Facial Nerve

Question 1

How long does it take for tOO% Wallerian degeneration to occur after a compressive conduction block

Answer 1

14 - 21 days.

Question 2

Defects greater than ___ cannot be rerouted and require cable grafting

Answer 2

15 - 17 mm.

Question 3

What is Sutherland’s classification for nerve injury

Answer 3

1st degree: reversible conduction block. 2”d degree: Wallerian degeneration occurs but endoneurium stays intact and recovery is usually complete. Yd degree: endoneurium is destroyed but perineurium stays intact and recovery is incomplete. 4th degree: all is destroyed except for the epineurium; recovery is poor. 5th degree: complete nerve transection; untreated recovery is not expected.

Question 4

Where on the lid is the implant placed

Answer 4

2 mm above the lash line.

Question 5

What % of patients with Ramsay Hunt syndrome have Vlllth nerve involvement

Answer 5

20%.

Question 6

What % of patients with Lyme disease have facial nerve paralysis as the sole manifestation

Answer 6

20%.

Question 7

How long does it take for 100°/o Wallerian degeneration to occur after complete nerve transection

Answer 7

3 - 5 days.

Question 8

What is the incidence of diabetes mellitus in patients with recurrent Bell’s palsy

Answer 8

31%.

Question 9

What is the incidence of facial palsy as the presenting symptom of tuberculous mastoiditis

Answer 9

39%.

Question 10

What is the minimal time for functional return of the facial nerve after anastomosis or grafting

Answer 10

4 - 6 months.

Question 11

What is the outcome of these patients who are treated with steroids alone

Answer 11

42% have a good outcome.

Question 12

After microneurovascular muscle transfer, what is the maximum muscle power attainable compared to normal

Answer 12

55%.

Question 13

What is the incidence of recurrent facial palsy

Answer 13

5-7%.

Question 14

Between which days after injury is the degree of axonotmesis and neurotmesis unclear

Answer 14

6 - 14.

Question 15

What is the mean interval to the 1st recurrence

Answer 15

9.8 years.

Question 16

What is the outcome of patients with Bell’s palsy who have 90% or more degeneration on ENoG within the 1st 14 days of onset and undergo decompression

Answer 16

91 % have a good outcome (House I or II) 7 months after paralysis.

Question 17

What is the cog

Answer 17

A ridge of bone that extends inferiorly from the tegmen epitympanum and partially separates the anterior epitympanic compartment from the mesoepitympanum.

Question 18

What causes hemifacial spasm

Answer 18

A vascular loop, most commonly of the anterior or posterior inferior cerebellar artery, impinging on the root of VI I.

Question 19

What is the most commonly proposed theory of the etiology of Bell’s palsy

Answer 19

Activation of a latent virus present within the geniculate ganglion leading to entrapment, ischemia, and degeneration of the labyrinthine segment of VII.

Question 20

What is the recommended treatment for Ramsay Hunt syndrome

Answer 20

Acyclovir 800 mg five times a day x I 0 days and prednisone taper x 14 days.

Question 21

What is Tangier’s disease

Answer 21

Autosomal recessive disorder of lipid metabolism characterized by low apolipoprotein A-1 and H DL levels. Clinical features include facial diplegia, neuropathy, and coronary artery disease.

Question 22

Which of these result in Wallerian degeneration

Answer 22

Axonotmesis and neurotmesis.

Question 23

What is the initial treatment for hemifacial spasm

Answer 23

Baclofen.

Question 24

When is ENoG evaluation meaningful

Answer 24

Between days 3 and 21 after complete loss of voluntary function.

Question 25

What happens if the implant is placed too deep

Answer 25

Can damage the levator muscle, causing ptosis.

Question 26

What are the surgical landmarks for the tympanic segment of VII

Answer 26

Cochleariform process, oval window, pyramidal process, semicanal for the tensor tympani, vertical groove on promontory for the tympanic nerve.

