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Radial nerve dysfunction
Definition
Radial nerve dysfunction is a problem with the radial nerve. Damage to the radial nerve leads to problems with movement in the arm and wrist and with sensation in the back of the arm or hand.
Alternative Names
Neuropathy - radial nerve; Radial nerve palsy; Mononeuropathy
Causes
Radial neuropathy occurs when there is damage to the radial nerve, which travels down the arm and controls movement of the triceps muscle at the back of the upper arm. It also controls the ability to bend the wrist backward and helps with the movement and sensation of the wrist and hand.
Mononeuropathy means a single nerve is damaged. With mononeuropathy, usually the nerve damage is caused locally. However, body-wide disorders may damage just one nerve.
Causes are:
- Injury
- Improper use of crutches
- Broken upper arm bone
- Long-term or repeated constriction of the wrist (for example, from wearing a tight watch strap)
- Pressure caused by hanging the arm over the back of a chair (for example, falling asleep in that position)
- Pressure to the upper arm from arm positions during sleep or coma
- Pinching of the nerve during deep sleep, such as when a person is intoxicated
- Long-term pressure on the nerve, usually caused by swelling or injury of nearby body structures
- Lead poisoning
In some cases, no cause can be found.
If other nerves are also affected, the health care provider should look for a medical problem that can affect nerves. Medical conditions such as diabetes and kidney disease can damage nerves.
Symptoms
The following symptoms may occur:
- Abnormal sensations
- Hand or forearm ("back" of the hand)
- "Thumb side" (radial surface) of the hand
- Fingers nearest to the thumb (2nd and 3rd fingers)
- Difficulty straightening the arm at the elbow
- Difficulty bending the hand back at the wrist, or even holding the hand
- Numbness, decreased sensation, tingling, or burning sensation
- Pain
Exams and Tests
The doctor or nurse will examine you and ask questions about your symptoms and medical history. You will be asked what you were doing before the pain started.
An exam of the arm, hand, and wrist may find:
- Difficulty straightening the arm at the elbow
- Trouble turning your arm outward
- Difficulty lifting the wrist or fingers
- Muscle loss (atrophy) in the forearm
- Weakness of the wrist and finger
- Wrist or finger drop
Tests may be needed. Tests for nerve dysfunction may include:
- Blood tests
- EMG
- MRI of the head, neck, and shoulder to look for other causes
- Nerve biopsy (rarely needed)
- Nerve conduction tests
- Ultrasound of the elbow
Treatment
The goal of treatment is to allow you to use the hand and arm as much as possible. Your doctor or nurse should find and treat the cause, if possible. In some cases, no treatment is needed and you will recover slowly on your own.
Surgery to repair the nerve or remove something that is pressing on the nerve may help.
Medical causes such as diabetes and kidney disease should be treated.
CONTROL OF SYMPTOMS
Medications may include:
- Over-the-counter analgesics or prescription pain medications to control pain (neuralgia)
- Anticonvulsant medicines (phenytoin, carbamazepine, gabapentin, and pregabalin) or tricyclic antidepressants (amitriptyline) to reduce stabbing pain
- Steroid (prednisone) injections around the nerve to reduce swelling may help some patients.
Other treatments include:
- Braces, splints, or other devices to help you use the hand in severe cases
- Physical therapy to help maintain muscle strength
Occupational therapy and vocational therapy or counseling to suggest changes at the worksite may be needed.
Outlook (Prognosis)
If the cause of the nerve dysfunction can be found and successfully treated, there is a good chance that you will fully recover. In some cases, there may be partial or complete loss of movement or sensation.
Nerve pain may be uncomfortable and may last for a long period of time. If this occurs, see a pain specialist to ensure you have access to all pain treatment options.
Possible Complications
- Mild to severe deformity of the hand
- Partial or complete loss of feeling in the hand
- Partial or complete loss of wrist or hand movement
- Recurrent or unnoticed injury to the hand
When to Contact a Medical Professional
Call your health care provider if you have had an injury to the arm, and you develop numbness, tingling, or weakness.
Prevention
Avoid prolonged pressure on the upper arm.
References
Katirji B, Koontz D. Disorders of peripheral nerves. In: Daroff RB, Fenichel GM, Jankovic J, Mazziotta JC, eds. Bradley’s Neurology in Clinical Practice. 6th ed. Philadelphia, Pa: Saunders Elsevier; 2012:chap 76.
Shy ME. Peripheral neuropathies. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 428.
Reviewed By: Luc Jasmin, MD, PhD, Department of Neurosurgery at Cedars-Sinai Medical Center, Los Angeles, and Department of Anatomy at UCSF, San Francisco, CA. Review provided by VeriMed Healthcare Network. David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.
