CGSC379 Midterm Review PDF

Hello Everyone! Below is a list of topics to focus on for the midterm. The test will be a mix of multiple choice, true false, matching/labeling and fill in the blank. Information from the first 5 lectures are fair game; however, the majority of the exam will include the following topics: Role...

Hello Everyone! Below is a list of topics to focus on for the midterm. The test will be a mix of multiple choice, true false, matching/labeling and fill in the blank. Information from the first 5 lectures are fair game; however, the majority of the exam will include the following topics: Role of the SLP ○ Scope of Practice for SLP Expert screening individuals for possible communication, hearing, and/or feeding and swallowing disorders in a cost effective manner Planning and conducting screening programs, selecting screening instruments, develop screening procedure Managing disorders including hearing loss ○ Hearing screening by SLPs Appropriate roles Collaborating with audiologist in the development of screen protocols, equipment selection, and quality improvement Performing hearing screenings Referring children who do not pass screening to services Referring children who are difficult to test to audiology Comuncatine screen results to family and recommend follow up Share screening result with appropriate programs, state public health agencies, state programs for children under 3 years, PCP, and others Provide counseling and education for families, educators, and others Collaborate with audiologists, school nurses, teacher, physicians and other professionals Modalities, technology, and instrumentation Slps use advanced instrumentation and technologies int he evaluation, management, and care of individuals Slps use state of the art hearing screening instruments, hearing aids, hearing assistance tech and others Fitting the hearing aids is out of scope but maintenance and assistance of aids is within scope Anatomy of the ear (outer, middle, inner and the 8th nerve). Be able to label parts of the ear. ○ EMBRYOLOGY OF THE EAR EAR FORMS BETWEEN 3-37 WEEKS OF GESTATION EAR IS FUNCTIONAL AT 20 WEEKS THE INNER EAR IS ENCLOSED IN A BONY LABYRINTH WITH A PROTECTED PRISTINE ECOSYSTEM ONLY ORGAN THAT DOES NOT GROW AFTER BIRTH COCHLEA IS THE SIZE OF A PEA! HAS REPRESENTATIVE TISSUE FROM ALL OTHER BODY SYSTEMS HAIR, SKIN, BONE, ORGANS, TEETH, PIGMENT ETC..... ○ The outer ear Called the pinna or auricle Pinna has natural resonation (boost) at about 1500 Hz Shape of pinna helps collect sound and localize Ear canal is approximately 2.5cm External auditory meatus Ear canal is “s” shaped Outer ⅓ is skin/cartilage Inner ⅔ bone/skin ○ Pinna Single piece of yellow elastic cartilage covered with Perichondrium and skin(except lobule and outer part of external auditory canal) Attached to the side of skull by ligaments and muscles (supplied by facial nerve),muscles are not well developed in human ○ Ear system Equalize pressure ○ The middle ear Tympanic membrane (3 layer) Skin, fiber, mucous Adult size is about 9mm, tympanic membrane/eardrum Pars tensa and pars flaccida OSSICLES: MALLEUS, INCUS AND STAPES ACTS AS A LEVER TO COMPENSATE FOR IMPEDANCE MISMATCH  ADDS ABOUT 27-30 DB BEFORE ENTERING COCHLEA MUSCLES: TENSOR TYMPANI AND STAPEDIUS ACOUSTIC REFLEX ARC (EFFERENT VS AFFERENT SYSTEMS) MIDDLE EAR SPACE SURROUNDED BY POROUS BONE EUSTACHIAN TUBE CHANGES ANGLE AND SIZE FROM INFANCY TO YOUNG TEEN ○ Function of Middle Ear Conduction Conduct sound from the outer ear to the inner ear Protection Creates a barrier that protects the middle and inner areas from foreign objects Middle ear muscles may provide protection from loud sounds Transducer Converts acoustic energy to mechanical energy Converts mechanical energy to hydraulic energy Amplifier Transformer action of the middle ear only about 1/1000 of the acoustic energy in air would be transmitted to the inner-ear fluids (about 30 dB hearing loss) ○ Conduction of speech frequencies External Auditory Meatus (23-29 mm) S shaped Resonant frequency 