Acoustic Acoustic NeuromaNeuroma

K. Kevin Ho, M.D.Vicente A. Resto, M.D., Ph.D.Department of Otolaryngology

University of Texas Medical Branch

Acoustic Neuroma &Hearing Loss

K. Kevin Ho, M.D.Vicente A. Resto, M.D., Ph.D.

UTMB Otolaryngology

http://www.pbase.com/accl/hong_kong

Medieval TimesMedieval Times

1912 Acoustic 1912 Acoustic NeuromaNeuroma SurgerySurgery

Jackler RK. 2000, p. 173: Tumors of the Ear and Temporal Bone

Historical Perspectives Historical Perspectives (cont(contd)d)

1905 Dr. Harvey Cushing1905 Dr. Harvey CushingMeticulous dissectionMeticulous dissectionHemostasisHemostasis: silver clips, bone wax, : silver clips, bone wax, electrocauteryelectrocauteryMortality: 20 % (1917) Mortality: 20 % (1917) 4% (1931)4% (1931)

1916 Dr. Walter Dandy1916 Dr. Walter DandyComplete removal of ANComplete removal of ANMortality: 10%Mortality: 10%

Early 1960s Dr. William HouseEarly 1960s Dr. William HouseTranslabyrinthineTranslabyrinthine approach using surgical approach using surgical drill and operating microscopedrill and operating microscope

Cerebellopontine Angle: AnatomyCerebellopontine Angle: Anatomy

EpidemiologyEpidemiology

6 % of all Intracranial tumors6 % of all Intracranial tumors

80 80 -- 90% of CPA tumors90% of CPA tumors

Incidence in US: 10 per million / yearIncidence in US: 10 per million / year

Vast majority in adulthoodVast majority in adulthood

95% Sporadic (unilateral)95% Sporadic (unilateral)

5% Neurofibromatosis type 2 (bilateral)5% Neurofibromatosis type 2 (bilateral)

No known race, gender predilectionNo known race, gender predilection

PathogenesisPathogenesis

Neither Neither NeuromaNeuroma or Acoustic (auditory)or Acoustic (auditory)

SchwannomaSchwannoma arising from vestibular nervearising from vestibular nerve

Benign tumor. Malignant degeneration Benign tumor. Malignant degeneration exceedingly rare.exceedingly rare.

Majority originate within the IACMajority originate within the IAC

Equal frequency on Superior and Inferior Equal frequency on Superior and Inferior vestibular nerves (vestibular nerves (controversial)controversial)

JacklerJackler Staging SystemStaging System

StageStage Tumor SizeTumor Size

IntracanalicularIntracanalicular Tumor confined to IACTumor confined to IAC

I (small)I (small) < 10 mm< 10 mm

II (medium)II (medium) 1111--25 mm25 mm

III (Large)III (Large) 2525--40 mm40 mm

IV (Giant)IV (Giant) > 40 mm> 40 mm

Phases of Tumor GrowthPhases of Tumor Growth

Intracanalicular:Intracanalicular:Hearing loss, tinnitus, vertigo Hearing loss, tinnitus, vertigo

Cisternal:Cisternal:Worsened hearing and Worsened hearing and dysequilibriumdysequilibrium

Compressive:Compressive:Occasional occipital headacheOccasional occipital headache

CN V: CN V: MidfaceMidface, corneal , corneal hypesthesiahypesthesia

Hydrocephalic:Hydrocephalic:Fourth ventricle compressed and obstructedFourth ventricle compressed and obstructed

Headache, visual changes, altered mental statusHeadache, visual changes, altered mental status

Phases of Tumor GrowthPhases of Tumor Growth

Jackler RK. 2000, p. 180: Tumors of the Ear and Temporal Bone

Intracanalicular Cisternal

Compressive Hydrocephalic

Hearing LossHearing Loss

Most frequent initial symptomMost frequent initial symptom

Most common symptom ~ 95% AN patientsMost common symptom ~ 95% AN patients

Asymmetric SNHLAsymmetric SNHL

DownDown--sloping / High Frequencysloping / High Frequency

Decreased Speech DiscriminationDecreased Speech Discrimination

Serviceable HearingServiceable Hearing

100 70 50 00

30

50

A

DB

C

PTT

(dB)

SDS (%)

Distribution of Hearing in ANDistribution of Hearing in AN

Myrseth: Neurosurgery, Volume 59(1).July 2006.67-76

PathophysiologyPathophysiology of Hearing Lossof Hearing Lossin Acoustic in Acoustic NeuromaNeuroma

