Behavioral assessment of peripheral nerve function.

Behavioral psychophysical techniques were used to obtain strength-duration curves for the ulnar nerve at both threshold and suprathreshold levels. The functions well match those obtained with electrophysiologic procedures, but overcome many of the difficulities associated with traditional electrodiagnosis. An alternate means of presenting the data provides a parameter, the critical duration, that describes the ability of the stimulated nerve to integrate or summate energy over time. The very brief criticial duration for normal ulnar nerve and the similar functions at threshold and suprathreshold levels suggest possible mechanisms for the transduction and coding of percutaneous electrical stimuli.