A randomized trial reported in Diabetes Care in September 2026 found that small nerve fiber density in the lower leg rose by an average of 56 percent in people with painful diabetic neuropathy who received spinal cord stimulation. The finding adds to a growing question in nerve science: how much can damaged nerves change?
By Alena Wiese
For decades, the standard story about diabetic nerve damage in the feet has run in one direction. Nerves thin out, sensation fades, and treatment aims mainly at dulling the pain. A person living with that story in west Orange County may hear it at every appointment.
A trial released Sept. 9, 2026 complicates that story, at least a little. Researchers at Wake Forest University School of Medicine reported in Diabetes Care that among 91 adults with treatment-resistant painful diabetic neuropathy at 13 U.S. centers, high-frequency spinal cord stimulation was associated with less pain, better sensation and an average 56 percent increase in small nerve fiber density in the lower calf.
So can damaged nerves in the feet recover? The honest answer is that some measures of nerve health appear able to improve in some people under some conditions, but no therapy has been shown to reliably restore normal nerves, and the new trial is one piece of evidence rather than a settled answer.
What did the PDN-Sensory trial measure?
The trial measured pain, sensory function and the density of tiny nerve fibers in skin samples, which is unusual for a pain device study. The trial, called PDN-Sensory, compared 10-kilohertz spinal cord stimulation, a device implanted near the spine that sends electrical pulses, with conventional medical management over six months.
According to the university’s release, 79.4 percent of participants who received a temporary stimulator had at least a 50 percent reduction in pain, compared with 4 percent in the conventional care group. Among those with a permanent implant who completed six months, 93.1 percent reached that level. Meaningful sensory improvement was seen in 55.2 percent of the stimulation group versus 25 percent of controls.
Robert W. Hurley, MD, PhD, of Wake Forest said in the release that “many participants experienced substantial pain relief and improved sensory function.”
Source: Spinal cord stimulation eases pain and improves sensation in people with diabetic nerve damage, Wake Forest University School of Medicine news release on a Diabetes Care study, via EurekAlert, September 2026. https://www.eurekalert.org/news-releases/1143219
How do scientists measure nerve damage in the skin?
Scientists measure small nerve damage mainly by counting nerve fibers in a small skin punch biopsy, a number called intraepidermal nerve fiber density. The thinnest fibers carry pain and temperature signals, and they are often the first to be lost in diabetes.
A 2025 systematic review and meta-analysis in the peer-reviewed journal Diagnostics pooled 19 studies with 863 healthy adults and 304 adults with neuropathy. In healthy people, average density was about 12.9 fibers per millimeter at the distal leg and 6.5 at the toes. People with neuropathy showed reductions of roughly 50 to 80 percent, with toe values near 2.0 fibers per millimeter. Healthy adults also lost about 1.35 fibers per millimeter every five years with age.
Those reference numbers show why a 56 percent average rise in calf fiber density drew notice. They also show how much variation exists by body site, age and lab technique, which the review’s authors flagged as a reason to standardize biopsy methods.
Source: Intraepidermal Nerve Fiber Density as an Indicator of Neuropathy Predisposition: A Systematic Review with Meta-Analysis, Diagnostics, May 2025. https://www.mdpi.com/2075-4418/15/11/1311
What does this trial not tell us?
The trial does not show that spinal cord stimulation restores normal nerves, and it does not apply to most people with milder neuropathy. The researchers acknowledged that participants knew which treatment they received, which can influence self-reported pain. The trial stopped early after meeting its effectiveness goals, which can inflate apparent benefit. Participants had severe, treatment-resistant disease.
The study was funded by Nevro Corp., which makes the stimulation system. Six months is a short window, and the release noted that longer follow-up is needed to learn whether the nerve and sensory changes last and matter clinically. Spinal cord stimulation is also a surgical procedure with its own risks and is typically considered only after other treatments have failed.
Where do light-based therapies fit in the evidence?
Light-based therapies have a smaller and less consistent evidence base for neuropathy than implanted devices, and results from one therapy should not be assumed for another. A randomized trial from the Federal University of São Paulo, published in Pain Management Nursing and publicized in November 2024, assigned 144 people with diabetic peripheral neuropathy to physical therapy with or without 890-nanometer monochromatic infrared light. After 18 sessions over 10 weeks, the light group showed improvements in pain and sleep quality at follow-up, especially among people with intense pain.
That trial tested a specific infrared device added to physical therapy. It is not the same as Class IV laser therapy, and it did not measure nerve fiber density. Its authors stressed training, protocol adherence and monitoring for side effects.
Source: Light-based therapy reduces pain associated with peripheral diabetic neuropathy, study proves, Federal University of São Paulo news release on a Pain Management Nursing study, via EurekAlert, November 2024. https://www.eurekalert.org/news-releases/1064723
What does a careful evaluation look like in Ocoee?
A careful evaluation starts by confirming what is causing the symptoms before any treatment is chosen. ReliefNow Laser Ocoee, 288 Moore Rd, Ocoee, 407-877-7117, serves Ocoee, Winter Garden and Windermere in west Orange County. Its chiropractors are Dr. Jeffrey N. Shebovsky and Dr. Kyle Learn, and its page lists peripheral neuropathy among the conditions it addresses, with services that include Class IV laser, non-surgical spinal decompression, focused shockwave, chiropractic care and customized rehabilitation.
Dr. Shebovsky, DC, earned his Doctor of Chiropractic with honors from New York Chiropractic College and has more than 30 years of clinical experience. Evaluation is the first step, including sensation testing and a check for lumbar disc or nerve root problems, which can produce leg and foot symptoms that resemble diabetic neuropathy. Conservative options may be considered for stable symptoms alongside medical diabetes care. They are not a substitute for that care, and the evidence for laser therapy in neuropathy remains limited. Foot ulcers, signs of infection, sudden weakness, or new bladder or bowel changes call for medical or emergency referral. Progress is measured with pain scores, repeat monofilament and vibration testing, balance and daily function.
The slower science of nerves
The most interesting part of the new trial may not be the pain numbers, which device studies often report, but the attempt to count nerve fibers at all. If more trials measure nerves directly, patients and clinicians will have a clearer picture of what changes and what does not. Until then, the evidence invites curiosity and caution in equal measure.
About the expert: Dr. Jeffrey N. Shebovsky, DC | ReliefNow® Laser Ocoee | 288 Moore Rd, Ocoee, FL 34761 | 407-877-7117 | https://reliefnowlaser.com/providers/ocoee/
This article is for informational purposes only and does not constitute medical advice. Consult a qualified healthcare provider before beginning any treatment program.
