Ch. 21 - Perhipheral Nerves and Muscles

Question 1

What is the secondary loss of myelin called in an axonal injury?

Answer 1

Wallerian degeneration

Question 2

Direct injury to an axon and degeneration of peripheral segment?

Answer 2

Axonal neuropathy

Question 3

When an axonal injury repairs what is the result?

Answer 3

Decreased amplitude of nerve conduction

Question 4

Why is there decreased amplitude when an axon is repaired?

Answer 4

Repaired axons have decreased density

Question 5

What is damage to Schwann cells or myelin called?

Answer 5

demyelinating neuropathy

Question 6

Does demyelinating neuropathy spare the underlying axon?

Answer 6

yes

Question 7

What is it called random internode demyelination called?

Answer 7

Segmental demyelination

Question 8

When myelin repairs is it retuned to normal?

Answer 8

No, the myelin is thinner with short internodes.

Question 9

What allows the examination of several adjacent myelin internodes along a segment of an individual axon?

Answer 9

Teased fiber preparation

Question 10

What is the result when myelination is repaired?

Answer 10

Slowed nerve conduction

Question 11

Peripheral nerve injury involving only a single nerve is called?

Answer 11

mononeuropathy

Question 12

What are the two causes of mononeuropathy?

Answer 12

Entrapment

Trauma

Question 13

What is an example and result of entrapment mononeuropathy?

Answer 13

Carpal tunnel syndrome which leads to thenar atrophy

Question 14

What is an example of traumatic mononeuropathy?

Answer 14

Shoulder dislocation which leads to axillary nerve palsy

Question 15

This type of peripheral nerve neuropathy is symmetric (bilateral), diffuse, and more pronounced in the distal segments of the longest nerves.

Answer 15

Polyneuropathy

Question 16

What is the typical presentation of polyneuropathy called?

Answer 16

“stocking and glove”

Question 17

What are typical contributors to polyneuropathy?

Answer 17

Diabetes mellitus and alcohol

Question 18

What type of peripheral nerve injury damages randomly, affects portions of individual nerves?

Answer 18

polyneuritis multiplex

Question 19

What is an example of the results of polyneuritis multiplex?

Answer 19

Right radial nerve palsy resulting in wrist drop (secondary)

Question 20

Polyneuritis multiplex is usually result of what?

Answer 20

Autoimmune diseases like rheumatoid arthritis (RA) and polyarteritis nodosa

Question 21

What is loss of sensation called? It is sometimes associated with what type of peripheral nerve injury?

Answer 21

Anesthesia,

polyneuropathy

Question 22

What is the “pins and needles” sensation called? It is associated with what type of peripheral nerve injury?

Answer 22

paresthesia,

polyneuropathy

Question 23

What is the most common life-threatening diseases of the PNS?

Answer 23

Guillian-Barre Syndrome (GBS)

Question 24

An acute demyelination disorder affecting motor axons that results in ascending weakness?

Answer 24

Guillian Barre Syndrome

Question 25

Why is Guillian Barre Syndrome possibly lethal?

Answer 25

cause death from failure of respiratory muscles --> respiratory failure

Question 26

The symptoms of decreased deep tendon reflexes and "rubbery legs" is associated with what syndrome?

Answer 26

GBS

Question 27

The symptoms of decreased DTR and "rubbery" legs is what?

Answer 27

Ascending paralysis

Question 28

Guillian Barre syndrome affects who most commonly?

Answer 28

Males, | Ages 15-35, 50-57

Question 29

What percentage of GBS self-resolve?

Answer 29

90%

Question 30

What percentage of GBS is idiopathic?

Answer 30

60%

Question 31

The 40% that is viral is caused by what?

Answer 31

Campylobacter jejune, EBV, cytomegalovirus (CMV), and HIV

Question 32

What kind of disease is GBS?

Answer 32

autoimmune

Question 33

What type of cells are present at the nerve roots in GBS?

Answer 33

macrophages

Question 34

What are the treatments for GBS?

Answer 34

Ventilation, plasmapheresis I.V. antibodies

Question 35

What is the etiologic category of GBS?

Answer 35

inflammatory

Question 36

This disease is a symmetric demyelinating (w/remyelination) disease with both motor and sensory abnormalities.

Answer 36

CIPD - Chronic inflammatory demyelinating polyneuropathy.

Question 37

What does CIDP stand for?

Answer 37

Chronic inflammatory demyelinating polyneuropathy.

Question 38

What is the MC gender and age group for CIDP?

Answer 38

Males (2x) | MC - 40-60

Question 39

CIDP affects what type of neurons?

Answer 39

Motor and sensory

Question 40

What is the typical appearance of re-myelinated neurons in CIDP?

Answer 40

"onion-skin" Schwann cells

Question 41

CIDP results in what?

Answer 41

Difficulty walking (ataxia), pain, paresthesia (numbness and tingling sensations), weakness, and decreased deep tendon reflexes

Question 42

What immune disorders is CIDP commonly associated with?

Answer 42

Lupus and HIV

Question 43

What is the treatment for CIDP?

Answer 43

plasmapheresis and immunosuppression

Question 44

What is the prognosis for CIDP?

Answer 44

Possibly recovery, most commonly some residual loss of function

Question 45

What is the #1 cause of peripheral neuropathy?

Answer 45

Diabetic peripheral neuropathy(DPN)

Question 46

What percentage of diabetics have diabetic peripheral neuropathy?

Answer 46

50%

Question 47

What type of peripheral neuropathy is diabetic peripheral neuropathy?

Answer 47

Axonal and demyelinating (mixed)

Question 48

Is diabetic peripheral neuropathy asymmetrical or symmetrical?

Answer 48

symmetrical

Question 49

What causes the vascular injury that leads to nerve injury in Diabetic PN?

Answer 49

hyperglycemia