Peripheral Neuroanatomy

Question 1

What roots are tested by the biceps reflex?

Answer 1

C5-C6

Question 2

What roots are tested by the knee jerk?

Answer 2

L3-L4

Question 3

What roots are tested by the ankle jerk?

Answer 3

S1-S2

Question 4

What roots are tested by triceps?

Answer 4

C7-C8

Question 5

What roots are tested by brachioradialis?

Answer 5

C5-C6

Question 6

What is the most common location of a herniated cervical disc?

Answer 6

C6-C7 disc w/ compression of the C7 nerve root

Question 7

What does an upper brachial plexus lesion look like?

Answer 7

waiter’s tip posture

C5,C6 lesion

Question 8

What is compressed in a lower brachial plexus injury? What are the causes?

Answer 8

breech birth and birth injury

C8-T1

Question 9

What is idiopathic brachial neuritis? What nerves are involved? How does it present? How do you treat it? and what are the causes?

Answer 9

superior trunk: C5,6,7
presents with pain in the shoulder, axilla and weakness and atrophy of the hands and shoulder girdle
caused by vaccinations
treat with steroids, PT

Question 10

What important things are innervated by the axillary nerve? What should I know about lesions?

Answer 10

motor: deltoid muscle
sensory: lateral upper arm
uncommon lesion

Question 11

What is the function of the musculocutaneous nerve?

Answer 11

motor: biceps
sensory: lateral forearm

Question 12

What is innervated by the median nerve?

Answer 12

thumb and thenar eminence, LOAF muscles (lumbricals, opponens, abductor pollicis brevis, flexors of first three digits)
sensory of digits 1,2, 3, lateral half of 4

Question 13

What is one commonly seen problem with the median nerve? Clinical manifestation?

Answer 13

carpal tunnel syndrome
see weakness of LOAF muscles (lumbricals, opponens, abductor pollicis brevis, flexors of the first three digits)
pain of wrist, median hand forearm sholder
symptoms worse at night
tinel sign (tapping on nerve to get pins and needles) and phalen signs

Question 14

How do you treat carpal tunnel?

Answer 14

splints, surgery (hand out of commision 2-4 wks), steroids

Question 15

What is innervated by the ulnar nerve?

Answer 15

hypothenar and interossei muscles; flexor carpi ulnaris

sensory to pinky and medial half of ring finger

Question 16

What is tardy ulnar palsy?

Answer 16

compression of the ulnar nerve at the cubital tunnel at the elbow. may be caused by injury that occurred years before the current symptoms

Question 17

What is Saturday night palsy?

Answer 17

compression of the radial nerve that occurs in the spiral groove of the forearm. Radial nerve does extensors of the upper limb

Question 18

What are the clinical features of saturday night palsy?

Answer 18

radial nerve (extensors) compression
causes wrist drop, loss of sensory to the dorsum of the and over the first web space, paradoxically weak grip (weakness caused by wrist drop, not by problems with median nerve)