Idiopathic neuropathy: 2 steps providers can take

It is estimated that over 20 million Americans have neuropathy.  Many people don’t know that prior to the advent of the obesity pandemic and the associated rising rates of diabetes, leprosy was the most common cause of neuropathy worldwide.  Although it is now widely recognized that diabetes is the most common cause of neuropathy, for up to 30% of patients the cause of their neuropathy remains unknown.  These cases are dubbed “idiopathic,” and as a neuropathy specialist I assure you that for many patients this becomes a chronic source of frustration and anxiety.

Some of the questions I hear from idiopathic neuropathy patients include:

  • What are the chances my neuropathy will get worse?
  • Isn’t there any treatment?
  • What else can be done to find the cause of my neuropathy?  

It is almost impossible to address these issues without a more specific neuropathy diagnosis.

Diagnosing neuropathy is a two-step process.  First, the diagnosis of neuropathy is confirmed.  This should include identifying the population of nerves involved, the type of nerve pathology, and the distribution of nerve pathology.  Detailed electrodiagnostic testing (electromyography and nerve conduction studies), and possibly a skin biopsy (to detect the involvement of small fiber nerves) or autonomic testing (to detect the involvement of autonomic nerves) may be required. Second, the cause for the neuropathy can be explored, starting with blood tests.  In some cases a nerve biopsy or genetic testing may be needed.  The more specific the characterization of the neuropathy, the easier it is to know how to look for what might be causing it.

I would argue that for any idiopathic neuropathy patient whose symptoms affect daily activities – whether that is because of pain, weakness, imbalance, or difficulty walking – further steps should be taken to help search for a more specific diagnosis.

Two steps that every health care provider can take include:

Making sure your patient is seen by a neuropathy specialist. A neuropathy (or neuromuscular) specialist is a sub-specialized neurologist.  These clinicians can sometimes uncover less common causes of neuropathy such as hereditary, toxic, autoimmune, and paraneoplastic etiologies.  They can also more readily discern when a patient might have a more unusual presentation of a common form of neuropathy.

Asking how long it has been since your patient had a neuropathy evaluation. In cases where patients were evaluated for neuropathy a number of years ago, a referral for a repeat evaluation can help determine the underlying cause of neuropathy and guide treatment choices.  In some cases the underlying cause of neuropathy may not be evident even after further evaluation, but on-going research helps us to learn more about neuropathy’s various causes, develop new tests, and consider new treatment approaches. Also, for some patients, interval electrodiagnostic testing can help clarify the diagnosis, especially if the neuropathy is progressing.

Hopefully these points can help idiopathic neuropathy patients obtain the clarity they seek and the medical care they need.

Shanna K. Patterson is a neurologist and serves on The Neuropathy Association’s Medical Advisory Committee.

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  • Jamie Stewart

    With all due respect, you make it seem as though it is easy to get a confirmed diagnosis. I have been to Mayo twice and Northwestern once with the same outcome. You have small fiber and large fiber neuropathy, probably caused by an autoimmune trigger, but nothing to confirm it. So in essence, still no diagnosis.

  • Suzi Q 38

    I have experience with this myself.
    One of the first symptoms I had were neuropathies in my hands and feet.
    This was considered symptoms of diabetes, but my blood sugar A1c was 5.5-5.8. Almost two years went by, and I eventually got worse and worse, with more and more troubling symptoms, including urinary incontinence and constipation.
    I had trouble getting even a neurologist to believe me.
    I kept asking for answers, and none were given. I asked for nerve tests and more MRI’s. They gave me PT instead. The doctor did not like the fact that I wanted certain tests to be run.
    The PT got me better, so they still held off on all of the tests.
    Finally, I had a huge problem occurred while I was out of the country on vacation. I could barely walk and was feeling tremendous pain in both legs.

    The neurologist finally requested the tests I wanted all along. One was an MRI of my upper spine. It showed a blockage with signal changes in my spinal cord.

    Anyway, now it was suspected MS, then all the tests to rule that out.

