Nerve Injuries Upper Limb

Question 1

Results from a wide separation between the head and the shoulder as occurs upon falling on the shoulder or in newborn during a difficult delivery with excessive traction on the neck. Results in tearing of C5 and partly C6 spinal nerves

Answer 1

Erb-Duchenne Palsy or Erb’s Palsy

Question 2

Most commonly affected nerves in Erb-Duchenne Palsy (3)

Answer 2

Suprascapular, musculocutaneous, and axillary nerves. [Keep in mind damage to C5/C6]

Question 3

Muscles whose function is affected by damage to the suprascapular nerve in Erb-Duchenne Palsy (3)

Answer 3

1) infraspinatus muscle
2) teres minor
3) supraspinatus muscle

Question 4

Muscles whose function is affected by damage to the musculocutaneous nerve in Erb-Duchenne Palsy (2)

Answer 4

1) biceps brachii

2) brachialis

Question 5

Muscle whose function is affected by damage to the axillary nerve in Erb-Duchenne Palsy (1)

Answer 5

Deltoid

Question 6

Motor deficits in Erb-Duchenne Palsy (4)

Answer 6

1) loss of lateral rotation of arm
2) loss of abduction of arm
3) loss of supination of forearm
4) loss of flexion of forearm

Question 7

Sensory deficits of C5 and C6. Loss of sensation on… (3)

Answer 7

1) lateral side of arm
2) forearm
3) thumb

Question 8

Arm hangs by the side and is rotated medially, the forearm is extended and pronated, and arm cannot be raised from the side.

Answer 8

Waiter’s tip position

Question 9

Patient presents with pronated forearm, medially rotated arm, and extending forearm resulting in Waiter’s tip position. What’s damaged?

Answer 9

Superior Trunk (C5/C6)

Question 10

Injury to inferior Trunk (C8 and mostly T1). Violent abduction of arm or presence of cervical rib. Name of this condition

Answer 10

Klumpke Palsy

Question 11

Results from hyperabduction of the arm as when a person grabs something to prevent a fall or when newborn’s arm is pulled during delivery. Can also result from the presence of a cervical rib placing traction on the lower trunk. Results in mostly tearing T1 and C8 to a limited extent.

Answer 11

Klumpke Palsy

Question 12

Most commonly affected nerves during injury to the inferior trunk (mostly T1). Branches of the medial cord (3)

Answer 12

1) ulnar nerve
2) medial part of median nerve
3) medial cutaneous nerves of arm and forearm

Question 13

Muscles innervated mostly by T1 whose function is affected in Klumpke Palsy (hint: it’s a group)

Answer 13

all of the intrinsic muscles of the hand

Question 14

Motor deficits from damage to T1 (2)

Answer 14

1) loss of flexion at MP joints (results in fingers hyperextended at MP joints due to unopposed action of extensors of forearm)
2) Loss of extension at PIP and DIP joints due to relatively unopposed action of long flexors from anterior forearm (innervated mostly by C8)

Question 15

Clinical presentation of Klumpke Palsy

Answer 15

Hyperextension of MP joints and flexion of PIP/DIP joints, results in all fingers appearing as claws

Question 16

Sensory deficits with damage to T1

Answer 16

Loss of sensations on the medial side of the arm and forearm

Question 17

How could you sustain an injury to the long thoracic nerve?

Answer 17

Results from surgery during a radical mastectomy or knife wound to upper-lateral chest.

Question 18

Muscle innervated by long thoracic nerve

Answer 18

serratus anterior

Question 19

Results of loss of serratus anterior due to injury to long thoracic nerve (2)

Answer 19

1) inability to rotate the scapula for abduction of the arm above the horizontal plane (patient cannot raise arm over head)
2) Winged Scapula - medial border of scapula protrudes posteriorly due to inability to hold medial border of scapula against chest wall

Question 20

Can occur in the quadrangular space from inferior displacement of the head of the humerus in shoulder dislocation or from fracture of surgical neck of humerus

Answer 20

injury to axillary nerve

Question 21

Results from an injury to the axillary nerve (2)

Answer 21

1) loss of function of deltoid muscle (inability to abduct the arm past 15 degrees)
2) loss of sensory innervation to upper lateral arm

Question 22

Axillary nerve innervates.. (2)

Answer 22

1) deltoid

2) teres minor

Question 23

Results from pressure from a poorly fitted crutch or from inebriated person draping their arm over back of chair and falling asleep (saturday night palsy)

Answer 23

damage to radial nerve in the axilla

Question 24

Motor loss from damage to radial nerve in axilla (3)

Answer 24

1) triceps brachii (loss of extension of forearm at elbow joint)
2) extensors of the wrist and digits (loss of extensors allows the long flexors of wrist to be unopposed)
3) wrist drop (due to loss of extensors of wrists and digits)

Question 25

Sensory loss from damage to the radial nerve in axilla (4)

Answer 25

1) posterior arm
2) posterior forearm
3) dorsolateral hand
4) proximal part of dorsal side of lateral 3.5 fingers

Question 26

Possible damage from a fracture of the mid-shaft of the humerus

Answer 26

can damage the radial nerve in the radial groove

Question 27

Why does damage to the radial nerve in the radial groove of the humerus not affect the triceps brachii nor the sensory innervation to posterior arm or forearm?

