Cranial Nerve Evaluation Acoustic 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 (4th ed.). Boston, MD: Butterworth-Hinemann. Cranial Nerve Function Fix, J.D. (2000). High-yeild neuroanatomy (2nd ed.). Philadelphia, PA: Lippincott, Williams & Wilkins. Cranial Nerves on the Web http://faculty.washington.edu/chudler/cranial.html http://www.meddean.luc.edu/MedEd/GrossAnatomy/h_n/cn/cn1/cn7.htm 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 Supplied Nerve 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 VII The Facial Nerve Case Study • 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 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. A c o u s t I c R e f l e x P a t h w a y s 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 Task Occipitofrontalis 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 Ra is e Ra is e an d Facial Nerve Responses an d lip s ile ) la te ra lly le ft rig ht t ig ht ly (p ou t) la te ra lly ja w ja w ja w ip pr es s (s m de (s ne er ) lo we rl co m Cl os e ov e ov e M M si er ) lip s (p uc k la te ra lly on e pr ot ur de at e an d on lip at e 1 im up ip up pe r im t ig ht ly eb ro ws Strength of Response 2 Ap pr ox ou th of l Pr ot ru de bo rd er of m up pe r an gl e Li ft Ey ey es e Ap pr ox Cl os e Ra is Examing the Function of the Muscles of Facial Expression 3 Strength of Facial Nerve Response as a Function of Time Blue: post-op. Purple: 3 months post-op 1 = No visible response 2= Trace response 3= Functional response 0 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 (4th ed.). Boston, MD: ButterworthHinemann. 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 (2nd ed.). Hamilton, Ontario: BC Decker Inc. Wiederholt, W.C. (1995). Neurology for the non-neurologists (3rd 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.
© Copyright 2024