Cranial Stimulation: A future Pain-Reducing Treatment for Fibro?

July 24, 2013

Transcranial direct current stimulation (tDCS) is used to treat many conditions including a variety of chronic pain conditions. The concept is simple enough the patient has an electrode placed on one area of the head where they want to stimulate and another electrode on another side of the head to complete the circuit. About milliampere of energy is put into the area to be stimulated. How it works is not entirely understood but the idea is to make the neurons in the area more malleable and able to make new connections while under the influence of the current. Several session may be needed to influence these connections. It essentially encourages the brain to rewire itself and in particular in ways that will reduce pain. Generally the therapy reduces pain immediately after but the idea is that after several session it may reduce pain for longer durations if not permanently reduce it. Certainly there are benefits to be seen with chronic pain conditions for the pain reduction of the sessions themselves, given it is a non-drug, non-evasive therapy. However if such treatments can have long lasting effects with chronic pain conditions then the research into them becomes that much more important. There have been a few studies looking into this method and its effectiveness on fibromyalgia. There have also been studies looking at other methods of stimulating the brain with other smaller devices. Two recent studies reflect different approaches to the idea of cranial electrical stimulation in treating fibromyalgia and have some interesting potential results that could affect future therapies.

Study one
Journal of Pain April 2013

This study was conducted at Harvard Medical School using 18 Fibromyalgia patients. The Journal of Pain states given “previous evidence supporting analgesic properties of noninvasive brain stimulation techniques in this condition, this study examined the effects of a novel, more focal method of transcranial direct current stimulation (tDCS), using the 4×1-ring configuration of high-definition (HD)-tDCS, on overall perceived pain in fibromyalgia patients. In this patient- and assessor-blind, sham-controlled, crossover trial, 18 patients were randomized to undergo single 20-minute sessions of anodal, cathodal, and sham HD-tDCS at 2.0 mA in a counterbalanced fashion.” The centre electrode was placed over the left primary motor cortex. In the study the patients were either getting real stimulation, anodal or cathodal, or sham stimulation on three separate occasions. At each of the sessions the patients received current that was slowly increased over 30 seconds up to 2 mA for a duration of 20 minutes. In the sham patients the current was shut down after the initial 30 seconds, which has no effect on cortical excitability and generally used for tDCS trials for blinding patients.

The results of the study
The study concludes, "4×1-ring HD-tDCS, a novel noninvasive brain stimulation technique capable of more focal and targeted stimulation, provides significant reduction in overall perceived pain in fibromyalgiapatients as compared to sham stimulation, irrespective of current polarity. This technique may have other applications in research and clinical settings, which should be further explored.” Abhishek Datta, PhD, chief technology officer of Soterix Medical and co-inventor of HD-tDCS, stated "'The phase 2 trial is about to begin, which will answer more questions. For example, the phase 1 study was just ‘one session’ of HD-tDCS. In phase 2, we are exploring repetitive sessions — 1 day per week. We need to find the right trial parameters (current intensity, duration, how many sessions) before we can plan a pivotal FDA trial.'" (

Pain levels scored on a numerical scale of 0 to 10 declined immediately after the stimulation to 30 minutes after stimulation for all three treatments (sham, anodal and cathodal stimulation). However, only the cathodal HD-tDCS demonstrated significant improvement over the sham treatment after stimulation. Cathodal and anodal HD-tDCS had significant pain reduction 30 minutes after stimulation. For the sham stimulation sub-group the mean scores dropped from 5.09 at baseline to 4.59 immediately after stimulation to 4.41 half an hour later. With the anodal sub-group mean pain scores dropped from 5.47 to 4.79 directly after stimulation and then to 4.07 half an hour later. Finally, in the cathodal sub-group the mean scores at baseline were 5.03 and dropped to 3.89 immediately after stimulation and then to 3.65 30 minutes later. “The reduction in pain levels continued at least 30 minutes after a single, 20-minute session of transcranial direct current stimulation (tDCS) of the left primary motor cortex (M1 area), supporting 'the theory that tDCS-induced modulatory effects on pain-related neural circuitry are dependent on modulation of M1 activity,' noted the trial investigators, led by Dr. Mauricio F. Villamar of Spaulding Rehabilitation Hospital and Massachusetts General Hospital, both in Boston." (Ob.Gyn News)

