Table 1.

Detailed Katz scoring algorithm

Classic (3)	Tingling, numbness, burning or pain in at least 2 of the digits (thumb, index, and long). Excluded if symptoms in the palm and dorsum of hand; small finger symptoms, wrist pain, or radiation proximal to the wrist allowed. *For index and long digits, must include shading >1/2 of the volar surface over middle phalanx and/or some of the distal phalanx. For thumb, must include volar shading over distal phalanx
Probable (2)	Same shading as Classic but allowed to extend into palm volarly unless confined to ulnar side of palm
Possible (1)	Tingling, numbness, burning, or pain in at least one of thumb, index, and long. May include dorsum of hand
Unlikely (0)	No shading of volar thumb, index, and long