Part 11: Nerve Injuries of UL

Question 1

Damage to brachial plexus is rare, usually required avulsion injury (eg motorbike accident with neck forced away from shoulder). If serratus anterior and rhomboids are still in action where is the lesion?

Answer 1

Serratus anterior and rhomboids are supplied by dorsal scapular and long thoracic which are branches from the roots in BP. Therefore lesion is distal to roots

Question 2

Erbs palsy is injury to where?

Answer 2

Upper limbs and trunk (C5,6). Often occur is birth (traction injury). Abductors, lat rotators and supinators are all paralysed leaving dropped shoulder with medial rotation, extended and pronated forearm.

Question 3

What is Klumpke’s paralysis?

Answer 3

Injury to lower roots/trunk (C8/T1). Unusual, can occur in birth when arm above head. Small muscles of hand most affected with claw hand, unable to extend fingers.

Question 4

Axillary nerve damage presents as?

Answer 4

Inability to abduct shoulder. Often sensory loss in egg shape over upper lateral arm. 5% shoulder dislocations cause axillary nerve damage

Question 5

Radial nerve damage occurs when and presents as what?

Answer 5

Occurs in # of humerus shaft.
Presents with wrist drop. Sensory loss is limited.
Triceps usually intact as branches come off before nerve reaches humerus

Question 6

Ulnar nerve damage occurs when and presents how?

Answer 6

usually injured behind elbow. Presents as claw hand with extension of MCPJ and flexion of IP joints as lumbricals and interosseous muscles unable to extend IP or flex MCPJ due to paralysis. injury at elbow or above gives straighter fingers as ulnar half FDP is paralysed also

Question 7

Median nerve injuries occur where and present how?

Answer 7

Most commonly injured at carpal tunnel.
Present with variable sensory loss of palm. Wasting of thenar eminence over time. Best tested on abductor pollicis brevis due to flexor pollicis brevis sometimes having ulnar innervation