Lecture 15: Upper Extremity Neurology

Question 1

What is damaged in “Waiter’s Tip Position” or Erb-Duchenne Palsy and what does it look like?

Answer 1

• damaged to Superior Brachial Plexus (C5/C6)
• dramatically inc. angle between neck and shoulder
• spinal roots removed from Spinal Cord
• adducted and medially rotated arm, extended elbow

Question 2

What is damaged in “Claw Hand” or Klumpke Paralysis and what does it look like?

Answer 2

• damaged Inferior Brachial Plexus (C7/C8/T1)
• dramatically inc. angle between trunk and upper limb
• affects short hand muscles = claw hand

Question 3

Compression of the CORDS of the Brachial Plexus is a result of what? What are the symptoms?

Answer 3

• from prolonged periods of working with UL extended over head
• pain down arm, loss of sensation, tingling, weakness of Hands

Question 4

What is the cause of Musculocutaneous N. damage and what is affected?

Answer 4

cause: blunt force trauma
symptoms: paralysis of anterior Brachial muscles

Question 5

What are the symptoms of damaged Axillary N. and what does it look like?

Answer 5

symptoms: loss of sensation over superolateral arm (Lateral Brachial Cutaneous N.)
appearance: atrophy of the Deltoid M.

Question 6

What is “Ape’s Hand”?

Answer 6

• injury to Median N. in the wrist

- adducted thumb and thenar eminence atrophy

Question 7

What is “Hand of Benediction”?

Answer 7

• injury to Median N. at the elbow
• inhibit 2nd/3rd digit flexion
• also has symptoms of Ape Hand

Question 8

What is “Claw Hand”?

Answer 8

• injury to Ulnar N.

- extensive loss of sensory and motor control in hand (cannot flex 4th/5th digits)

Question 9

What is “Handlebar Neuropathy”?

Answer 9

• compression of Ulnar N. at Hamulus of Hamate (like when riding a bike)
• sensory loss on medial side, weakness of intrinsic hand muscles

Question 10

What is “Wrist Drop”?

Answer 10

• injury of Radial N.

- impairment of elbow extension and thumb abduction/extension

Question 11

What do the Supraclavicular N.’s innervate?

Answer 11

cutaneous innervation of skin over Neck and Shoulder

Question 12

What two nerves come off of the Roots of the Brachial Plexus and what do they innervate?

Answer 12

1. Dorsal Scapular N. (Levator Scapulae/Rhomboids) –> C5

2. Long Thoracic N. (Serratus Anterior) –> C5-C7

Question 13

What two nerves come off of the Superior Trunk of the Brachial Plexus and what do they innervate?

Answer 13

1. Suprascapular N. (Supraspinatous and Infraspinatous)

2. Subclavian N. (Subclavius M.)

Question 14

What nerve comes off of the Lateral Cord of the Brachial Plexus and what does it innervate?

Answer 14

Lateral Pectoral N. (Pectoralis Major M.)

Question 15

What three nerves come off of the Posterior Cord of the Brachial Plexus and what do they innervate?

Answer 15

1. Superior Subscapular N. (Subscapularis M.) –> C5-C6
2. Inferior Subscapular N. (Subscapularis M. & Teres Major M.) –> C5-C6
3. Thoracodorsal N. (Latissimus Dorsi) –> C6-C8

Question 16

What three nerves come off of the Medial Cord of the Brachial Plexus and what do they innervate?

Answer 16

1. Medial Pectoral N. (Pectoralis Major and Minor M.)
2. Medial Brachial Cutaneous N. (medial upperarm skin)
3. Medial Antebrachial Cutaneous N. (medial forearm skin)

Question 17

What are the levels of innervation for the Branches of the Brachial Plexus?

Answer 17

1. Musculocutaneous N. –> C5-C7
2. Axillary N. –> C5-C6
3. Median N. –> C5-T1
4. Radial N. –> C5-T1
5. Ulnar N. –> C8-T1

Question 18

What does the Axillary N. innervate and what is the cutaneous branch that comes off of it?

Answer 18

innervates: Teres Minor and Deltoid M.
branch: Superior Lateral Cutaneous N. (skin upper lateral arm)

Question 19

What does the Musculocutaneous N. innervate and what is the cutaneous branch that comes off of it?

Answer 19

innervates: Biceps Brachii, Coracobrachialis, Brachialis M.
branch: Lateral Antebrachial Cutaneous N. (skin lateral forearm)

Question 20

What muscles do the Median N. directly innervate? (4)

Answer 20

• Pronator Teres M.
• Flexor Carpi Radialis M.
• Flexor Digitorum Superficialis M.
• Palmaris Longus M.

Question 21

What cutaneous branch comes off of the Median N. and what does it innervate?

Answer 21

Palmar Cutaneous Branch

• skin of the palm

Question 22

What does the Anterior Interosseous N. innervate? (3)

Answer 22

• Lateral 1/2 of Flexor Digitorum Profundus M.
• Flexor Pollicis Longus M.
• Pronator Quadratus M.

Question 23

What does the Recurrent Branch of the Median N. innervate? (3)

Answer 23

• 1/2 Flexor Pollicis Longus M.
• Abductor Pollicis Brevis M.
• Opponens Pollicis M.

Question 24

What do the Median and Lateral branches of the Median N. innervate? What are the their nerve branches?

Answer 24

innervate: 1st and 2nd lumbricals
branches: Common Palmar Digital N. –> Proper Palmar Digital N.

Question 25

What does the Ulnar N. directly innervate? (2)

Answer 25

- Flexor Carpi Ulnaris M. | - Medial 1/2 Flexor Digitorum Profundus M.

Question 26

What are the two cutaneous nerves that come off of the Ulnar N. and what do they innervate?

Answer 26

1. Dorsal Cutaneous Branch of Ulnar N. (Skin dorsal hand) | 2. Palmar Cutaneous Branch of Ulnar N. (palm skin)

Question 27

What does the Superficial Ulnar N. innervate? (3)

Answer 27

- Abductor Digiti Minimi M. - Flexor Digiti Minimi M. - Opponens Digiti Minimi M.

Question 28

What does the Deep Ulnar N. innervate? (4)

Answer 28

- 1/2 Flexor Pollicis Brevis M. - Adductor Pollicis M. - Dorsal/Palmar Interossei M. - 3rd/4th lumbricals

Question 29

What are the 3 cutaneous nerves of the Radial N. and what do they innervate?

Answer 29

1. Posterior Brachial Cutaneous N. (post. arm skin) 2. Inferior Lateral Brachial Cutaneous N. (inf. aspect of lateral arm) 3. Posterior Antebrachial Cutaneous N. (posterior forearm)

Question 30

What does the Radial N. directly innervate? (4)

Answer 30

- Triceps Brachii M. - Anconeus M. - Brachioradialis M. - Extensor Carpi Radialis Longus M.

Question 31

What does the Deep Radial N. innervate? (2)

Answer 31

- Extensor Carpi Radialis Brevis M. | - Supinator M.

Question 32

What does the Posterior Interossei M. travel under and what does it innervate?

Answer 32

- travels under supinator muscle | - innervates rest of forearm extensors

Question 33

What nerve travels through the Anatomical Snuff Box and what are its branches?

Answer 33

Superficial Radial N. branches: Dorsal Digital N. --> Dorsal Branches Dorsal Digital N.