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Acoustic-Neuroma-slides-061206 - Acoustic Neuroma &...

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Unformatted text preview: Acoustic Neuroma & Acoustic Neuroma Acoustic Neuroma Hearing Loss K. Kevin Ho, M.D. Vicente A. Resto, M.D., Ph.D. K. Kevin Ho, M.D. Department of Otolaryngology Vicente A. Resto, M.D., Ph.D. University of Texas Medical Branch UTMB Otolaryngology Medieval Times Medieval Times 1912 Acoustic Neuroma Surgery 1912 Acoustic Neuroma Surgery Jackler RK. 2000, p. 173: Tumors of the Ear and Temporal Bone Historical Perspectives (cont’d) Historical Perspectives 1905 Dr. Harvey Cushing 1916 Dr. Walter Dandy Meticulous dissection Hemostasis: silver clips, bone wax, electrocautery Mortality: 20 % (1917) 4% (1931) Complete removal of AN Mortality: 10% Early 1960s Dr. William House Translabyrinthine approach using surgical drill and operating microscope Anatomy Anatomy Cerebellopontine Angle: Cerebellopontine Angle: Anatomy Epidemiology Epidemiology 6 % of all Intracranial tumors 80 ­ 90% of CPA tumors Incidence in US: 10 per million / year Vast majority in adulthood 95% Sporadic (unilateral) 5% Neurofibromatosis type 2 (bilateral) No known race, gender predilection Pathogenesis Pathogenesis Neither Neuroma or Acoustic (auditory) Schwannoma arising from vestibular nerve Benign tumor. Malignant degeneration exceedingly rare. Majority originate within the IAC Equal frequency on Superior and Inferior vestibular nerves (controversial) Jackler Staging System Jackler Staging System Stage Tumor Size Intracanalicular Tumor confined to IAC I (small) < 10 mm II (medium) 11­25 mm III (Large) 25­40 mm IV (Giant) > 40 mm Phases of Tumor Growth Phases of Tumor Growth Intracanalicular: Cisternal: Worsened hearing and dysequilibrium Compressive: Hearing loss, tinnitus, vertigo Occasional occipital headache CN V: Midface, corneal hypesthesia Hydrocephalic: Fourth ventricle compressed and obstructed Headache, visual changes, altered mental status Phases of Tumor Growth Phases of Tumor Growth Intracanalicular Compressive Cisternal Hydrocephalic Jackler RK. 2000, p. 180: Tumors of the Ear and Temporal Bone Hearing Loss Hearing Loss Most frequent initial symptom Most common symptom ~ 95% AN patients Asymmetric SNHL Down­sloping / High Frequency Decreased Speech Discrimination Serviceable Hearing Serviceable Hearing SDS (%) 0 P T T (dB) 30 100 70 50 0 A B 50 C D Distribution of Hearing in AN Distribution of Hearing in AN Myrseth: Neurosurgery, Volume 59(1).July 2006.67­76 Pathophysiology of Hearing Loss Pathophysiology of Hearing Loss in Acoustic Neuroma Exact etiology is unknown Compressive effect on cochlear nerve Vascular occlusion of internal auditory artery Biochemical alterations inner ear fluids Normal or Symmetrical Hearing in Normal or Symmetrical Hearing in Acoustic Neuroma Selesnick 1993 AN patients Normal hearing Shaan Lustig 1993 1998 Magdziar z 126 100 546 369 5 6 29 10 (4%) (6%) (5%) (3%) 2000 Tumor Size and Hearing Tumor Size and Hearing Normal Hearing All ANs % Small (29 Patients) 45 (126 Patients) 24 (< 1cm) % Medium 42 59 12 16 (1­3 cm) % Large (> 3 cm) Lustig LR. Am J Otology 1998: 19; 212­8 Tumor size & Hearing Tumor size & Hearing Lack of conclusive correlation between tumor size and hearing < 20 mm > 20 mm Stipkovits EM et al. Am. J. Otology 1998: 19; 834­9 Tumor Growth Rate Tumor Growth Rate Battaglia et al. Otol Neurotol. 2006 Aug;27(5):705­712 Tumor Growth: Studies Tumor Growth: Studies N Bederson Follow­up 70 26 mo Selesnick 558 No + Growth Growth Growth (%) (%) (%) 40 7 53 3 yr ­ ­ 54 Charabi 126 3.8 yr 12 6 82 Raut 72 80 mo 42 19 39 Walsh 72 3.2 yr 50 14 37 Tumor Growth & Hearing Tumor Growth & Hearing B D A A B D Change in Tumor Volume (mm3) PTA Change in Tumor Volume (mm3) SDS Massick DD. Laryngoscope 2000: 110; 1843­9 Predicting Tumor Growth Predicting Tumor Growth Side Initial Volume Gender Age Herwadker A. Otology and Neurotology 2005: 26; 86­92 Estimating Tumor Growth Estimating Tumor Growth Serial MRI with and without GAD The only reliable study to estimate tumor growth rate Tumor Growth: Biomarkers Tumor Growth: Biomarkers O’ Reilly BF et al. Otol Neurotoloty 2000: 25; 791­6 Fibroblast Growth Factor Receptor Fibroblast Growth Factor Receptor O’ Reilly BF et al. Otol Neurotoloty 2000: 25; 791­6 Delayed Diagnosis Delayed Diagnosis Duration of Symptoms Prior to Diagnosis Symptoms Years Hearing Loss Vertigo Tinnitus Headache Dysequilibrium Trigeminal Facial 3.9 3.6 3.4 2.2 1.7 0.9 0.6 Jackler RK. 2000. Tumors of the Ear and Temporal Bone History and Physical History and Physical Hearing Loss Vertigo