How dangerous can cubital tunnel syndrome be?

Many patients with cubital tunnel syndrome mistakenly think its symptoms are the result of sleeping on their arm or even carpal tunnel syndrome. Seemingly minor signs that something is amiss with one or more fingers can turn into a more serious problem over time without appropriate treatment.

Overview of Cubital Tunnel Syndrome

Physicians also refer to this condition as an ulnar nerve entrapment. It is a compression of the ulnar nerve that occurs in the region of the elbow, resulting in irritation of the ulnar nerve.

Starting at the elbow, the ulnar nerve runs through tissue, called the cubital tunnel, under a bone bump at the interior part of the elbow. The point at which it runs under the bump is often called the funny bone, according to the American Academy of Orthopedic Surgeons. The shock-like sensation experienced when bumping this area occurs because the nerve is so close to the skin.

The ulnar nerve travels under forearm muscles into the hand on the palm side. It governs sensations in the little finger as well as half the ring finger. It controls most small hand muscles necessary for fine movement and some larger muscles in the forearm used for gripping.

The exact cause of this syndrome remains unknown. However, the American Society for Surgery of the Hand points out that bending the elbow for extended periods stretches and irritates the ulnar nerve. Direct pressure creates a sensation of the hand and the arm “falling asleep.” A patient’s anatomy might have issues that permit the nerve to repeatedly move over the bony bump instead of remaining in place, also causing irritation.


The Washington University School of Medicine in St. Louis notes that in early stages, symptoms appear only sporadically and are fairly mild. Initial signs might be some tingling or numbness, or both, at night when sleeping with elbows bent for an extended period.

As nerve compression advances, tingling and numbness in the small and ring fingers occur more frequently even though the nerve was exposed to irritating positions for shorter intervals. Manipulating objects or performing activities such as typing might become progressively harder.

Some Florida Hand Center patients complain of pain on the inside of the elbow and muscle aches on the inside of a forearm. With severe cases, there is a danger of nearly constant numbness, along with grip weakness, trouble coordinating fingers, muscle wasting, and ultimately, permanent clawing of the ring and small fingers. This wasting is irreversible and represents permanent damage to the hand.

Hand Treatment Options from the Florida Hand Center

Hand surgeons diagnose this mainly by clinical examination and symptoms, and may order specific testing (nerve conduction studies) to confirm this syndrome. When symptoms are mild and intermittent, they may recommend nonsurgical therapies such as patient awareness of arm positioning and use of splinting.

In most cases, the hand treatment is surgery to reduce pressure on the nerve. Endoscopic ulnar nerve decompression is an effective and minimally invasive surgery that relieves this condition.