Injury of Radial Nerve

What is Radial Nerve?

The radial nerve is one of the branches of the brachial plexus; it “bends” the arm in the spinal canal and controls many motor functions and tactile sensitivity of the shoulder, forearm, and hands.

Various lesions, united by the concept of “neuropathy of the radial nerve“, differ in a specific clinical picture and are an urgent problem for several branches of medicine – neurology, orthopedics, microsurgery, and traumatology – as they occur more often than any other type of nervous pathology of the upper extremities.

The nerve contains:

• motor fibers, which are liable for the muscles that extend the elbow joint, wrist joint, and finger joints
• sensory fibers, which are liable for the perception of sensations by the skin receptors on the outer and dorsal surfaces of the limb.

With damage to the nerve, depending on the level of injury, muscle control falls out, and certain areas of the skin cease to feel. The result is paralysis of the extensor muscles, which manifests itself in the typical lowered position of the hand. The patient cannot straighten the hand and fingers. The most common causes of damage to the nerve are injuries, fractures of the humerus or forearm bones, and tunnel syndromes (pinching). Find out more about radial nerve in our article.

History and Physics of Radial Nerve Neuropathy

The “anatomical snuffbox” area is a special zone of the radial nerve innervation on the hand. At the level of the elbow joint, the nerve divides into the sensory branch and the posterior interosseous nerve, which provides motor innervation in the forearm. Therefore, only the motor or sensory function of the nerve can fall out from the level of the elbow joint.

1. Closed damage to the ulnar nerve is considered to be its dislocation due to the internal epicondyle of the shoulder:

• patients complain of an unpleasant clicking sensation arising from flexion of the elbow joint, accompanied by paresthesia in the zone of innervation of the radial nerve distal to the elbow joint;
• when the forearm is bent, an elastic cord is palpated, jumping over the internal epicondyle. These patients need a doctor’s advice.

2. Fresh damage to the ulnar nerve at the level above the elbow joint is accompanied:

• by loss of flexion of the distal phalanges of the 4th and 5th fingers, dilution of 2-5 fingers, and adduction of 1 finger;
• by sensitivity on the entire palmar surface of the 5th and ulnar half of the 4th finger;
• on the hand back, the ulnar nerve innervates the ulnar half of the 3rd and 4th to 5th fingers;
• by damage in the distal half of the forearm, which does not interfere with the flexion of the distal phalanges of the 4th to 5th fingers; 

3. Damage to the median nerve above the elbow joint is accompanied: 

• by loss of pronation of the forearm, flexion of the hand, and 1-3 fingers, as opposed to 1 finger;
• by the disappearance of sensitivity on the palmar and dorsal surfaces of 1-3 fingers and the radial half of the palmar surface of the 4th finger.

4. Damage to the nerve in the distal parts of the forearm. Here, it is close to the skin, and it is often damaged, leading to sensory impairment.

Causes, Symptoms, and Diagnostics of Radial Nerve Damage 

To cure this disease, you first need to know the reasons, symptoms, and diagnostics.

Causes

“Sleep paralysis” or “paralysis of Saturday night” are synonyms for “radial nerve neuropathy”(RNN) associated with some of the common causes of its occurrence; this refers to the pose of a heavily drunk or tired person who fell asleep in a chair with their hand hanging down. In this position, the nerve undergoes prolonged compression, which becomes an etiopathogenetic factor; similarly, neuropathy of the nerve develops with prolonged use of crutches. With prolonged pressure on a nerve, its myelin sheath can be destroyed, and in more severe cases, axons – long conductive processes of nerve cells (neurons) – are damaged.

Common causes of damage to the radial nerve include fractures of the humerus, too tight and prolonged application of a hemostatic tourniquet, infectious and inflammatory processes, severe intoxication (lead compounds, alcohol, etc.).

Symptoms

The main symptoms of damage:

• “falling”, hanging wrist;
• debility when extending/flexing the hand;
• palm, fingers, forearm, shoulder numbness;
• tingling sensation, burning on the back of the hand;
• weakness when abducting the thumb.

With prolonged development of the disease and an increase in the degree of nerve damage, patients often experience a significant loss of motor functions of the upper limb, up to paralysis.

