Proximal forearm ulnar nerve conduction techniques

Compression of the ulnar nerve across the elbow is a common clinical diagnosis frequently referred for electrodiagnostic evaluation. Motor conduction studies with recording over the abductor digiti minimi and stimulating proximal and distal to the ulnar notch have been the standard technique employed in these evaluations--mean, 60.0 m/s; SD 5.0 m/s. Two other techniques are described, with data from normal subjects, recording from proximal forearm muscles. One technique is a refinement of a previously described method recording from the flexor carpi ulnaris--mean, 63.0 m/s; SD, 4.7 m/s. The second is a newly developed technique recording from the flexor digitorum profundus--mean, 63.0 m/s; SD, 5.5m/s. All three methods were found to have a small range of comparable normal values, and appear to be easily and quickly performed with reliable and reproducible information. The techniques described enhance specific localization of ulnar nerve lesions, and may prove useful when more distal recording sites are unavailable.