2000-5000 Hz Adds about 10-15 dB to those frequencies Middle Ear dynamics Tympanic membrane larger than oval window Size, shape and movement from larger surface to smaller creates concentrated energy Adds about 30 dB between 100 Hz and 2500 Hz Explains why it takes less dB SPL to activate “Human O” O dB HL on an audiogram for mid frequencies  Ear canal straight/leveled at first than as we mature, it angles downward ○ How sound is transferred to the inner ear ○ Be able to labe parts of inner and outer and middle ear Ear canal, ear drum, bones, cochlea, esuatchia tube, nerves ○ Inner ear Cochlea (hearing) Stapes pushes against oval window of cochlea Cochlea houses “organ of hearing” Semicircular canals, utricle, saccule (balance) “Vestibular system” Vestibule (connects the two) This is where you find the oval and round windows Internal auditory canal VIII nerve (cochlear and vestibular portions) Facial nerve (VII) Artery and veins ○ Cochlea Snail shaped bony structure (2 1⁄2 turns) 3 layers called scala Scala vestibuli (top layer) filled with perilymph Scala tympani (bottom layer) filled with perilymph Scala media (middle layer) filled with endolymph ○ Perilymph (high sodium, less potassium) ○ Endolymph (less sodium, higher potassium Helicotrema is narrow opening at the apex that connects scala tympani and scala vestibuli Oval window (stapes) and round window As Oval window pushes in, round window expands ○ Scala media Separated from scala vestibuli by Reissner’s membrane (top) Separated from scala tympani by Basilar membrane Organ of Corti is supported by the basilar membrane Basilar membrane changes in width from base (0.08-0.16mm) to apex (0.42-0.65mm) Basilar membrane is stiffer at the base, more flexible at the apex At base of cochlea, higher frequency and haircells responsible for sending infor for higher fre As cochlea turns, goes towards lower frequency, the apex ○ Organ of corti Has both outer and inner hair cells  Outer hair cells = 12000 in rows, w shape Inner hair cells = 3500 in one single row ○ Do not make contact with tectorial mebrane Tectorial membrane lays overtop of the hair cells Outer hair cells make contact with tectorial membrane, inner hair cells do not Outer hair cells are primarily efferent (brain to ear) Inner hair cells are afferent (ear to brain) ○ The cochlea Base to apex ranges ○ Acoustic to neural Displacement of perilymph in larger Scala Tympani and Vestibuli put pressure on basilar membrane in Scala Media Basilar membrane moves in one direction while tectorial membrane moves in opposite direction Causes “shearing” of the hair cells Hair cells bend (shorten or lengthen) “Gate” at base of cell opens and allows chemical exchange which creates neural signal Neural signal is transmitted along VIII nerve ○ Called Action Potentials in the central system In order from top to bottom ○ The organ of corti ○ Tectorial membrane Thinner than a hair  Develops from a unique set of genetic instructions Resembles jello Looks like a solid but behaves like a liquid Held together by electrostatic forces “THE SIZE AND ARRANGEMENT OF PORES WITHIN IT, AND THE WAY THOSE PROPERTIES AFFECT HOW WATER WITHIN THE GEL MOVES BACK AND FORTH BETWEEN PORES IN RESPONSE TO VIBRATION, MAKES THE RESPONSE OF THE WHOLE SYSTEM HIGHLY SELECTIVE. BOTH THE HIGHEST AND LOWEST TONES COMING INTO THE EAR ARE LESS AFFECTED BY THE AMPLIFICATION PROVIDED BY THE TECTORIAL MEMBRANE, WHILE THE MIDDLE FREQUENCIES ARE MORE STRONGLY AMPLIFIED.” ○ VIII Nerve Nerve endings gather thru central bony part of cochlea called the modiolus (near helicotrema) They travel through the inner auditory cana Become auditory nerve High frequency nerves wrap around the outside Low frequency nerves become the core Acoustic nerve joins the vestibular nerve to become VIII (cranial) nerve Nerve cells become spiral ganglion, not hair cells Enter the cerebellum (brainstem) at the cerebellopontine angle Central auditory pathway ○ Central auditory system Signal enters the central system at the cochlear nuclei High frequency sounds