Week 6-7 Cranial Nerves - Lecture

How would we test MOTOR component of CN V Trigeminal Nerve?

Clench your jaw open mouth, open jaw keep mouth open against clinician resistance deviate jaw to right deviate jaw to left

Study cranial nerves using University of Utah website

https://neurologicexam.med.utah.edu/adult/html/cranialnerve_normal.html

Slide 15

olfactory bulbs are bilateral, one on each side CN I ends/terminates in olfactory bulbs

(Diagnostic measures for voice and swallowing) Rigid videostroboscopy

woman receiving rigid videostroboscopy *you would not use a rigid videostroboscopy for swallowing studies

Regarding CN VIII, if there is a lesion connected to the brainstem that is interrupting the nerve path for audition, we are only going to have a partial impairment. Explain.

Because of bilateral projections

Slide 11 (part 3-4)

innervation patterns CN IX

slide 18

visual pathway (reinforces what khan video explained)

Video: Recovering from Bell's Palsy (CN VII LMN damage)

woke up one day with gradually increasing paralysis on right side of face Difficult to speak, eat, drink Went deaf in right ear Could't blink in right eye; had to tape it shut to keep it from drying out Diagnosed with Bell's Palsy on right side of face Taste sensation changed dramatically Doctor told him he had a 90% chance of some recovery; 10% chance of permanent paralysis video chronicles outside adventures, acupuncture visits multimodality approach to treatment: acupuncture, steroids, chinese herbs, oral doses of A, B3, B6, B12, C, E, and D1 Day 24 significant improvement

Mnemonics

(Name of CNs) On Old Olympus Towering Top A Friendly Viking Grew Vines and Hops (Function of CNs) Some Say Marry Money But My Brother Says Big Brains Matter More

CN XI Spinal Accessory

Motor Nerve SVE medulla and ventral horn of C1 C5 innervates the sternocleidomastoid and the trapezius muscles DAMAGE leads to weak head rotation and inability to shrug shoulders (inability to shrug is due to nerve damage, not necessarily muscle weakness, muscle weakness will likely develop)

University of Utah Video - CN IX and X (MOTOR)

Patient says "kuh, kuh, kuh" open mouth, stick out tongue, and say "ahhhh" as clinician watches action of palate The motor division of CN 9 & 10 is tested by having the patient say "ah" or "kah". The palate should rise symmetrically and there should be little nasal air escape. With unilateral weakness the uvula will deviate toward the normal side because that side of the palate is pulled up higher. With bilateral weakness neither side of the palate will elevate and there will be marked nasal air escape.

When we have nerves with both a sensory and motor component, there can be breakdowns on both sides of that coin. Explain the possible consequences of damage to CN V.

SENSORY Sensory peripheral sensory nerve = loss of sensation on the same side (ipsilateral) Tic douloureux/trigeminal neuralgia - chronic pain in one or more of the zones (opthalmic, maxillary, and mandibular) on the face; lesions will match same side as where pain is; rare (only fewer than 200,000 new cases in US per year); very debilitating ; difficult talking, chewing, swallowing, overall movement causes of trigeminal neuralgia : lesions, slow-growing tumor, inflammation, no known etiology Treatment for trigeminal neuralgia: severing the nerve or pain meds; one-way nerve MOTOR Motor lower LMN damage results in flaccid paralysis of muscles on the same side; jaw deviates toward the injury Upper UMN results in very little weakness (because of bilateral innervation, there could be a different outcome depending on whether there is an UMN lesion or LMN lesion) *flaccid "flacksid"

Instructor recommends bundling CN 3,4,6 for studying purposes because __________________.

They all have to do with the eye

Slide 12

Think about the progression Note that bilateral innervation is indicated by box shape Nate that unilateral innervation is indicated by circle

University of Utah Video - CN VIII, part 2 Vestibular (testing)

VESTIBULAR The vestibular division of CN 8 can be tested for by using the vestibulo-ocular reflex as already demonstrated or by using ice water calorics to test vestibular function. The later test is usually reserved for patients who have vertigo or balance problems or in the comatose patient when one is testing brainstem function *Pretty reliant on patient verbal responses

Utah website

https://neurologicexam.med.utah.edu/adult/html/cranialnerve_normal.html

Create your own checklist with name, classification, major function, how to assess

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Practice drawing the CN face

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Fasciulations (abnormal motor response) in the tongue would be a sign of what?

