Cranial Nerve EvaluationAcoustic Neuroma and the Facial

Nerve

Alyssa Capeling

Sara Holaly

Shawn McGinley

Kathy Olson

Outline• Overview of cranial nerves• Cranial nerves affecting speech and hearing• Acoustic Neuroma• Cranial nerve VII

– Function– Course and innervation– Evaluation

• Overview• Case study

– Case history– Audiologic assessment– Facial muscule evaluation– Taste

• Treatment options

• Summary• References

Cranial Nerve Function

Love, R.J. & Webb, W.G. (2001). Neurology for the speech language pathologist (4 th ed.). Boston, MD: Butterworth-Hinemann.

Cranial Nerve Function

Fix, J.D. (2000). High-yeild neuroanatomy (2nd ed.). Philadelphia, PA: Lippincott, Williams & Wilkins.

http://faculty.washington.edu/chudler/cranial.html

http://www.meddean.luc.edu/MedEd/GrossAnatomy/h_n/cn/cn1/cn7.htm

Cranial Nerves on the Web

Cranial Nerves for Speech and Hearing

• Cranial Nerve V: Trigeminal– Function: mastication and sensation (pain, temperature,

propioception, and touch) to face, teeth, gums, anterior 2/3 of tongue, part of external ear canal, and tympanic membrane

• Also helps with flattening and tensing the soft palate for eustacian tube opening and anterior and superior movement of the larynx

– Testing: • Motor: feel masseter muscle as the patient bites down then relaxes;

have the patient open/close jaw against resistance, have the patient move jaw laterally against resistance

• Sensory: firmly stroke cotton swab across different areas of the face and tongue with the patient’s eyes closed

Cranial Nerves for Speech and Hearing

• Cranial Nerve VII: Facial– Function: controls movements of facial expression

(wrinkle forehead, close eyes, close mouth, pull back corners of mouth, pull down corners of mouth), taste on anterior tongue, stapedious reflex, controls lacrimal gland, sublingual gland, submadibular gland, and secretory glands of mouth and nasal cavity

• Also helps to move larynx up and back

– Testing:• Motor: wrinkle forehead, look up at ceiling, close eyes as

tightly as possible, pucker lips, smile• Sensory: have patient distinguish between different tastes

with eyes closed and tongue out of mouth

Cranial Nerves for Speech and Hearing

• Cranial Nerve VIII: Vestibulocochlear– Function: sound sensitivity, maintain equilibrium– Testing:

• Hearing: audiologic testing– SLP may do screening, and neurologist may use tuning forks to

test acuity and lateralization– Audiologists perform complete diagnostic testing

• Equilibium: patient interview (may complain of tinnitus and/or dizziness)

– Audiologists may perform ENG (electronystagmography) testing and ABR (Auditory Brainstem Response) testing

– ENTs may order MRIs (magnetic resonance imaging)

Cranial Nerves for Speech and Hearing

• Cranial Nerve IX: Glossopharyngeal– Function: helps to clear the pharynx during swallowing

via dialation of the pharynx and elevation of the larynx; controls taste on the posterior 1/3 of the tongue, assists with pharyngeal gag, activates and regulates secretion from the parotid gland

– Testing: • Difficult to distinguish from CN X

• Sensory: test gag reflex by rubbing posterior pharyngeal wall

• Motor: swallowing assessment

Cranial Nerves for Speech and Hearing

• Cranial Nerve X: Vagus– Function: controls muscles of phonation and swallowing,

innervates cardiac and smooth muchles of esophagus, stomach, and intestine, mediates sensation of visceral muscles of pharynx, larynx, epiglottis, throax, and abdomen, controls taste in pharynx and epiglottis, controls intrinsic muscles of larynx, controls palatal function

• Recurrent laryngeal branch: intrinsic muscles of larynx except cricothyroid

• Superior laryngeal branch: innervates cricothyroid

– Testing:• Palatal function: view at rest and during /a/, test gag reflex• Laryngeal function: lanyngoscopy, voice assessment including

sustained /a/, perceptial assesssment of pitch and loudness, cough vs coup, stress testing (counting), may do instrumental analysis,

Cranial Nerves for Speech and Hearing

• Cranial Nerve XI: Spinal Accessory– Function: help turn, tilt, rotate,

forward/backward movement of head, raise the sternum, shrugging the shoulders

– Testing: have patient move head against resistance, have patient shrug shoulders while you push down

Cranial Nerves for Speech and Hearing

• Cranial Nerve XII: Hypoglossal– Function: controls shortening, narrowing, elongating,

and flattening of tongue via innervation of intrinsic muscles of tongue, controls tongue protursion, retraction, drawing up and back via innervation of the extrinsic tongue muscles, and assists with elevation of the hyoid

