Nerve conduction velocity and cross-sectional area in ulnar neuropathy at the elbow.

INTRODUCTION

In the precise localization of ulnar neuropathy at the elbow (UNE) we have noted discrepancies between electrodiagnostic (EDx) and ultrasonographic (US) findings. We aimed to explore the relationship between the 2 techniques.

METHODS

Four study-blind examiners took a history and performed neurologic, EDx, and US examinations of a group of prospectively recruited patients with UNE. They assessed the relationship between ulnar nerve cross-sectional area (CSA) and motor nerve conduction velocity (MNCV).

RESULTS

In 106 patients with UNE at the retrocondylar (RTC) groove, the highest CSA and lowest MNCV were noted in the same short segment. In 54 patients with UNE at the humeroulnar aponeurosis (HUA), the highest CSA and lowest MNCV were noted proximal to the HUA.

DISCUSSION: MNCV and CSA were highly correlated in UNE. Ulnar nerve slowing proximal to the entrapment at the HUA was surprising, but consistent with previous studies done on carpal tunnel syndrome. Muscle Nerve 56: E65-E72, 2017.