    To make a long story short. if your patient is experiencing neuropathies in both hands and feet, don’t just think diabetes or L Spine.
    Check out the T spine and C spine as well. You may be dealing with a huge spinal problem rather than diabetes.

  • Lee Robbins

    This (neuropathy diagnosed as idiopathic — which means they don’t know) is a VERY important issue. I have experienced this myself and was fortunate enough to determine the almost certain cause with the assistance of a extremely good internist friend, a neurologist who gave me a hint though not a diagnosis and the availability of testing equipment.

    The issue, which I learned from them, is that the damage that is likely to occurnot entirely dependent (and perhaps not mostly) on the AVERAGE level of blood glucose (indicated by the A1c number) but instead by the SPIKING LEVEL and FREQUENCY of spikes of glucose. In other words, you can have a moderate A1c level (mine was 5.8 to 5.9 from the onset of the peripheral neuropathy around 10 years ago until now) but still have high spikes.

    With a readily purchaseable blood sugar meter I soon learned that my 60 min. level of glucose after eating one of the following for example, a bagel, 2 slices of pizza, a bowl of tortilla chips, was around 250. My internist friend informed my that levels above 180 start to cause immediate damage to the peripheral nerves and sustained levels above 130 also do so.

    So I started carefully controlling my carb intake, which is an indicator of the likelihood of rapid entry of glucose into your blood stream, and my peripheral neuropathy which had gradually been getting worse stopped getting worse and has improved, to the amazement of the last neurology resident who examined me, to the point where it essentially barely bothers me. Additional factors my internist friend taught mwhich helped control spiking are to consume proteins and possibly fat and fiber with the carbs I do eat which again slows entry. In addition 10 minutes walking (exercise) after eating also improves glucose metabolism, and with aging (I am now 73) we have added a small daily dose of metformin which has similar glucose management effects for diabetics and pre-diabetics. I am currently diagnosed as marginally pre-diabetic. Also helpful, as commonly known, is increased exercise and losing about 15 lbs. (I am now 6′ and 175 lbs).

    In short, it is a scandal that the spiking issue is rarely discussed and the post-eating (post-prandial) testing to check for spiking has been rarely done (it costs a little more and is an mild inconvenience for the patient). It is my hypothesis (I teach research) that a great deal of the “idiopathic neuropathy) is due to exactly this issue. The book by the Neuropathy Association which I bought DOES discuss this issue though Wilkipedia was unwilling to accept it as a valid soruce for my similar article correction there. I am disappointed that Dr. Patterson has not included this critical issue in her discussion and hope she will do so in the future. Anyone concerned may contact me if you wish at

    • Suzi Q 38

      My a1c is similar to yours, but I have not taken the blood tests after I eat. Probably because my fasting blood glucose level is usually below 99. The average fasting in the morning is 89.
      So are you saying that I should take it an hour after I eat?

  • euonymous

    Neuropathy is scary. Here’s my story: in the ever present quest to be “healthy” I had begun taking lots of vitamins and supplements. And I had my husband taking them, too. It seemed like a good idea from what I’d read (ahem). Then I ran into a dear friend at the post office who was wearing a neck brace. She explained that her husband had talked her into taking a bunch of supplements and one of them caused a nerve problem in her neck. Yikes. Her doctor took her off all the supplements and had her wear a brace for several weeks. Yikes again. Got me thinking. I had noticed that my toes and the front parts of my feet felt strange. As though they had Scotch tape on them. Things didn’t feel right. Not painful, but strange. (My hands were fine.) I figured out it was some sort of neuropathy and dropped all those supplements immediately. Which was a mistake, of course. I’m one of those Factor V Leiden (genetic thing) people with a predisposition to blood clots; my doctor figured that out a few years back when I had a blood clot after a tumble skiing. As I recall she said everyone with a blood clot gets this test but I was the only one, in all her years of practice, that had come back positive. (Thanks. I’m honored.) I’d been taking an aspirin a day thinking that was a good idea, or so I’d read. By stopping the aspirin suddently I triggered another blood clot and am now on Coumadin forever, but that’s another story. Stopping all the various supplements was a good thing, although I probably should have weaned myself off them rather than go “cold turkey”. It’s been some months now and the neuropathy has just about vanished. Spooky. I think doctors need to ask about what nonprescription stuff their patients are taking (with the best of intentions) and advise them on how to get off them if that seems like a good idea.

