If you’ve ever hit your funny bone, you know what some of the symptoms of cubital tunnel syndrome feel like. Nerve compression syndromes cause symptoms including pain, numbness, and weakness. Nerves can become pinched for a variety of reasons. Most people are familiar with carpal tunnel syndrome, a condition where the median nerve is pinched in the wrist. Carpal tunnel syndrome is the most common nerve compression syndrome of the upper extremity. The second most common problem is cubital tunnel syndrome.
In the case of cubital tunnel syndrome, one of the other nerves of the upper extremity—the ulnar nerve—is pinched as it passes behind the elbow. This is the same nerve that causes the tingling sensation of hitting your “funny bone.” Hitting your funny bone is actually a sensation caused by irritating the ulnar nerve behind the elbow. When struck, this causes a shooting sensation and tingling in the small and ring fingers. The ulnar nerve transmits signals to your brain about sensations in these fingers; that’s why the fingers tingle when you hit the nerve in your elbow.
Normally the ulnar nerve is stretched by approximately 2 cm as you bend your elbow back and forth. There is the least amount of tension on the nerve when your elbow is straight, and the amount of tension on the nerve steadily increases especially as the elbow is bent beyond 90 degrees. Raising your arm away from your body also increases the tension on the ulnar nerve. In this position, there is significant tension on the ulnar nerve. Different structures have been implicated as causing irritation to the ulnar nerve in the back of the elbow. Depending on a particular individual, one of these structures may cause irritation to the ulnar nerve leading to symptoms of cubital tunnel syndrome.
In patients with cubital tunnel syndrome, the ulnar nerve is pinched in one of several locations in the back of the elbow. Common symptoms of cubital tunnel syndrome include:
- Pain, tingling, and numbness in the small and ring fingers. These are often called pins and needles symptoms
- Weakness of the muscles in the hand
- Symptoms may be felt when you have your elbow bent for a long time
These weakened muscles, called the intrinsic muscles of the hand, help with finger movements. Patients with more severe symptoms of cubital tunnel syndrome may experience a tendency to drop objects or have difficulty with fine movements of the fingers.
The diagnosis of cubital tunnel syndrome is made after a thorough history and examination. X-rays or other tests may be ordered if there is a concern of something abnormal pressing on the nerve. Nerve tests, called EMGs, can help to determine the extent and location of nerve compression.
People tend to have more significant symptoms of cubital tunnel syndrome at the time of diagnosis compared to carpal tunnel syndrome. For this reason, many people who see their doctor for cubital tunnel syndrome will develop permanent weakness of some of the musculature of the hand resulting from the chronic nerve injury.
Other conditions that can cause similar symptoms include cervical spine problems, such as a herniated disc. Another condition that can lead to tingling and numbness in the fingers is called thoracic outlet syndrome. Lastly, the ulnar nerve can be pinched in a location other than the cubital tunnel, although the cubital tunnel is the most common location for the ulnar nerve to be compressed.
Treatment of cubital tunnel syndrome usually begins with some simple steps. Many cases of cubital tunnel syndrome will resolve with a few simple treatments:
- Anti-inflammatory medications
- Splinting the elbow, especially at night
- Padding the elbow for work and leisure activities
- Avoid leaning on your elbow
If these simple treatments fail, surgery may be necessary to remove the pressure on the ulnar nerve. Because the nerve can be pinched at one of several locations behind the elbow, it is important to know specifically where the nerve is pinched or to release pressure from all of the possible areas of compression. In some patients, treatment consists of moving the nerve to the front of the elbow, so the nerve is under less tension when the elbow is bent; this is called an ulnar nerve transposition.
Depending on the severity of nerve damage, symptoms may resolve very quickly, or they may never entirely resolve. In the most severe cases of cubital tunnel syndrome, some of the symptoms may persist despite surgical treatment.