Peripheral Neuropathy Diagnosis
It is estimated that peripheral neuropathy will ultimately affect half of all diabetic patients. With the number of patients diagnosed as diabetic skyrocketing, it is clear that peripheral neuropathy is a huge problem. It is unknown how many more patients are affected by peripheral neuropathy from other causes such as sciatica, alcohol abuse and chemotherapy.
If you have diabetic nerve pain symptoms, you already experience the diabetic foot pain or diabetic leg pain common to this condition. This is peripheral sensory neuropathy.
Peripheral Neuropathy is primarily a clinical diagnosis
That is, the diagnosis is made by symptoms and physical examination rather than what you may think of as traditional laboratory tests. Tingling, burning and numbness are the complaints physicians hear most often. The disease state can quickly progress to negatively impact activities of normal daily life including sleep, balance, walking and sexual function. Loss of sensation is most common in the lower extremities, putting patients presenting with neuropathy symptoms such as this at risk for serious complications because the protective mechanisms are therefore lost. It can lead to ulcerations and collapse of the joints of the foot, and is the primary cause of non-traumatic limb loss in the United States. Diabetic peripheral neuropathy is the single most reliable predictor of lower extremity amputation in the diabetic population.
Loss of vibratory sense is usually determined by a 128MHz tuning fork test. Comparison of the upper and lower extremities with regard to this tuning fork test will often yield a clear demonstration to the sufferer of the loss of vibratory sense in the lower extremity. Light touch is often lost from distalmost extremities, and is bilaterally symmetrical. That means it starts at the tips of your toes and affects both sides fairly equally. Here is something you can try: Use the bristle of a paint brush. With your eyes closed, ask a friend to touch different areas of your feet. Did you feel it?
Balance can be tested by walking in a straight line in low light. How did you do?
Close your eyes when standing on both feet in a protected area. Do you sway or stumble? This can be a sign of loss of proprioception, an important sensory feedback loop.
Motor weakness or even loss can be simply evaluated by testing the reflexes at the Achilles or Patellar tendons. More complex tests, such as EMG or NCV can be performed for truly objective values. These are most often performed by a neurologist.
Sural nerve neurometry is gaining acceptance as well. With a hand held device in the office setting, the nerve function can be evaluated in a 2 minute procedure. Neurometry can be repeated to follow the progress of therapy.
Epidermal nerve fiber density testing (ENFDT) is the gold standard. This involves taking a punch biopsy of the sural nerve, and sending it to a specialized pathology lab, where the sample is compared to a control group. Results will show the number of nerve fibers present. This test can also be helpful in following the progress of neuropathic pain treatment.
Progress and Therapy
Neurometry and ENFDT can be used to follow the progress of therapy when remedial treatments are used. Palliative therapies, such as prescription neuropathy
medications including Pregabalin, Gabapentin, and tricyclic antidepressants, though very effective in relieving neuropathy symptoms in some cases, do not address the root cause of the problem. Therefore, change in these test results will be unlikely with those palliative therapies.
However, recent clinical studies have shown great promise in remedial treatment with high dose vitamin therapy.