TinnitusTinnitus Grand Rounds Grand Rounds

Edward Buckingham, M. D.Edward Buckingham, M. D.JeffJeff Vrabec Vrabec, M. D., Faculty, M. D., Faculty Sponcer SponcerFrancis Quinn, M.D., Series EditorFrancis Quinn, M.D., Series Editor

IntroductionIntroduction

■■ DefDef. - Perception of sound produced. - Perception of sound producedinvoluntarily within the bodyinvoluntarily within the body

■■ SypmtomSypmtom of threatening disease process or of threatening disease process orbenign annoyancebenign annoyance

■■ Psychological effects can be severe, evenPsychological effects can be severe, evenprecipitate suicideprecipitate suicide

Definition andDefinition and Epidemiology Epidemiology

■■ Objective,Objective, paraauditory tinnitus paraauditory tinnitus - vascular - vascularoror myoclonic myoclonic sources, less prevalent sources, less prevalent

■■ Subjective,Subjective, sensorineural tinnitus sensorineural tinnitus - auditory - auditorysystem, more prevalentsystem, more prevalent

■■ Prevalence increases with agePrevalence increases with age■■ Equal sex distributionEqual sex distribution■■ Severity of symptoms increases with ageSeverity of symptoms increases with age

ObjectiveObjective Tinnitus Tinnitus

■■ Stictly defStictly def. audible to physician or observer. audible to physician or observer■■ Encompasses allEncompasses all paraauditory paraauditory causes causes■■ PulsatilePulsatile or non- or non-pulsatilepulsatile■■ Vascular abnormalities - neoplasm, AVM,Vascular abnormalities - neoplasm, AVM,

arterial bruit, venous humsarterial bruit, venous hums■■ PalatomyoclonusPalatomyoclonus

ObjectiveObjective Tinnitus Tinnitus - 2 - 2

■■ H & PH & P■■ Relation to the heart rate, light exerciseRelation to the heart rate, light exercise■■ Thorough ENT exam,Thorough ENT exam, particulary otoscopy particulary otoscopy■■ Exam forExam for retrotympanic retrotympanic mass mass■■ Auscultate extAuscultate ext. canal, orbit, mastoid, skull,. canal, orbit, mastoid, skull,

and neckand neck■■ AudiogramAudiogram

Pulsatile TinnitusPulsatile Tinnitus

■■ Many causesMany causes■■ Possible algorithm fromPossible algorithm from Sismanis Sismanis■■ H & P most importantH & P most important■■ BIH, ACAD,BIH, ACAD, Glomus Glomus tumors 2/3 of causes tumors 2/3 of causes

BenignBenign Intracranial Intracranial Hypertension Hypertension((pseudotumor cerebripseudotumor cerebri) Syndrome) Syndrome

■■ Most common cause inMost common cause in Sismanis’s Sismanis’s study study■■ Increased ICP, no focalIncreased ICP, no focal neuro defecit neuro defecit except except

occasoccas. 6th or 7th nerve palsy. 6th or 7th nerve palsy■■ MechMech. systolic pulsation of CSF to medial. systolic pulsation of CSF to medial

aspect ofaspect of dural dural venous sinuses, compression venous sinuses, compressionof walls, turbulent blood flowof walls, turbulent blood flow

■■ Head imaging, r/o IC lesionHead imaging, r/o IC lesion■■ Diagnose by LP, ICP > 200 mm H2ODiagnose by LP, ICP > 200 mm H2O

BIH - 2BIH - 2

■■ Female 20 - 50Female 20 - 50 yrs yrs old and overweight old and overweight■■ IpsilateralIpsilateral IJV digital pressure subsides IJV digital pressure subsides■■ PossPoss. blurred vision,. blurred vision, fronto fronto-occipital HA,-occipital HA,

lightheadedness-lightheadedness-disequilibuiumdisequilibuium■■ PossPoss. LF HL with good discrimination,. LF HL with good discrimination,

whichwhich nomalizes nomalizes with IJV pressure with IJV pressure

BIH - TreatmentBIH - Treatment

■■ Weight lossWeight loss■■ AcetazolamideAcetazolamide,, furosemide furosemide■■ SubarachnoidSubarachnoid-peritoneal shunt-peritoneal shunt■■ OccasOccas. gastric bypass for weight reduction. gastric bypass for weight reduction

VascularVascular Neoplasms Neoplasms

■■ Classic tumors -Classic tumors - Glomus jugulare Glomus jugulare and andtympanicumtympanicum

