Lecture 9- CN 7, Facial Nerve Flashcards Preview

HESP 632 - Medical Audiology > Lecture 9- CN 7, Facial Nerve > Flashcards

Flashcards in Lecture 9- CN 7, Facial Nerve Deck (36)
Loading flashcards...
1

What are the different segments of the facial nerve?

- Brainstem
- Pontine
- Meatal
- Labyrinthine
- Tympanic
- Mastoid
- Extratemporal

2

What are the different components of the facial nerve?

- Branchial motor (special visceral efferent)
- Visceral motor (general visceral efferent)
- Special sensory (special afferent)
- General sensory (general somatic afferent)

3

What is the branchial motor component of the facial nerve?

- Supplies the muscles of facial expression
- Posterior belly of digastric muscle
- Stylohyoid and stapedius

4

What is the visceral motor component of the facial nerve?

Parasympathetic innervation of the lacrimal, submandibular, and sublingual glands, as well as mucous membranes of nasopharynx, hard and soft palate

5

What is the special sensory component of the facial nerve?

Taste sensation from the anterior 2/3 of tongue; hard and soft palates

6

What is the general sensory component of the facial nerve?

General sensation from the skin of the concha of the auricle and from a small area behind the ear

7

What is the posterior auricular branch?

Pulls ears back, pulls scalp back

8

What is the temporal branch?

Pulls ear forward and raises ear, moves scalp forward, moves eyebrows medially and down

9

What is the temporal and zygomatic branch?

Closes eyelids and creases skin around eye

10

What is the zygomatic and buccal branch?

Elevates upper lip, upper corner of the mouth and nasolabial folds

11

What is the buccal branch?

Mouth movements, flares nostrils

12

What is the marginal mandibular branch?

Pulls skin of chin up

13

What is the cervical branch?

Pulls down at corner of the mouth

14

What is differential diagnosis for acute facial nerve paralysis?

- Polyneuritis
- Trauma
- Otitis media
- Sarcoidosis
- Melkersson-Rosenthal
- Neurologic disorders

15

What is differential diagnosis for chronic or progressive facial nerve paralysis?

- Malignancies
- Benign tumors
- Cholesteatoma

16

What should examination of a patient with facial paresis/paralysis consist of?

History
- Time of onset
- Precipitating factors
- Speed of progression
- Associated symptoms

Physical examination
- House-Brackmann classifications

Topodiagnostic

Electrophysiologic tests

Lab tests PRN

Imaging

17

What are the grades of the House-Brackmann scale?

Grade I: Normal

Grade II: Mild

Grade III: Moderate

Grade IV: Moderately severe

Grade V: Severe

Grade VI: Total Paralysis

18

What is grade I of the House-Brackmann scale?

Grade I: Normal

19

What is grade II of the House-Brackmann scale?

Gross: slight weakness noticeable on close inspection

At rest: normal symmetry and tone

Motion:
- Forehead: moderate to good
- Eye: complete closure with minimum effort
- Mouth: slight asymmetry

20

What is grade III of the House-Brackmann scale?

Gross: obvious but not disfiguring asymmetry; may have hemifacial spasm

At rest: normal symmetry and tone

Motion:
- Forehead: slight to moderate movement)
- Eye: complete closure with effort
- Mouth: slightly weak with maximum effort

21

What is grade IV of the House-Brackmann scale?

Gross: obvious weakness and/or disfiguring asymmetry

At rest: normal symmetry and tone

Motion
- Forehead: no movement
- Eye: incomplete closure
- Mouth: asymmetric with maximum effort

22

What is grade V of the House-Brackmann scale?

Gross: only barely perceptible motion

At rest: asymmetry

Motion:
- Forehead: no movement
- Eye: incomplete closure
- Mouth: slight movement

23

What is grade VI of the House-Brackmann sclae?

No movement

24

What are topodiagnostic tests of facial nerve function?

- Schirmer's Test of Lacrimal Function
- Stapedial Reflex
- Electrogustometry
- Salivary Flow

25

What is the nerve excitability test?

Transcutaneous stimuli delivered over stylomastoid foramen.

Electrical pulses delivered at increasing current levels until facial twitch is noticeable.

26

What is the maximum excitability test?

Transcutanteous stimuli looking for twitch.

Increase current to get maximum response.

27

What is electromyography (EMG)?

Recording of spontaneous and voluntary muscle potentials.

Needle electrodes in facial muscle groups.

May help to predict recovery.

28

What is electroneuronography (ENoG)?

- Stimulating electrodes deliver suprathreshold electrical stimuli
- Recording electrode measures compound muscle action potential
- Reduction in response amplitude reflects number of damaged motor fibers
- Best 3 days to 3 weeks

29

What is the prognostic value of ENoG?

>90% degeneration at 3 weeks- surgery

<90% degeneration at 3 weeks- chance for good recovery

30

What is the presentation of Herpes Zoster Oticus?

- Severe pain
- Vesicles in concha
- Severe (grade V and VI) facial paralysis
- Frequently involves CN VIII giving hearing loss and vertigo
- May involve CN V, IX, X, XI, and XII