Cubital Tunnel Syndrome
Cubital tunnel syndrome occurs due to compression of the ulnar nerve at the elbow. It is the second most common nerve compression and causes tingling of the little and ulnar half of the ring finger with weakness of small muscles of the hand and/or the thumb.
Diagnosis
Diagnosis is made on a combination of subjective history and clinical findings:
- Inspect for evidence of hypothenar and first doral interosseous wasting and intrinsic muscle loss. In severe disease clawing of the little and ring fingers may occur.
- Froment's Sign: The patient is asked to hold a piece of paper between the thumb and a flat palm as the paper is pulled away. Positive response: flexion of the thumb to try to maintain a hold on the paper. https://www.youtube.com/watch?v=yJTIhm1VfSI
- Assess for sensory loss in the correct distribution, although more likely to be positive in severe cases. Decreased sensation should be restricted to the ulnar nerve distribution (the little and ulnar half of the ring finger). Preserved dorsal ulnar hand sensation suggests a more distal lesion, such as compression within Guyon’s canal.
- Elbow flexion test; elbow held fully flexed, with the wrist in neutral for 1 minute
Differential Diagnosis
- Ulnar nerve compression elsewhere
- Cervical nerve root entrapment (C8/T1 radiculopathy)
- Thoracic outlet syndrome
- Diabetic polyneuropathy
- Post fracture/ trauma of upper limb - secondary complication which may resolve with time or require review by orthopaedics
- Pancoast Tumour
- Other nerve entrapments
