The McGowan classification was published in 1950[^1] and is used for the categorization of lesions of the ulnar nerve into three different grades.
Classification
McGowan Grade | Description |
Grade I | Minimal lesion without objective motor deficits. Paresthesias in the supply area of the ulnar nerve. |
Grade II | Intermediate lesion with an incomplete weakness of the interosseous muscles. Possible hypoesthesia in the area of the ulnar nerve. Sweat production preserved. |
Grade III | Severe sensorimotor deficit, with complete paralysis of one or more muscles innervated by the ulnar nerve. |