Damage to CN XII

University of Utah Video - CN IX and X (SENSORY & MOTOR)

The gag reflex tests both the sensory and motor components of CN 9 & 10. This involuntary reflex is obtained by touching the back of the pharynx with the tongue depressor and watching the elevation of the palate

Slide 10

Upper Motor Neurons - main source of voluntary movement; help carry motor signals down spinal cord to activate lower motor neurons Lower Motor Neurons -

Slide 6

Ventral view of brain Order of CNs is based on this particular view Displays why nerves are ORDERED they way they are Order matches their progression throughout the ventral view of brain (anterior - posterior)

Knowledge check: Cranial Nerves

Which CNs are most relevant for speech-language pathology and audiology? SPEECH-LANGUAGE CN V (trigeminal), VII (facial), IX (glossopharyngeal) X (vagus) XII (hypoglossal) AUDIOLOGY VIII (vestibulocochlear) Can you list which CNs are mixed without looking at your notes? 5,7,9,10 What is the primary function of CN XII? tongue movement

(Diagnostic measures for voice and swallowing) ENT flexible laryngoscopy (video)

clinician performing flexible laryngoscopy on himself

Slide 14

good display of cribiform plate, helps us locate olfactory nerve

CN 12 Hypoglossal

https://neurologicexam.med.utah.edu/adult/html/cranialnerve_normal.html Motor Nerve GSE hypo = under glossal = tongue medulla Controls tongue movements by regulating intrinsic and extrinsic (all except palatoglossal, which is controlled by CN X) tongue muscles. Reminder: -Extrinsic muscles: genioglossus, styloglossus , and hyoglossus -Intrinsic muscles: Superior & inferior longitudinal, transverse & vertical DAMAGE atrophy, weakness and fasiculations of the tongue (fasciulations: abnormal motor response (see video))

Why is thicker liquid easier to swallow?

if there's a crack for something to go into your airway, liquid like water will find it! thicker liquid is easier to control viscosity matters because it helps material hang together, which gives us a little more time to engage the swallow 4 levels of thickness: thin (what we drink all the time) nectar honey pudding

Slide 17 (part 3-4 slides)

image of larynx and nerve innervation patterns 3 branches: Pharyngeal Branch, Superior laryngeal branch, Recurrent laryngeal branch

bell's palsy

intermittent sudden onset cause unknown LMN lesion; --> same side, full face, problem

slide 37

muscles innervated with CN 5 - Trigeminal nerve temporalis masseter medial pterygoid lateral pterygoid mastication - fancy word for chewing

(Diagnostic measures for voice and swallowing) Modified Barium Swallow (MBS) video

showed normal swallow showed abnormal swallow with pooling, aspiration (no cough) showed person repeatedly coughing, unable to complete a swallow one person took 10 minutes to complete a swallow? showed person with Reverse Aspiration (upper esophageal disorder) "moving -ray"; exposes patient to radiation looking for liquid to NOT go into airway intervention they tried: thick liquids, head turn (to try to close off weak side), mix medications with pudding or applesauce ADVANTAGES: -you can see what's happening DURING the swallow (which you cannot do with FEES)

CN XI (testing)

sternomastoid and trapezius muscle turn head right and up turn head against resistance turn head left and up turn head against resistance raise shoulders keep shoulders up against resistance

Connect the Bell's Palsy video (man who did daily chronicles) to diagram in slide 49 (image also on page 378 in textbook)

this gentleman had a LMN lesion, which can be seen labeled on the diagram as "lower motor neuron lesion"

slide 29 (part 3-4 slides)

tongue muscles controlled by CN XII

Student question regarding bilateral vs. unilateral innervation (in terms of CN 7)

unilateral innervation on both sides so, mandibular branch has unilateral single-sided innervation to BOTH sides so, there is still innervation happening to quadrants on both sides see slide 49 - pink area shows bilateral innervation for upper quadrants grey area unilateral for bottom two quadrants

University of Utah Video - CN II, part 3

3.) fundoscopy Direct visualization of the optic nerve head is an important and valuable part of assessing CN 2. Systematically look at the optic disc, vessels, retinal background and fovea Example: - has patient look out and slight to opposite side -uses tool to look at back of eye - looks at optic nerve head, disc vessels, compares veins to arterials, looks for venous pulsations, looks at fovea

Summarize cranial nerves and their functions presented in youtube video (drawn face)

CN I - Oflactory; Sensory; Sense of smell CN II - Optic; Sensory; Sense of sight or vision CN III - Oculomotor; Motor; Eye movement, Eyelid opening, pupilary constriction, lens accommodation (focusing on things we see at different distances) CN IV - Trochlear; Sensory; Eye movement CN V - Trigeminal; Sensory & Motor -Sensory: facial Sensation (what you feel on your face, e.g. pain or soft touch), somatosensation on anterior 2/3 of tongue -Motor: motor function opening/closing jaw (muscles of mastication, aids in chewing food) CN VI - Abducens; Sensory; Eye movement CN VII - Facial; Sensory & Motor - Sensory: taste to anterior 2/3 of tongue (DIFFERENT than somatosensation sense in CN V) -Motor: facial expression, lacrimation, salivation CN VIII - Vestibulocochlear; Sensory; Hearing and balance (literally and figuratively, our ears) CN IX - Glossopharyngeal; Sensory & Motor - Sensory: somatosensation & taste to posterior 1/3 of tongue - Motor: swallowing CN X - Vagus; Sensory & Motor - Sensory: taste to epiglottis - Motor: swallowing, talking, coughing CN XI - Accessory; Motor; shoulder shrugging and head turning (innervates your trapezius and sternocleidomastoid muscle) CN XII - Hypoglossal; Motor; Tongue movement