– Testing: look at the tongue at rest to look for atrophy, look for fasiculations and involuntary movement, have the patient protrude tongue, move it up and down, corner to corner, test strength using resistance during movement, listen to production of /t/, /d/, /t⌠/, /d3/, l/, /n/, /i/, /j/, /k/, /g/

Acoustic Neuroma• Definition: “…a benign tumor of Schwann cells that affects the

vestibulocochlear nerve (CN VIII).” (Fix, 2000, p. 81)– May also effect CN V and CN VII

• Symptoms: unilateral hearing loss, tinnitus, vertigo, nystagmus, nausea, vomiting– If damage to CN VII: facial weakness, loss of corneal reflex– If damage to CN V: paresthesia and loss of corneal reflex

• Diagnosis: MRI, ENG, and ABR• Treatment: Surgical removal

– Full recovery is possible with small tumors– If not diagnosed early, may become large and lead to damage of CN VII

and/or the brainstem during removal

Function of CN VII

• General Sensory:(afferent) carry sensation from the skin of the concha of the auricle, and posibly supplement sensation from the wall of the EAM and the external surface of the tympanic membrane

• Special Sensory: (afferent) taste sensation from the anterior two-thirds of the tongue

• Branchial Motor: (efferent) supplies muscles of facial expression and the stapedius, stylohyoid, and posterior belly of the digrastic muscles

• Visceral Motor: (parasympathetic efferent) for stimulation of the lacrimal, submandibular, and sublingual glands as well as the mucous membrane of the nose and hard and soft palates

Branches of CN VII that Supply Muscles of the Face and Neck

Branch Muscles SuppliedNerve to Stapedius Stapedius

Nerve to Posterior Belly of Digastric Posterior Belly of Digastric

Nerve to Stylohyoid Stylohyoid

Termoral Frontalis, Occiptalis, Orbicularis Oculi, Corrugator Supercilli, Procerus

Zygomatic Obicularis Oculi

Buccal Buccinator, Obicularis Oris, Nasalis, Labator Labii Superioris, Levator Labii Superioris Alaeque Nasi, Zygomaticus Major and Minor, Levator Anguli Oris

Mandigular Orbicularis Oris, Mentalis, Depressor Anguli Oris, Depressor Labii Inferioris, Risorius

Cervical Platysma

Posterior Aurical Occipitalis

General Examination Compnents of the Facial Nerve

• 1. Function of the muscles of facial expression

• 2. Taste from the taste buds

• 3.Somatic sensation from the external ear

• 4. Function of the stapedius

• 5. Secretomotor innervation of the lacrimal and salivary glands

Case Study• Patient: E. O. Age: 68• Prior Medical History

– Onset of hearing loss: January 1986– Diagnosis of Acoustic Neuroma: June 2002– Date of Surgical Tumor Removal: July 31,2002– Speech Tx history:

• In patient acute care: primary focus swallowing• In patient rehab: primary focus oral motor exercises• Home Health (4 weeks): Oral motor exercises and

swallowing strategies• Out patient: Oral motor exercises, speech articulation,

electrostimulation of facial muscles by physical therapy

Cranial Nerve VIIThe Facial Nerve

• Reported symptoms:– Immediately post surgery

• Unable to swallow – PEG tube removed in September• Unable to speak due to facial weakness• Severe drooping of left side of face, “crooked mouth”• Tongue felt “frozen and spotty”• Unable to blink eye• Ocassional blurriness• Balance disturbances• Decreased tearing in left eye

– Improvements 3 months post surgery• Increased facial movement• Easier to eat/swallow• Improved speech

Case Study

Acoustic Reflex Testing• The Acoustic Reflex: A bilateral

contraction of the stapedius muscles in response to loud sounds (80 dB SPL or above for people with normal hearing)

• Testing is conducted at 500 Hz, 1000 Hz, and 2000 Hz by using a 226 Hz probe tone to measure changes in immittance

• Purposes of the Acoustic Reflex:– protection from loud sounds– Attenuates low frequency sounds

and helps with our perception by reducing bodily noise.

