Radial Nerve Injury
What is a Radial Nerve Injury?
Radial nerve injury occurs when the radial nerve—one of the major nerves of the arm—is compressed, stretched, or severed. The radial nerve travels from the brachial plexus in the upper arm down through the forearm and into the hand. It controls the muscles that extend the wrist and fingers and provides sensation to part of the hand. Damage to this nerve can lead to weakness, loss of movement, and sensory disturbances in the arm, wrist, and hand.
Causes of Radial Nerve Injury
Radial nerve injuries can result from trauma, prolonged compression, or medical conditions. Common causes include:
- Fractures of the humerus, particularly midshaft fractures
- Compression from prolonged pressure, such as “Saturday night palsy” (arm draped over a chair)
- Lacerations, especially from penetrating trauma or surgery
- Entrapment syndromes, like radial tunnel syndrome
- Dislocations or overuse injuries, especially in athletes or laborers
- Iatrogenic injury, during surgical procedures involving the arm
Understanding the cause helps determine the best course of treatment.
What are the Symptoms of Radial Nerve Injury?
Symptoms vary based on the location and severity of the injury. Common signs include:
- Wrist drop, or inability to extend the wrist and fingers
- Weak grip strength, due to poor wrist stabilization
- Numbness or tingling, along the back of the hand and forearm
- Pain or burning sensation, particularly with nerve entrapment
- Muscle wasting, in severe or prolonged cases
- Difficulty performing fine motor tasks, such as typing or buttoning clothes
Prompt evaluation is important to avoid permanent nerve damage.
How is Radial Nerve Injury Diagnosed?
Diagnosis involves a combination of clinical assessment and diagnostic testing:
- Detailed medical history, to assess symptoms and potential injury mechanisms
- Physical examination, including strength, reflexes, and sensory testing
- Tinel’s sign or provocative maneuvers, to identify compression sites
- Electromyography (EMG) and nerve conduction studies, to evaluate nerve function and pinpoint the injury location
- Imaging, such as X-rays or MRI, if trauma or structural abnormalities are suspected
What are the Treatment Options for Radial Nerve Injury?
Treatment depends on the cause and severity of the injury:
- Rest and activity modification, to relieve pressure and allow healing
- Splinting or bracing, to prevent wrist drop and support function
- Physical or occupational therapy, to maintain motion and improve strength
- Anti-inflammatory medications, for pain and swelling
- Surgical repair, in cases of laceration, entrapment, or failure to recover with conservative care
- Nerve grafts or transfers, in complex or delayed cases