Exact etiology is unknownExact etiology is unknown

Compressive effect on cochlear nerveCompressive effect on cochlear nerve

Vascular occlusion of internal auditory Vascular occlusion of internal auditory arteryartery

Biochemical alterations inner ear fluidsBiochemical alterations inner ear fluids

Normal or Symmetrical Hearing in Normal or Symmetrical Hearing in Acoustic Acoustic NeuromaNeuroma

SelesnickSelesnick19931993

ShaanShaan19931993

LustigLustig19981998

MagdziarzMagdziarz20002000

AN AN patientspatients

126126 100100 546546 369369

Normal Normal hearing hearing

55

(4%)(4%)

66

(6%)(6%)

2929

(5%)(5%)

1010

(3%)(3%)

Tumor Size and HearingTumor Size and Hearing

Normal HearingNormal Hearing

(29 Patients)(29 Patients)All All ANsANs

(126 Patients)(126 Patients)

% Small % Small

(< 1cm)(< 1cm)

4545 2424

% Medium % Medium

(1(1--3 cm)3 cm)

4242 5959

% Large % Large

(> 3 cm)(> 3 cm)

1212 1616

Lustig LR. Am J Otology 1998: 19; 212-8

Tumor size & HearingTumor size & Hearing

Lack of conclusive correlation between tumor Lack of conclusive correlation between tumor size and hearingsize and hearing

< 20 mm > 20 mm

Stipkovits EM et al. Am. J. Otology 1998: 19; 834-9

Tumor Growth RateTumor Growth Rate

Battaglia et al. Otol Neurotol. 2006 Aug;27(5):705-712

Tumor Growth: StudiesTumor Growth: Studies

NN FollowFollow--up up No No Growth Growth

(%)(%)

--Growth Growth

(%)(%)

+ + Growth Growth

(%)(%)

BedersonBederson 7070 26 mo26 mo 4040 77 5353

SelesnickSelesnick 558558 3 yr3 yr -- -- 5454

CharabiCharabi 126126 3.8 yr3.8 yr 1212 66 8282

RautRaut 7272 80 mo80 mo 4242 1919 3939

WalshWalsh 7272 3.2 yr3.2 yr 5050 1414 3737

Tumor Growth & HearingTumor Growth & Hearing

A

D BA

B

D

Massick DD. Laryngoscope 2000: 110; 1843-9

Change in Tumor Volume (mm3)Change in Tumor Volume (mm3)

PTA SDS

Predicting Tumor GrowthPredicting Tumor Growth

Herwadker A. Otology and Neurotology 2005: 26; 86-92

Side Gender

Initial Volume

Age

Estimating Tumor GrowthEstimating Tumor Growth

Serial MRI with and without GADSerial MRI with and without GAD

The only reliable study to The only reliable study to estimate tumor growth rateestimate tumor growth rate

Tumor Growth: BiomarkersTumor Growth: Biomarkers

O Reilly BF et al. Otol Neurotoloty 2000: 25; 791-6

Fibroblast Growth Factor ReceptorFibroblast Growth Factor Receptor

O Reilly BF et al. Otol Neurotoloty 2000: 25; 791-6

Delayed DiagnosisDelayed Diagnosis

Duration of Symptoms Prior to DiagnosisDuration of Symptoms Prior to Diagnosis

Symptoms Years

Hearing Loss 3.9Vertigo 3.6Tinnitus 3.4Headache 2.2Dysequilibrium 1.7Trigeminal 0.9Facial 0.6

Jackler RK. 2000. Tumors of the Ear and Temporal Bone

History and PhysicalHistory and Physical

Hearing LossHearing LossVertigoVertigoDysequilibriumDysequilibriumTinnitusTinnitusHeadacheHeadacheNystagmusNystagmus

Early small lesion: Horizontal (vestibular)Early small lesion: Horizontal (vestibular)Late large: Vertical (brainstem compression)Late large: Vertical (brainstem compression)

Cranial neuropathyCranial neuropathyCN V, VIICN V, VIILower cranial nerves (IXLower cranial nerves (IX--XII)XII)

Frequency of SymptomsFrequency of SymptomsHearing LossHearing Loss ((8585--97% 97% ; ; 94%94% ) ) Vertigo Vertigo ((55--70 %70 % ; 39% ) ; 39% ) Dysequilibrium Dysequilibrium ((4646--70%70% ; 56 %) ; 56 %) Tinnitus Tinnitus ((5656--70%70% ; 64 %) ; 64 %) Facial nerve Facial nerve ((1010--77%77% ; 38 %); 38 %)Trigeminal nerve Trigeminal nerve ((1616--63%63% ; 26 %); 26 %)Headache Headache ((1212--38%38% ; 25% ); 25% )Visual symptomsVisual symptoms ((11-- 15 %15 % ; 7% ); 7% )Lower cranial nerves: Dysphagia, Hoarseness, Aspiration, Lower cranial nerves: Dysphagia, Hoarseness, Aspiration, Shoulder weakness (Jugular foramen syndrome)Shoulder weakness (Jugular foramen syndrome)

