Radial Nerve Palsy
What is Radial Nerve Palsy?
Radial nerve palsy is a condition that occurs when the radial nerve is injured or compressed, resulting in weakness or loss of movement in the wrist and fingers, particularly the ability to extend them. The radial nerve runs down the back of the arm and controls the muscles that straighten the wrist, fingers, and thumb. When this nerve is damaged, patients may develop “wrist drop,” where the wrist hangs limply due to an inability to extend it.
Causes of Radial Nerve Palsy
Radial nerve palsy can be caused by trauma, prolonged compression, or medical conditions. Common causes include:
- Fractures of the humerus (upper arm bone), especially mid-shaft breaks
- Prolonged pressure, such as falling asleep with the arm over a chair or bench (“Saturday night palsy”)
- Lacerations or penetrating injuries to the upper arm or forearm
- Crush injuries involving the arm
- Improper use of crutches
- Entrapment syndromes, like radial tunnel syndrome
- Systemic diseases, such as diabetes or lead poisoning (less commonly)
What are the Symptoms of Radial Nerve Palsy?
Symptoms typically involve motor and sensory impairments. These may include:
- Wrist drop, an inability to lift the wrist and fingers
- Weakness in grip strength
- Numbness or tingling on the back of the hand and fingers
- Difficulty straightening the fingers or thumb
- Loss of coordination during hand movements
- Pain or aching in the forearm or wrist (in some cases)
How is Radial Nerve Palsy Diagnosed?
Diagnosis involves a thorough clinical evaluation and diagnostic testing:
- Physical exam, assessing motor function and sensory changes
- Tinel’s sign, used to detect nerve irritation
- Electromyography (EMG) and nerve conduction studies, to locate the site and severity of nerve damage
- MRI or ultrasound, if a mass or structural issue is suspected
- X-rays, especially if a fracture or dislocation is involved
Early and accurate diagnosis helps guide appropriate treatment planning.
What are the Treatment Options for Radial Nerve Palsy?
Treatment depends on the cause and severity of the injury:
- Observation and splinting, especially for compressive injuries expected to resolve
- Physical and occupational therapy, to maintain range of motion and prevent stiffness
- Surgical decompression or repair, if the nerve is entrapped, lacerated, or not healing
- Tendon transfer surgery, for long-standing or irreparable nerve damage
- Pain management, if nerve pain is present