■■ Bruit not altered by neck pressure, headBruit not altered by neck pressure, headposition, posture, orposition, posture, or Valsalva Valsalva

■■ TympanometryTympanometry - regular perturbations - regular perturbations■■ OtoscopyOtoscopy - bluish or - bluish or redish redish mass mass poss poss..

pulsation and paling withpulsation and paling with pos pos. pressure. pressure

VascularVascular Neoplasms Neoplasms - 2 - 2

■■ DifDif.. Diag Diag. -. - hemotympanum hemotympanum, dehiscent, dehiscentjugular bulb, carotid artery abnormalityjugular bulb, carotid artery abnormality

■■ Radiograph prior toRadiograph prior to mryingotomy mryingotomy■■ Check H & N for massesCheck H & N for masses■■ Cranial nerve andCranial nerve and cerebellar cerebellar function function■■ If suspected CT scan, mass in ME or erodedIf suspected CT scan, mass in ME or eroded

jugular spine.jugular spine.

VascularVascular Neoplasms Neoplasms - 3 - 3

■■ ArteriographyArteriography■■ MRIMRI■■ Treatment is usually surgicalTreatment is usually surgical

ArteriovenousArteriovenous Malformations Malformations

■■ DevelopementalDevelopemental abnormalities abnormalities■■ Often larger than symptoms suggestOften larger than symptoms suggest■■ May enlarge rapidly and tend to recurMay enlarge rapidly and tend to recur■■ MayMay inpinge inpinge on adjacent structures on adjacent structures■■ PosteriorPosterior fossa fossa occipital artery and occipital artery and

transverse sinus AVM most commontransverse sinus AVM most common■■ AVM of mandible uncommon but notoriousAVM of mandible uncommon but notorious

cause ofcause of tinnitus tinnitus

AVM - 2AVM - 2

■■ Carotid artery/cavernous sinus from traumaCarotid artery/cavernous sinus from trauma■■ Pulsatile tinnitusPulsatile tinnitus often initial complaint often initial complaint■■ HA,HA, papilledema papilledema, bruit with thrill,, bruit with thrill,■■ Heart rate may slow with compressionHeart rate may slow with compression

AVM - TreatmentAVM - Treatment

■■ SurgicalSurgical■■ PreceededPreceeded by by angiography angiography with with

embolizationembolization■■ Tend to be larger than appear onTend to be larger than appear on angio angio..■■ Max benefit if surgery follows within 72 hrsMax benefit if surgery follows within 72 hrs

Venous HumVenous Hum

■■ Eddy currents in IJVEddy currents in IJV■■ Normal in children, some adults,Normal in children, some adults, esp esp. young. young

womenwomen■■ Attributed to Trans.Attributed to Trans. proc proc. C2, increased CO. C2, increased CO

(anemia,(anemia, thyrotoxicosis thyrotoxicosis, pregnancy), pregnancy)■■ Often presents with hearing lossOften presents with hearing loss

Venous Hum - 2Venous Hum - 2

■■ Gentle ant. neck pressure may relieveGentle ant. neck pressure may relieve■■ Head towardHead toward univolved univolved side decreases and side decreases and

to involved side increasesto involved side increases■■ Deep breathing andDeep breathing and Valsalva Valsalva increase increase■■ Treat by reassurance, and correctingTreat by reassurance, and correcting

underlying causeunderlying cause

PalatomyoclonusPalatomyoclonus

■■ Irregular clicking sound, 20-400Irregular clicking sound, 20-400 bpm bpm■■ Occurs intermittentlyOccurs intermittently■■ Palatal musculature and ET mucousPalatal musculature and ET mucous

membranemembrane■■ Also ear fullness, hearing distortionAlso ear fullness, hearing distortion■■ May have other muscle spasmsMay have other muscle spasms■■ Diagnose withDiagnose with Toynbee Toynbee tube in ear canal tube in ear canal

PalatomyoclonusPalatomyoclonus -2 -2

■■ TympanogramTympanogram movement synchronous with movement synchronous withcontractioncontraction

■■ EMG of palatal muscles confirmsEMG of palatal muscles confirms■■ Observable palatal fasciculation - MRIObservable palatal fasciculation - MRI■■ HypertrophicHypertrophic degeneration inferior olive degeneration inferior olive■■ Differentiate from tensor tympani spasm,Differentiate from tensor tympani spasm,

usually transientusually transient

PalatomyoclonusPalatomyoclonus -3 -3

■■ Treatment -Treatment - clonazepam clonazepam, diazepam, warm, diazepam, warmliquids, stress mgmt.liquids, stress mgmt.

