The number of people experiencing numbness, tingling, and pain in their feet with no known cause has been increasing over the last two decades, according to a new study published in the October 27, 2021, online issue of Neurology®, the medical journal of the American Academy of Neurology. Called small fiber neuropathy, the condition has different symptoms than large fiber neuropathy, which can cause weakness and balance issues. But in many cases people have both types of neuropathy.
For the study, researchers looked at records for everyone diagnosed with small fiber neuropathy in Olmsted County, Minn., and the adjacent counties during a 20-year period. They then compared those 94 people with 282 people of similar age and sex who did not have neuropathy. Participants were followed for an average of six years.
The study found that the condition occurred in 13.3 per 100,000 people, with the rate increasing during the study.
“This increase could be due in part to greater awareness,” said study author Christopher J. Klein, MD, of the Mayo Clinic in Rochester, Minn., and a Fellow of the American Academy of Neurology. “Another possibility is that increasing levels of overweight and obesity in our area could be a factor in the higher rates of small fiber neuropathy. Higher body mass index, or BMI, is a risk factor for diabetes and high triglycerides, which may also lead to neuropathy.”
The people in the study with neuropathy had an average BMI of 30.4, compared to 28.5 for the people who did not have neuropathy. A BMI of 18.5 to 24.9 is considered healthy; 25.0 to 29.9 is considered overweight; and 30.0 and higher is considered obese.
About 50% of the people with neuropathy had diabetes, compared to 22% of those without neuropathy.
The people with neuropathy were also more likely to have insomnia, at 86% compared to 54% for those without neuropathy. They were also more likely to have heart attacks, at 46% compared to 27%.
“Based on these findings, people with small fiber neuropathy should be screened for heart problems and their blood glucose should be monitored for signs of diabetes,” Klein said.
The people with neuropathy were also more likely to take opioids for pain.
For 67 of the people with neuropathy, no cause could be determined, called idiopathic neuropathy. For 14 people, the neuropathy was caused by diabetes. Other causes included Sjögren syndrome and lupus.
A total of 36% of the people developed large fiber neuropathy during the study, an average of five years after they developed the small fiber version.
“The good news is that most people with idiopathic neuropathy do not develop major impairments or disability, but they did have many other conditions and an increased risk of heart attack, so the development of treatments and prevention methods is crucial,” Klein said.
The main limitation of the study was that researchers looked back in time at medical records. A study examining all people with symptoms of small fiber neuropathy and following them over time should be conducted to confirm these findings, Klein said.
Reference: “Small Fiber Neuropathy Incidence, Prevalence, Longitudinal Impairments, and Disability” by Stephen A Johnson, Kamal Shouman, Shahar Shelly, Paola Sandroni, Sarah E Berini, P. James B. Dyck, Ernest Matthew Hoffman, Jay Mandrekar, Zhiyv Niu, Christopher J Lamb, Phillip A. Low, Wolfgang Singer, Michelle L. Mauermann, John Mills, Divyanshu Dubey, Nathan P. Staff and Christopher J. Klein, 27 October 2021, Neurology.
The study was supported by the Mayo Clinic Foundation, Mayo Clinic Center or Individualized Medicine and Mayo Clinic Center of MS and Autoimmune Neurology.
The American Academy of Neurology is the world’s largest association of neurologists and neuroscience professionals, with over 36,000 members. The AAN is dedicated to promoting the highest quality patient-centered neurologic care. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as Alzheimer’s disease, stroke, migraine, multiple sclerosis, concussion, Parkinson’s disease and epilepsy.
I guess they ruled out Chronic Venous Insufficiency as a cause?
Happy to participate in study. I have idiopathic peripheral neuropathy. I’m 55 diagnosed at 50. Hasn’t progressed for a while.
I’ve been to so many neuros. They all scan and do an emg, unless your Steven Hawking’s it turns up nonconclusive and all that pain and expense for nothing because they won’t look deeper. Don’t worry,most doctors say owe they don’t look deeper because there is no easy off the shelf, expensive drug for it.
Look up Dr Ken Berry on youtube. He has a video on nephropathy and how to attack it thru a process of testing. He is a Keto carnivore diet . Also Dr Ekberg and Dr Berg
Stop eating Sugar and Bread!
No ref to iatrogenic causes?
Long term use of PPI’s or H2 antagonists for GERD can cause malabsorption of vitamin b-12 which can lead to neuropathy. I think when someone is on one of those drugs, it should be standard practice to check b-12 levels.
I got neuropathy after tapering while tapering off Cymbalta very slowly. When I slowed the taper, it stopped, but now that I am off it completely, I have it all the time. Symptoms do improve when I eat less carbs and even more when I take Barley Life supplements from AIM Int.
There’s a research paper on the Herpes virus and its probability to be the reason for SFN. Hopefully the research gains momentum and better treatment options are discovered.
