1 / 24

Acoustic Neuroma Department of Otorhinolaryngoglogy

Acoustic Neuroma Department of Otorhinolaryngoglogy the 2nd Hospital affliatted to Medical college Zhejiang University Xu Yaping. Anatomy Cerebellopontine Angle -CPA (in the posterior fossa). Epidemiology. 6 % of all Intracranial tumors 80 - 90% of CPA tumors

jubal
Download Presentation

Acoustic Neuroma Department of Otorhinolaryngoglogy

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Acoustic Neuroma Department of Otorhinolaryngoglogy the 2nd Hospital affliatted to Medical college Zhejiang University Xu Yaping

  2. AnatomyCerebellopontine Angle-CPA (in the posterior fossa)

  3. 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

  4. Pathogenesis • Neither neuroma or acoustic (auditory) • Schwannoma arising from vestibular nerve • Benign tumor. Malignant degeneration exceedingly rare. • Majority originate within the IAC(the internal auditory canal) • Equal frequency on Superior and Inferior vestibular nerves (controversial)

  5. Jackler Staging System

  6. Phases of Tumor Growth • Intracanalicular: • Hearing loss, tinnitus, vertigo • Cisternal: • Worsened hearing and dysequilibrium • Compressive: • Occasional occipital headache • CN V: Midface, corneal hypesthesia • Hydrocephalic: • Fourth ventricle compressed and obstructed • Headache, visual changes, altered mental status

  7. Intracanalicular Cisternal Hydrocephalic Compressive

  8. Hearing Loss • Most frequent initial symptom • Most common symptom ~ 95% AN patients • Asymmetric SNHL • Down-sloping / High Frequency • Decreased Speech Discrimination • Lack of conclusive correlation between tumor size and hearing

  9. Estimating Tumor Growth • Serial MRI with and without GAD(Gadolinium) ---The only reliable study to estimate tumor growth rate • Gadolinium-enhanced MRI remains the gold standard ---It can detect tumors as small as 1 mm and differentiate AN from many CPA lesions

  10. Delayed Diagnosis Duration of Symptoms Prior to Diagnosis Symptoms Years • Hearing Loss 3.9 • Vertigo 3.6 • Tinnitus 3.4 • Headache 2.2 • Dysequilibrium 1.7 • Trigeminal 0.9 • Facial 0.6 ----Jackler RK. 2000. Tumors of the Ear and Temporal Bone

  11. 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 (IX-XII)

  12. Sudden Sensorineural Hearing loss • Idiopathic • 1-2 % 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

  13. Diagnosis • History and Physical Exam • Audiology testing: • Audiogram • ABR • OAE • Vestibular testings (eg. ENG, rotary chair, posturography) all lack diagnostic value • Radiography • MRI Gold Standard • CT

  14. Pure Tone

  15. ABR: Retrocochlear Pathology(Auditory Brainstem Response) • 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

  16. ABR patterns in AN • 10-20 % with only wave I • and nothing thereafter • 40-60 % with wave V • latency delay • 10-15 % have normal • findings

  17. OAE(Otoacoustic emissions) • 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 surgery

  18. MRI Brain w. & w/o GAD T1 pre-Gad T2 T1 post-Gad T1: Isointense to brain, hyperintense to CSF T2: Hyperintense to brain, hypointense to CSF T1+Gad: Enhancing

  19. CT Brain with contrast • Heterogeneous • enhancement on contrast • 2. Rare calcification • 3. Contraindication to MRI (metallic implants), claustrophobic patients • 4. May not be able to detect small tumor < 1.5cm • 5. Radiation

  20. Treatment options • Observation<5mm • Surgery : >1cm • Translabyrinthine • Retrosigmoid • Middle fossa • Radiotherapy • Conventional • Stereotactic:  knife <1-2cm

  21. 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

  22. 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 study-of-choice to estimate tumor growth is serial MRI

  23. THANKS

More Related