Forearm and Elbow Conditions
Cubital Tunnel Syndrome
While the exact cause of Cubital Tunnel Syndrome is unclear, it is recognized as the most common form of entrapment of the ulnar nerve and the second most common nerve compression syndrome of the upper extremity. It is believed that when the ulnar nerve, which stretches when the elbow is bent or sustains pressure, sometimes shifts over the bony medial epicondyle on the inside edge of the elbow and causes irritation.
The ulnar nerve is mainly a motor and sensory nerve for the hand, supplying the flexor carpi ulnaris (FCU) muscle and the ring and small flexor digitorum profundus (FDP) muscles in the elbow and forearm region. It may also become irritated when subjected to long periods of pressure such as that produced when leaning against a hard service. Irritation can also occur if it becomes damaged as a result of force placed on the cubital tunnel.
The symptoms are similar to those experienced with other elbow conditions, such as medial epicondylitis or "golfer's elbow" - the sharp pain experienced when the "funny bone" is hit. The "funny bone" is actually the prominent bony portion of the elbow over which the ulnar nerve runs. Common symptoms more distinctly related to cubital tunnel syndrome include, numbing in the hand and/or ring and little fingers, general pain and muscle weakness in the hand and thumb affecting grip strength and the ability to perform certain activities.
This type of ulnar entrapment neuropathy develops as a result of the anatomy of the elbow and biomechanics of the ulnar nerve at the elbow, which creates an environment predisposed to compression. Those most likely to experience cubital tunnel syndrome are adults working for long periods at a desk, as well as competitive athletes and workers involved in manual labor and accident resulting in trauma to the elbow. Occasionally, overzealously pursuing a weekend project that places uncommon stress and pressure on the elbow can also prompt the condition.
Following a thorough examination and assessment of patient history and lifestyle, an elbow flexion test and nerve conduction test may be indicated, in order to assess pain relative to position and signal speed traveling down the nerve. This will help indicate whether the nerve is compressed and to what degree. Before treatment is determined, an electromyogram (EMG) focusing on the forearm muscle may be used in order to evaluate nerve and muscle function. Poor muscle function may also indicate a problem with the ulnar nerve.
Most cases of cubital tunnel syndrome can be treated conservatively and may entail a period of rest from the activity causing the irritation, splinting and anti-inflammatory medication. A rehabilitation program may also be indicated, in order to help modify the movement responsible for the initial irritation. For those nonresponsive to conservative treatment, surgical decompression or transposition procedure may be necessary to relieve pain and restore function. The symptoms and severity of the condition will determine the best course of action.