Ulnar entrapment neuropathy in patients with type 2 diabetes mellitus: an electrodiagnostic study.

Aims: This study aimed to assess the prevalence and electrophysiological features of ulnar entrapment neuropathy in patients with type 2 diabetes mellitus (DM).

Methods: Nerve conduction studies (NCS) were performed in a sample of consecutive diabetic patients aged 25-75 years, referred by the Diabetology Unit. NCS of the median, ulnar, radial, peroneal and sural nerves were performed on the non-dominant side. Median entrapment neuropathy at the wrist (MNW) and ulnar neuropathy at the elbow (UNE) and wrist (UNW) were diagnosed according to standard electrodiagnostic criteria.

Results: Sixty-four patients were enrolled, 28 male (44%), average age 61, average DM duration 14.5 years. Polyneuropathy was diagnosed in 45 subjects (70%). UNE was detected in 22 patients (34%) (4 did not have polyneuropathy), in the abductor digiti minimi in 16, the first interosseus in 14 and in both in 8. UNW was detected in 7 (11%) subjects and MNW in 40 (63%). NCS alterations consistent with ulnar neuropathy were detected in a high proportion of patients (45%), suggesting that the ulnar nerve is very susceptible to focal entrapment in DM.

Conclusions: Upper limb sensory and motor NCS, including motor conduction velocity across the elbow, should be considered in the staging of DM patients.