enter at a different place than low frequency sounds ○ Keep tonotopic fidelity 40% of transmission stays ipsilateral (efferent) 60% of transmission crosses contralateral side (afferent) Codes for timing, intensity and frequency Transmit to the superior olivary complex First point of bilateral representation Codes timing and latency needed to localize sound Transmit to lateral lemniscus Still tonotopic Bilateral transmission thought to help with hearing in noise ○ Central system Relays to inferior colliculus Largest “relay station” Highly sensitive to bilateral stimulation Enters the medial geniculate body Last “station” before the auditory cortex  Found in the thalamus Important for auditory discrimination Reticular formation in central portion of brainstem Connects at multiple spots from brainstem to cerebrum Thought to regulate selective attention ○ Auditory cortex SOUND ENTERS THE TEMPORAL LOBES AT HESCHL’S GYRUS DIVERSE NEURAL RESPONSES TO ONSET, CESSATION AND PRESENCE OF SOUND SOUND (NEURAL SIGNAL) IS SENT TO........ ○ WERNICKE’SAREA(SPEECH PERCEPTION) ○ BROCA’SAREA(SENTENCE STRUCTURE, GRAMMAR AND SYNTAX) ○ SUPERIORTEMPORALGYRUS (SYNTAX, MORPHOLOGY) ○ INFERIOR FRONTAL GYRUS (WORKING MEMORY, SYNTAX) ○ MIDDLETEMPORALGYRUS (SEMANTICS, LEXICON) ○ AFFERENT/EFFE RENT Afferent = ascending pathway (primarily contralateral) Efferent =descending pathway (primarily ipsilateral) Most neurological networks have afferent and efferent pathways Olivo-cochlear bundle (located in pons) Connects separately to inner/outer hair cells Little is really known about auditory efferent system Thought to help with tolerance to loud sounds Thought to help with hearing in noise Can be tested using Acoustic Reflex Testing ○ Know this diagram for midterm  ○ Vestibular system Balance is a central function Only need one functioning ear Used in combination with proprioceptive and visual systems Provides postural control and stabilization of gaze Oscillopsia : visual images oscillate Caused by disruption of the vestibulo-ocular reflex Often coincides with other neurological disorders Vestibule Shared area with the cochlea Utricle and saccule Organs used to sense linear changes in movement Acceleration/deceleration Rate and direction of movement Semicircular canals Each canal on a different plane Monitors “body in space” information Responds to angular changes Ampulla Enlarged area at base of semicircular canal Cristea Sense organs for balance Otoliths (small crystals ) Made of calcium carbonate Typically free floating Getting “stuck” causes vertigo  Vestibular Nerve Joins cochlear portion to become VIII nerve ○ Vestibular System Cont. Also has endolymph and perilymph separated by endolymphatic duct (same as cochlea) Hair cells have a resting “firing” rate of neural activity (different from cochlea) Changes in position cause hair cell deflection which increases or decreases the firing activity Perceived by the brain as movement Otoliths (small crystals) sometimes get lodged and create positional vertigo ○ Audiogram (right vs left, air conduction vs bone conduction; X and Y axis labels ○ Audiogram 20 and above considered normal for this class ○ Hertz/Frequency/Pitch Equivalent to cycles per second (cps) Also known as the period of a sound Low frequency sounds = longer period High frequency sounds = shorter periods Denoted as Hz Perceived as pitch Humans hear 20 Hz to 20,000 Hz Human ear most sensitive to 125 - 8000 Hz Phonemes occur primarily between 500 - 4000 hz  ○ The science of sound What is sound: understanding the fundamentals of sound Pressure wave. Sound wave: particles bumping into each other ○ Sound measurement intensity Intensity versus loudness Intensity is a physics measure and is objective information Loudness is a perceptual phenomenon and is very subjective What is a decibel (dB)? Units of measurement based on the physical properties of sound waves Decibel = 1/10 Bel Which decibel scale should I use? Sound pressure level (dB SPL) Hearing level (dB HL) ○ What you see on the audiogram Sensation