Cubital tunnel syndrome is a condition brought on by increased pressure to the ulnar nerve at the elbow. There is a small piece of bone on the inner portion of the elbow (medial epicondyle) under which the ulnar nerve passes. This site is commonly called the “funny bone”. At this site, the ulnar nerve lies directly next to the bone and is susceptible to pressure. When the pressure on the nerve becomes great enough to disturb the way the nerve works, symptoms such as numbness, tingling and pain may be felt in the elbow, forearm, hand and/or fingers.
Pressure on the ulnar nerve at the elbow can develop in several ways. The nerve is positioned right next to the bone and has very little padding over it, so pressure on the bone also puts pressure on the nerve. In some patients, the ulnar nerve at the elbow clicks back and forth over the bony bump as the elbow is bent and straightened which can irritate the nerve.
Additionally, pressure on the ulnar nerve can occur from holding the elbow in a bent position for a long time, which stretches the nerve across the medial epicondyle. The connective tissue over the nerve may become thicker, or there may be variations of the muscle structure over the nerve at the elbow that cause pressure on the nerve. Cubital tunnel syndrome occurs when the pressure on the nerve is significant and sustained enough to disturb the way the ulnar nerve works. Symptoms usually include:
- Pain, numbness and/or tingling, most often occurring in the ring and little fingers.
- Often, symptoms will be felt when the elbow is held in a bent position for a period of time, such as when holding the phone or while sleeping.
- Some patients may notice weakness while pinching, occasional clumsiness and/or a tendency to drop things.
- In severe cases, sensation may be lost and the muscles in the hand may lose bulk and strength.
Symptoms may be manageable with certain medication and will usually subside without surgery.