Answer 27

Triceps: receives innervation the axilla

Posterior Arm/Forearm: cutaneous branches given off proximal to radial groove

Question 28

Motor loss from damage to radial nerve in radial groove of humerus (1)

Answer 28

Loss of extension of wrists and digits, resulting in wrist-drop

Question 29

Sensory loss from damage to radial nerve in radial groove

Answer 29

over the dorsolateral hand (via superficial branch of radial nerve) and dorsum of proximal part of lateral 3.5 fingers

Question 30

Supracondylar fractures can damage what nerve and/or artery?

Answer 30

Median nerve or brachial artery

Question 31

Loss of motor functions of median nerve from supracondylar fracture of humerus (3)

Answer 31

1) loss of innervation to most flexors and all pronators of anterior forearm
2) loss of innervation by median nerve specifically anterior interosseous nerve to flexor digitorum profundus (lateral part), flexor pollicus longus, and pronator quadratus muscle
3) loss of motor innervation to thenar and lateral two lumbrical muscles

Question 32

Result of damage to median nerve at supracondylar ridge when patient attempts to make a fist

Answer 32

Hand of Benediction

Question 33

Sensory loss from damage to median nerve from supracondylar fracture of humerus (2)

Answer 33

1) lateral 2/3 of palm (due to loss of palmar cutaneous branch and digital branches of median nerve)
2) palmar side and nail beds (dorsal side over distal phalanx) of lateral 3.5 fingers (due to loss of digital branches of median nerve)

Question 34

Severance of recurrent branch of median nerve results in…

Answer 34

Loss of opposition of thumb and atrophy of thenar muscles

Question 35

True/False: There is sensory loss resulting from a severance of the recurrent branch of median nerve

Answer 35

false

Question 36

How is the median nerve damage in the carpal tunnel?

Answer 36

Entrapment of the nerve due to pressure from swelling tendon sheaths or arthritic inflammation (nerve not lesioned by compromised by pressure)

Question 37

Motor result of median nerve damage in the carpal tunnel

Answer 37

Progressive weakness of thenar muscles (loss of opposition of thumb) and atrophy of thenar eminence

Question 38

Sensory deficit of median nerve from pressure in carpal tunnel (2)

Answer 38

Paresthesia, hypothesia, or anesthesia of digital branches of median nerve due to inflammation or pressure…..

1) lateral 3.5 digits (palmar) and nail beds (dorsal)
2) distal lateral 2/3 of palm

Question 39

Lack of sensation

Answer 39

Anesthesia

Question 40

Diminished sensation

Answer 40

Hypoesthesia

Question 41

Paresthesia

Answer 41

Abnormal sensation such as pins and needles; tingling or burning; etc..

Question 42

True/False: Sensations on proximal part of lateral palm are lost with an impaired median nerve in the carpal tunnel

Answer 42

false

Question 43

This branch of the median nerve crosses superficial to flexor retinaculum and does not enter the carpal tunnel. Not affected in the syndrome of the same name.

Answer 43

palmar cutaneous branch of median nerve

Question 44

Treatments for carpal tunnel impairment of the median nerve (2)

Answer 44

1) reduce inflammation and limit repetitive movements

2) carpal tunnel release (surgical decompression of the nerve by severing the flexor retinaculum)

Question 45

Loss of muscle function with lesion of ulnar nerve at medial epicondyle (3)

Answer 45

1) loss of flexor carpi ulnaris (weak flexion and adduction of hand)
2) loss of medial half of flexor digitorum profundus to ring and little fingers. Patients cannot flex their DIP joints. (flexion of middle phalanx intact due to flexor digitorum superficialis)
3) loss of interosseous muscles. Patient cannot adduct-abduct fingers

Question 46

Characteristic hand presentation of damage to ulnar nerve at medial epicondyle

Answer 46

Ulnar claw hand

Question 47

Damage to ulnar nerve at wrist results in paralysis of most intrinsic muscles. What are the two exceptions?

Answer 47

1) thenar muscles

2) lateral lumbricals