University of Utah Video - CN 1

CN I is tested one nostril at a time by using a nonirritating smell such as tobacco, orange, vanilla, coffee, etc. Detection of the smell is more important than the actual identification Example: -patient blocks right side of nose -clinician places something under left nostril -clinician asks if patient can smell something -clinician asks patient to identify what they smell

CN - 1 Olfactory Nerve

SVA (Special Visceral Afferent) - SMELL Found in the roof of the nasal cavity Olfactory neurons (nerves cells, tracts, pathways) group together to form the olfactory nerve which travels through the cribriform plate to form the olfactory bulbs on the basal surface of the frontal lobe Olfactory cells are only found in mammals and are replaced every 30 60 days ANOSMIA impaired ability to smell

What if someone has bilateral damage to vocal cords?

close approximation of vocal folds difficult to get any mobility of vocal folds difficulty chewing and swallowing poor respiratory control

Slide 28 (part 3-4 slides)

cortex to innervation into intrinsic and extrinsic tongue muscles, CN XII

University of Utah Video - CN VII, Sensory CN VII Facial - Sensory

sensory applicators have been soaked with certain flavors clinician touches tongue with applicator stick out tongue, hold it out, and identify what it is you're tasting before you put your tongue back in remember, keep tongue extended because the minute the tongue goes back into the mouth, the person is able to use other cues, so this wouldn't isolate the sensory aspect of the CN VII nerve

CN VII - Sensory

(Pictures of paralysis on one side of face due to LMN damage in Bells Palsy, demonstrates the motor aspect of CN VII damage very well, but what about the sensory aspect?) Taste Taste is the sensory modality tested for the sensory division of CN 7. The examiner can use a cotton tip applicator dipped in a solution that is sweet, salty, sour, or bitter. Apply to one side then the other side of the extended tongue and have the patient decide on the taste before they pull their tongue back in to tell you their answer

How would we test CN VII Facial Nerve (university of utah video)?

(assessing facial movement) raise eyebrows close eyes tight (don't let clinician open them) bring lips together tight (don't let clinician pull them apart)

Note that any patient who has received heart surgery could potentially get referred to an SLP if there are any vocal changes pre-op to post-op. But, vocal changes are not ALWAYS due to damage to recurrent laryngeal branch of CN 10, sometimes it can just be a normal part of recovery.

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Review youtube video to learn about muscles in CN 3,4,6 https://www.youtube.com/watch?v=vd7OOJ7c1q4

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In class practice for CN III

1.) Name and Number of the CN 2.)Determine if it is sensory, motor, or mixed/both? A: 3.)List the primary function(s) of the CN A: 4.)List 2 features or additional details about it (i.e. structural details) A: 5).How can you test to see if it is functional? A: 6.)What do the clinical signs and symptoms look like if it is impaired? A: 7.)Is there a common syndrome or name for if it is impaired? A:

In class practice for CN IV

1.) Name and Number of the CN 2.)Determine if it is sensory, motor, or mixed/both? A: 3.)List the primary function(s) of the CN A: 4.)List 2 features or additional details about it (i.e. structural details) A: 5).How can you test to see if it is functional? A: 6.)What do the clinical signs and symptoms look like if it is impaired? A: 7.)Is there a common syndrome or name for if it is impaired? A:

In class practice for CN I

1.) Name and Number of the CN A: CN I- Olfactory nerve 2.)Determine if it is sensory, motor, or mixed/both? A: Sensory 3.)List the primary function(s) of the CN A: smell 4.)List 2 features or additional details about it (i.e. structural details) A: Olfactory bulbs are bilateral, only found in mammals, and are replaced every 30-60 days; CN I terminates in the olfactory bulbs 5).How can you test to see if it is functional? A:CN I is tested one nostril at a time by using a nonirritating smell such as tobacco, orange, vanilla, coffee, etc. Detection of the smell is more important than the actual identification 6.)What do the clinical signs and symptoms look like if it is impaired? A: inability to smell or taste 7.)Is there a common syndrome or name for if it is impaired? A: Anosmia - impaired ability to smell

