CTS: Diabetes Predicts Symptoms Post-Injection

Further proving that diabetes exacerbates just about everything, researchers from Brigham and Women’s Hospital have found that diabetic carpal tunnel patients undergoing one corticosteroid injection were at greater risk of future symptoms. The researchers, led by Philip Blazer, M.D., director of the Harvard Hand and Upper Extremity Surgery Fellowship, found that the diabetic patients in the study (13% of the wrists enrolled) were at a 2.6-fold greater risk of reporting recurring symptoms within a year of follow-up.

Dr. Blazer told OTW, “Corticosteroid injection is a bit controversial for carpal tunnel. There are some who use it frequently and some who never use it. In reviewing the literature, the authors found there was limited literature on the population most likely to benefit from a non-surgical solution. Our perspective was that there was room for a paper looking at how we used injection, for a selected group of patients, with positive testing and excluding those with severe testing results. Many of the prior studies also did not have electrodiagnostic confirmation of the diagnosis.”

Asked if more is known about why diabetic patients fare worse, Dr. Blazer noted, “Not really. Diabetes does make patients more likely to develop carpal tunnel and causes documented changes in nerve physiology. Furthermore, there are other diseases (e.g., trigger finger) where the response to injection is worse if the patient has diabetes, so it was not a large surprise.”

“We expected a large percentage of patients to report symptom improvement, but we were surprised by the percentage that remained symptom free at a year. In a selected group of patients (mild to moderate positive EMG), a large percentage of patients will get symptom relief and that relief lasts beyond a year in almost a third of the group.”