• Posted March 29, 2023

Nerve 'Pulse' Therapy May Help Ease Sciatica

People suffering from sciatica gain lasting relief from a procedure that uses a fine needle to heat nerve roots near the spine, a new clinical trial shows.

The minimally invasive procedure, called pulsed radiofrequency (RF), provided superior pain reduction and disability improvement out to one year for patients with sciatica, according to findings published March 28 in the journal Radiology.

The procedure could help people with sciatica avoid or delay back surgery, said lead researcher Dr. Alessandro Napoli, an associate professor of radiology with the Policlinico Umberto I -- Sapienza University of Rome in Italy.

"Pulsed radiofrequency with this method can relieve pain in 10 minutes, with no surgery, no hospitalization, and faster recovery and return to daily activities. It is an important card to play,"Napoli said.

People with sciatica have a sharp pain that shoots through their hips and buttocks and down one leg. The condition is typically caused by a herniated or slipped spinal disc that's putting pressure on the sciatic nerve, the largest nerve on the body.

The standard of care is a steroid injection aimed at calming the nerve down, said Dr. Jack Jennings, a professor of radiology and orthopedic surgery at the Washington University School of Medicine in St. Louis.

"The steroids are basically to fool the nerve, to say nothing's wrong,"said Jennings, who wrote an editorial accompanying the new study.

The clinical trial added pulsed RF to the standard steroid injection to see if it would provide better, longer-lasting pain relief.

In pulsed RF, doctors use CT scans to slide a fine needle precisely into the nerves that are causing sciatic pain.

The needle is then heated using pulses of radio waves. The heat disrupts the nerve, preventing it from sending pain signals to the brain.

"It is similar to a reset of an operating system,"Napoli said.

The procedure takes about 10 minutes and is performed on an outpatient basis without general anesthesia, researchers said in background notes.

Napoli said he thinks the two treatments, pulsed RF and steroids, work together, adding to the steroids' anti-inflammatory activity and pulsed RF's nerve signal disruption.

About 350 people with sciatica were randomly assigned in the clinical trial to receive either steroids alone or steroids combined with pulsed RF. Everyone was followed for up to a year to see how well the treatments lasted.

By the end of the year, 96% of the pulsed RF group had experienced an improvement in pain compared with 69% of those who only received steroids, results showed.

About 68% of the pulsed RF group experienced complete pain relief, compared with 13% of the steroid group.

On the other hand, twice as many people treated with steroids alone (25 versus 12) had intractable pain that required further treatment, up to and including surgery.

The patients who received pulsed RF treatment also experienced less disability, researchers said.

"To me, the most impressive part of this was the durability out to one year and the number of people that had complete response,"Jennings said of the results. "These numbers are very good in our world of pain."

The study replicates the results of a 2017 clinical trial that showed pulsed RF plus steroids could be used to treat pain caused by pinched nerves, said Dr. Jianguo Cheng, director of the Cleveland Clinic's Multidisciplinary Pain Medicine Fellowship Program.

"The results of the current study are strikingly consistent with what we reported,"Cheng said. "A significant strength of this study is that it has a much larger sample size and it is a multicenter study, providing stronger evidence supporting the combination therapy."

Pulsed RF is used more often in Europe than in the United States to treat sciatica, Jennings said, even though the procedure has been long approved by the U.S. Food and Drug Administration.

Steroid injections can damage the body, and the effects wear off over time, Jennings noted.

"They have a shelf life with the person. You can't just inject them every three or four months for the rest of their life. They ultimately stop working. So to me, if you can increase the durability and get a year or more relief from [pulsed RF], that's incredible,"Jennings said.

"I hope this study does increase knowledge and broader adoption of the procedure, and I do think it will,"he added.

Jennings hopes that a follow-up clinical trial will test pulsed RF alone against steroids, to see if the therapy would work on its own.

More information

The Cleveland Clinic has more about sciatica and radiofrequency therapy.

SOURCES: Alessandro Napoli, MD, PhD, associate professor, radiology, Policlinico Umberto I -- Sapienza University of Rome, Italy; Jack Jennings, MD, PhD, professor, radiology and orthopedic surgery, Washington University School of Medicine in St. Louis, Mallinckrodt Institute of Radiology; Jianguo Cheng, MD, PhD, director, Cleveland Clinic Multidisciplinary Pain Medicine Fellowship Program; Radiology, March 28, 2023