Ulnar neuropathy at the elbow in diabetes

To compare the prevalence of diabetes in a consecutive sample of patients with ulnar neuropathy at the elbow (UNE) with that in patients with carpal tunnel syndrome (CTS) and to assess differences in demographic, clinical, and electrophysiologic findings between diabetic, idiopathic, and posttraumatic UNE.

Six thousand eight hundred seventy-one and 434 consecutive patients diagnosed with CTS and UNE, respectively, were admitted to an outpatient electromyography service between 1995 and 2006. Twenty-six UNE and 452 CTS patients also had diabetes.

Prevalence of diabetes in UNE was 6.0% and did not differ from that in CTS (6.6%); there were more male diabetic UNE patients (61.5%) than diabetic CTS patients (35.8%). There was no difference in occupation, duration of symptoms, association with CTS, polyneuropathy, and many neurographic findings of the ulnar, median, and radial nerves between diabetic and idiopathic or posttraumatic UNE patients when UNE groups were matched by sex and age, except for differences in sensory action potential amplitudes of diabetics vs. the other two groups.

The prevalence of diabetes is the same in UNE and CTS patients. The patients with UNE and diabetes are clinically and electrophysiologically indistinguishable from other groups of UNE patients, except for a reduction in sensory action potential amplitudes in the diabetic UNE group, presumably owing to diabetic polyneuropathy. Subjects with UNE and diabetes could therefore be treated in the same way as patients with idiopathic forms.