14. Upper Extremity Neurology

Question 1

What Nerves of the Cervical Plexus innervates the skin of the neck and shoulder?

Answer 1

Supraclavicular Nerves

from Anterior rami of C4

Question 2

What are the three major divisions of the Lateral Cord of the Brachial Plexus?

Answer 2

Lateral Pectoral Nerve

Musculocutaneous Nerve

1/2 of the Median Nerve

(also Lateral antebrachial cutaneous N)

Question 3

What are the branches and terminal divisions of the Posterior Cord of the Brachial Plexus?

Answer 3

Branches: Inferior Subscapular, N

Superior Subscapular N, and Thoracodorsal N

Terminal Branches: Axillary Nerve, Superior lateral brachial cutaneous N, Radial Nerve

Question 4

What are the three branches and two terminal branches of the Medial Cord?

Answer 4

Branches: Medial Pectoral, Medial Brachial Cutaneous, Medial Antebrachial Cutaneous.

Terminal Branches: Ulnar Nerve and 1/2 of the Median Nerve

Question 5

What Nerves come directly off the Root for C5?

Answer 5

Dorsal Scapular Nerve

Long Thoracic

Question 6

Which roots contribute to the Long Thoracic Nerve?

Answer 6

C5, C6, C7

Question 7

What two Nerves come directly off of the Superior Trunk?

Answer 7

Suprascapular and Subclavian

Question 8

What disease might come about due to an injury to C5 and C6’s Anterior Rami??

Answer 8

Erb-Duchenne’s Palsy

Question 9

What might be the cause of Klumpke’s Palsy?

Answer 9

Lower Brachial Injury

or

Injury to the Ulnar Nerve

Question 10

What might happen if you spend an extended time working with your arm above your head?

Answer 10

Compression of the Brachial Plexus

Weakness and tingling in the Arms, pain radiating down the arm, loss of sensation in the arm.

Question 11

If you took a blunt force trauma to the arm and injured your proximal Musculocutaneous Nerve, what sensory branch may also be inactivated, and what part of your arm might you not feel?

Answer 11

Lateral Antebrachial Cutaneous Nerve

Lateral Part of the Anterior Forearm

Remember that the Musculocutaneous Nerve comes out of the Lateral Cord, and branches distal to it’s day job, which is innervating the biceps - so it makes sense that it would be lateral, and beyond the bicep.

Question 12

Where does the Intercostobrachial Nerve come from?

What does it do?

Answer 12

A Thoracic Spinal Nerve

Provides Sensory Innervation to the most medial part of the posterior brachium.

Question 13

What would you see in injury to the Axillary Nerve?

Answer 13

Inability to abduct the arm to 90 degrees (the Supraspinatus can get it up about 15 degrees) and atrophy of the Deltoid Muscle

Loss of sensation to the superior lateral portion of the arm.

Question 14

What might cause “Wrist Drop?”

Answer 14

Radial Nerve Damage

Question 15

What causes “Hand of Benediction?”

Answer 15

Damage to the Median Nerve

at ELBOW

2 and 3 extended and 4 and 5 flexed

Question 16

Where can Ulnar Nerve Damage Occur?

Answer 16

Posterior to the Medial Humeral Epicondyle (funny bone area)

Between the Ulnar and Humeral Heads of the Flexor Carpi Ulnaris (we didn’t learn about these heads)

The Wrist

The Hand

Question 17

What can be the result of damage to the Ulnar Nerve?

Answer 17

Claw Hand

Question 18

Pressure to the medial side of the Hand can cause “Handlebar Neuropathy.” What nerve is affected in this disease?

Answer 18

The Ulnar Nerve

Question 19

What gives rise to the Median Brachial Cutaneous Nerve and the Median Antebrachial Cutaneous Nerve?

Answer 19

Medial Cord

Question 20

What gives rise to the Lateral Antebrachial Cutaneous Nerve?

Answer 20

Musculocutaneous Nerve

Question 21

The Axillary Nerve gives rise to what sensory branch?

Answer 21

Superior Lateral Brachial Cutaneous Nerve

The name describes the position of the Deltoid, which is where the Axillary nerve innervates both Muscle and Skin.

Question 22

The Radial Nerve gives rise to what three sensory branches?

Answer 22

Posterior Brachial Cutaneous

Posterior Antebrachial Cutaneous

Superficial Radial Nerve (gives rise to the Dorsal Digital Nerves after it crosses the Anatomical Snuffbox)

Question 23

What sensory branches come off of the Median Nerve?

Answer 23

Palmar Cutaneous Branch of the Median Nerve

(Can feel the Palm in Carpal Tunnel)

Common Palmar Digital Nerves

Proper Palmar Digital Nerves

Question 24

What are the sensory branches of the Ulnar Nerve?

Answer 24

Palmar Cutaneous Branch of the Ulnar Nerve

Dorsal Cutaneous Branch of the Ulnar Nerve

Superficial Ulnar Nerve (gives rise to Common and Proper Palmar Digital Nerves)

Question 25

The Radial Nerve innervates most of the lateral part of the dorsal Hand, but what nerve innervates the most distal, dorsal part of the 2nd, 3rd, and 4th digit?

Answer 25

The Proper Palmar Digital Nerves of the Median Nerve

The Median Nerve wraps over the fingertips and gets the dorsal tips of Digits 2, 3, and 4,