The Importance of Nerve Damage in the Diabetic Foot

Those who have diabetes are at an increased risk of problems with their feet. This risk includes the potential for a foot ulcer, infection and an amputation of a toe, foot or leg if things get really bad. The reason for this risk is that the higher levels of glucose in the blood affect many body systems including the circulation, nerve sensation and the ability to fight an infection. The feet depend on a good circulation of blood and a good nerve sensation to know that something is wrong with the foot, so action can be taken. Of these potential risks, the nerve damage or neuropathy is important. Without that sensation there could be damage to the foot and they do not know that damage has happened as they can not feel it. This could range from a blister and ingrown toenail to an ankle sprain or fracture. If they can not feel it, it will keep getting worse and they can keep walking around on it and not know. The sensation of pain exists for a reason to warn us of damage.

Being able to detect the nerve damage early is really important. If it gets detected early, then efforts can be made to stop it getting any worse and various protective strategies can be put in place to lower the chance of damage happening. There are a number of tests that clinicians can use to measure this. They can use simple monofilaments to poke the foot to see if it can be felt. Sometimes they use a tuning fork to check if the foot can feel vibration. This is an important one as vibration is the sensation that often is lost first. Hot and cold temperature sensation may also be checked for. A number of tests may be combined to give an overall picture. Some of the tests have a formal protocol that has been tested for its validity and reliability and then can be used on a regular basis with confidence. These tests will almost always test a number of different sites on the foot. One of those is the Ipswich Touch Test that uses a monofilament on several different sites on the foot. There are a number of videos around on how to perform the Ipswich Touch Test, so check some of them out. The big advantage of this test is that it is quick and simple, but gives an accurate picture of the status of the nerve sensation.

Once the signs of this loss of sensation from the nerve damage has been detected, then the importance of controlling the blood glucose levels is extremely important as there are some serious consequences to the foot if the nerve damage progresses. If the damage progresses, then those with this need to check their feet every day to see if there is any damage. They need to be particularly careful to protect the foot from damage by checking that their shoes fit properly and that there are no pressure points (which they cannot feel!). They need to take steps to avoid potential trauma and damage to the feet.

Craig Payne is a University lecturer, runner, cynic, researcher, skeptic, forum admin, woo basher, clinician, rabble-rouser, blogger and a dad.