Radial neuropathy at the spiral groove


Nerves of the left upper extremity.
  • 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

Cutaneous innervation of the upper limb
  • 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)

Differential Diagnosis

Upper extremity peripheral nerve syndromes

Median Nerve Syndromes

Ulnar Nerve Syndromes

Radial Nerve Syndromes

Proximal Neuropathies




  • Clinical diagnosis

Diagnosis (Vs. CVA)

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


  • Wrist splint with 60 degrees of dorsiflexion to avoid contractures[1]
  • Usually spontaneously resolves, but may take 2-4 months, during which splint should be worn


  • Discharge with neurology follow up

See Also

External Links


  1. Bunney EB, Gallagher EJ: Peripheral Nerve Disorders; in Marx JA, Hockberger RS, Walls RM, et al (eds): Rosen’s Emergency Medicine: Concepts and Clinical Practice, ed 8. St. Louis, Mosby, Inc., 2014, (Ch) 107: p 1428-1441.