Cubital Tunnel Syndrome
Cubital Tunnel Syndrome is a condition of entrapment and irritation of the ulnar nerve at the elbow. Symptoms of Cubital Tunnel Syndrome are often similar to those of Carpal Tunnel Syndrome, at least from the perspective of the patient. In both ailments, a major nerve to the hand becomes compressed and chronically irritated. Patients frequently present with complaints of numbness and tingling in the fingers and hand. Other times, patients complain of loss of strength in the hand, dropping objects involuntarily, or cramping of the hand. Occasionally pain may occur in the hand, wrist, forearm, or elbow regions. In severe cases, patients may notice loss of muscle mass in the hand.
Cubital Tunnel Syndrome is caused by compression of the ulnar nerve, as it passes by the elbow. What is commonly referred to as the “funny bone” isn’t really a bone. Instead, it is the ulnar nerve, as it travels in a groove between two bony points, the olecranon and the medial epicondyle. The ulnar nerve runs in a tunnel, the cubital tunnel, which is surrounded by bone and connective tissue. When there is chronic overuse of the elbow, swelling of the surrounding soft tissue may occur, causing compression of the nerve. The nerve, itself, may also be irritated directly, as its natural course is to stretch the “long way” around the elbow joint. Repetitive flexing of the elbow may put the ulnar nerve through many cycles of stretching, thereby irritating it. These factors combine to disturb the microscopic blood supply to the nerve, often leading to the symptoms of Cubital Tunnel Syndrome described above.
Like many other nerves, the ulnar nerve is responsible for supplying innervation for both sensation and muscle function to the hand. The pinky finger and ring finger, along with the skin along that side of the hand, are innervated by the ulnar nerve. Thus, patients with Cubital Tunnel Syndrome often notice numbness and tingling in their hand, particularly in that distribution. The motor component of the ulnar nerve provides input to some of the larger muscles in the forearm and many of the small muscles in the hand. These forearm muscles assist in making a fist and moving the wrist, and the smaller muscles in the hand allow for fine motor control. Therefore, patients with cubital tunnel syndrome may present with loss of gripstrength or cramping of the hand. Typically patients will complain of difficulty when using the hand for fine manipulation, such as in writing or holding a newspaper or magazine. If the muscles of the hand have their innervation disrupted for long enough, the muscles may begin to shrink and atrophy from disuse. This is reflective of a later stage of Cubital Tunnel Syndrome. And if the disturbance to the nerve exists for long enough, nerve damage may be permanent.
At California Hand Center, the diagnosis of Cubital Tunnel Syndrome is made by taking into consideration a combination of patient history, physical exam, and possibly a nerve test. Treatment centers around conservative measures initially, such as behavioral modification and splinting. Oral anti-inflammatories may also be employed. If these measures are not adequate, then surgical decompression of the nerve and re-positioning it to a less vulnerable location may be performed.