A recent study reported in the journal ‘Pain medicine’ could point to a new type of treatment for people who suffer from Fibromyalgia syndrome. In this small study a group of patients received over 20 brief twice weekly treatment sessions of direct current stimulation to the brain over a 3 month period. The improvement in the treatment group was quite impressive (see below).
The use of transcranial direct current stimulation for treating chronic pain is not new, but studies using this technique in patients with FMS had not previously shown dramatic improvements. The concept behind this type of therapy is that the application of low voltage current to the cortex of the brain can change the excitation level of nerve cells or neurones. Although the nature of FMS cannot yet be proven, current evidence seems to support the theory that it is characterized by central ‘sensitisation’. One hypothesis to explain this suggests that this is due to the resting state of neurones in patients with FMS being ‘over-excited’ and always at or near the threshold for firing. This is sometimes called ‘hyper-vigilance’ If the ‘thermostat’ for pain could be ‘reset’ back down towards normal this could help kick start people into the sort of lifestyle changes needed to bring about long term improvements.
In this study, the authors claim that the use of a combination of high and low frequencies to deliver current helps to ‘permit passage of the low-frequency components to deeper cortical tissues with minimal attenuation’. Since other studies seem to indicate that the problems with signal interpretation, amplification and/or networking in FMS lies deep in the brain, this would seem like a good area of the brain to target.
The positive results reported in this study are quite impressive for those of us used to reviewing FMS studies – they reported major improvements in pain, sleep quality, fatigue and overall quality of life. Results were reported for two groups with 35 patients each: one group received the direct current treatment, the other group ‘sham’ or placebo therapy. On average the patients had a 10 year history of FMS, so these were patients with quite chronic symptoms. The average reduction in the number of ‘tender points’ in the treated group was 7.4 (from a starting point of 17) so it is important to make it clear that this treatment did not cure the patients of their pain. However, the change in the placebo group was 0.2 (not significant). The pain threshold reduced from 36 by 19.6 in the treatment group, but by only 3.2 in the placebo group. The quality of life index (FIQ) improved by 15 from 61.5 in the treatment group with no change in the placebo treatment group. Side effects were few, with 0.3% reporting a short-lived headache.
I was at the session at the American College of Rheumatology meeting where this research was presented in 2010. There was a lot of interest in the results which almost seemed too good to be true. We have had a lot of ‘false dawns’ in FMS treatment, and as a result I’m a bit cautious and keen to wait for the full evidence to come out. The results in the full paper published in Jan 2012 are unchanged, but it is interesting that the conclusion states that the treatment ‘provided modest improvements to pain, tender point measures, fatigue and sleep’. Before we all go out and order a ‘Neuropoint’ machine (see above) to deliver this high/low frequency current to our FMS patients, we really need someone else to independently replicate these results. I do wonder if the ‘blinding’ was effective or if the patients receiving the real treatment felt something more than the placebo group. The paper notes under ‘conflicts of interest’ that the lead author (JBH) has intellectual property interest in the technique used to deliver the current and is a shareholder in the Cerephex Corporation set up to market the equipment used in this study.
The Cerephex Corporation web pages indicate that a follow up study has been carried out: “at 45-months past end of treatment, 76% of surveyed patients reported reduced or eliminated need for pain medications, and 71% report reduced or eliminated need to see doctors or caregivers”. This is an even more impressive result than that reported in the original trial – but again, it needs to be independently verified. If validated, it would seem that the course of treatment could be considered something that provides long lasting relief and not just short term symptom relief. The device – which they are calling ‘Neuropoint’ has not yet been licenced by the FDA and to my knowledge is not yet available in Europe. I understand that a larger trial is about to commence to get further evidence to support an FDA approval.
Jeffrey B. Hargrove, Robert M. Bennett David G. Simons, Susan J. Smith, Sunil Nagpal, and Donald E. Deering. A Randomized Placebo-Controlled Study of Noninvasive Cortical Electrostimulation in the Treatment of Fibromyalgia Patients
Pain Medicine 2012; 13: 115–124