6. Upper extremity nerves - oxi apo Flashcards Preview

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Flashcards in 6. Upper extremity nerves - oxi apo Deck (69)
1

axillary y- origin

C5 -C6

2

causes of axillary nerve injury

1. fractured surgical neck of humerus
2. anterior dislocation of humerus

3

presentation of axillary nerve injury

1. flatened deltoid
2. Loss of arm abduction at shoulder (>15 degrees)
3. Loss of sensation over deltoid muscle and lateral arm

4

musculocutaneous nerve origin

C5-C7

5

causes of musculocutaneous nerve injury

upper trunk compression

6

presentation musculocutaneous nerve injury

1. loss of forearm flexion and supination
2. loss of sensation on lateral forearm

7

Radial nerve - origin

C5-T1

8

causes of radial nerve injury

1. midshaft fracture of humerus
2. compression of axilla

9

causes of radial nerve injury - compression of axilla due to (e.g )

1. crutches
2. sleeping with arm over chair ( Saturday night palsy )

10

Saturday nigh palsy

radial nerve injury due to sleeping with arm over chair

11

presentation of radial nerve injury

1. wrist drop
2. decreased grip strength
3. loss of sensation of over posterio arm / forearm and dorsal hand

12

foream is the part of the body which extends from

the elbow to the wrist

13

arm is the part of the body which extends from

shoulder to the elbow

14

radial nerve injury - wrist drop due to loss of

elbow, wrist and inger extension

15

radial nerve injury - decreased grip extensor - why ?

ewrist extension is necessary for maximal action of flexors

16

median nerve - origin

C5-T1

17

causes of median nerve injury

1. supracondylar fracture of humerus ( proximal lesion
2. carpal tunnel syndrome ( distal lesion )
3. wrist laceration ( distal lesion )

18

median injury - presentation

1. ape hand
2. Pope's blessing
3. loss of wrist flexion
4. loss of thumb opposition
5. loss of lumbricals of 2nd and 3rd digits
6. loss of flexion of lateral fingers
7. loss of sensation over thenar eminence
8. loss of sensation at dorsal and palmar aspects of lateral 3.5 fingers ( proximal lesion )
9. Tinel sign ( in carpal tunnel syndrome ) sensation on in proximal lessions

19

ape- hand deformity

lack of ability to abduct, flex and oppose the thumb due to paralysis of the thenar muscles

20

tinel sign

tingling on percussion

21

pope's blessing sign is also called

hand of benediction

22

pope's blessing sign ( Hand od benediction )

the ability to flex the digits 2-3 metacarpophalangeal joints is lost as is the ability to flext and extend the proximal and distal interphalangeal joints

23

ulnar nerve origin

-T1 C

24

causes of ulnar nerve injury

1. fracture of medial epicondyle of humerus funny bone ( proximal lesion )
2. fractured hook of hamate ( distal lesion )

25

funny bone

the part of the elbow over which passes the ulnar nerve

26

presentation of ulnar nerve injury

1. ulnar claw on digit extension
2. radial deviation of wrist UPON FLEXION ( proximal lesion )
3. Loss of wrist flexion
4. loss of flexion of medial fingers
5. loss of abduction and adduction of fingers ( interossei )
6. loss of actin of medial
2. lumbrical muscles
7. loss of sensation over medial 1.5 fingers including hypothenar eminence

27

interossei refer to

muscles between certain bones bran

28

Recurrent branch of median nerve - origin

C5-T1

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causes of recurrent branch of median nerve injury

superficial laceration of palm

30

presentation of recurrent branch of median nerve injury

1. ape hand ( loss of thenar muscle group : opposition , flexion abduction
2. loss of sensation

31

flatened deltoid - nerve ?

axillary

32

ape hand - nerve

1. median
2. recurrent branch of median nerver

33

ulnar claw - nerve ?

ulnar

34

decreased grip strength - nerve

radial

35

pope's blessing - nerve

median

36

tinel sign of hand?

carpal tunnel syndrome

37

supracondylar fracture of jumerus - nerve injury ?

median

38

werist drop - nerve ?

radial

39

loss of foreman supination - nerve ?

musculocutaneous

40

radial nerve injury - nerve sensation ?

loss of sensation over posterior arm / forearm and dorsal hand

41

median nerve injury - sensation

loss of senation over thenar eminence and at dorsal and palmar aspects of lateral 3.5 fingers

42

• A man fractures his arm through the surgical neck of the humerus. What other arm insult damages the same nerve likely injured in this man?

Anterior dislocation of the humerus (both this and a surgical neck of the humerus fracture can damage the axillary nerve [C5–C6])

43

• A 22-year-old man fractures his arm through the midshaft of the humerus. A nerve that spans which nerve roots was likely injured?

The radial nerve (C5–T1)

44

• A woman with a cervical disk herniation is weak in the finger and wrist extensors. Her grip is weak. What nerve roots are likely impaired?

C5–T1 (the radial nerve)

45

• Days after a shoulder injection, a man has persistent pain. He cannot abduct his shoulder past 15°. Does he have sensation loss?