AcoustIc

Reflex

Pathways

Acoustic Reflex Responses• Shawn’s Response Levels• Right Ipsilateral (Stimulus and Probe Right) 85 dB SPL• Right Contralateral (Stimulus Right, Probe Left) 90 dB SPL• Left Ipsilateral (Stimulus and Probe Left) 85 dB SPL• Left Contralateral (Stimulus Left, Probe Right) 90 dB SPL

• E.O.’s Response Levels• Right Ipsilateral: Present at expected levels• Right Contralateral: Absent• Left Ipsilateral: Absent• Left Contralateral: Absent

• Patient with Left Facial Nerve Disorder Only• Right Ipsilateral: Present at expected levels• Right Contralteral: Absent• Left Ipsilateral: Absent • Left Contralateral: Present at expected levels

Examing the Function of the Muscles of Facial Expression

Muscle TaskOccipitofrontalis Raise eyebrows

Orbicularis Oculi Close eyes tightly

Obicularis Oris Approximate lips

Zygomaticus Minor Protrude upper uip (pucker)

Lebator Anguli Oris Lift upper border of lip on left

Zygomaticus Major Raise later angles of lips (smile)

Buccinator Approximate & compress lips (clinician can’t open)

Mentalis Rase and protrude lower lip (pout)

Temporalis Masseter Close jaw tightly

Pterygoid Lateralis and Medialis left Move jaw laterally to the left

Pterygoid Lateralis and Medialis right Move jaw laterally to the right

Examing the Function of the Muscles of Facial Expression: Zygomaticus Major

Examing the Function of the Muscles of Facial Expression: Zygomaticus Minor

Examing the Function of the Muscles of Facial Expression

Strength of Facial Nerve Response as a Function of Time

0

1

2

3

Raise

Eyebr

ows

Close

eyes

tigh

tly

Appro

ximat

e lip

s

Protru

de u

pper

lip (p

ucke

r)

Lift u

pper

bor

der o

f lip

on o

ne s

ide(s

neer

)

Raise

angle

of m

outh

up

and

later

ally

(sm

ile)

Appro

ximat

e an

d co

mpr

ess

lips

Raise

and

prot

urde

lower

lip (p

out)

Close

jaw ti

ghtly

Mov

e jaw

late

rally

righ

t

Mov

e jaw

late

rally

left

Facial Nerve Responses

Str

en

gth

of

Re

spo

nse

Blue: post-op.Purple: 3 months post-op1 = No visible response

2= Trace response3= Functional response

Distribution of Change in Responses (from immediately post op. to 3 months post)

No change in response

36%

Improved from "Trace response"

to "Functional response"

9%

Improved from "No Visible

Response" to "Trace

Response"55%

Examing Taste from the Taste Buds

• Four basic modalities of taste– Sweet vs. salty– Bitter and sour

• Protrude tongue• One side swabbed with solution

– point to taste modality

• Other side swabbed– Compared with first side

• Rinse with water • Repeat with next taste

Treatment Options

• Oral Motor Exercises

• Articulation Drill

• Occupational and Physical Therapies

• Surgical Options

Summary

• Cranial Nerves for Speech and Hearing

• Acoustic Neuroma

• Facial Nerve

• Case Study

References

Bhatnager, S.C. & Andy, O.J. (1995). Neuroscience for the study of communication disorders. Baltimlore, MD: Williams & Wilkins.

Facial Nerve. (n.d.). Retrieved October 22, 2002, from http://www.meddean.luc.edu/lumen/MedEd/GrossAnatomy/h_n/cn/cn1/cn7.htm

Fix, J.D. (2000). High-yeild neuroanatomy (2nd ed.). Philadelphia, PA: Lippincott, Williams & Wilkins.

Garrison, D. W. (1986). Cranial nerves: A systems Approach. Springfield, IL: Charles C. Thomas.

Love, R.J. & Webb, W.G. (2001). Neurology for the speech language pathologist (4 th ed.). Boston, MD: Butterworth-Hinemann.

Nelson, M.A. & Hodge, M.M. (2000). Effects of facial paralysis and audiovisual information on stop place identification [electronic version]. Journal of Speech, Language, and Hearing Research, 43, 158-171.

Neuroscience for Kids – Cranial Nerves. (n.d.). Retrieved September 6, 2002, from http://faculty.washington.edu/chudler/cranial.html.

Pauwels, L.W., Akesson, E.J., Stewart, P.A., Spacey, S.D. (2002). Cranial nerves in health and disease (2 nd ed.). Hamilton, Ontario: BC Decker Inc.

Wiederholt, W.C. (1995). Neurology for the non-neurologists (3 rd ed.). Philadelphia, PA: W.B. Sanders Company.

Yokoyama, T., Nishizawa, K., Sugiyama, K., & Yokota, N. (1999). Intraoperative evoked facial muscle responses and recovery process of the facial nerve in acoustic neuroma surgery [electronic version]. British Journal of Neuroscience, 13, 570-575.