A numerical grading scale for peripheral nerve function.

A numerical grading scale for median and ulnar function is outlined. This system, based upon the known pathophysiology of chronic nerve compression, creates a hierarchical scale of mutually exclusive categories for motor and sensory function. The scale is responsive to incorporating new technologies for sensorimotor evaluation if these should offer advantages in computer-assisted evaluation, validity, or reliability. The scale is assumed to be nonuniform, and nonparametric statistical analysis, such as use of the Wilcoxon rank-sum test, is appropriate. Where motor function may predominate the peripheral nerve function, such as the ulnar nerve, in contrast to the median nerve, the scale may be uniquely defined to reflect this attribute. Pilot study examples of application of the numerical scoring system are given, and specific areas to better define the scale through research are suggested.