What is fascinating and intriguing about this treatment is “The ability of tDCS and repetitive transcranial magnetic stimulation (rTMS) to modify the excitability of cortical neural circuits, particularly the primary motor cortex (M1), gives them the potential to target one of the pathophysiological mechanisms of fibromyalgia, 'where pain can be characterized by a lack of inhibitory control over somatosensory processing,' said Dr. Villamar and his associates.” (Ob.Gyn.News)

Study two

March 4, 2013 Neuroscience

This second study was completed by the University of Virginia School of Nursing. It involved 46 patients with fibromyalgia and divided them into three groups; a control group receiving normal care, a group receiving normal care with the addition of a sham device that emitted no electrical stimulation, and a group receiving normal care pulse the device with a dose of electrical stimulation. What is unique about this study is that it involves an Alpha Stim device, manufactured by Electromedical Products International, which delivers stimulation below the level of sensation, is attached to the earlobe and is suitable for at home use. The sham group and the Stim group used the device from an hour every day and answered questionnaires about their pain levels, fatigue, sleep patterns and ability to function daily.

They found that the regular cranial electrical stimulation offered statistically significant changes to pain levels, fatigue, sleep and ability to function. What perhaps is most fascinating about this type of research and this study in particular is that they found there is a cumulative effect to the cranial electrical simulation in the pain processing portions of the brain. The researchers preformed functional MRIs on the portions of the sham and STIM study groups to take a look at the activity in the brains pain processing centers. While within the scanners the researchers induced painful stimulus (the pressure to the thumbnail test) and analyzed the differences between the two groups in in brain activity in response to pain. The results indicated those using the actual cranial electrical stimulation device illustrated a decrease in activity in specific pain processing regions compared to the sham device.

So really “'exploring deactivation in response to pain may yield a better understanding of the mechanisms involved in central pain processing, particularly as it relates to chronic pain,' Anderson and Taylor write in the journal EXPLORE. 'This study reflects our earliest understanding of what the cumulative effects of cranial electrical stimulation might be,' said Anderson, an assistant professor of nursing. 'And given the lack of understanding about the mechanism of relief, expanding our research to larger studies might confirm that cranial electrical stimulation may change the symptoms experienced by persons with fibromyalgia.'Also given that the cranial electrical stimulation devices are suitable for at-home use and are FDA-approved, the device used in Taylor and Anderson's study – which attaches to patients' ear lobes and emits tiny electrical pulses – may become an effective complement to care for some of the 5 million Americans who suffer fromfibromyalgia. 'These pilot data are the beginning of a line of study,' Taylor added, 'and early evidence of a novel, unobtrusive and non-invasive way to complement the treatment of a disease that challenges the quality of life for millions. We are hopeful that someday we might really change lives with this technology.'" (Medical Press)


It is a fascinating field of study not only because it offers treatment in the area of chronic pain but also because of the potential to retrain the brain. Within the mechanism of central sensitization the brain is training itself to become more sensitive to pain, more heightened to it and more acutely aware of stimulus it seems. We are left with chronic pain which is very difficult to manage and treat. With the ability to focus these pulses of current to specific areas of the brain to stimulate connections and rewire it there is this potential of turning back the pain clock and potentially feeling less pain in over time with more treatment as the brain adapts. That is certainly worth the research and certainly why we see studies on this for more than one chronic pain condition and it remains to be seen how different forms of this stimulation will be effective for different types of chronic pain or which types of chronic pain the treatments are most effective with this treatment in the long term. However, even if the treatments themselves ofter short term pain relief without this cumulative effect in the brain there is still a very valid reason to explore this treatment that does not involve medications, and therefore side effects, for effective pain management.

hi dancer, ty for posting this. it was a bit long for me to digest in one sitting so i will get back to it another time



Wow! This sounds impressive! It should help millions of people who suffer chronic pain! Good find, dancermom!

My personal concern is that I cannot tolerate TENS, even on the lowest setting, regulated by trusted Doctors, it shoots me through the ceiling, because of this, a 'spinal stimulator' implant was ruled out, but I wonder if this would be different.

I know, I'm strange, I guess I'm just wired differently!