In class practice for CN II

1.) Name and Number of the CN A: CN II - Optic nerve 2.)Determine if it is sensory, motor, or mixed/both? A: Sensory 3.)List the primary function(s) of the CN A: Vision 4.)List 2 features or additional details about it (i.e. structural details) A: all information entering the right visual field goes to the left side of brain; all information entering the left visual field goes to the right side of brain eye is connected to brain via optic nerve optic nerve exits the back of the eye and goes into the brain the optic nerve from both eyes converge (this point is the optic chiasm), and then they break off again 5).How can you test to see if it is functional? A: CN II is tested in 3 steps: visual acuity, visual fields, fundoscopy 6.)What do the clinical signs and symptoms look like if it is impaired? A: 7.)Is there a common syndrome or name for if it is impaired? A: Damage anywhere along the pathway results in visual field deficits (damage can occur anywhere along the pathway, but will have a different pattern of visual field deficit)

In class practice for CN V

1.) Name and Number of the CN A: CN V - Trigeminal 2.)Determine if it is sensory, motor, or mixed/both? A: Mixed/ both 3.)List the primary function(s) of the CN A: sensory: opthalmic, maxillary, and mandibular (discriminative touch in Forehead, Maxilla/Cheek, Mandible/Chin, and also tongue/palate motor: mastication (chewing) 4.)List 2 features or additional details about it (i.e. structural details) A: located in pons, bilateral innervation 5).How can you test to see if it is functional? A: 6.)What do the clinical signs and symptoms look like if it is impaired? A: trigeminal neuralgia (example from student) - loud music or loud noise causes face pain (tenor tympani connection?), can't eat hard items; intermittent symptoms; bilateral impact jaw deviation (with motor issue) 7.)Is there a common syndrome or name for if it is impaired? A: trigeminal neuralgia

In class practice - CN VIII

1.) Name and Number of the CN A: CN VIII Vestibulocochlear 2.)Determine if it is sensory, motor, or mixed/both? A: Sensory 3.)List the primary function(s) of the CN A: Hearing and equilibrium 4.)List 2 features or additional details about it (i.e. structural details) A: splits into two large divisions: the vestibular nerve and the cochlear (or auditory) nerve vestibular nerve on top; superior connects to vestibular components cochlear nerve underneath; inferior connects to auditory or cochlear components 5).How can you test to see if it is functional? A: Weber-Rinne testing 6.)What do the clinical signs and symptoms look like if it is impaired? A: -Equilibrium Disturbances of equilibrium Impaired equilibrium, vertigo, dizziness, Nystagmus -Audition Conductive or sensorineural hearing loss Brainstem lesion partial impairment (bilateral projections 7.)Is there a common syndrome or name for if it is impaired? A: Nystagmus

In class practice CN VII

1.) Name and Number of the CN CN VII Facial 2.)Determine if it is sensory, motor, or mixed/both? A: Mixed 3.)List the primary function(s) of the CN A: Facial muscles, taste 4.)List 2 features or additional details about it (i.e. structural details) A: 5).How can you test to see if it is functional? A: 6.)What do the clinical signs and symptoms look like if it is impaired? A: 7.)Is there a common syndrome or name for if it is impaired? A: Bell's Palsy (LMN damage)

University of Utah Video - CN II, part 1 (CN II is tested in 3 steps: visual acuity, visual fields, fundoscopy)

1.) Visual acuity The first step in assessing the optic nerve is testing visual acuity. This can be done with a standard Snellen chart or with a pocket chart (Rosenbaum). Have the patient use their glasses if needed to obtain best-corrected vision. Have the patient hold the pocket chart at the focal length that is best for them which is usually 14 inches. Have them recite the line with the smallest letters that they can read and record the acuity Example: - patient put on their reading classes - patient placed card over right eye - patient held reading pamphlet at comfortable distance and read smalles printed line (that they are able to read)

Cranial nerves

12 PAIRS of cranial nerves (a great example of how our nervous system is redundant) Have specialized functions for vision, audition, gustation, sensation and motor for our face, voice and swallowing Have sensory or motor functions BUT some CNs have both CN 1 olfactory and CN 2 optic are part of the forebrain ALL others are in the Brainstem Olfactory, Optic, Oculomotor, Trochlear, Trigeminal, Abducens , Facial, Vestibulocochlear, Glossopharyngeal, Vagus , Spinal Accessory, Hypoglossal * mixed or both are terms used interchangeably

University of Utah Video - CN II, part 2 (CN II is tested in 3 steps: visual acuity, visual fields, fundoscopy)