level (dB SL) ○ Decibel referents (scales) dB SPL (Sound Pressure Level) Used in measuring hearing aid performance/function 0.0002dynes/cm2 dB IL (Intensity Level) Used in electrical measurements/calibration of audiometers Watts/cm2 dB HL (Hearing Level) Used on hearing tests/audiograms Each frequency calibrated to “human 0” Logarithmic/exponential Scale dB SL (Sensation Level) Refers to the level above threshold, used for speech Perception testing Threshold = 50% accurate detection or ⅔ dB nHL (Neural Hearing Level) Used in Auditory Brainstem testing  ○ Correction factors needed to compare to dB HL ○ Most often referred to as eHL (estimated hearing level) ○ DECIBELS FOR AUDIOGRAMS Logarithmic scale used for measuring hearing Written as dBHL DB hearing level Human ear can typically detect 0-140 dBHL >120 dB=pain O dB is NOT the absence of sound Approximate equivalent of 0.0002 dynes/cm 2 (pressure wave) Some people can hear at “negative” dB levels Denotes the amplitude/intensity of the sound wave Perceived as loudness ○ SOUND MEASUREMENT Measurement of relative intensity Logarithmic scale versus linear scale ○ Main takeaways dB SPL= a 20log 10 logarithmic measurement of sound pressure level. Reference level is = 20 micropascals. Number of decibels above or below a reference of 20 micropascals. -dB HL= Number of dB above or below audiometric zero. 1kHz (1,000 Hz). People on average heard this tone at 7dB SPL. -Created a concept of audiometric zero. -0 is the threshold that reflects a different sound pressure level. ○ Audiograms Inverse graph Normal hearing is at the top/ Deafness is at the bottom Frequency vs. intensity X axis= Frequency Y Axis= Intensity Air conduction vs. bone conduction “total ear” vs. inner ear and beyond Left ear vs. right ear Symmetrical vs. asymmetrical Masked vs. unmasked Using a competing noise in the non-test ear Allows testing of Targeted ear only w/o interference  The audiogram ○ Categorizations of hearing loss Conductive outer/middle ear Sensorineural Cochlea and or VIII nerve Mixed Both conductive and sensorineural combined unilateral/bilateral One ear/two ears symmetrical/asymmetrical Essentially equal/ uneven losses Vibrotactile Feel the sound / not true hearing Auditory neuropathy Viii nerve involvement only ○ AUDIOLOGY SYMBOLS Air conduction Symbols (hearing measured using a headset or insert earphones) O = Right ear (unmasked) X = left ear (unmasked) ▪ masked R ac ○ Red triangle  masked L ac ○ Red smooth corner rectangle Bone Conduction Symbols (vibrating sound placed on bone surrounding the ear) < = right ear (unmasked) > = left ear (unmasked) ▪ masked R bc ○ bracket masked L bc ○ Bracket Red is right, blue is left ○ Audiology symbols continued Masking: using noise to occupy one ear while testing the other (Symbol with arrow attached = NR (no response) S = Soundfield (speakers) *both ears are working together so gives limited information about each ear Soundfield can be unaided or aided R = aided with right ear only L = aided with left ear only CI = cochlear implant ○ Audiogram ○ Example of bilateral symmetrical sensorineural hearing loss  Bone conduction and air conduction symbols the same pretty much Mild to moderately severe hearing loss ○ Right ear only CHL When testing with headphone, presenting sound goes through all parts of ears (middle, outer, inner), when conductive loss, patient hears sounds better with bone conductor than with headphone thats why brackets towards the top of the graph ○ Bilateral symmetric mixed hearing loss Symmetric bc not difference between left and right ear Mixed bc symbol is in different ranges ○ Degree of Hearing Loss Different criteria for children vs adults !!!!!! Minimal is NOT inconsequential !! (Fred Bess) Hearing loss can cross categories Can change over time (decreasing levels)  Gives information on levels of hearing....actual function of each individual may vary ○ Degree of Hearing Loss Cont. Adult vs. children NOT a percentage!! Hard of Hearing/Deaf (audiogram vs identity) Configurations: Flat/sloping