Clinical Applications of the thoracic Limb

Question 1

Brachial plexus avulsion

Answer 1

• avulsion (pulling/tearing), traction or abduction
• complete or incomplete
• cranial or caudal

Question 2

Crainial TBPI (traumatic brachial plexus injury)

Answer 2

• difficulty advancing limb at the shoulder (extending shoulder)(suprascapular n.)
• Should instability (suprascapular, subscapular n.)
• Weak elbow flexion (musculocutaneous n.)
• Sensory deficits (musculocutaneous
• C6-C7

Question 3

Caudal TBPI

Answer 3

• inability to bear weight (radial n.)
• loss of carpal and digit extension (knuckling) (radial n.)
• Loss of panniculus reflex (lateral thoracic n.)
• Sensory deficits (radial, median, ulnar n.)
• C8-T2

Question 4

Complete TBPI

Answer 4

-both cranial and caudal. Signs associated with each TBPI seen

Question 5

Horner’s syndrome

Answer 5

• sympathetic denervation
• preganglionic- neck trauma or disc rupture, brachial plexus avulsion (caudal), axillary lesion, cranial thoracic dz, neck tumor, traumatic venipuncture

Question 6

Brachial Plexus Block

Answer 6

• sensory and motor function of the forelimb
• regional analgesia to the shoulder and distally
• amputations, fracture repair, any deep invasive surgery of the forelimb

Question 7

Lateral thoracic nerve

Answer 7

• use to test the panniculus reflex

- innervates the cutaneous trunci m.

Question 8

Suprascapular nerve

Answer 8

innervates the lateral stabilizers of the shoulder (infraspinatus and supraspinatus m.)

Question 9

Axillary n.

Answer 9

• motor and sensory
• loss of sensation to the lateral aspect of the brachium and caudal scapular region (caudal circumflex humeral a.)
• motor to the flexors od the shoulder
• decreased shoulder stability

Question 10

Musculocutaneous n.

Answer 10

• motor and sensory
• there will be little change in gate, but you will see a slight straightening of the elbow
• difficulty flexing the elbow
• loss of sensory on the medial aspect of the forearm

Question 11

Median n. and Ulnar n.

Answer 11

• dropped carpus
• loss of flexion of carpus
• sinking of carpus and fetlock
• loss of autonomous innervation to the palmar aspect of the paw with the loss of both the median, ulnar and the communicating br. of the musculocutaneous n.
• loss of cutaneous sensation to the lateral aspect of the paw and fifth digit

Question 12

Radial n.

Answer 12

• can bear weight but knucked over
• motor and sensory
• proximal- loss of ability to extend the elbow, carpus and digits (happens at brachial plexus)
• TBPI, trauma, calving, post-anesthetic recovery (horses)
• loss of cutaneous senstation on the dorsal and lateral aspect of the antebrachium and paw

Question 13

RUMM block

Answer 13

• selective blocking of the radial, ulnar, median and musculocutaneous n.
• procedures on the elbow and distal (distal radius, ulna, carpus, digits)
• Radial n.- proximal to the lateral epicondyle of the humerus
• Ulnar, median and musculocutaneous n.- proximal to the medial epicondyle of the humerus
• medial & lateral side of forelimb

Question 14

Ring Block

Answer 14

• local anesthesia for distal limb procedures
• wounds/lacerations
• onychectomy (declaw)
• radial, ulnar, median, superficial br. of radial n.