Jackler RK. 2000, p. 182: Tumors of the Ear and Temporal Bone

Symptoms in AN patients with Symptoms in AN patients with Normal HearingNormal Hearing

Lustig LR. Am J Otology 1998: 19; 212-8

Sudden Sudden SensorineuralSensorineural Hearing lossHearing loss

IdiopathicIdiopathic

11--2 % SSNHL patients have AN2 % SSNHL patients have AN

1010-- 26 % AN patients have a history of SSNHL26 % AN patients have a history of SSNHL

Most experts advocate obtaining MRI in all Most experts advocate obtaining MRI in all patients who present with SSNHLpatients who present with SSNHL

DiagnosisDiagnosis

History and Physical ExamHistory and Physical ExamAudiology testing:Audiology testing:

AudiogramAudiogramABRABROAEOAE

Vestibular testings (Vestibular testings (egeg. ENG, rotary chair, . ENG, rotary chair, posturography) all lack diagnostic valueposturography) all lack diagnostic valueRadiographyRadiography

MRIMRI Gold StandardGold StandardCTCT

Pure Tone and Speech Pure Tone and Speech AudiometryAudiometry

ABR: ABR: RetrocochlearRetrocochlear PathologyPathology

Increased interpeak intervals I-to-III interval of 2.5 ms, III-to-V interval of 2.3 ms, and I-to-V interval of 4.4 ms

Interaural wave V latency difference (IT5) Greater than 0.2 ms

Poor waveform morphology ie. only some of the waves are discernible

Absent waveform

ABR patterns in ANABR patterns in AN

1010--20 %20 % with only with only wave I and nothing wave I and nothing thereafterthereafter

4040--60 %60 % with wave V with wave V latency delaylatency delay

1010--15 %15 % have normal have normal findingsfindings

Fraysse B et al. First International Conf. on Acoustic Neuroma. 1992

ABR: Diagnostic EfficiencyABR: Diagnostic Efficiency

Generally, Efficiency increases with SizeGenerally, Efficiency increases with Size

Sensitivity: > 90 % for tumor > 3 cm Sensitivity: > 90 % for tumor > 3 cm

No response for severe/ profound SNHL No response for severe/ profound SNHL ((RupaRupa 2003)2003)

False negative Rate: False negative Rate: 15 % (Wilson 1992 15 % (Wilson 1992 6/40)6/40)

33 % (5/15) for 33 % (5/15) for IntracanalicularIntracanalicular TumorTumor

False positive Rate:False positive Rate:> 80 % (> 80 % (JacklerJackler 2005)2005)

Positive predictive value:Positive predictive value:15 % (Weiss 1990 15 % (Weiss 1990 4/26)4/26)

12 % (12 % (WalstedWalsted 1992 1992 23/185)23/185)

ABR: Sensitivity & Tumor sizeABR: Sensitivity & Tumor size

Gordon ML. American Journal of Otology. 1995; 16: 136-9

IT 5 & Tumor SizeIT 5 & Tumor Size

Chandrasekhar SS et al. Am J Otol 1995;16:63-7

Stacked ABRStacked ABR

Attempt to improve Attempt to improve detection rate in small detection rate in small < 1 cm < 1 cm ANsANsStackingStacking of derived of derived band responseband responseOut of 25 Out of 25 ANsANs, 5 , 5 tumors less than 1 cm tumors less than 1 cm missed in Standard missed in Standard ABR were picked up by ABR were picked up by Stacked ABR.Stacked ABR.

