Ulnar nerve dysfunction

Definition

Ulnar nerve dysfunction is a problem with the nerve that travels from the wrist to the shoulder, which leads to movement or sensation problems in the wrist and hand.

Alternative Names

Neuropathy - ulnar nerve; Ulnar nerve palsy

Causes

Ulnar nerve dysfunction is a common form of peripheral neuropathy. It occurs when there is damage to the ulnar nerve, which travels down the arm. The ulnar nerve is near the surface of the body where it crosses the elbow, so long-term pressure on the elbow may cause damage.

The damage involves the destruction of the nerve covering (myelin sheath) or part of the nerve (axon). This damage slows or prevents nerve signaling.

A problem with one single nerve group (such as the ulnar nerve) is called mononeuropathy. The usual causes are:

• Direct injury
• Long-term pressure on the nerve
• Pressure on the nerve caused by swelling or injury of nearby body structures

Entrapment involves pressure on the nerve where it passes through a narrow structure.

The ulnar nerve is commonly injured at the elbow because of elbow fracture or dislocation. Prolonged pressure on the base of the palm may also damage part of the ulnar nerve. Temporary pain and tingling of this nerve is common if the elbow is hit, producing the experience of hitting the "funny bone" at the elbow.

In some cases, no cause can be found.

Symptoms

• Abnormal sensations in the 4th or 5th fingers, usually on the palm side
• Numbness, decreased sensation
• Pain
• Tingling, burning sensation
• Weakness of the hand

Pain or numbness may awaken you from sleep. Activities such as tennis or golf make the condition worse.

Exams and Tests

An exam of the hand and wrist can reveal ulnar nerve dysfunction. Signs may include:

• "Claw-like" deformity (in severe cases)
• Difficulty moving the fingers
• Wasting of the hand muscles (in severe cases)
• Weakness of wrist and hand bending

A detailed history may be needed to determine the cause of the neuropathy.

Tests may include:

• Blood tests
• Imaging scans
• Nerve conduction tests
• Recording of the electrical activity in muscles (EMG)
• X-rays

Treatment

The goal of treatment is to allow you to use the hand and arm as much as possible. The cause should be identified and treated. Sometimes, no treatment is required and you will get better on your own.

Treatments may include:

• A supportive splint or elbow pad to help prevent further injury
• Corticosteroids injected into the area to reduce swelling and pressure on the nerve
• Surgery to relieve pressure on the nerve, if the symptoms get worse, movement is difficult, or there is proof that part of the nerve is wasting away. Surgical decompression may be recommended if the symptoms are from entrapment of the nerve.
• Over-the-counter analgesics or prescription pain medications to control pain (neuralgia)
• Other medications, including gabapentin, phenytoin, carbamazepine, or tricyclic antidepressants such as amitriptyline or duloxitine, to reduce stabbing pains.
• Physical therapy exercises to help maintain muscle strength
• Occupational counseling, occupational therapy, job changes, or retraining