Question 27

What is the outcome of Bell's palsy left untreated

Answer 27

Complete recovery in 71 %; permanent diminished function in I 6%; poorer prognosis if\>60 years of age and if onset of recovery \>3 months after initial onset of paralysis.

Question 28

How can dynamic rehabilitation be achieved in a patient with a 1 0-year history of facial paralysis following radical parotidectomy

Answer 28

Crossfacial nerve graft plus microneurovascular muscle transfer.

Question 29

What factors increase the risk of recurrent Bell's palsy

Answer 29

Diabetes mellitus and family history.

Question 30

Which methods of facial nerve reconstruction have the potential for spontaneous emotional response

Answer 30

Direct anastomosis and cable grafting.

Question 31

What electrophysiologic test is more useful 3 weeks after the onset of complete facial paralysis

Answer 31

EMG.

Question 32

What is the narrowest intratemporal portion of the fallopian canal

Answer 32

Entrance to the fallopian canal at the lateral aspect of the lAC (fundus).

Question 33

Which anastomotic technique is preferred by most surgeons

Answer 33

Epineural anastomosis using 3 - 8 sutures of 8-0 or I 0-0 synthetic monofilament suture.

Question 34

What is Heerfordt's syndrome

Answer 34

Facial nerve palsy with anterior uveitis, parotid gland enlargement, and fever.

Question 35

T/F: Addition of acyclovir to prednisone for treatment of Bell's palsy has not been shown to result in significant improvement of facial nerve function

Answer 35

False.

Question 36

T/F: Evidence of viral etiology for Bell's palsy is well documented

Answer 36

False.

Question 37

T /F: There is a consistent topographic representation of fibers from a specific section of a nerve innervating certain parts of the face.

Answer 37

False.

Question 38

What sort of EMG pattern is associated with nerve degeneration

Answer 38

Fibrillation potentials.

Question 39

What is the most common cause of unilateral facial palsy in a newborn infant

Answer 39

Forceps delivery.

Question 40

When the facial nerve is sacrificed, what must be done prior to reconstruction

Answer 40

Frozen section confirmation of negative nerve margins.

Question 41

What are the limits of the tympanic segment of VII

Answer 41

Geniculate ganglion to the 2nd genu (adjacent to the pyramidal process).

Question 42

What organisms are most often associated with facial palsy due to chronic otitis media

Answer 42

Gram-negative organisms and Staphylococcus aureus.

Question 43

Which of these is used most often

Answer 43

Greater auricular nerve.

Question 44

How is the facial nerve identified using the tympanic nerve

Answer 44

Groove for the tympanic nerve is followed superiorly to the cochleariform process.

Question 45

What is the advantage of the microneurovascular muscle transfer over the temporalis muscle sling in the treatment of facial paralysis

Answer 45

Has the potential to restore spontaneous muscle expressions.

Question 46

What viruses are most commonly implicated in the etiology of Bell's palsy

Answer 46

Herpes simplex and herpes zoster viruses.

Question 47

What is the best functional outcome of cable grafting

Answer 47

House grade III or IV.

Question 48

After primary anastomosis, what is the typical return of facial nerve function

Answer 48

House grade ll or II I.

Question 49

What test should be performed on Afro-Caribbean migrants with idiopathic facial nerve palsy

Answer 49

HTLV-1 antibody screen.

Question 50

What if the nerve is only partially transected

Answer 50

If greater than 1 /2 remains, reapproximate the remaining nerve and perform regional decompression. If less than 1/2 remains, remove the injured segment and repair as with complete transection.

Question 51

If a tumor-free proximal nerve stump is unavailable for nerve grafting, what method should be used for optimal functional outcome

Answer 51

If reconstruction is undertaken within 2 years of division, grafting of the proximal portion of another cranial nerve to the distal stump of the facial nerve is the next best choice.

Question 52

What is the significance of the Bell's phenomenon prior to gold weight implantation

Answer 52

If the patient has a good Bell's reflex, then the surgeon can be more conservative, choosing a lighter implant to avoid ptosis.

