OS 203 2 Axilla and Brachial Plexus - Sheet1 (1)

Question 1

PE of nerve injury: cooperative patient (2)

Answer 1

2-pt discrimination (innervation density), semmes-weinstein test (touch threshold)

Question 2

PE of nerve injury: unconscious patient (3)

Answer 2

Wrinkle test (10 mins; if smooth, nerve injury); tactile adherence (smooth & slipper, nerve injury); sensory testing

Question 3

sensory testing: tests for median, radial, ulnar nerves

Answer 3

median - test for abductor pollicis brevis; radial - extensor digitorium communis or pollicis longus; ulnar - flexor digiti minimi

Question 4

2 main categories of nerve injuries (which is shorter)

Answer 4

Seddon (shorter), Sunderland

Question 5

Seddon & Sunderland equivalents

Answer 5

Neurpraxia = 1st deg; Axonotmesis = 2nd deg; Neurotmesis = 3rd-5th deg

Question 6

Injury, degeneration, regeneration in 1st degree

Answer 6

Myelin sheath, conduction block, complete recovery

Question 7

Injury, degeneration, regeneration in 2nd degree

Answer 7

MA, Wallerian degeneration, complete recovery

Question 8

Injury, degeneration, regeneration in 3rd degree

Answer 8

MAE, Wallerian degeneration, incomplete recovery

Question 9

When is electromyogram and nerve conduction velocity test done?

Answer 9

10-14 days after injury

Question 10

Motor and sensory axons are excitable up to?

Answer 10

motor - 7 days; sensory - 11 days

Question 11

Wallerian degeneration starts when?

Answer 11

10-14 days after injury

Question 12

Stimulation distal to the site of injury…

Answer 12

Normal or slightly abnormal, so you can’t differentiate between neuropraxia and neurotmesis

Question 13

Stages of nerve regeneration

Answer 13

axon fragmented -> macrophage clean distal to injury -> axon sprouts/filaments through regeneration tube formed by Schwann cells -> axon regenerates, new myelin sheath

Question 14

Posterior triangle borders

Answer 14

anterior - sternocleidomastoid, posterior - anterior border of the trapezius, inferior - middle third of the clavicle (M3)

Question 15

from the posterior triangle, brachial plexus emerges where

Answer 15

between the anterior and middle scalene muscles

Question 16

main supinator of the forearm

Answer 16

biceps

Question 17

musculocutaneous supplies what? (3)

Answer 17

coracobrachialis, biceps brachii, brachialis

Question 18

what supplies the brachialis? it will eventually become a what?

Answer 18

musculocutaneous nerve; becomes a sensory nerve called the lateral antebrachial cutaneous nerve

Question 19

the median nerve distally supplies the? passes through? and supplies recurrent muscle

Answer 19

AIN / anterior interosseus nerve, passes through carpal tunnel

Question 20

supplies intrinsic muscles of the hand

Answer 20

ulnar nerve

Question 21

when the ulnar nerve gets trapped in the cubital tunnel behind the medial epicondyle…

Answer 21

cubital nerve syndrome (tardy ulnar palsy)

Question 22

fracture of the elbow can result to

Answer 22

paralysis of the ulnar nerve

Question 23

prolonged ulnar nerve palsy can cause

Answer 23

claw hand deformity or ape hand/papal benediction sign (*EH DAPAT MEDIAN NERVE TONG APE/PAPAL EH…)

Question 24

radial nerve goes into the what of the humerus and divides into what?

Answer 24

radial groove in distal 1/3 humerus, superficial cutaneous (dorsal web space) and deep motor (extensors of wrist) -> posterior interosseus -> extensors of fingers

Question 25

radial paralysis leads to? and if more proximal?

Answer 25

wrist drop, numbness of dorsal web space, if more proximal, loss or weakness of elbow extension

Question 26

(axillary) the posterior cord goes out to the quadrangular space to supply what?

Answer 26

motor and sensory function of the deltoid (also, teres minor)

Question 27

how can the axillary nerve be injured? effects?

Answer 27

proximal fractures of humerus, surgical neck, dislocation of humerus; lack of abduction, weakness in external rotation, numbness of deltoid patch

Question 28

regions on skin from which sensation is carried by cutaneous branches of a spinal nerve

Answer 28

dermatomes

Question 29

long thoracic nerve: innervates what? action? injury?

Answer 29

serratus anterior, laterally rotates outwards/protracts scapula, scapular winging

Question 30

dorsal scapular nerve innervates what? action?

Answer 30

major & minor rhomboids, medially rotates/retracts scapula

Question 31

the only branch at the trunk level; innervation? action?

Answer 31

suprascapular nerve; supraspinatus (shoulder abduction) and infraspinatus (external rotation)

Question 32

lateral pectoral nerve innervates? action?

Answer 32

clavicular head of pec major, adducts and internally rotates shoulde

Question 33

medial pectoral nerve innervates? action?

Answer 33

sternal head of pec major & minor, adducts shoulder

Question 34

subscapular nerve innervates? action?

Answer 34

subscapularis and teres major; internally rotates shoulder

Question 35

thoracodorsal nerve innervates? action?

Answer 35

latissimus dorsi; adduction and internal rotation of shoulder

Question 36

innervates thenar muscles (except...)

Answer 36

median nerve; except deep head of flexor pollicis brevis and adductur pollicis

Question 37

median nerve: roots and respective innervations and actions

Answer 37

C6: forearm pronator; C7: wrist flexor; C8 - long finger flexor; T1: small hand (intrinsic)

Question 38

brachial plexus injuries (3)

Answer 38

stretch (neuropraxia), rupture, avulsion

Question 39

pre & post ganglionic injury: what kind of injury? scapular winging? suture?

Answer 39

pre: avulsion, present (serratus anterior damage *recall: innervated by long thoracic nerve), can't be sutured (also: normal in NCV... so normal sensory?);; post: rupture, none, can be sutured

Question 40

causes of upper and lower brachial plex injury

Answer 40

upper: extreme lateral flexion; lower: extreme abduction

Question 41

upper & lower: damaged roots

Answer 41

upper - C5-C6; lower - C8-T1

Question 42

extreme lateral flexion caused by

Answer 42

shoulder dystocia in babies, fall in adults

Question 43

upper brachial plexus injury results to

Answer 43

erb-duchenne paralysis

Question 44

extreme abduction caused by

Answer 44

babies arms pulled during delivery, adults breaking fall

Question 45

lower brachial plexus injury results to

Answer 45

klumpke's paralysis (claw hand)

Question 46

treatment priority (adult)

Answer 46

elbow flexion, shoulder stability/abduction, hand sensation, hand function

Question 47

treatment priority (obstetric)

Answer 47

hand function/sensation, elbow function, shoulder stability/abduction, shoulder external rotation

Question 48

for neuromas-in-continuity

Answer 48

neurolysis

Question 49

for post-ganglionic/rupture/graftable proximal nerve

Answer 49

nerve repair/grafting

Question 50

if pre-ganglionic/not graftable

Answer 50

nerve transfer

Question 51

artificial bridges for axons; length limited to? ECM?

Answer 51

conduits,

Question 52

late treatment (>12 mos.) (2)

Answer 52

muscle transfers, tendon transfers

Question 53

rate of axons regeneration

Answer 53

1mm/day or 1 in/month

Question 54

motor end plates degenerate at

Answer 54

12-18 months