Median nerve - axillary and upper arm lesions
Causes
- Traumatic/compression:
- Penetrating trauma
- Humerus fracture
- Compression during sleep
- Compression by aberrant brachialis muscle
- Iatrogenic
- Arteriovenous fistula
Symptoms & signs
- Proximal lesions of musculocutaneous nerve result in sensorimotor deficits in all innervated muscles and all sensory areas.
- Weakness of forearm pronation.
- Weakness of radial wrist flexion.
- Weakness of thumb opposition.
- Weakness in flexion of the thumb interphalangeal joint.
- Simian hand because of unopposed actions of extensor pollicis longus and adductor pollicis muscles.
- Thenar atrophy.
- Benediction hand because of inability to flex index finger and weakness in flexion of middle finger.