Conditions Of Brachial Plexus, Pectoral Region & Axilla

Question 1

What can brachial plexus injuries affect? 1️⃣

Answer 1

-motor function and cutaneous sensation within the upper limb

Question 2

What can traction injuries affect? 1️⃣

Answer 2

-either upper nerve root or the lower nerve roots of the brachial plexus

Question 3

What do injuries to the upper brachial plexus usually result from? 1️⃣

Answer 3

excessive increase in the angle between the neck and shoulder

May occur in:

• trauma
• during birth of a baby if the shoulders become impacted in the pelvis(shoulder dystocia) and excessive traction is applied to the baby’s neck

Question 4

Which roots are affected in an upper brachial plexus injury and what does this cause? 1️⃣

Answer 4

C5 & C6 roots

-cause sensory alteration in these dermatomes and paralysis of muscles predominantly supplied by these nerve roots

C5: shoulder abduction and external rotation
C6: elbow flexion, wrist extension and supination

Question 5

What muscles become paralysed in an upper brachial plexus injury? 1️⃣

Answer 5

• deltoid
• teres minor
• biceps brachii
• brachioradialis
• brachialis
• coracobrachialis

Question 6

Describe Erb’s palsy 1️⃣

Answer 6

-limb hangs by side in medial rotation with an adducted arm and extended elbow ‘Waiter’s tip’ position

Question 7

What do injuries to the lower brachial plexus usually result from? 1️⃣

Answer 7

-forced hyperextension or hyperabduction

E.g.

• when someone falls from a height and grabs onto something on the way down
• if baby’s arm is delivered first and traction is applied to the arm to deliver the rest of the baby

Question 8

What is injury to the lower roots of the brachial plexus known as? 1️⃣

Answer 8

Klumpke’s palsy

Question 9

Which nerve roots are affected in a lower brachial plexus injury and what does this cause? 1️⃣

Answer 9

C8: finger flexion, finger extension

T1: finger abduction and adduction

Question 10

What muscles are paralysed due to a lower brachial plexus injury? 1️⃣

Answer 10

• intrinsic muscles of the hand
• flexors within the forearm that are supplied by the ulnar nerve

-muscles supplied by C8 and T1 fibres within the median and radial nerve

Question 11

What does the pattern of deformity due to a lower brachial plexus injury classically present as? 1️⃣

Answer 11

‘Claw hand’

-hyperextension of all the MCP joints, flexion of interphalangeal joints, abduction of thumb and wasting of the interossei

Question 12

What occurs as a result of damage to the long thoracic nerve? 2️⃣

Answer 12

• long thoracic nerve innervated serratus anterior therefore serratus anterior becomes paralysed
• serratus anterior normally holds the scapula against the ribcage so if paralysed, ‘winging of the scapula’ occurs
• medical border of scapular no longer held against chest wall so protrudes posteriorly

Question 13

How can the winging of the scapula be seen clearly? 2️⃣

Answer 13

• ask patient to place palm of their hand on a wall and push
• the force is transmitted along their upper limb to the scapula, which lifts off the underlying ribs
• ask patient to hold their unaffected shoulder with the hand of the affected limb and pull the unaffected shoulder forwards
• this places traction on the scapula of the affected limb and elevates its medial border

Question 14

What are the causes of dysfunction of the long thoracic nerve? 2️⃣

Answer 14

Most commonly trauma:

-vulnerable to surgical trauma during a mastectomy with axillary clearance as it passes superficial to the serratus anterior muscle in the medial wall of the axillary and can be ‘striped’ along with the axillary nodes and fat

• blunt trauma to the neck or shoulder causing depression of the shoulder girdle
• wearing a heavy backpack. Both can cause traction injuries to the long thoracic nerve

Question 15

What is axillary lymphadenopathy? 3️⃣

Answer 15

Enlargement of the axillary lymph nodes

Question 16

What are the causes of axillary lymphadenopathy? 3️⃣

Answer 16

-infection of the upper limb
Infection can also cause lymphangitis (inflammation of lymphatic vessels) and red, warm, tender streaks are visible in the skin of the upper limb
-infections of the pectoral region and breast
-metastases from breast cancer
-leukaemia or lymphoma
-metastases from malignant melanoma in the upper limb

Question 17

When are axillary lymph node dissections performed? 4️⃣

Answer 17

-often as part of the staging of breast cancers

Question 18

What can interruption of lymphatic drainage from the upper limb result in? 4️⃣

Answer 18

-lymphoedema: a condition whereby accumulated lymph in the subcutaneous tissue leads to painful swelling of the upper limb.

Question 19

Give 2 risks of an axillary lymph node dissection 4️⃣

Answer 19

Risk of damage to

• long thoracic nerve which leads to a winged scapular deformity
• thoracodorsal nerve (supplies latissimus dorsi)