibromyalgia patients were put in acute pain (using capsaicin solution), and ‘zapped’ with low frequency rTMS’ (I HZ) to see if rTMS reduced acute, short term pain. Then the FM patients were zapped with higher frequency (10 HZ) rTMS for 30 minutes a day for 20 sessions over a month to determine rTMS effectiveness at reducing chronic pain.
“In addition, the effect on fibromyalgia pain was persistent for at least 4 weeks following treatment, indicating the induction of a neuroplastic, and potentially disease modifying, event.” Tzabazis et. al.
The milder TMS (1 Hz) temporarily cut out the pain in the healthy controls, but the FM patients needed something stronger. Cranking the rTMS unit up to 10 HZ and then ‘zapping’ them 20 days over 3 month resulted, according to one self-report measure, with a sixty percent reduction in pain. Significant improvements in Fibromyalgia Impact Scores, however, were not reported.
Rather astonishingly, the pain reductions remained strong four weeks after the study ended with the FM patients still reporting almost 60% reductions in pain.
While longer-follow ups in FM have not been done, the effects may be lasting for some. In some depression trials rTMS series repeats occurred every 6-12 months. The duration of response to rTMS is highly variable, however, and other patients require more frequent repeats.
Shake Out Period
“The capacity to differentially target specific structures deep within the brain may suggest numerous additional applications for this relatively new but fast evolving treatment approach of rTMS” Tzabazis et. al.
The high frequency rTMS we saw in the study increases brain activity, but low frequency rTMS can depress brain activity. Two earlier TMS studies suggested that turning down prefrontal cortex activity could reduce pain and improve mood in FM, as well.
Animal experiments in the 1970’s indicating that repetitive stimulation of neurons could change their long-term functioning set the stage for rTMS. The ability to change neuronal is called ‘neuroplasticity’; in effect rTMS is trying to reverse negative neuroplastic changes and induce new ones
With the advent of deeper reaching rTMS machines, much of the brain appears open for tweaking. Any under or overactivated part of the brain could potentially be reset by rTMS. Clinician target areas of the prefrontal cortex with reduced activity in depression, for instance . Thus far, the machine has helped Parkinson’s patients move better, people with depression elevate their mood and people with stroke recover better. rTMS machines have been able to restore working memory – a key problem in ME/CFS – to normal levels in bipolar patients.
Even patients with treatment resistant depression can respond well. One study suggested 50% respond well and 1/3rd fully recover. One person with 30 years of depression reported :”I feel like the person I used to be 30 years ago! I’ve got my brain back”.
With the rTMS field expanding rapidly, it will take some time to understand the limits of this technology. A recent review of five rTMS FM studies found different parts of the brain (prefrontal cortex, motor cortex, now anterior cingulate) being targeted . In general rTMS appears to be at least as effective as opioids at relieving pain, has fewer side effects and is considerably more expensive.
Cost and Time
rTMS is not cheap. According to one source a typical session is about $300 and the recommended series of sessions topping of between 6-$10,000. Dr. Clauw, however, reported at the Ottawa IACFS/ME Conference that the rTMS machine is not particularly expensive ($25K) and suggested a series of sessions would run about 2K.
A newer technology called transcranial brain stimulation (TBS) that takes 1-7 minutes to work instead of the 20-40 minutes rTMS could reduce costs significantly.
rTMS appears to be effective at reducing pain for some people with FM, and, since some of the same brain regions are affected in ME/CFS, it may be effective there as well. (Check out Jess’s blog to see how painful ME/CFS can be.)
As brain imaging studies produce a clearer picture of which parts of the brain are over or under-activated in FM/ME/CFS, rTMS should become more effective at reducing pain and fatigue. Newer technologies that work more quickly may reduce costs. New approaches such as doing multiple sessions in a day may be able to improve effectiveness and drive down costs.
We know FM drugs often have underwhelming results, that mind/body therapies are a help but not cure, and that many people with FM/ME/CFS have exhausted their treatment options. Approved for treatment resistant depression, rTMS may be, if you can afford it, a good option for treatment resistant fibromyalgia and perhaps ME/CFS as well.