■■ BotulinumBotulinum toxin injection in severe cases toxin injection in severe cases

IdiopathicIdiopathic Stapedial Stapedial Muscle MuscleSpasmSpasm

■■ Rough, rumbling, or crackling noiseRough, rumbling, or crackling noise■■ Triggered by external noisesTriggered by external noises■■ Brief and intermittentBrief and intermittent■■ Rarely disruptive and prolongedRarely disruptive and prolonged■■ Variable intensityVariable intensity tympanometry tympanometry to induce to induce

spasmspasm

IdiopathicIdiopathic Stapedial Stapedial Muscle MuscleSpasm - 2Spasm - 2

■■ Acoustic reflex - prolonged continuedAcoustic reflex - prolonged continuedincreased impedance during and after soundincreased impedance during and after soundstimulusstimulus

■■ Treatment -Treatment - clonazepam clonazepam, diazepam, diazepam■■ Symptoms may last only monthsSymptoms may last only months■■ Surgery to divide tendon as last resortSurgery to divide tendon as last resort

SubjectiveSubjective Tinnitus Tinnitus

■■ TinnitusTinnitus originates within auditory system originates within auditory system■■ More commonMore common■■ Little known about physiologic mechanismLittle known about physiologic mechanism■■ Hyperactive hair cells or nerve fibersHyperactive hair cells or nerve fibers■■ Chemical imbalanceChemical imbalance■■ Reduced suppressive influence of CNSReduced suppressive influence of CNS

Auditory PathwayAuditory Pathway

■■ Cochlear hair cells, bipolar neurons of spiralCochlear hair cells, bipolar neurons of spiralganglion make up 8th nerve, terminate onganglion make up 8th nerve, terminate oncochlear nucleuscochlear nucleus

■■ Three pathways - dorsal acousticThree pathways - dorsal acoustic stria stria,,intermediate acousticintermediate acoustic stria stria, trapezoid body, trapezoid body

■■ SuperiorSuperior olivary olivary nuclei nuclei■■ LateralLateral lemniscus lemniscus

Auditory Pathway - 2Auditory Pathway - 2

■■ Bilateral auditory input from outsetBilateral auditory input from outset■■ Central auditory lesions do not causeCentral auditory lesions do not cause

monoauralmonoaural disability disability■■ InferiorInferior colliculus colliculus arranged arranged tonotopically tonotopically■■ MedialMedial geniculate geniculate body, body, ipsilateral ipsilateral■■ Primary Auditory Cortex, Sup. Temp.Primary Auditory Cortex, Sup. Temp.

GyrusGyrus ( (Brodmann’sBrodmann’s areas 41 and 42) areas 41 and 42)

Auditory Brainstem ResponseAuditory Brainstem Response

■■ Auditory evoked responsesAuditory evoked responses■■ ElectrophysiologicElectrophysiologic recordings of response recordings of response

to soundto sound■■ Can be recorded from all levels of auditoryCan be recorded from all levels of auditory

pathwaypathway■■ ABR most applied clinicallyABR most applied clinically■■ Waves from 8th nerve, caudal andWaves from 8th nerve, caudal and rostral rostral

brainstembrainstem

ABR - 2ABR - 2

■■ Wave I - synchronously stimulatedWave I - synchronously stimulatedcompound action potentials from distalcompound action potentials from distal(cochlear) end of 8th nerve(cochlear) end of 8th nerve

■■ Wave II - Also 8th nerve but near brainstemWave II - Also 8th nerve but near brainstem■■ Wave I & II -Wave I & II - ipsilateral ipsilateral to ear stimulated to ear stimulated■■ Later waves have multiple generatorsLater waves have multiple generators■■ Wave III - caudal pons withWave III - caudal pons with cont cont. cochlear. cochlear

nuclei, trapezoid body, sup.nuclei, trapezoid body, sup. olivary olivarycomplexcomplex

ABR - 3ABR - 3

■■ Wave V - most prominent andWave V - most prominent and rostral rostral■■ LateralLateral lemniscus lemniscus near inferior near inferior colliculus colliculus

probably onprobably on contralateral contralateral side to ear side to earstimulatedstimulated

