Cubital Tunnel Syndrome

Also referred to as ulnar nerve entrapment or ulnar neuropathy, cubital tunnel syndrome occurs as the result of excessive pressure placed on the ulnar nerve in the area of the elbow joint. Cubital tunnel syndrome is regarded as the second most commonly occurring entrapment neuropathy sustained by the peripheral nerves within the upper limbs, following carpal tunnel syndrome. The joint of the elbow is found at the junction of the radius, ulna, and the humerus bones of the arm. Along the medial side of the elbow lies the cubital tunnel, which is a protective passageway comprised of sturdy connective tissue. This passageway secures the ulnar nerve at the joint of the elbow, as it travels down the arm.

At the elbow, the cubital tunnel runs underneath a small bony bump known as the medial epicondyle or “the funny bone.” Due to the proximity of the ulna nerve to the medial epicondyle at the elbow, any strike can cause the individual to suffer from intense, shock-like sensations. Depending on the severity of the blow, these sensations can be temporary and typically resolve within a few minutes. The ulnar nerve provides sensory feedback and muscle control to the ring and little fingers of the hand. It also controls the movements of the larger muscles found along the forearm that aid in grip. The ulnar nerve can become compressed or injured in five different areas of the elbow: the medial intermuscular septum, arcade of Struthers, deep flexor pronator aponeurosis, medial epicondyle, and cubital tunnel.

Patients suffering from cubital tunnel syndrome experience significant pain, paresthesia, and weakness at the elbow and through the hand. Other common symptoms of cubital tunnel syndrome include:

• Numbness and tingling sensations within the little finger and the ring finger
• Difficulty moving the little finger and ring finger
• Impaired finger coordination and weakened grip

If this condition is left untreated, over time the patient is at risk for losing function of the hand due to muscle wasting, which cannot be reversed. Patients suffering from severe symptoms of cubital tunnel syndrome, or whose symptoms have been present for six weeks or more, are strongly encouraged to speak with their doctor.

Causes of Cubital Tunnel Syndrome

The precise mechanism of cubital tunnel syndrome is not well understood. In general, symptoms related to this condition are believed to arise as the result of excessive compression and injury to the ulnar nerve at the elbow. There are a number of ways in which the ulnar nerve can become injured, though the most common cause is irritation of the nerve from keeping the elbow bent for extended periods of time. In some instances, when the elbow is bent, the ulnar nerve slips out from underneath the protective medial epicondyle. Over time, the ulnar nerve can become irritated and inflamed from this movement. The ulnar nerve can also become irritated as the result of excessive pressure placed on the elbow by leaning on it for long periods of time.

Previous studies have revealed several factors that are known to place individuals at an increased risk for developing complications related to cubital tunnel syndrome. For instance, individuals whose work requires that they maintain elbow flexion for extended periods of time are at risk for developing the condition. This can include holding a telephone for much of the day. Also, jobs that require the individual to engage in many repetitive tasks are also considered a risk factor. Similar to many other nerve disorders, individuals who suffer from diabetes mellitus are at augmented risk for developing complications related to cubital tunnel syndrome. Further, obesity is also related to an elevated risk for developing the condition.

Treatments for Cubital Tunnel Syndrome

Most cases of cubital tunnel syndrome can be effectively managed without the need for surgery using conservative methods. In particular, patient education on the condition and its causes is an important component of treatment. In many instances, simple modification of an individual’s physical activity may be effective in managing symptoms. These modifications can include such things as adjusting posture, wearing an elbow brace at night, padding the posterior area of the elbow, or even using a hands-free device when talking on the phone. Previous studies have shown that nearly 90% of patients reporting mild symptoms of cubital tunnel syndrome can achieve symptom relief using these techniques.

Patients may also wish to take non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or naproxen, as needed. These will aid in reducing the patient’s pain and discomfort associated with the irritated ulnar nerve and will also help reduce swelling of the area. In some instances, steroid injections may be necessary to provide relief from pain and discomfort. For this procedure, a steroid medication, such as cortisone, is injected into the area of the ulnar nerve. This medication acts by blocking the transmission of pain signals from the peripheral nerves to the spinal cord and brain.
In some cases of cubital tunnel syndrome, the symptoms of pain and discomfort may not be responsive to non-surgical methods. For these cases, surgery may be the only option.

There are several types of surgical procedures used to treat severe cases of cubital tunnel syndrome. These procedures include:

• Cubital tunnel release: This procedure involves cutting the cubital tunnel ligament in order to make the passageway larger
• Ulnar nerve anterior transposition: This procedure involves moving the ulnar nerve into a new position in front of the medial epicondyle
• Medial epicondylectomy: This procedure involves partially removing the medial epicondyle

For most cases of cubital tunnel syndrome, the outcome from surgery is good. Typically, recovery can take approximately three to six weeks. In some instances, your doctor may then recommend that you participate in physical therapy to facilitate rehabilitation and prevent further injury.

Conclusion

Cubital tunnel syndrome is the second leading nerve injury sustained by the upper limbs. This condition results in pain, numbness, and tingling sensations in the elbow, ring finger, and little finger. It can also result in muscle weakness in the hand and forearm. The precise cause of cubital tunnel syndrome is not well understood, though excessive compression of the ulnar nerve is typically regarded as the source of symptoms. Most instances of the condition can be treated effectively using conservative methods. In rare instances, surgery may be required. For these cases, outcomes following surgery are favorable.

References

1. Abuelem T, Ehni BL (2009) Minimalist cubital tunnel treatment. Neurosurgery 65: 145–149.
2. Dellon AL, Hament W, Gittelshon A (1993) Non- operative management of cubital tunnel syndrome: An 8-year prospective study. Neurology 43:1673–1677.
3. Friedrich JM, Robinson LR (2011) Prognostic indicators from electrodiagnostic studies for ulnar neuropathy at the elbow. Muscle Nerve 43:596–600.
4. Macadam SA, Bezuhly M, Lefaivra KA (2009) Outcomes measures used to assess results after surgery for cubital tunnel syndrome: A systematic review of the literature. J Hand Surg Am 34:1482-1485.
5. Macadam SA, Gandhi R, Bezuhly M, Lefaivre KA (2008) Simple decompression versus anterior subcutaneous and submuscular transposition of the ulnar nerve for cubital tunnel syndrome: A meta-analysis. J Hand Surg Am 33:1311–1312.
6. Palmer BA, Hughes TB (2010) Cubital tunnel syndrome. J Hand Surg Am 35:153-163.