Summary of upper limb nerve injuries (dave's notes)

Question 1

Where must damage be if they whole brachial plexus is not functioning? What would the examination findings be?

Answer 1

The nerve roots must be avulsed. Results in an immobile limb, anaesthesia and horner’s syndrome.

Question 2

If only serratus anterior and the rhomboids are intact, where is the lesion?

Answer 2

Distal to the upper trunk.

Question 3

What does a C5/6 injury result in? By what name is this known?

Answer 3

Erb’s paralysis.

Loss of abductors, lateral rotators. Arm hangs down medially rotated and pronated.

Question 4

What does damage to the lower roots result in?

Answer 4

Damage to the small muscles of the hand

Question 5

What can a shoulder dislocation or humerus fracture result in? How does this manifest?

Answer 5

Axillary nerve damage. Paralyses deltoid and numbs an egg shaped patch.

Question 6

What does a lesion just distal to the upper trunk result in?

Answer 6

Only serratus anterior and rhomboids would remain intact.

Question 7

What would you test to check musculocutaneous nerve function?

Answer 7

Rarely damaged. Test for biceps elbow flexion.

Question 8

Where is the radial nerve most commonly injured? How does this present?

Answer 8

Most commonly injured higher up.

Presenteds with wrist/MCP drop, with minimal anaesthesia. If damage is higher up test for elbow flexion.

Question 9

Where is the ulnar nerve most commonly damaged? How does this present?

Answer 9

Most commonly injured behind the elbow or wrist, resulting in a claw hand.
If injured higher up than this the finders are kept straight, and with time the interossei become wasted on the dorsum.

Question 10

Where is the median nerve most commonly injured? How does this present?

Answer 10

At the wrist, with cuts or carpal tunnel syndrome.
Sensory loss is variable but will include pads of the thumb and index finger.
With time the thenar eminence becomes wasted.