    • b12dkelton

      Please request a blood test to check if you might be B12 deficient. It is a forgotten illness that causes debilitating symptoms (often confused with MS) it can sometimes be fatal.

      • Suzi Q 38

        I am a bit low on b12. The neuro gave me a shot.
        The MS doctor told me to stop taking B12 vitamins.
        I am not sure why. I will ask him again.

    • Suzi Q 38

      Thanks for your story.
      Right now, I only take vitamin D, about 2000 u, and another physician friend of mine tells me I should also take Vitamin B12 sublingual.
      I will have the neuropathies.

  • Steven

    I have a very rare disease called Dercum disease or adiposis dolorosa. I am a male and this disease is most common with women, only about 17% of men get it.

    I have seen many specialist including a neurologist, GI, surgeons and plastic surgeons, along with a pain management DR who took me off of drugs previously prescribed to me by other pain doctors. My primary thought I had gout. NO, I do not. I should mention that I have had over 250 angiolipomas removed. I have had this disease since I was 13. I am now 49. I had never been obese but rather skinny at 6’2″ tall since 6th grade and 140lbs, until I reached the age of 30 I had a 29″ waist. I am now fluctuating between 275 and 295 lbs. My neurologist says she has not been able to find a connection between Dercums’ and Neuropathy. She says it is the tumors pushing on nerves causing my symptoms. Besides constant pain other symptoms are;

    Sensations besides pain? Here are some of them:

    pin pricks
    crawling sensation
    feeling of water or worms running under my skin especially in the limbs.

    Rare, but feelings of being pushed hard

    and I have tremors or seizure type movements
    It feels like I am walking directly on my foot bones. This was relieved by hydrocodone but I was taken off of it, even though it gave me a greater quality of life and movement. When my neurologist test me for Neuropathy The sensations are always different between hot and cold and the sharp test. I also have gate problems and I am now on a walker after several serious falls. I can not walk a straight line. MRI’s of my brain have been perfect.


    Dercum disease (adiposis
    dolorosa) symptoms are almost always out of proportion to the physical
    findings, which include the following:

    Dercum disease (adiposis
    dolorosa) patients are usually 50% over the normal weight for their age.
    In some patients, only localized fat, without general obesity, is

    Lipomas are multiple, painful,
    symmetrically distributed, fatty deposits that are either diffuse or
    localized. The abdominal region and the lower extremities are common
    sites, especially around the knees. The ankle is an uncommon site of

    Hyperalgesia is found in the fatty tissue below the skin on light pressure and touch.
    Other findings include acral swelling, bruises
    depression, suicidal thoughts
    allergies to environment and foods
    loss of hearing or tinnitus
    the Dercum’s hump at the base of the neck/top of the
    heartburn or acid reflux (mine turns into an inability
    to swallow foods or dysphagia)
    breathing issues such as asthma, frequent bronchitis or
    pneumonia. I have to use a Cpap machine, I frequently have to yank it off because i feel like I am drowning.
    sudden weight gain or loss
    swelling in limbs and trunk
    nerve disorders, uncontrollable sudden movements
    weakness in arms, legs and/or hands
    tendency to bruise easily
    over healing – wide scars, not keloid for me
    stiffness in joints after resting
    body temperature fluctuations – run hot or really cold
    for no reason
    Irritable Bowel Syndrome or other digestive issues
    tender feet, feels like walking on glass or gout like

    I am now considered 100% disabled by my Psychologist and a Federal Administration Judge.

    I use to be a workaholic, working 12 hours or more in a day. I try to do as much as I can but over doing it one day catches up with me the next and I pay painfully for it.

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