A New Electrical Approach to Fibromyalgia Pain

For people living with fibromyalgia, pain can feel as though the body's alarm system has been amplified. Touch, pressure, or other sensations that might barely register for someone else can become painful. The altered pain processing makes the condition notoriously difficult to treat, and has doctors looking beyond the muscles and joints to the nervous system itself.

Researchers from Carnegie Mellon University and the University of Pittsburgh are testing a technology that delivers electrical pulses directly to the brain that are strong enough to activate neurons. The technique, called pulsed transcranial electrical stimulation, or pTES, delivers short, high-amplitude electrical pulses through electrodes placed on the scalp. Unlike more conventional forms of transcranial electrical stimulation, pTES is designed to produce electrical activity strong enough to directly activate cortical neurons.

Their paper, “Feasibility and pain sensitivity effects of pulsed transcranial electrical stimulation in people with fibromyalgia,” has been accepted for publication in Brain Stimulation. The research builds off of previously published work reducing the pain of pTES, making noninvasive brain stimulation more practical for treating chronic pain, depression, and other conditions.

“This form of noninvasive brain stimulation is designed to directly activate neurons involved in pain processing,” explains Jeehyun Kim, a biomedical engineering Ph.D. student at Carnegie Mellon University and lead author of the paper.

In a small pilot study, nine people with fibromyalgia received stimulation targeting motor areas of the brain associated with the arm and leg, along with a sham stimulation of the occipital region. Participants completed daily sessions over several weeks while researchers monitored pain sensitivity and the impact of fibromyalgia on daily activities.

Most participants were able to tolerate the stimulation at intensities strong enough to activate cortical neurons. Some experienced temporary scalp discomfort, fatigue, or mild headaches. The team also found that a low-level background train of electrical pulses, or "hums" as the team calls it, significantly reduced scalp discomfort during treatment. In this experiment, the background hum substantially reduced the scalp pain caused by pTES by an average of nearly two points on a 0-to-10 pain scale.

“An exciting finding here is that the stimulation reduced experimental pressure pain, so we know that pTES is engaging the brain's pain-relieving circuits,” says Dr. Ben Alter, an anesthesiologist at the University of Pittsburgh, Director of Translational Pain Research, and co-principal investigator of the paper. “This proof-of-concept leads us to believe that pTES will be clinically useful, although we will need larger clinical trials to demonstrate efficacy for pain.”

The study's small size means the findings are preliminary and cannot yet show that pTES is an effective treatment for fibromyalgia. 

“These early findings suggest that pTES may be a promising way to influence pain processing in people with fibromyalgia,” says Pulkit Grover, professor of electrical and computer engineering at Carnegie Mellon University and co-principal investigator of the paper. “However, we need much larger studies to determine whether the effects are reliable and clinically meaningful.”

While this study is exploratory, its design is primarily concerned with feasibility and tolerability. Larger controlled trials will be needed to determine whether the stimulation produces reliable changes in pain sensitivity, and more importantly, whether those changes translate into lasting improvements in people's lives.