■■ Little difference in ABR inLittle difference in ABR in tinnitus tinnitus

Evaluation - SubjectiveEvaluation - Subjective Tinnitus Tinnitus

■■ Etiologic factors -Etiologic factors - otologic otologic, cardiovascular,, cardiovascular,metabolic,metabolic, neurologic neurologic,, pharmacologic pharmacologic,,dental, psychologicaldental, psychological

■■ H/O noise exposure and related symptoms -H/O noise exposure and related symptoms -hearing loss, vertigohearing loss, vertigo

■■ Exact characterization ofExact characterization of tinnitus tinnitus quality quality■■ Perceptual locationPerceptual location

Evaluation - SubjectiveEvaluation - Subjective Tinnitus Tinnitus

■■ Head injury, whiplash injury, meningitis,Head injury, whiplash injury, meningitis,multiple sclerosismultiple sclerosis

■■ Medications - aspirin, aspirin compounds,Medications - aspirin, aspirin compounds,aminoglycoside antbioticsaminoglycoside antbiotics, NSAIDS,, NSAIDS,heterocyclineheterocycline antidepressants antidepressants

■■ TMJ, dental abnormalities prevalentTMJ, dental abnormalities prevalent■■ PsychologicPsychologic factors, factors, somatoform somatoform disorder disorder■■ DepressionDepression

Evaluation - SubjectiveEvaluation - Subjective Tinnitus Tinnitus

■■ AudiometryAudiometry - - assymetrical assymetrical hearing loss, hearing loss,unilateralunilateral tinnitus tinnitus - MRI r/o post - MRI r/o post fossa fossa

■■ Complete questionnaire for perceivedComplete questionnaire for perceivedseverityseverity

Measurement ofMeasurement of Tinnitus Tinnitus

■■ Pitch, loudness, minimum masking level,Pitch, loudness, minimum masking level,residual inhibition/post maskingresidual inhibition/post masking

■■ Minimum masking level most clinical useMinimum masking level most clinical use■■ Pitch - match most prominent pure tone,Pitch - match most prominent pure tone,

poor reliability, octave differencepoor reliability, octave difference■■ Loudness - Adjust pure tone toLoudness - Adjust pure tone to tinnitus tinnitus■■ Most < 7 dB SL, may be 2 dBMost < 7 dB SL, may be 2 dB

Measurement ofMeasurement of Tinnitus Tinnitus

■■ Minimal masking level - number of decibelsMinimal masking level - number of decibelsto coverto cover tinnitus tinnitus

■■ Residual inhibition - response of patientsResidual inhibition - response of patientstinnitustinnitus post masking post masking

Diagnostic TestsDiagnostic Tests

■■ None available to objectively measure orNone available to objectively measure orconfirmconfirm tinnitus tinnitus

■■ ABR, PET,ABR, PET, SpOAE SpOAE, magnetic activity, magnetic activity

OtoacousticOtoacoustic Emissions Emissions

■■ Low-intensity sounds produced by cochleaLow-intensity sounds produced by cochleaas response to acoustic stimulusas response to acoustic stimulus

■■ Outer hair cell motility affectsOuter hair cell motility affects basilar basilarmembrane -membrane - intracochlear intracochlear amplification, amplification,cochlear tuningcochlear tuning

■■ Generates mechanical energy propagated toGenerates mechanical energy propagated toear canalear canal

■■ Vibration of TM produces acoustic signalVibration of TM produces acoustic signalmeasured by sensitive microphonemeasured by sensitive microphone

SpontaneousSpontaneous Otoacoustic OtoacousticEmissionsEmissions

■■ Measurable without stimulationMeasurable without stimulation■■ Present in 60% with normal hearingPresent in 60% with normal hearing■■ Twice as common in femalesTwice as common in females■■ No relationship yet inNo relationship yet in tinnitus tinnitus

Distortion ProductDistortion Product Otoacoustic OtoacousticEmissionsEmissions

■■ Produced when two pure-toneProduced when two pure-tone simuli simuli,,different frequency simultaneouslydifferent frequency simultaneously

■■ Present in all normal hearingPresent in all normal hearing■■ Damaged outer hair cells - no DPOAEDamaged outer hair cells - no DPOAE■■ 30% damage without30% damage without audiogram audiogram change change■■ Will have abnormal OAEWill have abnormal OAE■■ No correlation inNo correlation in tinnitus tinnitus yet yet