Well I have chronic pain from rt SI joint that is permanently dislocated and now arthritic. Neuropathy started I think as a RPS because I have mod – severe Neuropathy started rt leg from injury, progressed to both legs and RLS severe bil legs and now arms. Lived like that for 26 years! Did have Tramadol for the pain, gone now due OPIOID blocked for chronic pain! I use up to 2 tubes, could do 3 of Dyclofenac to smear from above the knee to bottom of my feet! Use to have THC:CBD 1:1,Too expensive, works very well!
Too funny James! I agree with you all the way!
Yes cbd works for my neuropathy! For weeks, my hands and feet were burning, electric like shots sensations on torso. Nothing worked to stop it. Then my son gave me some cbd and the next morning, I went from a pain scale of 10 to a 2! Try it, might work out.
I take a statin for cholesterol, I have had pain in every joint in my body ever since….. Is it neuropathy, gout, arthritis, or from a chipped vertebrae in my neck I sustained in a car wreck????? CBD treatment helps with chiropractic adjustments, but good old fashioned stretching and yoga help more when everything else falls just short…I am not just going to sit around….
I was diagnosed with severe neuropathy but I moved and had to have the test done again but it came back fine. Even though the butthead had to keep a blow dryer on my feet and he didn’t note that in the record. So don’t move to Illinois
Im skinny as a twig not obest no diabetes all yo could.havs i dont hav why do i hqv this
I’m type 2 and has serious burning in my hands and feet for months. I did some research and found out about benfotiamine(my dr had never heard of it) twice a day now no burning in my feet and hands every few months but only if I’m hard on my them.
Best thing I have used to.treat this is nutritional yeast which contains B12
I have RSD also known as CRPS. Which I got in a work accident. I found alot of Doctors have no clue of what RSD/CRPS is. Mine travel from the injured foot/ leg to the other. Moves to my arm time to time. Neuropathy is no joke. There is no cure and something I’ve been living with for 13 years. First Neurologist said I would be in wheelchair for the rest of my life. I refused to listen. I have been on crutches for 13 years. Burning, stabbing feels like Bob wire is wrapped around my lower extremities. I went through so many Doctors the first 6 months and physical therapy for two years. Nothing changed. I have a great Dr. for the last 10 years. I’ve come to terms with this being my new life. I refuse to let it own me. I find joy even when in deep pain. Meditation, good attitude,good diet and doing things at my pace helps. But I’m never pain free..
I’ve dealt with neuropathy since a car wreck at age 33, I’m 59 now. SO many things overlap with women it seems. We’re not taken seriously. After all these years, I’ve always been a huge proponent of PT. I’ve done stretches every day to live my life without giving in to the doctors’ predictions. I JUST got diagnosed with Psoas Syndrome and Rt.SI joint dislocated- at 0°- now at about 10-15°, after 2 weeks of PT. It took me almost 10 months to get the correct diagnosis. I even had gallbladder surgery but, the same pain remained. Ping ponging between 5 doctors, with an excruciating pain in my right SIDE. NEVER would have thought it would have been from my back injury 26 years ago. I thought i KNEW every possible pain affiliated with it… nope. Had a TIA a year ago Memorial Day, that also affected my left side. Always my left side was more pronounced with neuropathy pain. BOTH my feet will be on FIRE, throbbing…I stick them in the pool when it’s open, even at 3am, or in the snow in the winter, just to sleep. Gabapebtin helps that. Tizanindine helps with horrible muscle spasms that bruise from the inside out.. They’ve tried to stick me on SO many different drugs through the years that I flatly REFUSED- INCLUDING OXYCONTIN! Now,we see the new movie, “Dopesick”- and the havoc it has wreaked on our society. Side note:I touched on being dismissed earlier- as a woman of a certain age, and was told to, “learn yoga, take up meditation”! Which I already practice. It enrages me to be spoken to in a condescending manner. They tell us to, “Listen to your bodies. Be your own advocate”. But, when NO ONE IS LISTENING, what are we supposed to do? TALK LOUDER!!!
I was taking Prilosec for a period of time which I eventually was told by a rheumatologist that I had a b12 deficiency, thus is what worked taking b12 and b3 . I was in so much pain I could barely walk ,it felt like my feet and hands were in battery acid . After around one year of taking the vitamins all my pain and burning is gone now I only have a small amount of tingling when I am resting, when I am up and about there is zero tingling or pain .
Thank you Julie! I am tapering off Cymbalta and have started experiencing intense neuropathy, I will try slowing it down and cutting back on carbs; because like James said, I’m not SH so my tests were inconclusive and so now I have no answers and more debt!
With all the politically correctness going on now, why are they still using the word obese? You can’t tell someone that they need to lose weight if you wont fix a bad foot or blown knees so the patient can actually get active again.