Diagnosing Nerve Disease in Diabetic Patients

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Back to basics in diagnosing diabetic polyneuropathy with the tuning fork! by J.-W.G. Meijer and colleagues. Diabetes Care 28:2201–2205, 2005.

What is the problem and what is known about it so far?

One of the problems people with diabetes have most often is polyneuropathy, a disease of the nerves that gets worse with time. Nerve damage occurs because people with diabetes often have less blood flow and higher blood glucose levels than people without diabetes. It is a major problem, especially with the feet, because diabetic patients with nerve damage cannot feel pain and do not realize they have injuries. This can lead to painful foot ulcers, or sores, and even amputation.

Why did the researchers do this particular study?

Nerve damage in diabetic patients is a major problem because of the cost of treatment and the risk of amputation. However, there currently is no agreement among doctors and researchers on the best single test to detect and diagnose the problem. Researchers did this study to look at the commonly used tests and to try to figure out the best way to diagnose nerve disease.

Who was studied?

Researchers studied 24 diabetic patients with foot sores caused from nerve disease, 24 diabetic patients without sores or nerve disease, and 21 "control" patients without diabetes. All patients came from the Diabetes Outpatient Clinic at the University Hospital Groningen, Groningen, the Netherlands.

How was the study done?

Participants were placed into groups, and researchers performed several tests to measure the nerve reflexes of diabetic patients. These tests included the 128-Hz tuning fork and pin prick tests on the big toe; nylon testing on the sole of the foot; Achilles tendon reflex testing; testing for symptoms like nerve pain, muscle strength, and unsteady walking; and studies using machines that record the electrical activity of muscles and nerves.

What did the researchers find?

Researchers found that the test using the 128-Hz tuning fork was the most effective. The tuning fork test produced results similar to those of more complicated tests, like the pin prick test or measuring symptoms like numbness and unsteady walking. The tuning fork test is easier to manage, faster, and can be used by more health care professionals than the other tests.

What were the limitations of the study?

One limitation is that there may have been patients with diabetic nerve disease in the test group that was supposed to have only patients with no sores or nerve damage. The procedures usually used to test for this condition were done by the patients, so the only way to identify group members was by lack of foot sores currently or in the past and lack of outward signs of nerve disease. However, the researchers believe that if there were patients with nerve damage in the no-nerve-damage group, it did not affect the results of the study.

What are the implications of the study?

The researchers decided that the 128-Hz tuning fork test is a useful and reliable way to diagnose nerve disease. It is easy to manage and can be used in diabetes clinics or general doctors' offices. It allows health care professionals to accurately screen large numbers of patients and therefore is recommended for diagnosing diabetic nerve disease.

For more information on treating foot problems in people with diabetes, see the American Diabetes Association position statement on preventive foot care in diabetes.

FOR MORE INFORMATION

Diabetic Neuropathy

101 Foot Care Tips for People With Diabetes, by Jessie H. Ahroni (Alexandria, Va., ADA, 2000)

The health care costs of diabetic peripheral neuropathy in the U.S., by A. Gordois and colleagues. Diabetes Care 26:1790-1795, 2003.