An electrodiagnostic technique for assessing palmar proper digital nerves of the hand. Normative data and clinical application.

Introduction: There is no standard electrodiagnostic technique for palmar proper digital nerves (PaPDNs). In this study we investigated sensory nerve action potentials (SNAPs) to PaPDN stimulation in normal subjects and patients. Methods: SNAPs of PaPDNs were recorded in response to selective antidromic stimulation at the web space and mixed nerve stimulation at the wrist in 14 controls. The selectivity of PaPDN stimulation and the effect of recording electrode position on SNAP amplitude were studied. The technique was tested in 2 patients with PaPDN lesions. Results: The technique yielded selective PaPDN stimulation at the web space. SNAP amplitude to PaPDN stimulation was influenced by age and was larger than SNAP amplitude to wrist stimulation. The recording electrode positions influenced SNAP amplitude. In patients, we documented PaPDN lesions, which were confirmed at surgery, whereas conventional wrist mixed nerve stimulation yielded negative findings. Conclusions: Selective PaPDN stimulation at the web space is feasible and may be helpful for electrodiagnosis of PaPDN lesions. Muscle Nerve 52: 972–980, 2015