28: UE Neurology

Question 1

Cervical plexus levels

Answer 1

C1-4

Question 2

Important cervical plexus nerve for the UE

Answer 2

Supraclavicular N

Question 3

Three branches of the supraclavicular N and what it supplies

Answer 3

Lateral, middle, and medial supraclavicular N’s -> skin over neck and shoulder

Question 4

Muscular branches of brachial plexus roots: innervate which four Muscles?

Answer 4

Anterior/middle/posterior scalenus + longus coli M

Question 5

Injury to superior brachial plexus (C5 and C6): how does it occur?

Answer 5

Dramatically increasing the angle between the neck and shoulder

Question 6

What can occur with injury to superior brachial plexus?

Answer 6

Stretch/rupture/avulsed spinal roots off the spinal cord

Question 7

What would an individual with an upper brachial plexus injury look like?

Answer 7

Adducted + medially rotated arm, extended elbow = Erb-Duchenne Palsy (Waiter’s Tip Position)

Question 8

How does injury to the inferior brachial plexus occur

Answer 8

Dramatically increasing the angle between trunk and upper limb

Question 9

What is the result of inferior brachial plexus injury?

Answer 9

Affects short muscles in the hand -> Klumpke paralysis -> Claw hand

Question 10

Nerve branches from the divisions

Answer 10

None

Question 11

What two things does the medial antebrachial cutaneous N travel with

Answer 11

Ulnar N -> then basilic V

Question 12

What can cause compression of brachial cords?

Answer 12

Prolonged periods of working with upper limb extended over the head (like painting a ceiling)

Question 13

What happens if cords of the brachial plexus are compressed?

Answer 13

Pain radiating down arm, loss of sensation, tingling, and weakness of hands

Question 14

How does injury to musculocutaneous N occur?

Answer 14

Is rare, but can happen with blunt force trauma

Question 15

What happens if musculocutaneous N is injured?

Answer 15

Paralysis of anterior brachial muscles

Question 16

What happens if the axillary N is injured?

Answer 16

Atrophy of deltoid, loss of sensation over superolateral arm (bc of superior lateral brachial cutaneous N)

Question 17

What A does the median N travel with?

Answer 17

Brachial A

Question 18

When does the palmar cutaneous branch of the median N appear?

Answer 18

Before the median N enters the carpal tunnel, and it travels superficial to the flexor retinaculum -> has some clinical significance on whether a sensory issue is arising from wrist or higher up

Question 19

What happens with an injury of the median N in the wrist?

Answer 19

Adducted thumb, thenar eminence atrophy -> Ape’s Hand

Question 20

What happens with median N injury at the elbow?

Answer 20

Inhibits flexion of 2nd and 3rd digits -> hand of benediction + Ape’s hand

Question 21

Where does the ulnar N become superficial

Answer 21

When it enters the hand, passing over the flexor retinaculum

Question 22

What does the palmar cutaneous branch of the ulnar N travel with?

Answer 22

Ulnar A

Question 23

Four positions where the ulnar N can be injured

Answer 23

1. Posterior to medial humeral epicondyle
2. Between the two heads of flexor carpi ulnaris M (the cubital tunnel)
3. Wrist
4. In hand

Question 24

Ulnar N injury results in??

Answer 24

Loss of sensory and motor in the hand -> Claw hand

Question 25

If pressure is placed on the hamulus of the hamate bone, like when riding a bike? What happens?

Answer 25

Ulnar N is compressed -> loss of sensory to medial side of hand and weakness of intrinsic hand muscles -> handlebar neuropathy

Question 26

Largest terminal branch of the brachial plexus

Answer 26

Radial N

Question 27

What artery does the radial N run with?

Answer 27

Deep brachial A

Question 28

What happens if the radial N is injured?

Answer 28

Impairment of elbow extension + thumb adduction and extension -> “wrist drop”

Question 29

An important thoracic spinal nerve

Answer 29

Intercostobrachial N

Question 30

What does the intercostobrachial N supply?

Answer 30

Cutaneous innervation to uppermost medial brachium

Question 31

C5 dermatome

Answer 31

Over deltoid

Question 32

C6 dermatome

Answer 32

Lateral antebrachium, hand

Question 33

C7 dermatome

Answer 33

Central hand, posterior antebrachium, 3rd digit

Question 34

C8 dermatome

Answer 34

Medial hand and antebrachium, 5th digit

Question 35

T1 dermatome

Answer 35

Medial brachium

Question 36

T2 dermatome

Answer 36

Anterior border of axilla