Morphological changes of the epineurium in leprosy: a new finding detected by high-resolution sonography.

INTRODUCTION: From histopathological studies of peripheral nerves in leprosy, it is known that the epineurium can be thickened. We measured the epineurial thickness of the ulnar nerve by high resolution sonography (HRUS).

METHODS: The epineurium of the ulnar nerve was measured above the elbow on transverse scan in 25 healthy controls and 26 leprosy patients.

RESULTS: The mean epineurial thickness was 0.77 mm (95% confidence interval [CI] 0.66-0.88) in symptomatic ulnar nerves (n = 20), 0.58 mm (CI 0.51-0.65) in asymptomatic nerves (n = 30), and 0.49 mm (CI 0.44-0.54) in healthy controls (n = 25) (P = 0.0001). This thickening was related to the cross-sectional area of the ulnar nerve, but not with increased blood flow.

CONCLUSIONS: The epineurium of the ulnar nerve can be measured with the use of HRUS, and it is often strikingly thickened in leprosy patients, especially in those with ulnar involvement.