Diagnostics

Dysfunction can be suspected during a detailed examination of the patient. An additional examination method, ENMG (electroneuromyography), is performed – a study of electrical conduction along the nerve. Ultrasound of the nerve is helpful; it shows anatomical changes in the nerve (rupture, swelling, defect, compression, etc.).

Treatment and Consequences of Radial Nerve Damage 

 When your illness has been diagnosed, you need to start immediate treatment.

Treatment

In case of damage, the affected limb is immobilized, any physical activity is limited, and it is a high probability of brain disorders. Doctors may prescribe non-steroidal anti-inflammatory drugs, diuretics to relieve puffiness, pain relievers, vitamin complexes, physiotherapy, and massage, only by prescription and under the supervision of a doctor. In some cases, hormone therapy is used.

With persisting nerve compression, the ineffectiveness of conservative treatment, and the timing of the cause of the lesion, for example, a recent fracture, microsurgical surgery on the radial nerve may be necessary. It is needed to observe the state for several months; if functional consistency of the limb is not insufficiently effective, an orthopedic operation is performed.

Consequences of Neuropathy

If a long time has passed after the injury, and the neuropathy is untreated, there is a risk of developing neurogenic contracture of the hand. In this case, the compressed and finally affected nerve no longer performs its functions and ceases to innervate the muscles. This occurrence leads to irreversible functional changes – muscle contracture (stable limitation in flexion and extension, persistent decrease in muscle extensibility). Such complications can be eliminated only with the help of separate operations associated with the transposition of tendons and muscles.

Prevention

You can prevent nerve injury by avoiding sustained pressure on your shoulder. Avoid repetitive movements or being in a confined position while sitting or sleeping. If you are doing work that requires repetitive movement, take steps to protect yourself by taking breaks and switching between tasks that require different activities.

Recovery and Conclusion of Radial Nerve Damage

Recovery is just as important as treatment. Therefore, it is essential to know how long it will last and follow all the rules.

Recovery Time and Prospects

The long-term prognosis of radial nerve injury varies greatly depending on the cause and severity of the injury. In most cases, complete recovery is possible. First-line treatments usually heal most nerve injuries within 12 weeks. If nerve damage is the result of diabetes or alcoholism, talk to your doctor about how to manage your symptoms. 

Younger patients with nerve damage tend to fully recover. If surgery is required, it can take six to eight months.

Conclusions

Limb peripheral nerve injury is from 1.5 to 3.5% of cases of general injuries, and the lost ability to work takes one of the first places, leading to permanent disability in 28–75% of cases. Currently, the diagnosis and treatment of peripheral nerves do not have a standardized, generally accepted system for assessing the level, degree, and nature of these injuries. Patients are divided according to the level of peripheral nerve damage. This makes it possible to clarify and objectify the causes of their injuries, as well as to find mistakes made at the stages of diagnosis and treatment.

Most often, the shoulder has damaged the trunks of the radial nerve (45.8%), and on the forearm – the median and ulnar nerves (15.3%). The tactic of the “justified waiting “by surgeons of spontaneous reinnervation of axons in the nerve trunk for 8-10 months leads to unsatisfactory treatment results and even disability.

FAQs

• How to treat damaged nerves?

The damaged nerve can be restored with the help of microsurgery and optical magnification. However, it must be sewn up immediately; otherwise, its function will never be restored. Moreover,  the chances of further vital activity of the nerve are reduced.

• Can nerves be stitched together?

In some cases, damaged nerve fibers can be sutured by microsurgeons. However, this is painstaking work, which may not always be successful. Therefore, scientists are looking for a way to restore tissue innervation and, accordingly, impaired functions from the outside.

• Why do doctors say that radial nerves are not being restored?

The division process is impossible; otherwise, the radial nerve cell will not be able to perform its functions because it will first need to lose all contacts and then restore them. That’s why people say that nerve cells are not restored.

• How can people sleep with radial nerve pain?

When sleeping on your side, place a pillow in front of you to support the whole arm, limit elbow flexion, and keep the wrist and fingers flat in a neutral position. You could consider sleeping on your back with your arms at your sides or on pillows to keep your elbows and wrists in the optimal position.

• What restores nerve tissue?

Mature oligodendrocytes can help repair nerve tissue by creating new myelin sheaths that surround nerve fibers and are responsible for transmitting nerve impulses from the brain to organs and tissues and vice versa.