Question 53

What is the management of intraoperative facial nerve transection

Answer 53

Immediate repair with primary anastomosis if possible.

Question 54

What are negative prognostic factors for Ramsay Hunt syndrome

Answer 54

Increased age and a simultaneous onset of paralysis with vesicular eruption.

Question 55

What are the complications of gold weight implantation

Answer 55

Induced astigmatism, ptosis, migration, extrusion, persistent inflammation.

Question 56

What is the relationship of the 2"ct genu of the facial nerve to the lateral semicircular canal and short process of the incus

Answer 56

Inferior to the lateral semicircular canal and medial to the short process of the • lOCUS.

Question 57

Which cranial nerve is most often grafted to the distal facial nerve

Answer 57

Ipsilateral hypoglossal.

Question 58

What is the primary drawback of hypoglossal-facial nerve grafting

Answer 58

Ipsilateral tongue paralysis.

Question 59

What is the advantage of the dorsal radial cutaneous nerve

Answer 59

It branches as it approaches the wrist, making distal separation into bundles for facial nerve branch anastomosis easier.

Question 60

What are the landmarks of the tympanic segment of VII from the mastoid approach

Answer 60

Lateral SCC and the cog.

Question 61

What are the surgical landmarks for VII in its mastoid segment

Answer 61

Lateral SCC, fossa incudis, and the digastric ridge.

Question 62

What is the next most accurate test when ENoG is unavailable

Answer 62

Maximal stimulation test.

Question 63

What is the relationship of VII to the lateral SCC and the fossa incudis

Answer 63

Medial to the fossa incudis and inferior to the lateral canal.

Question 64

The triad of recurrent facial palsy, oro facial edema, and lingua plicata is classic for what disease

Answer 64

Melkersson-Rosenthal syndrome (orofacial granulomatosis).

Question 65

What is the procedure of choice for patients with hemifacial spasm

Answer 65

Microvascular decompression.

Question 66

What are other indications for free muscle transposition surgery for facial reanimation

Answer 66

Mobius syndrome or destruction of muscles secondary to trauma.

Question 67

Where is the facial nerve most commonly injured during mastoid surgery

Answer 67

Near the 2"d genu as it enters the mastoid cavity.

Question 68

What are the indications for surgical exploration of the facial nerve following temporal bone trauma

Answer 68

NET \>3.5 rnA side-to-side threshold differences or ENoG \>90% degeneration.

Question 69

What are the 3 types of nerve injury

Answer 69

Neuropraxia, axonotmesis, and neurotmesis.

Question 70

Which of these has a more rapid rate of Wallerian degeneration

Answer 70

Neurotmesis.

Question 71

What should be done if motor unit potentials are detected on EMG

Answer 71

No further therapy is indicated.

Question 72

What is a major contraindication to this procedure

Answer 72

Paralysis of 1 X or X.

Question 73

What prognostic information does ENoG provide

Answer 73

Patients with 95% degeneration or greater have a 50% chance of unfavorable recovery; if at least I 0% function is retained in the I st 21 days of paralysis, 80 - I OO% functional recovery is highly likely.

Question 74

What is the most common area of facial nerve injury following trauma

Answer 74

Perigenicular area.

Question 75

What sort of EMG pattern is associated with nerve regeneration

Answer 75

Polyphasic action potentials.

Question 76

Where are intracranial lesions that cause bilateral facial paralysis located

Answer 76

Pons.

Question 77

Where does the facial nerve lie in relation to the cochleariform process

Answer 77

Posterosuperior.

Question 78

What are the limits of the mastoid segment of VII

Answer 78

Pyramidal process to the stylomastoid foramen.

Question 79

What differentiates herpes zoster oticus from Ramsay Hunt syndrome

Answer 79

Ramsay Hunt syndrome is herpes zoster oticus + facial nerve paralysis.