2.) Visual fields There are several different screening tests that can be used to assess visual fields at the bedside. First hold up both hands superiorly and inferiorly and ask the patient if they can see both hands and do they look symmetric. Then test each eye individually using your fingers in the four quadrants of the visual field and ask the patient to count fingers held up or point to the hand when a finger wiggles using yourself as a control. A second screening test is to use a grid card. Have the patient focus on the dot in the center of the grid then ask if any part of the grid is missing or looks different. A third method is to use a cotton tip applicator. Testing one eye at a time ask the patient to say "now" as soon as they see the applicator come into their side vision as they focus on the examiner's nose. All of these tests are screening tests. Formal perimetry is the most accurate way of assessing visual fields. Example: - clinician asks patient to look at his nose and tell him whether they see any dissymmetry - clinician holds up hand and asks patient if they can see both hands - patient holds card over right eye - Have the patient focus on the dot in the center of the grid card - Ask if any part of the grid is missing or looks different Example: - have patient cover one eye and focus on clinician's nose -Then test each eye individually using your fingers in the four quadrants of the visual field - ask the patient to count fingers held up or point to the hand when a finger wiggles using yourself as a control (essentially, patient is being asked if there is 1, 2 or no fingers being held up as clinician positions their fingers in different quadrants on the side Example: - have patient cover one eye and focus on clinician's nose - use a cotton tip applicator - testing one eye at a time ask the patient to say "now" as soon as they see the applicator come into their side vision as they focus on the examiner's nose

CN 10 Vagus

90% sensory and 10% motor: GVA, GVE, SVA, SVE Medulla Controls muscles for phonation and swallowing Also controls cardiac muscles, smooth muscles of the esophagus, stomach and intestines GVA - mediates general sensation, pain, tension and temperature from the pharynx, larynx, thorax, abdomen, heart, bronchi, esophagus and carotid sinus GVE large part of the parasympathetic system mediates your visceral response SVA mediates Taste from the pharyngeal area (so we do have taste sensation in pharyngeal area!) SVE iinnervates muscles of the pharynx, larynx, soft palate (except the tensor palatini ) and upper esophagus **Has several branches 3 VAGUS BRANCHES 1.)Pharyngeal Branch -Pharyngeal constrictor muscles except stylopharyngus (CN 9)(Superior, middle and inferior constrictors) -All velum muscles except tensor veli palatini (CN V) (levator palatini , palatoglossus) 2.)Superior laryngeal branch -Internal: sensory from mucous membranes of larynx, epiglottis, base of tongue, and aryepiglottic folds -External: motor to the cricothyroid (pitch); specific innervation to larynx; if patient can't do a pitch glide, they have damage to their superior laryngeal branch of CN 10 3.)Recurrent laryngeal branch -Intrinsic muscles of larynx except cricothyroid ) and sensory to the vocal cords -Left side wraps around the aorta - SLPs are usually called in post surgery after someone has received surgery for some sort of blockage, and the recurrent laryngeal branch of CN 10 got damaged/nicked during surgery; patient would have hoarse voice quality or some sort of vocal change pre-op to post-op DAMAGE -breathy unilateral VF paralysis -decreased pitch control (if patient can't do a pitch glide, they have damage to their superior laryngeal branch of CN 10) - SLPs are often called in post surgery after someone has received surgery for some sort of blockage or thyroid surgery, and the recurrent laryngeal branch of CN 10 got damaged/nicked during surgery; patient would have hoarse voice quality or some sort of vocal change pre-op to post-op -hoarseness -frequent coughing -decreased pharyngeal motility -nasal regurgitation -high risk for aspiration (food and liquid going into lungs instead of stomach) - uvula pulled to the side (due to soft palate innervation); this is why they are asked to say "ahhhhhhhh" Note that any patient who has received heart surgery could potentially get referred to an SLP if there are any vocal changes pre-op to post-op.

University of Utah Video - CN VIII, part 1 Auditory (testing)

AUDITORY/COCHLEAR (one division) Testing auditory acuity: -lightly brushes fingers back and forth next to one ear, then the other; asks patient if they can hear fingers; asks patient if there's a difference between 2 sides -Weber-Rinne test using tuning fork; For Weber porition, clinician taps tuning fork, places it in the middle of forehead, and asks patient if they hear it on either side or in the middle; For Rinne portion, clinician places tuning fork on the mastoid process and asks patient when they can no longer hear the tuning fork; Another way to use Rinne is to ask is it louder at the mastoid, or air conduction (through ear)? Normal response would be air conduction. The cochlear division of CN 8 is tested by screening for auditory acuity. This can be done by the examiner lightly rubbing their fingers by each ear or by using a ticking watch. Compare right versus left. Further screening for conduction versus neurosensory hearing loss can be accomplished by using the Weber and Rinne tests. The Weber test consists of placing a vibrating tuning fork on the middle of the head and asking if the patient feels or hears it best on one side or the other. The normal patient will say it is the same in both ears. The patient with unilateral neurosensory hearing loss will hear it best in the normal ear while the patient with a unilateral conductive hearing loss will hear it best in the abnormal ear. The Rinne test consists of comparing bone conduction (placing the tuning fork on the mastoid process) versus air conduction (placing the tuning fork in front of the pinna). Normally, air conduction is greater than bone conduction. For neurosensory hearing loss air conduction is still greater than bone conduction but for conduction hearing loss bone conduction will be greater than air conduction *Pretty reliant on patient verbal responses

