Cubital Tunnel Syndrome
What is a Cubital Tunnel Syndrome?
Cubital tunnel syndrome is a condition that affects the ulnar nerve where it crosses the inside part of the elbow. Often patients refer it to hitting the funny bone, but in fact it’s the nerve which is ‘funny’.
Anatomy
The ulnar nerve passes behind the inside of elbow behind a bone of the arm – called the medial epicondyle. As it passes beyond the elbow joint it goes through the ‘tunnel’formed by muscle, ligament & bone. Sometimes you may be able to feel the nerve as you bend and straighten the elbow.
The ulnar nerve supplies feeling (sensory) to the little & ring finger. It also supplies motor power to 15 out of 20 small muscles in hand.
Causes:
The most common is ‘idiopathic’meaning no specific cause if found. The ulnar nerve has a large excursion as the elbow moves from flexion into extension which may cause it to be irritated. One common cause if frequent bending of the elbow, constant direct pressure. It may happen in patients who have arthritis of elbow with extra bone pressing on the nerve. Fracture dislocation of elbow or swelling in elbow joint can also cause ulnar nerve compression symptoms.
Symptoms:
The common symptoms are tingling and numbness in the ring and little fingers with aching sensation in forearm. These may be worsened by bending the elbow or resting on a hard surface.
Typical symptoms include:
- Clumsiness of hand
- Difficulty in holding small change, doing buttons, shoelaces, playing fine instrument etc.
- In long standing cases there may be muscle wasting.
- Sometimes the little finger may stand out and not come together with the other fingers.
Diagnosis:
The cubital tunnel syndrome is usually a clinical diagnosis. Tapping around the nerve just distal to the elbow can cause a shooting sensation in the fingers called Tinel sign. There may be numbness in the little & ring fingers.
Tests:
- X-rays:Most cases of cubital tunnel syndrome do not require an X-ray but, your doctor may ask for them to look for bone spurs, arthritis, or other places that the bone may be compressing the nerve.
- Nerve Conduction Studies (NCS/EMG):These tests can determine how well the nerve is working and help identify where it is being compressed.Nerves are like “electrical cables” that travel through your body carrying messages between your brain and muscles. When a nerve is not working well, it takes too long for it to conduct.Nerve conduction studies can also determine whether the compression is also causing muscle damage. Muscle involvement is a sign of more severe nerve compression.
- MRI of the neck may be requested to rule out a spine problem mimicking CTS
Nonsurgical Treatment
In the very early stages when the symptoms are mild Non-Steroidal Anti-Inflammatory medications like ibuprofen may be useful. Avoid activities that require you to keep your arm bent for long periods of time.
- A soft elbow support bandage may ease pressure on the nerve
- Make sure that your chair is not too low. Do not rest your elbow on the armrest.
- Avoid leaning on your elbow or putting pressure on the inside of your arm.
- Keep your elbow straight at night when you are sleeping.
Surgery:
The goal of surgery is to release the pressure on the nerve. There are different options and they are used depending on the presenting symptoms and it’s unclear if one is better than the other.