Question 80

Which etiology of facial nerve palsy has a worse prognosis: Bell's palsy or Ramsay Hunt syndrome

Answer 80

Ramsay Hunt syndrome.

Question 81

What is the most likely cause of bilateral facial palsy in a young adult

Answer 81

Sarcoidosis.

Question 82

What is lingua plicata

Answer 82

Scrotal tongue.

Question 83

What is the relation of the lateral SCC to the fossa incudis

Answer 83

Short crus of the incus is inferolateral to the lateral SCC; the fossa incudis is at the tip of the short crus.

Question 84

What is the outcome of these patients who undergo surgical decompression \>14 days after injury

Answer 84

Similar outcome as patients treated with steroids.

Question 85

What are some other options for improvement of function after facial paralysis

Answer 85

Static fascial slings, dynamic muscle slings, free muscle transfers, gold weight upper lid implants, lid-tightening procedures, brow lift.

Question 86

Which reconstructive options restore facial nerve function most quickly

Answer 86

Static slings, gold weights, tarsorrhaphies.

Question 87

Into which plane is a gold weight placed

Answer 87

Suborbicularis.

Question 88

Which approach is best in patients with normal hearing

Answer 88

Supralabyrinthine approach.

Question 89

Which of these can provide the most length

Answer 89

Sural nerve (35 em).

Question 90

What are some possible nerves used for cable grafting

Answer 90

Sural, greater auricular, dorsal radial cutaneous, supraclavicular nerves.

Question 91

What is a jump graft

Answer 91

The greater auricular nerve is sutured end-to-side to XII and end-to-side to the distal facial nerve.

Question 92

Why must the dose of acyclovir be larger for patients with varicella zoster virus (VZV)

Answer 92

The thymidine kinase of VZV is much less sensitive to acyclovir than the herpes simplex virus.

Question 93

What is the most accurate predictor of poor recovery of facial nerve function following injury

Answer 93

Total paralysis of immediate onset.

Question 94

T/F: Enhancement of the facial nerve is commonly seen on MRI of patients with Bell's palsy and is likely to resolve in 2 - 4 months

Answer 94

True.

Question 95

T/F: Evidence of viral etiology for Ramsay Hunt syndrome is well documented

Answer 95

True.

Question 96

T/F: Primary anastomosis after rerouting generally leads to a better functional outcome than cable grafting

Answer 96

True.

Question 97

T/F: No improvement in functional outcome has been demonstrated with the use of tubes or conduits in facial nerve anastomosis or grafting

Answer 97

True.

Question 98

T /F: Postoperative radiation does not significantly affect the outcome after facial nerve grafting.

Answer 98

True.

Question 99

What if primary anastomosis is not possible

Answer 99

Use a cable graft with great auricular nerve as the donor.

Question 100

What can be done to ameliorate this problem

Answer 100

Use of a mid-tongue Z-plasty~ use of only part of the hypoglossal nerve (jump graft); reinnervation of the hypoglossal nerve with the ansa cervicalis.

Question 101

Branches of the facial nerve anterior to ____ do not require reconstruction for return of function.

Answer 101

Vertical line from lateral canthus.

Question 102

What is the relationship of the tympanic portion of VII to the cog

Answer 102

VII lies anterior to the cog in the floor of the anterior epitympanum.

Question 103

What test should be performed when 100°/o neural degeneration is recorded with ENoG

Answer 103

Voluntary EMG recording; regenerating nerve fibers conducting at different rates can result in an overestimation of neural degeneration on ENoG.

Question 104

How is the facial nerve identified using the semicanal for the tensor tympani

Answer 104

When followed posteriorly, its inferior border is continuous with the upper margin of the oval window and the inferior border of VII.

Question 105

What is the treatment for otogenic facial palsy in association with acute suppurative otitis media

Answer 105

Wide myringotomy, cultures, and IV antibiotics.

Question 106

Can a patient with a gold weight have an M Rl

Answer 106

Yes.