CN IX: Glossopharyngeal

Bilateral innervation MOTOR Innervates stylopharngeous muscle -Elevates the larynx and pharynx -Stimulate parotid gland (saliva) SENSORY: Gag Reflex -Sensation triggers the motor response of CN X, which is carried out by CN X Mixed motor and sensory, GVA, GVE, SVA,SVE Medulla (location) Motor functions relevant to speech: stylopharyngeus and superior pharyngeal constrictor Sensory functions relevant to speech: pharynx, tongue, eustachian tube, middle ear, gag reflex, ALSO the carotid body *Responsible for Touch and Taste from the posterior 1/3 of tongue (remember CN 7,12 are responsible for 2/3 anterior portion) DAMAGE -reduced pharyngeal sensation, reduced gag, and reduced pharyngeal elevation during swallow -seldom damaged alone, usually together with CN 10 vagus *So patient could have difficulty FEELING that the food is there (sensory component) and also PUSHING that food down safely (motor component) CLINICAL CORRELATES Clinical Correlates -Discrete lesion partial paresis of unilateral stylopharyngeal muscle (impairment of ipsilateral pharyngeal elevation in deglutition) -Loss of general & taste sensation from ipsilateral posterior third of tongue -Loss of gag reflex -Excessive oral secretion with decreased control of parotid gland (e.g. drooling) - student asked about lack of oral secretion (as opposed to excessive); instructor said it is typically excessive, but there are lots of pharmaceudicals that cause dry mouth - High risk for choking (although the damage to sensation might actually make it so they don't choke as quickly as we would, since they wouldn't feel it as well)

How would we test SENSORY component of CN V Trigeminal Nerve (university of utah video)?

DISCRIMINITIVE TOUCH uses broken tongue depressor clinician touches patient with broken tongue depressor and asks patient to say whether it's sharp or dull Clinician asks,"Does it feel the same on both sides?" LIGHT TOUCH uses a piece of cotton wool say "yes" after you feel clinician touching you Clinician asks,"Does it feel the same on both sides?" TEMPERATURE Clinician asks, "does this feel warm or cool? BLINK REFLEX look up and to the left *Remember we have to test both sides because it's bilateral

Can SLPs do FEES or MBS exams?

ENT is typically performing most of these procedures Radiologist is typically performing the MBS (Modified Barium Swallow) **SLP is involved**

CN Classification table

GENERAL General Somatic Efferent (GSE) Controls muscles derived from somites , skeletal, extraocular, glossal 3,4,6,12 General Somatic Afferent (GSA) Mediates pain, touch, temperature from skin and joints 5 General Visceral Efferent (GVE) Regulates autonomic functions of smooth muscle and glands 3,5,7,9,10 General Visceral Afferent (GVA) Mediates pain, temp, pressure 9,10 SPECIAL Special Visceral Efferent (SVE) Controls muscles of the face, larynx , pharynx 5,7,9,10,11 Special Somatic Afferent (SSA) Conducts special sensory information, vision, audition, equilibrium 2,8 Special Visceral Afferent (SVA) Mediates information for taste and olfaction 1,7,9,10

CN 6 - Abucens

GSE 3 rd nerve that contributes to eye movement Pons Innervates the Lateral Rectus Muscle moves the eye laterally (side-to-side eye movement) Damage eye will deviate in Damage to the Eye gaze center (MLF) where CN 3,4, and 6 receive input from the vestibular system results in inability to conjugate eye movement/focus https://www.youtube.com/watch?v=vd7OOJ7c1q4

CN 4 - Trochlear

GSE (general somatic efferent) Midbrain at the level of the inferior colliculi Enters the ocular orbit with CN 3 to innervate the superior oblique muscle Superior oblique = down and out Contributes to ocular movement Damage results in Diplopia double vision Damage = fixed up and medial

CN III - Ocularmotor

GSE (general somatic efferent) GVE (general visceral efferent) eye movement MIDBRAIN at the level of the superior colliculus 4 ocular muscles: Superior rectus up and in Medial rectus adducts Inferior rectus down and in Inferior oblique up and out Levator palpebrae superioris eye lid Reflexes of the eye, lens and light accommodation Damage can lead to diplopia, double vision

There are 7 types of CNs based on their function. What are the 7 types?