Yes, as he has likely injured his axillary nerve (C5–C6) and will have sensation loss over the deltoid muscle and lateral arm

46

• A man lacerates the medial aspect of his hand at the thumb base and severs a nerve. What type of motor deficit do you expect?

Thenar muscle and thumb opposition/abduction/flexion weakness (ape hand), due to recurrent branch of the median nerve damage (C5–T1)

47

• A patient recently requiring an ankle cast is on crutches for 6 weeks. He is now having problems with wrist extension. Why might this be?

Radial nerve injury secondary to improper crutch use

48

• A boy fractures his humerus "funny bone" and compresses a nerve. What deficits will be seen in his wrist as a result?

Radial deviation of the wrist on flexion (seen with proximal lesions such as this) (he has injured his ulnar nerve)

49

• A patient thinks he has fractured his humerus "funny bone" after banging his elbow on a table. What part of the bone was affected?

The medial epicondyle of the humerus

50

• A girl loses lateral forearm sensation. She has trouble flexing and supinating her forearm. Where is the lesion causing her symptoms?

Her upper trunk in the brachial plexus is likely compressed, leading to musculoskeletal nerve (C5–C7) dysfunction

51

• A man falls down the stairs and lands on the heels of his hands with his hands outstretched. He is at risk for injury to what nerve?

Ulnar nerve (C8–T1)

52

• A radiologist tells you that your patient has fractured his hook of the hamate. Will the patient have radial deviation on wrist flexion?

No, as this is a distal ulnar nerve (C8–T1) lesion (proximal ulnar muscles will not be affected and wrist flexion should be normal)

53

• A patient has no sensation over her deltoid muscle and lateral arm. Her deltoid muscle appears flattened. What will a shoulder exam reveal?

Impaired abduction past 15° (the findings suggest axillary nerve [C5–C6] dysfunction)

54

• The palmar surface of the first three digits is innervated by which main upper extremity nerve?

Median nerve

55

• The thenar muscles are innervated by what branch of the median nerve?

The recurrent branch (C5–T1)

56

• Cutaneous sensation on the lateral dorsum of the hand is provided by what nerve?

Radial nerve (superficial branch)

57

• A chef places his index and middle fingers on a burner, senses the heat and quickly jerks away, thanks to sensation by which nerve?

Median nerve (C5–T1)

58

• A patient loses the ability to flex and supinate the forearm following a car accident. What nerve was likely damaged?

Musculocutaneous nerve (C5–C7)

59

• A Pope's-blessing palsy can result from damage to what part of the brachial plexus?

The median nerve distribution (C5–T1)

60

• After falling from a tree, a woman has no sensation over her shoulder and cannot abduct her arm. What could the lesion be?

She likely has a fractured surgical neck of the humerus or a humeral head dislocation, damaging the axillary nerve (C5–C6)

61

• A patient suffers a midshaft humerus fracture damaging the extensor compartment. He has a wrist drop. What sensory deficit is expected?

Deficit over the posterior arm, dorsal hand, dorsal thumb (this is radial nerve [C5–T1] dysfunction)

62

• A man using crutches for 3 months can no longer extend his wrist due to nerve compression. What other muscles might be affected?

Elbow, wrist, and finger extensors, including grip strength (this is radial nerve [C5–T1] dysfunction)

63

• A patient has a supracondylar fracture of the humerus with nerve injury. What motor deficits do you expect on arm exam?

Lost sensation over thenar eminence and dorsal and palmar aspects of lateral 3½ fingers (there is damage to median nerve proximally)

64

• A man fractures his humerus and loses sensation over the dorsal aspect of his lateral hand. The damaged nerve arises from which roots?

Median nerve arises from the C5–T1 roots

65

• A patient fractures the medial epicondyle of the humerus. What sensory and motor deficits are expected on physical exam?

Paresthesia of medial 1½ fingers, inability to flex medial fingers/wrist, radial deviation of wrist (this is an ulnar nerve injury)

66

• A man loses sensation over the medial 1½ fingers and hypothenar eminence after a wrist injury. What findings are there on hand motor exam?

Interosseous and medial 2 lumbrical weakness, ulnar claw on digit extension (this is ulnar nerve injury)

67

• A man loses sensation over the medial 1½ fingers and hypothenar eminence after a wrist injury. What findings are there on hand motor exam?

Interosseous and medial 2 lumbrical weakness, ulnar claw on digit extension (this is ulnar nerve injury)

68

• A man has wrist drop with loss of elbow, wrist, and finger extension. He slept with his arm draped over a couch. Is there sensory loss?

Yes, as this is Saturday night palsy affecting the radial nerve (C5–T1), and he will have posterior arm/forearm & dorsal hand sensory loss

69

• A typist has tingling in his thenar eminence. Percussing his wrist makes the tinging more intense. What nerve is likely impaired?

Median nerve (C5–T1) (this is a positive Tinel sign, suggestive of carpal tunnel syndrome)

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