Merck Manual

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Cubital Tunnel Syndrome

(Ulnar Neuropathy)


David R. Steinberg

, MD, Perelman School of Medicine at the University of Pennsylvania

Reviewed/Revised Apr 2022 | Modified Sep 2022
Topic Resources

Cubital tunnel syndrome is compression or traction of the ulnar nerve at the elbow. Symptoms include elbow pain and paresthesias in the ulnar nerve distribution. Diagnosis is suggested by symptoms and signs and sometimes nerve conduction studies. Treatments include splinting and sometimes surgical decompression.

The ulnar nerve is commonly irritated at the elbow or, rarely, the wrist. Cubital tunnel syndrome is most often caused by leaning on the elbow or by prolonged and excessive elbow flexion. It is less common than carpal tunnel syndrome Carpal Tunnel Syndrome Carpal tunnel syndrome is compression of the median nerve as it passes through the carpal tunnel in the wrist. Symptoms include pain and paresthesias in the median nerve distribution. Diagnosis... read more Carpal Tunnel Syndrome . Baseball pitching (particularly sliders), which can injure the medial elbow ligaments, confers risk.

Symptoms and Signs of Cubital Tunnel Syndrome

Symptoms of cubital tunnel syndrome include numbness and paresthesia along the ulnar nerve distribution (in the ring and little fingers and the ulnar aspect of the hand) and elbow pain. In advanced stages, weakness of the intrinsic muscles of the hand and the flexors of the ring and little fingers may develop. Weakness interferes with pinch between the thumb and index finger and with hand grip.

Patients with chronic cubital tunnel syndrome may present with an ulnar claw hand. An ulnar claw hand is metacarpophalangeal joint extension and interphalangeal joint flexion of the small and ring fingers caused by an imbalance between intrinsic and extrinsic hand muscles.

Diagnosis of Cubital Tunnel Syndrome

  • Clinical evaluation

  • Sometimes nerve conduction studies

Diagnosis of cubital tunnel syndrome is often possible clinically. However, if clinical diagnosis is equivocal and when surgery is being considered, nerve conduction studies Nerve conduction studies When determining whether weakness is due to a nerve, muscle, or neuromuscular junction disorder is clinically difficult, these studies can identify the affected nerves and muscles. In electromyography... read more are done. Cubital tunnel syndrome is differentiated from ulnar nerve entrapment at the wrist (in Guyon canal) by the presence of sensory deficits over the ulnar dorsal hand, by the presence of ulnar nerve deficits proximal to the wrist on muscle testing or nerve conduction velocity testing, and by the elicitation of ulnar hand paresthesias by tapping the ulnar nerve in the cubital tunnel at the elbow (positive Tinel sign). Cubital tunnel syndrome may be confused with proximal nerve compression such as that caused by thoracic outlet syndrome (TOS) Thoracic Outlet Compression Syndromes (TOS) Thoracic outlet compression syndromes are a group of poorly defined disorders characterized by pain and paresthesias in a hand, the neck, a shoulder, or an arm. They appear to involve compression... read more or C8-T1 cervical radiculopathy (see table ). Anterior subluxation of the ulnar nerve during elbow flexion may produce similar symptoms with normal electrodiagnostic test results. Dynamic ultrasonography can confirm the diagnosis and differentiate it from the less common snapping triceps syndrome (subluxation of medial head of triceps over medial epicondyle).

Treatment of Cubital Tunnel Syndrome

  • Splinting

  • Sometimes surgical decompression

Treatment of cubital tunnel syndrome involves splinting at night, with the elbow extended at 45°, and use of an elbow pad during the day. Surgical decompression can help if conservative treatment fails.

NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
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