L11 Upper Limb Nerve Injuries

Question 1

How do you approach a neurological problem?

Answer 1

Anatomically localise the lesion - whether UMN/ LMN lesion
Consider pathophysiology
Differential diagnosis

Question 2

Where do the lower motor neurons arise from?

Answer 2

The anterior horn cell of the spinal cord

Question 3

What type of nerves are cranial nerves and spinal nerves?

Answer 3

LMN

Question 4

UMN lesions of the upper limb result in:

Answer 4

aka pyramidal insufficiency
Held in flexed posture if chronic
Increased tone
Pyramidal weakness (muscle weakness) because flexor muscles are stronger than extensors
Brisk reflexes
Decreased control of active movement, slowness
Sensory level

Question 5

LMN lesions lead to what in the upper limb

Answer 5

Wasting/ fasciculations
Flaccid tone (decreased muscle tone)
Weakness in either a myotomal distribution or a peripheral nerve distribution
Dermatomal/ peripheral nerve distribution of sensory loss

Question 6

What are the 3 anatomical regions for localising the region?

Answer 6

Roots
Brachial plexus
Peripheral nerve

Question 7

What is a myotome?

Answer 7

The relationship between a spinal nerve and the muscle via the ventral rami

Question 8

What is a dermatome?

Answer 8

The relationship between a spinal nerve and the skin via the dorsal rami
A dermatome is an area of the skin supplied by nerve fibres originating from a single dorsal nerve root

Question 9

Coordination problems would localise towards the?

Answer 9

Cerebellum

Question 10

What landmark corresponds to the C7 dermatome?

Answer 10

The middle finger

Question 11

What landmark corresponds to the C6 dermatome?

Answer 11

The index finger & thumb

Question 12

Which muscle does the C5 root innervate and what is the resulting muscle action?

Answer 12

Deltoid

Shoulder abduction

Question 13

Which muscle does the C6 root innervate and what is the resulting muscle action?

Answer 13

Biceps, brachialis, brachioradialis

Elbow flexion

Question 14

Which muscles does the C7 root innervate and what is the resulting muscle action?

Answer 14

Triceps, superficial extensors of the forearm, flexors of the forearm
Elbow extension
Wrist flexion & extension

Question 15

Which muscles does the C8 root innervate and what is the resulting muscle action?

Answer 15

Forearm extensors, deep forearm flexors

Finger flexion & extension

Question 16

Which muscles does the T1 root innervate and what is the resulting muscle action?

Answer 16

Intrinsic muscles of the hand

Finger abduction

Question 17

Which root and nerve is responsible for the biceps reflex?

Answer 17

C5

Musculocutaneous nerve

Question 18

Which root and nerve are responsible for the supinator jerk?

Answer 18

C6 reflex

Radial nerve

Question 19

Which root and nerve are responsible for the triceps jerk?

Answer 19

C7 conveyed through the radial nerve

Question 20

Which root and nerve are responsible for the finger jerk?

Answer 20

C8 conveyed through the median and ulnar nerves

Question 21

What happens to reflexes in LMN lesions?

Answer 21

They are depressed/ reduced

Question 22

What are the consequences of nerve root impingement?

Answer 22

Pain
Sensory loss
Weakness
Reflex loss

Question 23

What can cause a nerve root impingement?

Answer 23

Slipped/ herniated disc

Nucleus pulposus herniating into the spinal canal

Question 24

Name the types of nerve injury

Answer 24

Avulsion
Rupture
Brachial plexus trauma
Neuropraxia blunt injury

Question 25

Which type of brachial plexus injury has the worst prognosis?

Answer 25

Root avulsion | Preganglionic - close to the root involves the CNS which does not regenerate

Question 26

Loss of which nerves results in medial winging of the scapula? (inferior border of the scapula moves medially)

Answer 26

Long thoracic nerve (serratus anterior) | Dorsal scapular nerve (rhomboids)

Question 27

What is a flail arm?

Answer 27

Results from cervical root avulsion - loss of the primary nerve therefore resulting in lack of mobility and sensory loss

Question 28

What is the cause of ERB's palsy?

Answer 28

Avulsion of C5/ C6 roots

Question 29

What are the muscles affected by Erb's palsy?

Answer 29

Biceps - flexes arm Brachioradialis - flexed arm in semi prone position Deltoid - abducts arm Supraspinatus - abducts arm Supinator - externally/laterally rotates arm

Question 30

Name three compression sites causing thoracic outlet syndrome

Answer 30

Between anterior and middle scalene muscles Beneath the clavicle in the costoclavicular space Beneath the tendon of pec minor

Question 31

Name two causes of brachial plexopathy related to cancer

Answer 31

Metastatic brachial plexopathy - infiltration of lower brachial plexus from pan coast tumour Post radiation brachial plexopathy

Question 32

Pain is a characteristic feature which of the following types of brachial plexus injuries: Metastatic brachial plexopathy - infiltration of lower brachial plexus from pan coast tumour Post radiation plexopathy OR Brachial neuritis - Parsonage-Turner Syndrome

Answer 32

Metastatic brachial plexopathy - infiltration of lower brachial plexus from pan coast tumour Brachial neuritis - Parsonage Turner Syndrome

Question 33

What does damage to the long thoracic nerve cause?

Answer 33

Winged scapula

Question 34

What muscle does the long thoracic nerve innervate?

Answer 34

Serratus anterior

Question 35

Name two common sites of compression of the median nerve

Answer 35

Wrist - carpal tunnel syndrome | Elbow

Question 36

Name the muscles of the hand innervated by the median nerve

Answer 36

Lateral 2 lumbricals Opponens pollicis Abductor pollicis brevis Flexor pollicis brevis

Question 37

Where does the superficial sensory branch of the ulnar nerve branch off?

Answer 37

In the distal forearm

Question 38

Which structure does the ulnar nerve go around?

Answer 38

Medial epicondyle

Question 39

What is Froment's sign and what is it indicative of?

Answer 39

When a pt is asked to take a piece of paper from the examiner in their thumb and forefinger, the thumb flexes - this is froment's sign It is indicative of ulnar palsy - weakness in adductor pollicis

Question 40

Damage to which nerve causes 'Saturday night palsy'?

Answer 40

Radial nerve