Causes and Treatment of Radial Nerve Injuries

The radial nerve runs down the arm and to the fingertips. If it's injured, radial nerve pain usually occurs when your palm is pressed against something and your wrist is bent back.

It's typically a sharp, radiating, or burning pain in the back of the hand, around the thumb, and in the middle and index fingers. Often, the pain is accompanied by the inability to fully straighten your arm or fingers.

Along its path to your fingertips, the radial nerve sends messages to muscles in your arm and hand to trigger movement and receives sensory messages to send back to the spinal cord and brain. Depending on where the nerve damage occurs, sensory and motor symptoms can vary.

Injury at the Axilla

Immediately after branching from the brachial plexus (a network of nerves situated at the root of the neck), the radial nerve travels under the arm close to the armpit (axilla). Improper use of crutches is a common cause of radial nerve compression at this point.

Symptoms:

• The radial nerve is responsible for controlling the triceps muscles situated at the back of the arm. Because of this, any damage to the nerve at the axilla will cause weakness of the arm, particularly if you're pushing something away.
• It may also be impossible to bend your wrist back, resulting in "wrist drop."
• Finger extensor muscles may also be weakened, making it difficult to fully open your hand.
• In addition to weakness, people with a radial nerve injury at the axilla may experience tingling and numbness from the back of the arm to the hand, especially along the side and back of the thumb.

Injury at the Spiral Groove

From the axilla, the radial nerve travels down the arm and wraps around the humerus (the large bone between the shoulder and elbow) in a channel known as the spiral groove. The nerve can become compressed within this groove,

Symptoms:

• This interferes with your ability to bend your wrist back and straighten your fingers.
• A spinal groove injury causes the weakening of the brachioradialis muscle of the forearm, and the triceps muscles will be unaffected.
• The weakness will be more noticeable when the muscle is extended rather than when it is flexed.

Posterior Interosseous Nerve Injury

Just before the elbow, a section of the radial nerve branches off to the posterior interosseous nerve, which is responsible for straightening muscles below the elbow.

Unlike other branches of the radial nerve, the posterior interosseous nerve has no sensory receptors and is purely responsible for muscle movement. As a result, injuries are characterized by muscle weakness but no abnormal sensation.

Symptoms:

• The inability to extend your fingers is often a tell-tale sign.
• Despite the lack of abnormal sensations, an injury to the posterior interosseous nerve can be very painful, especially when the fingers are extended.

Superficial Radial Neuropathy

As the radial nerve passes the elbow, it continues down to the back of the hand, where it serves a purely sensory function.

At that point, the nerve is most susceptible to injury at the wrist, such as when the wrists are bound or handcuffs are worn too tightly.

Symptoms:

• The pattern of numbness is usually worst from the wrist to the back of the thumb.
• It may also be accompanied by a "pins and needles" sensation or shooting pains up or down the back of the hand.

Prognosis and Treatment

When a radial nerve injury is diagnosed, treatment is usually conservative and includes:

• Wrist splinting to maintain function
• Pain management with nonsteroidal anti-inflammatory drugs (NSAIDs)
• Physical therapy
• When pain is severe, a nerve block may be recommended.

Recovery time can range from a couple of weeks to six months. If your pain and disability don't improve, your healthcare provider may order nerve conduction studies or electromyography (EMG).

You may need surgery if the nerve is:

• Entrapped, such as in radial tunnel syndrome, and requires surgical release
• Compressed by a growth, such as a tumor, that needs to be removed
• Lacerated and needs repair or reconstruction, such as with a nerve graft or transfer

Frequently Asked Questions

What type of healthcare provider treats radial nerve pain?

Your primary care doctor or a neurologist will usually evaluate and treat radial nerve pain. If you need surgery, you would see a hand surgeon. Hand surgeons can be orthopedic surgeons, neurosurgeons, plastic surgeons, or general surgeons who are subspecialized in hand operations. If your radial nerve is damaged due to a fracture, you may be treated by an orthopedic surgeon (bone specialist). As part of your treatment, you may also see a physical therapist.

How long after radial tunnel release does it take for the nerve to heal?

Full recovery after radial tunnel release is expected to take between about six and eight months for most people. However, if the nerve has been extensively damaged before surgery, it can take longer than that.

Can injections injure the radial nerve?

Yes, it is possible—but rare—for injections to injure the radial nerve. Radial nerve damage has been reported following numerous procedures, including vein punctures and intramuscular injections.

How can I sleep with radial nerve pain?

To avoid triggering your radial nerve pain when you're trying to sleep:

• Don't lie on the injured arm or sleep with your head on that arm.
• Keep your elbow straight or bent less than 90 degrees.
• If on your side, put a pillow in front of you to support the arm and keep your wrist and fingers flat.
• Try sleeping on your back with your arms at your sides, possibly supported by pillows.

Also, ask your healthcare provider if wearing a wrist or elbow splint at night might help alleviate your pain.