Brachial Plexus Lesions

Question 1

Long thoracic nerve (C5,6,7) injury results in…

Answer 1

winged scapula- cant stabilize and limited ability to raise arm above head (lost serratus anterior fn)

often caused by mastectomy

Question 2

damage to suprascapular (C5,6) causes..

Answer 2

loss of supraspinatus and infraspinatus- weak abduction and lateral rotation of shoulder

Question 3

thoracodorsal damage leads to… (C6,7,8)

Answer 3

loss of lats- weakness adducting and internally rotating and extending arm

weakness climbing, rowin,g pushing out of chair

Question 4

damage to axillary nerve leads to

Answer 4

loss of deltoid and teres minor- loss of rounded contour of shoulder from atrophy

limited abduction of arm and lateral rotation of arm, loss of sensation to lateral arm/shoulder

usually from surgical neck fractures or shoulder dislocations

Question 5

musculocutaneous (C5,6,7) damage leads to…

Answer 5

loss of anterior compartment upper arm muscles- supination and flexion of forearm as well as sensory loss on lateral aspect (this nerve becomes lateral cutaneous)

Question 6

brachial plexus lesions leads to both ___ and ____

Answer 6

sensory and motor deficits

Question 7

describe antagonism in muscle fn

Answer 7

muscle groups antagonize each other- flexors balance out extensors, supinators for pronators, etc

loss of one will lead to exaggerated effect of the other

Question 8

contrast upper and lower brahcial plexus lesions

Answer 8

upper- C5 an C6 ventral rami affected (more common)

lower- C8 and T1 ventral rami

Question 9

usual factor causing upper brachial plexus injuries

Answer 9

excessive stretching from lateral space b/w head and shoulder- stretch or evulse superior roots of C5 and C6

Question 10

Erb’s palsy- nerve roots and muscles affected, arm position after lesions

Answer 10

upper brachial plexus injuries- paralysis or weakness of muscles innervated by C5 and C6

deltoid, supra/infraspinatus, biceps, brachioradialis, supinator, etc

limb is adducted, internally rotated, pronated, extended at elbow after injury
-waiters tip hand w/ fingers and wrist curled into flexion also possible

Question 11

causes of erbs palsy

Answer 11

accidents- motorcycle, football, equestrian

obstetrical trauma leaving birth canal

Question 12

loss of sensation from erbs palsy

Answer 12

loss of sensation in C5 and 6 dermatomes- lateral arm and forearm

Question 13

mechanical cause of lower brachial plexus injury

Answer 13

upper limb being pulled up superiorly- falling and graspng at something or pulling baby out by arm

c8 and T1 roots stretched or evulsed

Question 14

klumpke palsy - site of injury, muscles and sensation

Answer 14

damage to C8 and T1

paralysis of short intrinsic muscles of hand, muscle imbalance b/w digital flexors and extensors (claw hand)

loss of sensation along C8 and T1 dermatomes- medial arm and hand

Question 15

horners syndrome

Answer 15

damage to sympathetic nerves traveling from T1, can present w/ klumpke palsy

Question 16

high median nerve injury - site and impact

Answer 16

nerve damage in cubital fossa

weakness/paralysis of anterior forearm muscle, atrophy of thenar muscle (loss of opposition), sesnsory deficit of 3.5 fingers (FDS and half the FDP are lost)

Question 17

hand of benediction

Answer 17

result of high median nerve injury when pts try to make fist- cant flex thumb, 2nd, or 3rd digits

Question 18

common injury damaging radial nerve

Answer 18

humeral fractures near radial groove

Question 19

loss of fn w/ radial nerve damge

Answer 19

paralysis of wrist/finger extensors and supinators

common sign is wrist drop- inability to extend

loss of sensation b/w thumb and index finger on dorsal hand

Question 20

loss of fn w/ ulnar nerve damage

Answer 20

affect most of the intrinsic hand muscles- thin and weak hand, loss of fine movement (atrophy of dorsal interossei)

loss of sensation to pinky and half of ring finger

Question 21

making a fist w/ loss of ulnar nerve

Answer 21

4th and 5th digits cant flex due to loss of part of FDP and lumbricals- results in ulnar claw hand (everything flexed except 4th and 5th digit)

Question 22

contrast two types of hand of benediction

Answer 22

median nerve damage- occurs when pt closes fist

ulnar nerve damage- when pt opens fist, loss of lumbricals mean loss of extension of interphalangeal joints

Question 23

nerve roots of anterior limb

Answer 23

shoulder C5-C6

upper compartment- C5-6

serratus anterior- C567 (reach your arms to heaven)

forearm- superficial: C6,7,8
deep: C7, C8, T1
BS muscles (brachioradialis and supinator by C5 and 6)

hand: C8 and T1

Question 24

nerve roots of posterior limb

Answer 24

lat- C6,7,8 (handcuff your date)

shoulder- C5,6

upper compartment- C6,7,8

forearm- C6,7,8

dorsal hand- C8 and T1