Don M et al. Am J. Otology; 1997: 21; 148-151

OAEOAEReflect Reflect cochlearcochlear/ OHC / sensory hearing/ OHC / sensory hearing

Not primarily used as screening toolNot primarily used as screening tool

Presence of OAE in SNHL Presence of OAE in SNHL RetrocochlearRetrocochlear

However, 50 % AN demonstrate both cochlear and However, 50 % AN demonstrate both cochlear and retrocochlearretrocochlear hearing losshearing loss

Risk stratification for hearing preservation surgeryRisk stratification for hearing preservation surgery

Kim AH. Otol Neurotol. 2006 Apr;27(3):372-9

Preoperative TEOAE

MRI Brain w. & w/o GADMRI Brain w. & w/o GAD

T1: T1: Isointense to brainIsointense to brain, , hyperintense to CSFhyperintense to CSF

T2: T2: HyperintenseHyperintense to brain, to brain, hypointense to CSFhypointense to CSF

T1+Gad: T1+Gad: EnhancingEnhancing

T1 pre-Gad T1 post-GadT2

CT Brain with contrastCT Brain with contrast

Heterogeneous Heterogeneous enhancement on contrastenhancement on contrast

Rare calcificationRare calcification

Contraindication to MRI Contraindication to MRI (metallic implants), (metallic implants), claustrophobic patientsclaustrophobic patients

May not be able to detect May not be able to detect small tumor < 1.5cmsmall tumor < 1.5cm

RadiationRadiation

Treatment optionsTreatment options

ObservationObservation

Surgery Surgery TranslabyrinthineTranslabyrinthine

RetrosigmoidRetrosigmoid

Middle fossaMiddle fossa

RadiotherapyRadiotherapyConventionalConventional

StereotacticStereotactic

Conservative ManagementConservative Management

Advanced age (> 65 )Advanced age (> 65 )

Short life expectancy (< 10 years) Short life expectancy (< 10 years)

Slow growth rateSlow growth rate

Poor surgical candidate / poor general healthPoor surgical candidate / poor general health

Minimal symptomsMinimal symptoms

Only hearing earOnly hearing ear

Patience preferencePatience preference

Observation: Observation: RautRaut 20042004Prospective cohort study of 72 patientsProspective cohort study of 72 patients

Age at presentation: 60.8 yearsAge at presentation: 60.8 yearsMean followMean follow--up: 80 monthsup: 80 months

Mean tumor size at diagnosis: 9.4 mmMean tumor size at diagnosis: 9.4 mmMean tumor growth rate: 1 Mean tumor growth rate: 1 mmmm/ year/ year87% growth rate < 2 87% growth rate < 2 mmmm/ year/ yearTumor growth Tumor growth

+ : 39 %+ : 39 %0: 42%0: 42%-- : 19% : 19%

No correlation between growth and age, gender, No correlation between growth and age, gender, size at presentation, or presenting symptomssize at presentation, or presenting symptoms32 % failed conservative management32 % failed conservative management

Raut V et a.: Clin Otolaryngol 29:505514, 2004.

PreopPreop Predictive factors for Hearing Predictive factors for Hearing Preservation SurgeryPreservation Surgery

Rohit MS et al. Ann. Oto. Rhino. Laryng. 2006: 115 (1); 41-6

Loss of Serviceable Hearing during Loss of Serviceable Hearing during ObservationObservation

Walsh RM et al. Laryngoscope 2000: 110; 250-5

ConclusionsConclusions

Tumor size has no correlation with Tumor size has no correlation with audiovestibularaudiovestibular symptoms in Acoustic symptoms in Acoustic neuromaneuroma

Understanding tumor growth rate is important Understanding tumor growth rate is important for predicting symptom progression and for predicting symptom progression and treatment planningtreatment planning

The studyThe study--ofof--choice to estimate tumor growth choice to estimate tumor growth is serial MRIis serial MRI

Thank You

Acoustic NeuromaMedieval Times1912 Acoustic Neuroma SurgeryHistorical Perspectives (contd)Cerebellopontine Angle: AnatomyEpidemiologyPathogenesisJackler Staging SystemPhases of Tumor GrowthPhases of Tumor GrowthHearing LossServiceable HearingDistribution of Hearing in ANPathophysiology of Hearing Lossin Acoustic NeuromaNormal or Symmetrical Hearing in Acoustic Neuroma Tumor Size and HearingTumor size & HearingTumor Growth RateTumor Growth: StudiesTumor Growth & HearingPredicting Tumor GrowthEstimating Tumor GrowthTumor Growth: BiomarkersFibroblast Growth Factor ReceptorDelayed DiagnosisHistory and PhysicalFrequency of SymptomsSymptoms in AN patients with Normal HearingSudden Sensorineural Hearing lossDiagnosisPure Tone and Speech AudiometryABR: Retrocochlear PathologyABR patterns in ANABR: Diagnostic EfficiencyABR: Sensitivity & Tumor sizeIT 5 & Tumor SizeStacked ABROAEMRI Brain w. & w/o GADCT Brain with contrastTreatment optionsConservative ManagementObservation: Raut 2004Preop Predictive factors for Hearing Preservation SurgeryLoss of Serviceable Hearing during ObservationConclusions