Diabetic Neuropathy: Practical Pearls

August 6, 2016

Preventing complications of diabetes is much more desirable than dealing with them once they develop. Our blogger offers tips on diabetic neuropathy.

Quick question: What percentage of patients have significant loss of sensation secondary to neuropathy, yet are completely asymptomatic? 

Approximately 50%.1

Yes, about 50%. That’s scary! Up to ~20% of patients have symptoms of diabetic neuropathy at the time of diagnosis of diabetes. To me, these statistics drive home the point that preventing complications of diabetes is much more desirable than dealing with them once they develop. This month, I offer three interesting and practical pearls on diabetic neuropathy.

1. Do you really need special equipment to check for neuropathy?

What if, after searching your entire clinic, you discover that you don’t have a monofilament? Or, if you’re like me, you didn’t bring your 128-Hz tuning fork to work? (The latter is an alternative to the trusty monofilament.) Fear not, because you can use your hand. The Ipswich Touch Test (IpTT) is the name of this other option if all else fails.

It’s simple: the patient closes his or her eyes, then the physician lightly places his or her index finger on the patient’s first, third, and fifth toes for 1 to 2 seconds.2 A study found that the IpTT was just as sensitive and specific as the monofilament.3

2. Do you check for Charcot foot?

Also known as Charcot neuroarthropathy, this potentially disabling complication is a progressive destruction of soft tissues and bone at weight-bearing joints. Affecting 0.15 to 2.5% of individuals with diabetes, it is characterized by pathologic fractures, joint dislocations, and deformities. 

Patient presentations can vary widely – from only mild edema without deformity, to significant edema with deformity. You’ll often see a hot, edematous, erythematous, insensate foot with intact skin, with the erythema resolving when you elevate the foot. Be aware that ulceration can also be present in the ~40% of patients with Charcot neuroarthropathy.

3. Don’t forget to check in between the toes.

I know you know this, but here’s a friendly reminder: please look at the feet! Discolored skin can be an early signal of vascular insufficiency. Calluses can eventually lead to ulcers. Lesions that are in between the toes can easily escape detection.

Since John Hare, MD, the Medical Director of Joslin Diabetes Center’s Affiliated Center's program, stated this so eloquently, I’ll close with his words. “Hemoglobin A1C readings should ideally be at 7.0% or lower. Those that are consistently near or higher than 8% cause concern that any diabetes complication, including neuropathy, may develop. The good news is that the Diabetes Control and Complications Trial shows that people who keep their blood sugars consistently in this healthful range can decrease their risk of nerve damage by more than 50%. Getting diabetes under better control also may help limit the amount of damage caused by neuropathy once it's developed."4

References:

1. Boulton A, et al. Diabetic neuropathies: a statement by the American Diabetes Association. Diabetes Care. 2005;28(4):956-962.

2. Miller JD, et al. How to do a 3-minute diabetic foot exam. J Fam Pract. 2014;63(11):646-649, 653-656.

3. Rayman G, et al. The Ipswich Touch Test: a simple and novel method to identify inpatients with diabetes at risk of foot ulceration. Diabetes Care. 2011;34(7):1517-1518.

4. Diabetic Neuropathy (Nerve Damage) – An Update. http://www.joslin.org/info/diabetic_neuorpathy_nerve_damage_an_update.html. Accessed July 15, 2016.