A painless nerve-zapping device called Transcutaneous Electrical Nerve Stimulation (TENS) has long been used to ease arthritis, back pain, and other ailments.
Now, researchers say TENS might also work to ease the fatigue and pain that can come with long COVID.
"This wearable TENS system offered immediate, on-demand relief from pain and fatigue, making it easy to integrate into daily activities," said study co-lead author Bijan Najafi. He's research director of the Center for Advanced Surgical & Interventional Technology at UCLA Health.
The results of his team's small study were published recently in Nature Scientific Reports.
Long COVID is now thought to affect 1 in 13 U.S. adults, according to background information in the study. Fatigue, pain, and muscle weakness are among its myriad possible symptoms.
Wearable TENS devices work by delivering low-wattage doses of electrical currents to nerves.
The new study involved 25 people diagnosed with chronic musculoskeletal pain, fatigue, and gait difficulties linked to long COVID. They were randomly assigned to wear either a working, high-dose TENS device or a "placebo" device that only issued very low doses of current.
Everyone used the devices for three to five hours per day for one month.
Benefit from TENS was found: Folks wearing the real device experienced an average of more than a 26% reduction in pain compared to those wearing the placebo device, Najafi's group reported. They also had an average 8% improvement in their walking ability.
Overall, just over 71% of people using the real TENS device thought they had noticed a health benefit versus 61.4% of those with the placebo device.
A big plus was that most participants found the technology easy to use, so compliance rates were high, researchers noted.
Still, "our sample size was limited, so further research is needed to confirm these findings," Najafi stressed.
The devices might also help other types of patients, he added.
"While this study focused on managing pain and fatigue caused by long COVID, it may also have potential applications for addressing similar symptoms in individuals with other respiratory diseases, those who have experienced extended ICU stays and developed post-hospitalization weaknesses, and conditions involving chronic fatigue and pain, such as fibromyalgia or chemotherapy-related side effects," Najafi noted in a UCLA news release. "But further studies are needed to confirm these potential uses."
The study was largely funded by the National Science Foundation, with the Quell TENS device supplied free of charge to researchers by its maker, Neurometrix Inc.