General motor General sensory General somatic General visceral Special somatic Special visceral Afferent vs Efferent (Table 17-1)

CN VII - Facial

Mixed motor and sensory GVE (general visceral efferent) SVA (special visceral afferent) SVE (special visceral efferent) Located in pons LOT of innervation connected to the face Motor function relevant to speech: muscles of facial expression and stapedius Primary muscles innervated: Depressor anguli oris , depressor labii inferioris , levator anguli oris , mentalis, orbicularis oculi, orbicularis oris , platysma, risorius , buccinators and zygomaticus Sensory : taste to the anterior 2/3 of the tongue MOTOR: Bilateral cortical innervation to upper quadrants of facial muscles (2 upper quadrants) -Forehead, eye/orbital area, above nares (nose) Unilateral cortical innervation to lower quadrants of facial muscles (2 lower quadrants) -Below orbital area, nares, lip/jaw So, in a way, we have 4 zones (2 upper quadrants from bilateral innervation; 2 lower quadrants from unilateral innervation) Also stimulates salivary glands DAMAGE LMN damage = paresis or paralysis entire ipsilateral face; the whole same side of the face; because of bilateral innervation pattern, the upper face will not be as affected UMN damage = lower face paresis or paralysis of contralateral face; opposite side; damage is in lower quadrant on contralateral side * Upper face bilaterally innervated from cortex so will not be affected; (higher up the damage is, the more likely the damage will be evident on opposite side; the lower the damage is, it will stay on same side)

CN V - Trigeminal

Mixed nerve - Sensory & Motor GSA (General Somatic Afferent) Cutaneous sensations from face, head, oral cavity, sinuses, anterior 2/3rds of tongue, external auditory meatus, & tympanic membrane SVE (Special Visceral (Branchial) Efferent) Trigeminal Motor nucleus (in pons) ■Masticators ■Additional muscles Tensor veli palatini (soft palate) Tensor tympani (middle ear) "tri" for 3 regions of innervation Pons level Mediates pain, temperature, touch, and proprioception for mastication for the face, head, oral and nasal cavities, anterior 2/3rds of the tongue, anterior pinna, anterior external auditory meatus and external surface of the tympanic membrane 3 divisions/zones: opthalmic (eye region) maxillary (roof of mouth, upper jaw), and mandibular(lower jaw) SENSORY Bilateral innervation Discriminative touch in three areas innervated: -Forehead -Maxilla/Cheek -Mandible/Chin - Also tongue/palate Damage: -Sensory peripheral sensory nerve = loss of sensation on the same side -Tic douloureux /trigeminal neuralgia chronic pain on the face treatment -Treatment: severing the nerve or pain meds MOTOR Bilateral innervation The motor portion controls muscles of mastication Internal and external pterygoid, temporalis and masseter Other muscles include: mylohyoid, anterior belly of the digastric, tensor veli palatine and the tensor tympani Damage: -lower LMN damage results in flaccid paralysis of muscles on the same side and the jaw deviates toward the injury upper UMN results in very little weakness

Normal vs. abnormal vocal fold behavior (slide 20; part 3-4 slides)

NORMAL: vocal folds are apart during breathing together, vibrating during speech ABNORMAL bowed or paralyzed vocal cord during breathing is not completely open during speech, is not adequately coming together

CN VIII - Vestibulocochlear

SSA Medulla and pons Mediates equilibrium and hearing Dual function role - equilibrium and hearing splits into two large divisions: the vestibular nerve and the cochlear (or auditory) nerve vestibular nerve on top; superior connects to vestibular components cochlear nerve underneath; inferior connects to auditory or cochlear components Auditory Nerve -Bilateral projections to cortex -Tonotopic representation throughout path & auditory cortex Damage -Cochlear: hearing loss types depends on location -Vestibular: balance disorders, vertigo, nystagmus (vision condition in which the eyes make repetitive, uncontrolled movements) *Think Pruitt Taylor Vince actor with Nystagmus* CLINICAL CORRELATES -Equilibrium Disturbances of equilibrium Impaired equilibrium, vertigo, or dizziness -Audition Conductive or sensorineural hearing loss Brainstem lesion partial impairment (bilateral projections -Testing Cover one ear with 3x5 card, scratch, whisper in other

CN 2 - Optic Nerve

SSA (Special Somatic Afferent) VISION Damage anywhere along the pathway results in visual field deficits (damage can occur anywhere along the pathway, but will have a different pattern of visual field deficit)

Slide 11 (part 1-2 slides)

UMN - think "brain," think cerebral hemisphere LMN - think "brainstem" (most CNs are in brainstem)

slide 30 (part 3-4 slides)

UMN lesions Point A on diagram marks an UMN lesion; tongue deviates to OPPOSITE side of lesion LMN lesions tongue deviates to SAME side of lesion *With damage to XII, tongue deviates towards one side or the other, where deviation occurs will determine where tongue deviates to *Tongue deviates towards weaker sides because stronger muscles on one side sort of push it over *Just ask yourself, have things crossed yet or not?