DPOAEDPOAE

■■ Norton - oscillating or prolonged evokedNorton - oscillating or prolonged evokedemission in 5/6emission in 5/6 tinnitus tinnitus patients and 0/2 patients and 0/2withoutwithout

■■ TheyThey suggent suggent that evoked emission and the that evoked emission and thetinnitustinnitus might be related to the same might be related to the sameunderlying pathology, but the former is notunderlying pathology, but the former is notthe cause of the latterthe cause of the latter

TinnitusTinnitus Treatment - Counseling Treatment - Counseling

■■ Etiologic factorsEtiologic factors■■ After work-up,After work-up, unlikelihood unlikelihood of tumor or of tumor or

life-endangering diseaselife-endangering disease■■ 25% improve or go away, 50% decrease,25% improve or go away, 50% decrease,

25% persist, very small portion increase25% persist, very small portion increase■■ Avoid loud noise, wear ear protectionAvoid loud noise, wear ear protection■■ AvoidAvoid caffeinated caffeinated beverages, stimulants beverages, stimulants

(coffee, tea, colas, chocolate)(coffee, tea, colas, chocolate)■■ Stop smokingStop smoking

Tinnitus TreatementTinnitus Treatement - Medication - Medication

■■ Avoid previously mentioned medicinesAvoid previously mentioned medicines■■ Nicotinic acid (BNicotinic acid (B66),), carbamazepine carbamazepine,,

baclofenbaclofen, others; none beneficial, others; none beneficial■■ LidocaineLidocaine beneficial - IV, short 1/2 life, beneficial - IV, short 1/2 life,

poor side effectspoor side effects■■ Oral analogs -Oral analogs - tocainide tocainide,, flecainide flecainide acetate - acetate -

no benefitno benefit

TinnitusTinnitus Treatment - Treatment - Meds Meds

■■ MelatoninMelatonin - 3.0 mg - 3.0 mg qhs qhs does not relieve does not relievetinnitustinnitus

■■ Sleep disturbance - 46.7%Sleep disturbance - 46.7% vs vs. 20% placebo. 20% placebobenefit (p=0.04)benefit (p=0.04)

■■ BenzodiazepinesBenzodiazepines - - clonazepam clonazepam,, oxazepam oxazepam,,alprazolamalprazolam may provide benefit may provide benefit esp esp. with. withconcurrent depressionconcurrent depression

■■ AlprazolamAlprazolam - 76% had reduction in - 76% had reduction inloudness 5% of placeboloudness 5% of placebo

TinnitusTinnitus Treatment - Treatment - Meds Meds

■■ Overall,Overall, meds meds should not be major strategy, should not be major strategy,certain sufferers may benefit incertain sufferers may benefit in conjuntion conjuntionwith other therapywith other therapy

Environmental MaskingEnvironmental Masking

■■ For mildFor mild tinnitus esp tinnitus esp. bothersome in quiet. bothersome in quiet■■ Home environmental maskersHome environmental maskers■■ Broad-band noise, between FM stationsBroad-band noise, between FM stations■■ Particularly useful at nightParticularly useful at night■■ Required noise soft usually does not disturbRequired noise soft usually does not disturb

family membersfamily members

Hearing Aids and MaskersHearing Aids and Maskers

■■ SaltzmannSaltzmann and and Ersner Ersner (1947) - hearing aids (1947) - hearing aidsamplified background noise, maskamplified background noise, mask tinnitus tinnitus

■■ If hearing loss try HA, less interferenceIf hearing loss try HA, less interferencewith speech, no noise to produce damage,with speech, no noise to produce damage,improve speech understandingimprove speech understanding

■■ CommercialCommercial tinnitus tinnitus maskers with or maskers with orwithout HAwithout HA

■■ Complete or partial maskComplete or partial mask■■ No clear guidelines for useNo clear guidelines for use

Hearing Aides and MaskersHearing Aides and Maskers

■■ NarrowbandNarrowband noise (less 1/2 octave) tonal noise (less 1/2 octave) tonalcharacter, more annoyingcharacter, more annoying

■■ Conservative approach - lowest level withConservative approach - lowest level withadequate relief, need not be wornadequate relief, need not be worncontinuouslycontinuously

■■ No protocol which ear, unilateral, bilateralNo protocol which ear, unilateral, bilateral

Electrical StimulationElectrical Stimulation

■■ DC (direct current) to round window orDC (direct current) to round window orpromontory could reducepromontory could reduce tinnitus tinnitus

