Such symptoms depend on whether autonomic, sensory, or motor nerves — or a combination of them — are involved. Autonomic nerve damage can affect bodily functions or blood pressure, or create gastrointestinal symptoms. Damage to sensory nerves can affect sensations and sense of balance, while damage to motor nerves can affect movement and reflexes. When both sensory and motor nerves are involved, the condition is known as sensorimotor polyneuropathy. (3) This lack of feeling increases the likelihood of injury to the affected areas, explains Matthew Villani, DPM, of HCA Florida Lake Monroe Hospital in Sanford, Florida. Without the pain to signal when there’s a problem, people with diabetic neuropathy can allow small abrasions or blisters on their feet, for example, to fester as sores or ulcers. “The ulcers can become infected because there are open wounds, which can also progress into bone infection. Unfortunately, commonly it requires amputations if it does progress to that point.” (4) After that, your doctor can do a physical examination, “checking motor and sensory function, checking deep tendon reflexes, as well as looking for symptoms such as allodynia and hyperalgesia,” Williams says. “Then we can also perform electrodiagnostic testing; the most common being electromyography and nerve conduction testing, where we can stimulate nerves and record responses, calculate the speed at which signals are being transmitted, and see if there are any areas where nerves are not transmitting signals normally,” Williams says. With needle examinations, Williams says, “We can put small needles into individual muscles, and, based on what we see and hear with the needle in the muscle, get information about how the nerves supplying that muscle are functioning. So there are a number of different tests that could be helpful to identifying neuropathy, as well as localizing where the abnormality is most likely to be coming from.” Frequently, blood tests can check for elevated blood sugar (to see if your symptoms may be related to type 2 diabetes), vitamin deficiencies, toxic elements, hereditary disorders, and evidence of an abnormal immune response. (11) Your doctor may also do a nerve biopsy, which usually entails removing a small portion of a sensory nerve to look for abnormalities, or a skin biopsy to see if there is a reduction in nerve endings. (12) To give yourself the best chance of an accurate diagnosis — and relief of your symptoms — be prepared to describe your symptoms in detail, when you experience them, how long an episode lasts, and the amount of discomfort, pain, or loss of sensation or movement you experience. The more specific you can be about the symptoms you are experiencing, the easier it will be for your doctor to understand what is going on.
