Current And Emerging Insights On Treating Diabetic Peripheral Neuropathy
Peripheral neuropathy is not exclusive to metabolic disease of the nerves. Entrapment of the nerve trunk from hypertrophic deep fascia or muscular structures as well as limb deformity can cause tension or compression on the peripheral nerve. Any trauma including surgery can lead to entrapment. The range of symptoms can go from intermittent paresthesias to the development of drop foot in more severe cases. Patients with peripheral neuropathy will often present with symptoms they describe as burning, tingling, temperature changes and an “electric shock” like feeling down the leg to the foot.
The diagnosis and treatment of small fiber neuropathy has improved and intra-epidermal nerve fiber density testing should be a standard test when assessing neuropathy. In 2010, the European Federation of Neurological Societies and Peripheral Nerve Society decided that the intra-epidermal nerve fiber density test is in fact a reliable and effective measure to assess the progression of small fiber neuropathy although it gives no information on etiology.6
This test is a simple 3 mm skin biopsy located 10 cm superior to the lateral malleolus. One then places this into Zamboni’s solution and stains the sample with protein-gene product 9.5. The results often come with a picture of the biopsy under a microscope.
If the test shows a loss of density of these small fibers, it is then likely that the patient will have difficulty with temperature regulation as well as sweat gland problems leading to dry skin and cracking of the skin. Accordingly, it would be important to have the patient apply emollients to the skin on a regular basis. Also, these patients are more likely to benefit from pharmacologic agents as they are less likely to respond to surgery alone.
How Effective Is Nerve Decompression For Neuropathy?
There has been a disconnect between the medical and surgical communities regarding surgical nerve decompression for those with diabetes. When Dellon first published his article on nerve decompression for patients with diagnosed nerve entrapment of the tarsal tunnel, many of the well known, diabetic neuropathy researchers came out strongly against the article and its premise.7 They tried to paint the procedure as experimental and some even tried to twist the premise of the article, intimating that we surgeons were “curing” diabetic neuropathy. This initial negative connotation to the procedure spread quickly among the academia in the medical community and into the podiatry community.
As a somewhat biased observer of this history and where we are now, the lead author feels they were wrong and remain wrong. Surgeons in the AENS have performed thousands of decompressions on people with and without diabetes with peripheral neuropathy, and have had very high success rates at restoring protective sensation and relieving pain.
Nickerson and colleagues looked retrospectively at patients who had tarsal tunnel decompression and found there was a less than 4 percent ulcer recurrence rate in patients with diabetes.8