CN Syndromes

WEBER SYNDROME Lesion location: Midbrain Affected structures: Corticospinal fibers, Oculomotor nerve Clinical symptoms: Contralateral hemiplegia, Ipsilateral ocular paralysis, Dilated pupil MILLARD-GUBLER SYNDROME Lesions location: Lower pons Affected structures: Corticospinal fibers, Facial nerve, abducens Clinical symptoms: Contralateral hemiplegia, Ipsilateral facial paralysis, Medial strabismus LOCKED-IN Lesion location: Bilateral pons Affected structures: All descending corticospinal fibers Clinical symptoms: Loss of all motor speech functions, quadrapelegia WALLENBERG Lesion location: Lateral medulla Affected structures: Trigeminal tract, Spinothalamic fibers, Vagus, glossopharyngeal Clinical symptoms: Loss of pain from ipsilateral face and contralateral body; muscle paralysis of pharynx, larynx and palate

Discuss the distinction between bilateral representation and bilateral innervation, regarding student question in class?

bilateral representation - e.g. all 12 pairs of CNs are bilateral (but they will have different innervation patterns) bilateral innervation - WHERE they innervate (we will talk about this more regarding CN VII and CN V)

slide 19

displays damage profile along CN 1 depending on where lesion rests point of decussation of optic nerve = optic chiasm shows different versions of heminopsia

Review youtube video on cranial nerves

https://www.youtube.com/watch?v=FtJtYMRVw7A

Khan academy video (visual processing)

nasal side of eyeball - closest to nose temporal side of eyeball - closest to temple RAY OF LIGHT COMING FROM LEFT VISUAL FIELD will hit the nasal side of left eye and the temporal side of right eye RAY OF LIGHT COMING FROM RIGHT VISUAL FIELD will hit the nasal side of right eye and the temporal side of left eye eye is connected to brain via optic nerve optic nerve exits the back of the eye and goes into the brain the optic nerve from both eyes converge (this point is the optic chiasm), and then they break off again INFORMATION TRANSMITTED TO THE BRAIN (this example considers how "same" ray of light hits left and right eye) retina is lining back of eyeball as light enters left eye, information is sent via axons through the back of the eye into the optic nerve; then it will cross at the optic chiasm and continue onto the opposite side (right side) as light enters right eye, information is sent via axons through the back of the eye in to optic nerve; it does NOT cross, but continues onto same side *all light that hits the temporal side of either eyeball does not cross the optic chiasm *all information entering the right visual field goes to the left side of brain *all information entering the left visual field goes to the right side of brain

Student questioned about how easy a videostroboscopy would be for children clients

nasal spray that numbs area (ENT usually performs this) videostroboscopy: used for voice and swallowing disorders

Why do we care about CN I (sense of smell) as SLPs?

olfaction is instrinsically linked with gustation, so could have feeding implications sense of smell is very connected to potential of chewing and swallowing disorders if patient can't taste what they are eating, are they going to be inclined to try new things in order to adjust to dietary challenges? Prob not sense of smell is a STRONG memory trigger (think about where it is located in the brain); sense of smell

Test of CN IX and X

open mouth and say "ahhhhhhhhh: assessing gag reflex but lightly touching back of throat

CN XII (testing)

please stick out tongue no evidence of fasiculation or wasting please place tongue in left cheek, don't let me push it over please place tongue in right cheek, don't let me push it over (looking for tongue deviation, tongue strength)

slide 20

primary processing job of visual cortex is to help modulate this type of content: figure ground closure movement (linked to occipital lobe)

(Diagnostic measures for voice and swallowing) FEES (fiberoptic endoscopic evaluation of the swallow)

uses flexible scope (same as one used in video where ENT used it on himself) exam is recorded so they can view video later, and show client later patient is given food and liquids of different consistencies that have been dyed blue with food coloring FEES is used to help clinicians establish swallow safety strategies for particular patients FEES is used to develop specific rehablitation swallowing excecies ADVANTAGES -direct view of throat and voice box -can be performed at bedside -real food and liquid is used -used throughout entire meal to examine fatigue - no radiation exposure DISADVANTAGES - can't see what's happening DURING swallow, only before and after (screen went white when person swallowed) e.g. clinician looked for timely swallow while patient chewed carrot

youtube video slide 19 (part 3-4 slides)

video stroboscopy vocal folds are damaged vocal folds are not adducting properly; causing breathy, hoarse, voice lack of pitch modulation breathy, unilateral, vocal fold paralysis collapsed structure on left side of image

12 PAIRS of cranial nerves (a great example of how our nervous system is redundant) have specialized functions for what 5 major functions?

vision audition gustation sensation and motor for our face voice and swallowing