Wartenberg sign
Reading File
Finding Sources
Searching the Web
Wartenberg sign neurology clinical significance
Reading File
Reading File
The Wartenberg sign actually refers to two distinct eponyms — both named after neurologist Robert Wartenberg — one a clinical sign of ulnar nerve palsy, and the other a syndrome of radial nerve compression.
1. Wartenberg Sign (Ulnar Nerve Palsy)
Definition: Persistent abduction and extension of the small (5th) finger during attempted adduction, due to weakness of the third volar interosseous muscle and the small finger lumbrical (both ulnar nerve–innervated), with unopposed action of the extensor digiti minimi (radial nerve).
Mechanism:
- The 3rd palmar interosseous muscle and small finger lumbrical adduct and flex the MCP of the little finger
- In ulnar nerve palsy, these are paralyzed
- The extensor digiti minimi (EDM), innervated by the radial nerve, pulls the little finger into abduction and extension unopposed
- Result: the little finger drifts away from the ring finger and cannot be fully adducted
Associated signs in ulnar nerve palsy (e.g., cubital tunnel syndrome):
| Sign | Finding | Mechanism |
|---|---|---|
| Wartenberg sign | Little finger abduction/extension at rest | Weak 3rd volar interosseous & lumbrical |
| Froment sign | Thumb IP flexion (FPL) during key pinch | Weak adductor pollicis |
| Jeanne sign | Thumb MCP hyperextension during key pinch | Weak adductor pollicis |
| Masse sign | Flattening of palmar arch | Weak opponens digiti minimi |
| Clawing | Ring & small finger claw deformity | FDP contraction + intrinsic paralysis |
Clinical context: Seen in cubital tunnel syndrome (ulnar nerve compression at elbow) and ulnar tunnel syndrome (Guyon's canal). The examiner asks the patient to hold all fingers adducted — the little finger visibly abducts.
2. Wartenberg Syndrome (Cheiralgia Paresthetica)
A separate eponym referring to compressive neuropathy of the superficial branch of the radial nerve (SBRN).
Anatomy: The SBRN emerges from under the brachioradialis tendon in the distal forearm. It is compressed between the brachioradialis and extensor carpi radialis longus (ECRL) tendons during forearm pronation (scissor-like mechanism).
Presentation:
- Pain, numbness, and paresthesias over the dorsoradial hand and thumb
- Inability to wear a wristwatch or jewelry over the nerve
- No motor deficit (pure sensory nerve)
Provocative tests:
- Forceful forearm pronation held for 60 seconds
- Tinel sign over the SBRN
Management:
- Nonoperative: activity modification, splinting in supination, NSAIDs
- Surgical decompression: if nonoperative treatment fails after 6 months
Summary: In clinical exam settings, "Wartenberg sign" most commonly refers to the little finger abduction sign in ulnar nerve palsy. "Wartenberg syndrome" refers to SBRN compressive neuropathy at the wrist/forearm.
Sources: Miller's Review of Orthopaedics 9th Ed., p. 693; Schwartz's Principles of Surgery 11th Ed.; Sabiston Textbook of Surgery
This is a shared conversation. Sign in to Orris to start your own chat.