Neurophysiological classification of ulnar entrapment across the elbow.

Ulnar nerve entrapment across the elbow (UAE), a common entrapment, requires neurophysiological evaluation for a diagnosis, but a standardised neurophysiological classification is not available. The aim of our study was to evaluate the validity of a neurophysiological classification of UAE, developed by us. To this end, we examined whether sensorimotor deficits, as observed by the physician and as referred by the patients, increased with the neurophysiological severity according to the classification. We performed a multiperspective assessment of 63 consecutive arms from 52 patients with a clinical diagnosis of UAE. Neurophysiological, clinical and patient-oriented validated measurements were used. The neurophysiological classification is based on the presence or absence of evoked responses and on the normality or abnormality of conduction findings. A strict relationship was observed between the degree of neurophysiological severity and the clinical findings (sensorimotor deficits). Moreover, a significant positive correlation between hand functional deficit and neurophysiological classification was observed. Conversely, a clear correlation between neurophysiological pattern and symptoms was not found. The neurophysiological classification is easy to use and reliable, but further multicentric studies should be performed.