Nerve Lesions

Question 1

What would lesion to Long Thoracic Nerve cause

Answer 1

Winged Scapula

Question 2

What is the cutaneous innervation of axillary nerve?

Answer 2

Skin over superlateral arm

Question 3

What test could you do to check for damage to axillary nerve?

Answer 3

Palpate for deltoid muscle while elevating UE against resistance (beyond 15 Deg)

Question 4

What test could you do to check for damage to musculocutaneous nerve?

Answer 4

Flexion of elbow against resistance

Question 5

What is the cutaneous innervation of radial nerve?

Answer 5

Skin over posterior arm and forearm; dorsal surface of lateral hand to proximal phalanges of digits 1-3, 1/2 of 4

Question 6

What anomaly would be present for radial nerve damage?

Answer 6

Wrist drop due to loss of wrist extension

Question 7

What test shows lesion to median nerve if the elbow is injured?

Answer 7

Patient is unable to form the OK sign due to damage to pronator quadratus; flexor pollicis longus; and lateral 1/2 of FDP

Question 8

Damage to recurrent median nerve would have what anomoly?

Answer 8

Ape Hand: Atrophy to thenar eminence muscles

Question 9

Define Carpal Tunnel Syndrome?

Answer 9

Compression of median nerve in carpal tunnel; causes tingling sensation to tip of thumb and digits 2,3; weakness and wasting to thenar muscles

Question 10

What causes pronator syndrome?

Answer 10

Median nerve entrapment between two heads of pronator teres

Question 11

What is the cutaneous innervation to the hand by the median nerve?

Answer 11

Palmer aspect: lateral 3 and 1/2 digits

Question 12

What two anomalies arise from damage to median nerve?

Answer 12

1. Ape hand
2. Benedict sign

Question 13

Ape hand

Question 14

Benediction Sign

Answer 14

• Damage to Median Nerve
• Occurs when attempting to form a fist
• loss of thumb flexion; thumb opposition; and DIP flexion at digits II and III

Question 15

What aspect of palm in innervated by Ulnar nerve?

Answer 15

Medial 1 and 1/2 digits

Question 16

Handlebar Palsy

Answer 16

• Caused by lesion of Ulnar Nerve
• Seen in cyclists due to too much pressure to Guyon’s tunnel in wrist due to wrist pressing on handlebar on bike

Question 17

What nerve innervates palmar interossei and dorsal interossei and how can you use these two muscles to test for lesion?

Answer 17

1. Ulnar nerve
2. Test PAD: have patient try to hold tongue depressor between fingers
3. Test DAB: have patient try to abduct fingers against force

Question 18

Partial Claw

Answer 18

1. Passive sign of damage to Ulnar nerve
2. Loss of medial two lumbricals
3. MCP joints of digits 4,5 are hyperextended; loss of balance between ED and FDP of digits 4,5

Question 19

What branch of the median nerve innervates the deep anterior forearm muscles?

Answer 19

Anterior Interosseous Nerve

Question 20

Damage to Upper plexus (C5-C6) due to wide seperate of neck and shoulder can have what anamoly?

Answer 20

Erb’s Palsy (Waiter’s Tip)

• Scapula: Unstable (Dorsal Scapular; Long Thoracic Nerve)
• Shoulder: Adducted (Suprascapular; Axillary)
• Elbow: Extended (Musculocutaneous)
• Forearm: Pronated (Musculocatantous)
• Wrist: Flexed (Radial)

Question 21

Backpacker’s palsy

Answer 21

• Damage to Superior Trunk will affect suprasacular n and causes sensory deficits associated with Radial, Axillary, and Lateral Musculocutaneous

Question 22

Klumpke Paralysis or Claw hand

Answer 22

• Injury to inferior plexus (C8-T1): Upper limb suddenly pulled superiorly
• Causes injury to ulnar nerve and Median nerve to lumbricals