Ski-slope Cookie Bite Reverse slope High Frequency ○ What is an audiogram Tells the hearing abilities Measure loudness, pitch Types of Hearing loss (Conductive, Sensorineural and Mixed) ○ Categorizations of hearing loss Conductive outer/middle ear Sensorineural Cochlea and or VIII nerve Mixed Both conductive and sensorineural combined unilateral/bilateral One ear/two ears symmetrical/asymmetrical Essentially equal/ uneven losses Vibrotactile Feel the sound / not true hearing Auditory neuropathy Viii nerve involvement only Characteristics of low and high tones ○ Left is low and bassy tone, right has the high pitches ○ ????? Degrees of Hearing Loss (Normal to profound)  ○ Types of tympanograms ○ ○ TYPES OF TYMPANOGRAMS A = peak compliance btwn +50 and -100 daPa -100 to -200 dapa is considered borderline normal/abnormal  As = peak compliance normal but very shallow depth < 0.3 ml Ad = peak compliance normal but very deep (large) Immittance >1.4 ml C = peak compliance in negative pressure Beyond -100 daPa, up to and incl. -400 daPa B = flat tracing with no peak Fluid Perforation or tube ○ Immittance testing Acoustic immittance vs. impedance Ease of /opposition to transfer of acoustic energy Units of measure Compliance (Immitance) units in cm3 or ML daPa (decapascals) or mmH2O units of ear canal pressure Diagnostic equipment and screening equipment Includes both tympanometry and acoustic reflex testing 4 primary components; Transducer, air pump, manometer, microphone ○ TYMPANOMETRY Measures the “flexibility” of the eardrum Gives info on the Health of the TM and Middle ear Used to diagnose middle ear dysfunction NOT a test of hearing ability Requires use of a probe tip inserted in ear canal creating an airtight seal May not get seal if : Perforation, tubes or oddly shaped canal Mechanically changes air pressure in ear canal +200 to -400 daPa (as compared to atmosphere) Creates “probe tone” at 226 Hz Infants 3 times in 6 months Chronic : lasting more than 8 weeks Persistent : lasting > 6 weeks with treatment ○ Serous otitis media ○ Middle Ear Pathologies Tympanic perforation Foreign object Blow to the head Barotrauma (scuba diving; flying) Otitis media Cholesteatoma Benign growth filled with skin cells/debris Mastoiditis Infectious invasion of the porous mastoid bone Otosclerosis Fixation of the ossicular chain Fixation of stapes only = ankylosis Often a Genetic disorder appearing in mid ‘40s, mostly women Malleus fixation (cannot move) Loss of sound transmission Genetic or from chronic ear infections Ossicular Discontinuity Trauma to tympanic membrane Head trauma (sports, falls, auto accidents....) Eustachian tube dysfunction Allergies, asthma, respiratory disorders Anatomical shape and size (Refer to slide in previous lecture) Enlarged adenoids Changes in air pressure Glomus tumor Not malignant  Very slow growing Can disrupt the ossicular chain (needs surgical removal) ○ Inner Ear Pathologies Vestibular Schwannoma also called an Acoustic Neuroma (Usually) unilateral slow growing tumor of VIII nerve Very poor speech discrimination compared to thresholds Patients report full feeling in the ear Neurofibromatosis NF1 rarely involves the ear NF2 faster growing acoustic tumors (bilateral) Cochlear neuritis = inflammation of VIII nerve Usually sudden onset of hearing loss/deafness Removal of tumors severs VIII nerve, complete deafness Facial Nerve Disorders Bell’s Palsy (most common) Test finding: Ipsilateral acoustic reflex absent w/normal hearing Diabetes Children and Adults Progressive bilateral sensorineural hearing loss Meniere’s Disease Usually seen as hearing loss, vertigo and tinnitus Fullness in the ear Hearing loss can fluctuate Often a “dumping ground” for unknown etiologies ○ Inner Ear Disorders Noise Induced Hearing Loss Repeated exposure leads to progressive loss Single episode >140 dB HL can cause deafness Classic “noise notch” in hearing test Presbycusis Aging of the ear Can involve degradation of cochlear structures and/or central auditory cell structures Typically, very poor