Radial neuropathy at the spiral groove

Background

• Radial nerve predisposed to compression in area where runs next to humerus (i.e. spiral groove)
• Often occurs after prolonged pressure
  • Frequently from inebriated individuals sleeping with arm resting on hard surface (i.e. "Saturday night palsy")

Clinical Features

• Weakness of wrist extensors ("wrist drop"), finger extensors, and brachioradialis
• Triceps retains full strength
• Possible sensory loss over the dorsum of the hand, sometimes extending up the posterior forearm
• Thumb abduction is affected (abductor pollicis longus is a radial-innervated muscle)

Vs. CVA

• Relative preservation of triceps strength
• Sensory loss isolated to the dorsum of the hand
• Brachioradialis should also be weak

Differential Diagnosis

• CVA

Upper extremity peripheral nerve syndromes

Median Nerve Syndromes

• Carpal tunnel syndrome
• Pronator teres syndrome
• Anterior interosseous neuropathy

Ulnar Nerve Syndromes

• Ulnar neuropathy at the elbow and wrist

Radial Nerve Syndromes

• Radial neuropathy at the spiral groove (ie. "Saturday night palsy")
• Posterior interosseous neuropathy

Proximal Neuropathies

• Suprascapular neuropathy
• Long thoracic neuropathy
• Axillary neuropathy
• Spinal accessory neuropathy
• Musculocutaneous neuropathy

Other

• Brachial plexopathy
• Cervical rediculopathy

Evaluation

• Clinical diagnosis

Management

• Wrist splint with 60 degrees of dorsiflexion to avoid contractures
• Usually spontaneously resolves, but may take 2-4 months, during which splint should be worn

Disposition

• Discharge with neurology follow up

See Also

• Peripheral nerve syndromes

References

Authors

Ross Donaldson, Kevin Lu, Daniel Ostermayer, Neil Young