■■ DC may produce permanent damage,DC may produce permanent damage,cannot be used clinicallycannot be used clinically

■■ AC (AC (alternatigalternatig current) current)■■ ExternalExternal stim stim to to tympanic tympanic membrane, membrane,

transtympanicallytranstympanically on promontory, on promontory,tanscutaneouslytanscutaneously in pre and post auricular in pre and post auricularregionregion

Electrical StimulationElectrical Stimulation

■■ ExtExt. AC. AC stim stim. results mixed, some. results mixed, somepromisingpromising

■■ One commercialOne commercial extracochlear extracochlear wearable wearabledevice marketed 1985device marketed 1985

■■ 19861986 Dobie Dobie 1 in 20 benefited 1 in 20 benefited

IntracochlearIntracochlear Electrical ElectricalStimulationStimulation

■■ Observations that cochlear-implant patientsObservations that cochlear-implant patientsreduction inreduction in tinnitus tinnitus while listening to while listening tospeechspeech

■■ Few received CI explicitly forFew received CI explicitly for tinnitus tinnitus■■ 1984 House 5 patients severe to profound1984 House 5 patients severe to profound

HL, CI placed forHL, CI placed for tinnitus tinnitus relief, no relief, no stim stim..only one reported benefit listening toonly one reported benefit listening tospeech.speech.

IntracochlearIntracochlear Electrical ElectricalStimulationStimulation

■■ 19891989 Hazell Hazell - six totally deaf, CI implant - six totally deaf, CI implantand trials with sinusoidaland trials with sinusoidal stim stim..

■■ Able to reduceAble to reduce tinnitus tinnitus in all 6 with 100 Hz in all 6 with 100 Hzsinusoidsinusoid

■■ Two forego speech processor and used justTwo forego speech processor and used justforfor tinnitus tinnitus relief relief

■■ One turn on current, turn offOne turn on current, turn off tinnitus tinnitus “like a “like alight switch”light switch”

SurgerySurgery

■■ Effective in treating conditions,Effective in treating conditions, tinnitus tinnitus is issymptomsymptom eg eg.. otosclerosis otosclerosis, acoustic, acousticneuromaneuroma,, glomus jugulare glomus jugulare

■■ LituratueLituratue discusses cochlear discusses cochlear neurectomy neurectomyandand microvascular microvascular decompression of the decompression of thecochlear nervecochlear nerve

■■ Results not consistentResults not consistent■■ FewFew otologists otologists advocate use of surgery advocate use of surgery■■ Validates hypothesisValidates hypothesis tinnitus gen tinnitus gen. central. central

NeurophysiologicalNeurophysiological Approach to Approach toTinnitusTinnitus and Habituation and Habituation

■■ New theoryNew theory■■ Previous theories share belief that processPrevious theories share belief that process

producingproducing tinnitus tinnitus restricted to auditory restricted to auditorypathway and cochleapathway and cochlea

■■ Models focused onModels focused on tinnitus tinnitus generation, generation,treated auditory pathway as passive,treated auditory pathway as passive,unchangeable transmitters of signal tounchangeable transmitters of signal toauditory cortexauditory cortex

NeurophysiologicalNeurophysiological Model Model

■■ Diagnostic efforts concentrated onDiagnostic efforts concentrated onpsychoacousticalpsychoacoustical description (loudness, description (loudness,pitch,pitch, maskability maskability))

■■ These no help in predicting treatmentThese no help in predicting treatmentoutcome, nooutcome, no explaination explaination why same why samedescriptdescript produced drastic different produced drastic differentannoyanceannoyance

■■ This model postulates -This model postulates - tinnitus tinnitus results resultsfrom multiple interactions of a number offrom multiple interactions of a number ofsubsystems in nervous systemsubsystems in nervous system

NeurophysiologicalNeurophysiological Model Model

■■ Auditory pathway role in development andAuditory pathway role in development andappearance ofappearance of tinnitus tinnitus as sound perception as sound perception

■■ Other systems, limbic system,Other systems, limbic system, tinnitus tinnitusannoyanceannoyance

■■ Problem - perception becomes associatedProblem - perception becomes associatedwithwith neg neg. emotions, fear , and threat. emotions, fear , and threat

■■ Limbic system activates autonomic nervousLimbic system activates autonomic nervoussystem resulting in annoyancesystem resulting in annoyance