speech recognition compared to hearing test results Trauma Longitudinal fracture usually involves middle/outer ear systems (often repairable) Transverse fractures typically involve inner ear systems (non repairable) Ototoxicity “Mycin” Drugs: Aminoglycosides Anti-inflammatory (aspirin, blood thinners)  Chemotherapy drugs Quinine (malaria ○ Central Pathologies Multiple Sclerosis Demyelination of nerves Plaque adhesions at the brainstem Disrupted Blood supplies TIA (transient ischemic attacks) Arteriosclerosis (hardening of the arteries) Aneurysm (burst blood vessel) Hereditary Motor Sensory Neuropathies (HMSN) Charcot-Marie-Tooth (mutation on the X chromosome) Friedrich’s Ataxia (mutaion of the FXN gene that produces frataxin protein. Voluntary movement Otoacoustic emissions ○ Otoacoustic Emissions (Outer hair Cell Function) Transient Distortion Product ○ OTOACOUSTIC EMISSIONS DISCOVERED BY DAVID KEMP IN 1978 CLINICALLY AVAILABLE IN EARLY ‘90S LOW LEVEL SOUNDS CREATE A COCHLEAR RESPONSE THAT CAN BE RECORDED IN THE EAR CANAL RESPONSE CREATED BY OHC (OUTER HAIR CELLS) SEPARATES COCHLEAR FROM RETROCOCHLEAR SITE OF LESION SEPARATES SENSORY FROM NEURAL REQUIRES NORMAL CONDUCTIVE (OUTER/MIDDLE) SYSTEM ○ TUBES OR FLUID WILL OBLITERATE THE RESPONSE ○ THAT MEANS AS ESSENTIALLY NORMAL TYMPANOGRAM (TYPE A) ○ OTOACOUSTIC EMISSIONS TEOAE (PRIMARILY SCREENING) DPOAE (PRIMARILY DIAGNOSTIC) Not a Direct test of hearing levels Absent in moderate to profound hearing loss Test of OHC cochlear function Used in diagnosis of ANSD and other VIII nerve disorders Conductive pathology obliterates OAE response Emissions Can occur spontaneously or be evoked Evoked emissions used for testing We create a sound that evokes (Stimulates) an Emission Two test Procedures: Transient Evoked (TEOAE) Distortion Product (DPOAE)  ○ OTOACOUSTIC EMISSIONS Transient Evoked (TEOAE) Uses a broadband click stimulus (not specific to any one frequency) Typically used as a screener (newborns, preschoolers etc…) Also can be used as a crosscheck for adults Distortion Product (DPOAE) Uses 2 frequencies (F1-F2) at 2 different intensities (L1 and L2) Used for diagnostic information (not screening) Measures the distortion product of 2 simultaneous frequencies Presentation of F1 and F2 causes OHC to create a 3rd sound L1 and L2 separated by 15 dB SPL (65/50) ○ TRANSIENT EVOKED OAE Used in Universal Newborn Hearing Screening Not present if hearing loss is >30 dB HL Slight/minimal hearing losses may pass this test Does NOT give frequency specific info Is used as a pass or fail (screening) Uses computer averaged data collection Has artifact rejection software…..However Poor seal Crying, talking, moving Equipment noise, esp. in nursery, NICU Use of oxygen equipment ○ DISTORTION PRODUCT OAE Used to give frequency specific information Compromised patients (cognitive, autism, severe disabilities) Diagnostic information (not a screener) Can elicit response in moderate-severe hearing loss or less Tests frequencies 1000-8000 Hz (Typically) Specialized High Frequency equipment used in ototoxicity monitoring or noise induced monitoring Distortion Product is 60 dB SPL less than the two stimulus tones (f1 and f2) Distortion product occurs at a lower frequency than f1 and f2 ○ Basilar Membrane and tonotopic organization ○ Properties of Sound ○ Properties of sound Four Physical parameters describing simple harmonic motion (pure tone) as a function of time: Frequency (f): the number of complete vibratory cycles per unit time  Amplitude (A): a derived unit of measurement describing an object’s distance from rest to maximal displacement ○ Peak of the wave Period (p): amount of time needed to complete one cycle of vibration Phase (φ): describes the relative timing of compressions and rarefactions of waves (i.e., how cycles relate to each other) Pure tones vs complex sounds ○ Pure tones (one single isolated pitch) “simple sound” Tuning forks Audiometers During hearing tests, we give pure tones ○ Complex sounds ((two or more pitches combined)) Everything else