Chapter 45 - Neurologic complications

Question 1

Blood supply to the nerve

Answer 1

1) vasa nervorum

2) diffusion

Question 2

Time threshold for irreversible nerve injury

Answer 2

6-10 hours (in animals)

Question 3

Ischemic monomelic neuropathy

Answer 3

No axonal degeneration and demyelination
Altered flow through vasa nervorum cause acute conduction block
persistence –> distal axonal infarction

Question 4

Chronic ischemic neuropathy vs acute pathology

Answer 4

pathogenesis appears to be the same

Question 5

Neurapraxia definition

Answer 5

transient nerve dysfunction

Question 6

Common causes of unilateral neuropathy

Answer 6

1) entrapment
2) trauma
3) ischemia
4) vasculitis

Question 7

Common causes of bilateral neuropathy

Answer 7

1) metabolic (diabetes, uremia)
2) toxic (alcohol, drugs, metal)
3) connective tissue disease, vasculitis
4) deficiency (vitamin)
5) inflammatory
6) monoclonal gammopathies
7) HIV infection

Question 8

Ischemic neuropathy in lower extremity presentation

Answer 8

1) unilateral sensory loss - stocking distribution; especially vibration
2) ankle weakness
3) depressed ankle reflex

Question 9

Distal latency and velocity of conduction in ischemic neuropathy vs diabetic and uremic neuropathy

Answer 9

well preserved in ischemic neuropathy

reduced in a symmetrical bilateral way in diabetic/uremic neuropathy

Question 10

Sensory nerve in ischemic neuropathy

Answer 10

Absent sensory potential amplitude but velocity is normal

Question 11

First line treatment for pain control - ischemic neuropathy

Answer 11

1) TCA
2) SSRI
3) Calcium channel alpha-2 delta (Gabapentin, pregabalin)

Question 12

Peripheral nerves matched to nerve roots

Answer 12

Axillary - C5, C6
Musculocutaneous nerve - C5, C6
Median nerve C5-T1
Radial C5-C8
Ulnar C8, T1

Question 13

Nerve injury during axillary artery exposure

Answer 13

Cords of the brachial plexus

Question 14

Nerve injury during brachial artery exposure

Answer 14

Median nerve

Ulnar nerve

Question 15

Nerve injury from positioning

Answer 15

Ulnar nerve

Question 16

Nerve injury during basilic vein exposure

Answer 16

ulnar nerve

Question 17

rate of Nerve injury during brachial artery catheterization

Answer 17

0.2-1.4%

Question 18

HD access causing IMN most likely with what type of AVF

Answer 18

Brachial artery use

Question 19

Consequence of axillary nerve injury

Answer 19

weakness of shoulder abduction

sensory deficit over deltoid

Question 20

Median nerve injury consequences

Answer 20

sensory deficit in D1-3 and radial aspect of D4
weakness in thenar muscle
weakness on flexor of digit and wrist

Question 21

Consequences of ulnar nerve injury

Answer 21

numbness in D5 and ulnar aspect of D4
weakness of hypothenar muscle
weakness in abduction and adduction of all digits and flexion of D4, D5

Question 22

Consequences of injury to radial nerve

Answer 22

weakness of wrist and finger extension

Question 23

Lumbosacral nerves and correlated nerve roots

Answer 23

Lateral femoral cutaneous nerve L2-L3
Femoral nerve L2-L4
Obturator nerve L2-L4
Posterior femoral cutaneous nerve S1-S3
Sciatic nerve L4-S3
Common peroneal L4-S2
Tibial nerve L4-S3

Question 24

Blood supply to lumbosacral plexus

Answer 24

5 sets of paired lumbar arteries from abdominal aorta, deep circumflex iliac and iliolumbar and gluteal branches of IIA

Question 25

Rate of lumbosacral plexus injury after open aortic work

Answer 25

0.3%

Question 26

Course of the femoral nerve

Answer 26

Femoral nerve --> saphenous nerve

Question 27

Blood supply of the femoral nerve

Answer 27

iliolumbar artery deep circumflex iliac lateral circumflex femoral

Question 28

Symptoms of femoral nerve injury

Answer 28

1) paresis/paralysis of quadriceps 2) diminished/absent extension of knee 3) reduced/absent patellar reflex 4) loss of sensation along saphenous nerve

Question 29

Origin of the thigh cutaneous nerves

Answer 29

Medial - femoral anterior - femoral lateral - lumbosacral plexus

Question 30

Course of the saphenous nerve

Answer 30

1) subfascial plane along SFA 2) proximal popliteal fossa: more superficial and penetrates fascia to accompany GSV 3) course with GSV to ankle

Question 31

Course of the sural nerve

Answer 31

1) from tibial nerve in popliteal fossa below fascia 2) descends laterally to SSV in groove between medial and lateral heads of gastrocnemius 3) communicating branch from peroneal nerve joins in mid calf 4) exists fascia down towards lateral malleolus

Question 32

Rate of saphenous nerve sensory loss with GSV harvest below knee

Answer 32

60% 12.5% for endoscopic harvest

Question 33

Rate of sural nerve injury in SSV endoablation thermo

Answer 33

4%

Question 34

Symptoms of saphenous nerve injury

Answer 34

1) decreased sensation to anteromedial calf and ankle 2) parethesia 3) dysesthesia

Question 35

Symptoms of sural nerve injury

Answer 35

dysesthesia in posterior calf/lateral ankle

Question 36

Course of the sciatic nerve

Answer 36

1) posterior portion of midthigh into common peroneal and tibial nerve 2) Tibial nerve accompanies popliteal artery through pop fossa 3) continues distally with posterior tibial neurovascular bundle 4) terminates in medial and lateral plantar nerves (parallel to PT artery) 2) common peroneal nerve takes a lateral course from posterior aspect of midthigh 3) crosses knee joint posterior to fibular head 4) wraps proximal fibula 5) divides into superficial and deep peroneal nerve 6) superficial peroneal runs deep to fascia in lateral compartment 7) extends to foot alone 6) deep peroneal nerve enters anterior compartment 7) descends along intermuscular septum accompanies anterior tibial artery

Question 37

Rate of peroneal nerve injury in SSV harvest

Answer 37

4.7%

Question 38

Consequence of PT nerve injury

Answer 38

1) weak plantar flex of ankle and toes 2) absent ankle jerk 3) sensory loss sole and lateral aspect of foot

Question 39

Consequence of peroneal nerve injury

Answer 39

1) weak dorsiflex, invert and evert ankle 2) weak dorsiflex of toes 3) sensory loss in dorsal foot and toes extend to lateral calf