Katz hand diagram classification of carpal tunnel syndrome
| Grade | Criteria | Comments |
|---|---|---|
| Classic | Symptoms include pain, numbness, tingling, and burning in at least 2 digits (thumb, index, and long) | Involvement of the fourth and fifth digits, wrist, and area proximal to the wrist is allowed Involvement of the palm or dorsum of the hand is not allowed |
| Probable | Symptom pattern same as classic | Palmar symptoms are allowed unless confined to the ulnar side |
| Possible | Symptoms involve only 1 digit (thumb, index, or long) | Symptoms may involve the dorsum of the hand |
| Unlikely | No symptoms involving thumb, index, or long digit |