Brachial Plexus and Shoulder Neuropathies

Upper Trunk

• Erb’s or Erb-Duchenne palsy
• Loss of C5 and C6
• Most common brachial palsy

Clinical

• Weakness of:
• shoulder abductors
• external rotators
• Elbow flexors
• Supinator
• Variable partial weakness of:
• Wrist extensor
• Elbow extensors
• Some muscles around the scapula
• Sensory deficit
• Shoulder
• Lateral aspect of arm
• May be no sensory deficit

Treatment

• Better prognosis than lower injuries, >50% recover completely

Lower Brachial Plexus

• Klumpke’s or Dejerine-Klumpke palsy
• Loss of conduction from T1 and sometimes C8
• Rarer than upper (Erb’s) palsy

Clinical

• All of the small muscles of the hand are affected
• The long finger flexors are sometimes affected
• Wrist flexors rarely affected
• Triceps usually spared
• Horner’s syndrome can occur
• Sensory deficit – ulnar portion of the hand and forearm

Causes

• Trauma
• Compression injuries
• Back-pack palsy – usually upper plexus
• Thoracic outlet syndrome – usually lower
• Cervical rib and scalene syndrome
• Hyperabduction syndrome
• Costoclavicular syndrome
• Compression during surgical procedure (especially with shoulder braces)
• Malignancy
• Pancoast tumour of the apex of the lung
• Usually presents with horners syndrome and lower brachial plexus injury
• Radiation injury
• Can be due to direct injury or scarring of adjacent structures
• Upper or lower affected
• Can occur up to 1-2 years after radiation
• Pain is often a prominent symptom
• Differentiating from tumour regrowth

	Cancer	Radiation
Severe pain	80%	20%
Part of plexus	Lower (75%)	Upper (75%)
Horners syndrome	Common	Uncommon
Lymphoedema	Uncommon	Common
Time since radiation	<1year	>1year (unless >60Gy)

• Brachial plexus neuritis
• Also called neuralgic Shoulder Amyotrophy or Parsonage-Turner syndrome
• Inflammatory condition of the plexus
• ?Cause – autoimmune mechanism postulated
• Often a triggering event such as infection, surgery or vaccination
• Young adults, M>F

Clinical

• Acute onset
• Severe shoulder pain is common
• Weakness within hours or days
• Usually upper plexus (and/or middle)
• Shoulder girdle and upper arm
• Winging of scapula
• Distal weakness is rare
• Pain usually abates within a few days leaving the weakness
• Sensory changes present in variable number (? only 25%)

Diagnosis

o NCS and EMG can be used to air diagnosis

Treatment

• Good prognosis
• Severe pain resolves with a week in 50% and 3months in the rest
• Weakness resolves slowly starting at 9-12months and taking up to 2 years.
• Glucocorticoids are sometimes trialled but no evidence to support routine use.

Long Thoracic Nerve

• Pure motor nerve to serratus anterior(C5-C7)
• Serratus runs from ribs laterally to anterior surface of scapula
• Weakness causes winging of scapula
• Multiple potential causes of injury, often traumatic

Axillary nerve

• C5-C6, innervates deltoid and teres minor muscles (ext rotation of humerus)
• Sensory innervation to lateral shoulder
• Affects flexion, abduction and external rotation of the shoulder.
• Commonly injured by anterior dislocation of the shoulder

Suprascapular nerve

• C4-C6, innervates supraspinatus and infaspinatus
• Weakness of shoulder abduction and external rotation
• No sensory deficit
• Carries nerve fibres from glenohumeral and AC joints
• Often painful
• Compression of nerve in scapular groove (or coracoids scapular notch) is common.
• Results from repetitive stretching – weight lifting, volleyball
• Usually improvement within 6 weeks of modification of activity
• Steroid injection can be done if severe pain.