Dysequilibrium Tinnitus Headache Nystagmus Early small lesion: Horizontal (vestibular) Late large: Vertical (brainstem compression) Cranial neuropathy CN V, VII Lower cranial nerves (IX­XII) Frequency of Symptoms Frequency of Symptoms Hearing Loss Vertigo Dysequilibrium Tinnitus Facial nerve Trigeminal nerve Headache Visual symptoms (85­97% ; 94% ) (5­70 % ; 39% ) (46­70% ; 56 %) (56­70% ; 64 %) (10­77% ; 38 %) (16­63% ; 26 %) (12­38% ; 25% ) (1­ 15 % ; 7% ) Lower cranial nerves: Dysphagia, Hoarseness, Aspiration, 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 Hearing Lustig LR. Am J Otology 1998: 19; 212­8 Sudden Sensorineural Hearing loss Sudden Sensorineural Hearing loss Idiopathic 1­2 % SSNHL patients have AN 10­ 26 % AN patients have a history of SSNHL Most experts advocate obtaining MRI in all patients who present with SSNHL Diagnosis Diagnosis History and Physical Exam Audiology testing: Audiogram ABR OAE Vestibular testings (eg. ENG, rotary chair, posturography) all lack diagnostic value Radiography MRI CT Gold Standard Pure Tone and Speech Audiometry Pure Tone and Speech Audiometry ABR: Retrocochlear Pathology ABR: Retrocochlear Pathology Increased interpeak intervals Interaural wave V latency difference (IT5) I­to­III interval of 2.5 ms, III­to­V interval of 2.3 ms, and I­to­V interval of 4.4 ms Greater than 0.2 ms Poor waveform morphology ie. only some of the waves are discernible Absent waveform ABR patterns in AN ABR patterns in AN 10­20 % with only wave I and nothing thereafter 40­60 % with wave V latency delay 10­15 % have normal findings Fraysse B et al. First International Conf. on Acoustic Neuroma. 1992 ABR: Diagnostic Efficiency ABR: Diagnostic Efficiency Generally, Efficiency increases with Size Sensitivity: > 90 % for tumor > 3 cm No response for severe/ profound SNHL (Rupa 2003) False negative Rate: 15 % (Wilson 1992 – 6/40) False positive Rate: 33 % (5/15) for Intracanalicular Tumor > 80 % (Jackler 2005) Positive predictive value: 15 % (Weiss 1990 – 4/26) 12 % (Walsted 1992 – 23/185) ABR: Sensitivity & Tumor size ABR: Sensitivity & Tumor size Gordon ML. American Journal of Otology. 1995; 16: 136­9 IT 5 & Tumor Size IT 5 & Tumor Size Chandrasekhar SS et al. Am J Otol 1995;16:63­ 7 Stacked ABR Stacked ABR Attempt to improve detection rate in small < 1 cm ANs “Stacking” of derived band response Out of 25 ANs, 5 tumors less than 1 cm missed in Standard ABR were picked up by Stacked ABR. Don M et al. Am J. Otology; 1997: 21; 148­151 OAE OAE Reflect cochlear/ OHC / sensory hearing Not primarily used as screening tool Presence of OAE in SNHL ↔ Retrocochlear However, 50 % AN demonstrate both cochlear and retrocochlear hearing loss Risk stratification for hearing preservation Preoperative TEOAE surgery Kim AH. Otol Neurotol. 2006 Apr;27(3):372­9 MRI Brain w. & w/o GAD MRI Brain w. & w/o GAD T1 pre­Gad T1: T2: T1+Gad: T2 T1 post­Gad Isointense to brain, hyperintense to CSF Hyperintense to brain, hypointense to CSF Enhancing CT Brain with contrast CT Brain with contrast Heterogeneous enhancement on contrast Rare calcification Contraindication to MRI (metallic implants), claustrophobic patients May not be able to detect small tumor < 1.5cm Radiation Treatment options Treatment options Observation Surgery Translabyrinthine Retrosigmoid Middle fossa Radiotherapy Conventional Stereotactic Conservative Management Conservative Management Advanced age (> 65 ) Short life expectancy (< 10 years) Slow growth rate Poor surgical candidate / poor general health Minimal symptoms Only hearing ear Patience preference Observation: Raut 2004 Observation: Raut 2004 Prospective cohort study of 72 patients Mean tumor size at diagnosis: 9.4 mm Mean tumor growth rate: 1 mm/ year 87% growth rate < 2 mm/ year Tumor growth Age at presentation: 60.8 years Mean follow­up: 80 months + : 39 % 0: 42% ­ : 19% No correlation between growth and age, gender, size at presentation, or presenting symptoms 32 % failed conservative management Raut V et a.: Clin Otolaryngol 29:505–514, 2004. Preop Predictive factors for Hearing Preop Predictive factors for Hearing Preservation Surgery Rohit MS et al. Ann. Oto. Rhino. Laryng. 2006: 115 (1); 41­6 Loss of Serviceable Hearing during Loss of Serviceable Hearing during Observation Walsh RM et al. Laryngoscope 2000: 110; 250­5 Conclusions Conclusions Tumor size has no correlation with audiovestibular symptoms in Acoustic neuroma Understanding tumor growth rate is important for predicting symptom progression and treatment planning The study­of­choice to estimate tumor growth is serial MRI Thank You ...
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