Overview
The ulnar nerve is an important nerve because it supplies feeling to the little and ring fingers of the hand and activates many of the small muscles in the hand (allowing strong gripping of objects in the hand).
The ulnar nerve travels to the hand via the inside back part of the elbow where it can be bumped (hitting your “funny bone”). As it passes around the elbow it is exposed. Usually the tingling you get when bumping the nerve lasts a few seconds only but the ulnar nerve can also be the cause of more serious and permanent problems in the fingers and hand.
An injury to the elbow such as a dislocation or fracture can damage or irritate the ulnar nerve. The inflamed nerve can swell and become squashed in the cubital tunnel. This gives the condition its name, ulnar nerve entrapment (often also called cubital tunnel syndrome).
Prolonged pressure on the nerve also can be a problem. Bending the elbow stretches the ulnar nerve and squashes it as it passes through the cubital tunnel. This disrupts the nerve’s ability to conduct messages between the hand and the brain. The muscles of the hand gradually start to weaken (so that it becomes difficult to open a jar or hold a hammer) and you lose protective sensation on the inner part of the hand.
What to Look for
Although the nerve is squashed around the elbow, most symptoms occur in the hand and fingers because the ulnar nerve controls movement and feeling.
You may experience…
- Tingling and numbness in little and ring fingers (especially at night).
- Numbness in your hand when the elbow is bent (holding the phone to your ear).
- Difficulty using your hand for day to day activities.
- Decreased grip and pinch strength and muscle weakness.
- Tenderness along the inside of the elbow.
Diagnosis
The majority of the diagnosis is in the history. Symptoms are often quite typical. You will need to have an Xray to make sure there is no bone problem causing the nerve compression around the elbow. This is particularly important if you have had a fall, blow or other injury to the elbow. You may be sent for nerve conduction studies to confirm the diagnosis or to act as a baseline test to monitor the nerve’s recovery. Surgical decompression of the ulnar nerve is performed as a day only procedure but it can take 3 months for the symptoms to improve after the operation.