Cubital Tunnel Syndrome is a condition that involves pressure or stretching of the ulnar nerve (also known as the “funny bone” nerve), which can cause numbness or tingling in the ring and small fingers, pain in the forearm, and/or weakness in the hand. The ulnar nerve runs in a groove on the inner side of the elbow.
There are a few causes of an ulnar nerve problem that contribute to this condition, including:
- PRESSURE: The nerve has little padding over it. Direct pressure (like leaning the arm on an arm rest) can press the nerve, causing the arm and hand — especially the ring and small fingers — to “fall asleep.”
- STRETCHING: Keeping the elbow bent for a long time can stretch the nerve behind the elbow. This can happen during sleep.
- ANATOMY: Sometimes, the ulnar nerve does not stay in its place and snaps back and forth over a bony bump as the elbow is moved. Repeated snapping can irritate the nerve. Sometimes, the soft tissues over the nerve become thicker or there is an “extra” muscle over the nerve that can keep it from working correctly.
Cubital tunnel syndrome can cause pain, loss of sensation, tingling, and/or weakness. “Pins and needles” are usually felt in the ring and small fingers. These symptoms are often felt when the elbow is bent for a long period of time, such as while holding a phone or while sleeping. Some people feel weak or clumsy.
Diagnosis is primarily made through a physical examination and symptoms. Other conditions, such as diabetes, thyroid disease, or a pinched nerve can produce similar symptoms. In some cases, tests may be done to rule out those conditions.
The first treatment is to avoid actions that cause symptoms, such as leaning on the “funny bone.”
An elbow pad can be worn to protect the nerve from direct contact. A night-time resting splint can be worn during sleep to prevent deep flexion of the elbow causing excessive tension on the nerve. A hand therapist can demonstrate ways to avoid nerve pressure.
Sometimes, surgery may be needed to relieve the pressure on the nerve. Surgery can involve releasing the nerve, moving the nerve to the front of the elbow, and/or removing a part of the bone. Therapy is sometimes needed after surgery, and recovery may take several months. Numbness and tingling may improve quickly or slowly. In some cases, symptoms may not resolve completely after surgery, especially if symptoms are severe.
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