NeurophysiologicNeurophysiologic Model Model

■■ Because annoyance primarily dependent onBecause annoyance primarily dependent onlimbic system which is a perception by thelimbic system which is a perception by theindividual and an associated emotionalindividual and an associated emotionalstate,state, psychoacoustical psychoacoustical characterization of characterization oftinnitustinnitus irrelevant irrelevant

HabituationHabituation

■■ DefDef. - The disappearance of reactions to. - The disappearance of reactions tosensory stimulus because of repetitivesensory stimulus because of repetitiveexposition of a subject to this stimulus andexposition of a subject to this stimulus andthe lack of positive or negativethe lack of positive or negativereinforcement associated with this stimulusreinforcement associated with this stimulus

■■ Brain ordering of tasks 1) importance ofBrain ordering of tasks 1) importance ofsignalsignal esp esp. if danger 2) novelty. if danger 2) novelty

■■ If signal notIf signal not assoc assoc. with event or indicate. with event or indicatedanger, not new, undergoes habituation, anddanger, not new, undergoes habituation, andafter repetition in not perceivedafter repetition in not perceived

HabituationHabituation

■■ Accomplished by directive counseling -Accomplished by directive counseling -educate patient of potential mechanisms ofeducate patient of potential mechanisms oftinnitustinnitus, discuss results of all, discuss results of all audiologic audiologic and andmedical tests andmedical tests and relavance relavance

■■ Once patient understands, level ofOnce patient understands, level ofannoyance decreasesannoyance decreases

■■ RepetativeRepetative visits reinforce and eliminate visits reinforce and eliminatenegative association evoked bynegative association evoked by tinnitus tinnitus

HabituationHabituation

■■ Directive counseling essential but notDirective counseling essential but notsufficient to achieve permanent habituationsufficient to achieve permanent habituation

■■ Need to enhance auditory backgroundNeed to enhance auditory background ie ie..partial masking, particularly in quietpartial masking, particularly in quiet envir envir..

■■ Increased background spontaneous andIncreased background spontaneous andevoked activity in auditory pathways,evoked activity in auditory pathways,reduces contrast ofreduces contrast of tinnitus tinnitus to background to backgroundnoise facilitating habituationnoise facilitating habituation

■■ Must avoid maskingMust avoid masking tinnitus tinnitus completely completely

HabituationHabituation

■■ ByBy def def. once signal is masked it cannot be. once signal is masked it cannot behabituated tohabituated to

■■ Reconditioning of connections inReconditioning of connections insubcorticalsubcortical centers cannot occur if stimulus centers cannot occur if stimulus((tinnitustinnitus) is absent) is absent

■■ TinnitusTinnitus masking 15 masking 15 yrs yrs no changes in no changes intinnitustinnitus, evidence of habituation, decreased, evidence of habituation, decreasedannoyanceannoyance

■■ One year habituation therapy - aware onlyOne year habituation therapy - aware onlysmall percent of time, annoyance decreasedsmall percent of time, annoyance decreased

Habituation - TechniqueHabituation - Technique

■■ Fitted binaurally with broad-band noiseFitted binaurally with broad-band noisegeneratorgenerator

■■ Use for at least 6 hrs per day, part. in quietUse for at least 6 hrs per day, part. in quiet■■ If HL, HA are also usedIf HL, HA are also used■■ Process requires 12 monthsProcess requires 12 months■■ JastreboffJastreboff insists 6 more months to ensure insists 6 more months to ensure

plastic changes in brainplastic changes in brain establised establised■■ After that time noise generatorsAfter that time noise generators

discontinueddiscontinued

Habituation - ResultsHabituation - Results

■■ JabstreboffJabstreboff reports 83% of patients exhibit reports 83% of patients exhibitsignificant improvement with combinedsignificant improvement with combinedtherapytherapy

SummarySummary

■■ Important to differentiate types ofImportant to differentiate types of tinnitus tinnitus■■ Must recognize whenMust recognize when tinnitus tinnitus part of part of

symptomatologysymptomatology of underlying disease of underlying diseaseverses merely auditory annoyanceverses merely auditory annoyance

■■ Patience and understanding of patient’sPatience and understanding of patient’sexperience importantexperience important

■■ Paraauditory tinnitusParaauditory tinnitus treatable by standard treatable by standardmedical/surgical therapymedical/surgical therapy

■■ SubjectiveSubjective tinnitus tinnitus treatment advancing treatment advancing