Radial neuropathy
Radial neuropathy is a mononeuropathy of the radial nerve, most often from compression against the humerus at the spiral groove during prolonged unconsciousness (Saturday night palsy), axillary pressure from crutches, or a midshaft humerus fracture, producing wrist drop, finger extensor weakness, and sensory loss over the dorsum of the first three fingers. Diagnosis is clinical with EMG for confirmation, and compressive palsies usually recover spontaneously with removal of pressure, splinting, and physical therapy.
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What this article covers
- Overview
Definition: radial neuropathy is a mononeuropathy of the radial nerve (C5 to T1), the nerve that supplies the extensors of the elbow, wrist, and fingers and the supinator.
- Epidemiology
Third most common upper extremity compressive neuropathy, after median and ulnar nerve compression.
- Risk factors
Prolonged unconsciousness or intoxication with the arm compressed under the body or draped over the back of a chair.
- Pathophysiology
Anatomic vulnerability: the radial nerve, from the posterior cord of the brachial plexus, winds along the humerus in the spiral groove, where sustained external pressure compresses it against bone.
- Clinical features
Wrist drop: inability to extend the wrist and fingers, the defining motor sign of a lesion above the elbow; this pattern plus a radial sensory deficit establishes the clinical diagnosis.
- Differential diagnosis
Stroke or another central lesion: hand weakness with upper motor neuron signs (hyperreflexia, spasticity, an extensor plantar response) and deficits beyond a single nerve territory.
- Diagnosis
Radial neuropathy is a clinical diagnosis, confirmed by electromyography when needed: wrist and finger extensor weakness (wrist drop) with sensory loss confined to the radial territory (dorsum of the…
- Management
First, remove the source of compression: stop axillary weight-bearing on crutches, remove a heavy wristwatch or other wrist compression, and avoid further pressure on the arm.
- Complications
Persistent wrist and finger drop, with impaired hand function and reduced grip, after axonal injury or transection.
- Prognosis
Compressive palsies (Saturday night palsy) typically recover spontaneously once pressure is removed.
- Prevention
Avoid sustained axillary pressure from crutches, the cause of axillary radial nerve compression, and stop crutch use or change the device at the first sign of wrist or finger extensor weakness.
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