Monofilaments & Diabetes

Diabetes is an insidious disease that changes the lives of thousands of people of all ages. Once diabetes has been diagnosed, though, the battle has just begun. Patients must be constantly tested for nerve damage in the extremities, particularly the feet, which can eventually lead to ulceration and amputation. Doctors use a monofilament, usually a small strand of nylon fiber, to regularly test the sensitivity and health of the diabetic's feet.

History

• In the 1800s, Dr. Von Frey used horsetail hair to test a patient's level of skin sensitivity. This technique was developed further with the advent of monfilaments by Drs. Josephine Semmes and Sydney Weinstein in 1960. They used several monofilaments of varying thickness which required progressively more pressure to make them bend. Although this system worked well, it proved to be expensive and could only be stocked by some practices. Eventually, a paper-handled monofilament was invented, leading to a less expensive monofilament test that could be stocked at all practices.

Function

• The monofilament test for diabetic patients consists of nylon strands on stiff paper handles being pressed against a patient's foot until they bend. If the patient cannot feel the sensation, the doctor moves on to a thicker monofilament that requires more pressure. The doctor notes the size of monofilament that eventually elicits a sensation. This gives him an idea of the sensitivity of the patient's feet over time and whether nerve damage is occurring.

Benefits

• The annual use of monofilament testing on diabetic patients can allow the doctor to monitor the level of nerve damage occurring in each patient, which usually provides enough warning to avoid permanent damage. In the past, severe nerve damage followed by foot ulcers and eventual amputation usually resulted from a badly informed doctor.

Misconceptions

• Monofilament testing has its shortcomings. Psychiatrictimes.org states that two studies presented to the American Diabetes Association have shown that monofilament quality varies among manufacturers and that these testing devices usually wear out– sometimes quite quickly. The evidence suggests that other testing is required to supplement the use of monofilaments, such as the use of a tuning fork or more sophisticated electronic equipment. However, costs are prohibitive compared to the relatively cheap monofilament test.

Identification

• There are identifiable symptoms to diabetic peripheral neuropathy or nerve damage caused by diabetes in the feet. The patient can often feel a burning or tingling sensation in the feet which can progress to a prickly or "pins and needles" feeling and muscle weakness. Eventually a lack of sensation occurs, indicating a dangerous condition that should be addressed immediately before an ulcer forms.