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
Workup
- Clinical diagnosis