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Radial Nerve Palsy

Medically reviewed by Last updated on Oct 31, 2022.

What is radial nerve palsy?

Radial nerve palsy is a condition that affects the radial nerve. The radial nerve starts in your upper arm and runs down to your wrist and fingers. It controls how your arm and hand move and feel. This condition may go away over time or you may always have it.

What causes radial nerve palsy?

  • Pressure:
    • Devices: Devices that press on the radial nerve may cause damage. For example, crutches can put pressure on the nerve in the armpit. A watch can put pressure on the nerve at the wrist.
    • Awkward body positions: Awkward body positions can also put pressure on the nerve. For example, you sleep on your arm or leave it draped over the back of a chair for several hours.
    • Bruises: A bruise that is caused by an injury may put pressure on the radial nerve.
    • Growths: Tumors or cysts (lumps) inside your wrist or arm may press against the nerve.
  • Fractures (breaks) or dislocations: If you fracture the bone in your upper arm, it may damage the radial nerve. Dislocations happen when joints (where 2 bones meet) in the shoulder or elbow slip out of place. This can also damage the radial nerve.
  • Cuts on your wrist or arm: Cuts can damage or separate the radial nerve.

What are the signs and symptoms of radial nerve palsy?

Your signs and symptoms depend on where the nerve is damaged.

  • Weakness or numbness: You may have weakness or numbness from your triceps down to your fingers. You may not be able to make a fist. You may not be able to straighten your elbow, or extend your fingers. You may begin to lose muscle in your upper or lower arm and it may look smaller.
  • Wrist drop: This is when your wrist hangs down limply and you cannot lift it.
  • Pinch and grasp problems: You may not be able to bring your thumb and fingers together (pinch) to grasp objects.

How is radial nerve palsy diagnosed?

Your healthcare provider will ask you questions about your symptoms and when they began. He or she may touch and move your arm and hand to see which muscles are affected. You may also have any of the following:

  • X-rays: You may need x-rays to check for broken bones or foreign objects in your arm.
  • Magnetic resonance imaging: This test is called an MRI. An MRI may be used to look at the soft tissues and blood vessels in your arm, and to check for cysts or masses. You will need to lie still during this test. The MRI machine contains a very powerful magnet. Never enter the MRI room with any metal objects. This can cause serious injury. Tell your healthcare provider if you have any metal implants in your body.
  • Electromyography and nerve conduction studies: Electromyography (EMG) and nerve conduction studies (NCSs) are tests that measure the electrical activity of your muscles. Your muscles are tested at rest and while you are using them. An EMG test may also check the nerves that control your muscles. NCSs check if your radial nerve is working more slowly than normal.

How is radial nerve palsy treated?

Recovery time depends on how badly the nerve was damaged. It may take weeks to months for a nerve to heal. In some cases, it may take up to a year to regain normal movement and feeling in your arm or hand. You may need these or other treatments:

  • Pain medicine: You may be given medicine to take away or decrease pain. Do not wait until the pain is severe before you take your medicine.
  • Splint or cast: You may need a splint or cast to help support your wrist and hand while the radial nerve heals. A splint or cast helps extend your fingers and wrist so you can use them as much as possible.
  • Physical therapy: Physical therapy helps you with special exercises. These exercises help make your bones and muscles strong and flexible.
  • Transcutaneous electrical nerve stimulation: This therapy applies a gentle electric current to your muscles and may help reduce your pain.
  • Surgery: You may need surgery to repair the radial nerve. Ask your healthcare provider for more information about radial nerve surgery.

Treatment options

The following list of medications are in some way related to or used in the treatment of this condition.

View more treatment options

What are the risks of radial nerve palsy?

Weakness, numbness, or pain in your arm or hand may be worse with treatment. You may also have long-term swelling, burning, and changes to the color of the skin on your injured arm. Without treatment, you may lose all movement and feeling in your arm or hand. You may have long-term pain. The muscles in your hand may start to tighten and shorten. This may cause your hand to curl into a fist and you may not be able to use it.

When should I contact my healthcare provider?

  • You have a fever.
  • You see redness, swelling, or pus around your wound.
  • You have questions or concerns about your condition.

When should I seek immediate care?

  • Your splint or cast is too tight or causes pain. The skin around your splint stings or burns.
  • Weakness and numbness in your arm and hand are worse after treatment.
  • Pain is worse after treatment, with swelling, burning, and changes in the color of the skin on the injured arm.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your healthcare providers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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