Acoustic Neuroma K. Kevin Ho, M.D. Faculty Advisor: Vicente A. - - PowerPoint PPT Presentation
Acoustic Neuroma & Hearing Loss Acoustic Neuroma K. Kevin Ho, M.D. Faculty Advisor: Vicente A. Resto, M.D., Ph.D. The University of Texas Medical Branch Department of Otolaryngology Grand Rounds Presentation December 6, 2006 K. Kevin
Faculty Advisor: Vicente A. Resto, M.D., Ph.D. The University of Texas Medical Branch Department of Otolaryngology Grand Rounds Presentation December 6, 2006
Jackler RK. 2000, p. 173: Tumors of the Ear and Temporal Bone
1905 Dr. Harvey Cushing
Meticulous dissection Hemostasis: silver clips, bone wax,
electrocautery
Mortality: 20 % (1917) 4% (1931)
1916 Dr. Walter Dandy
Complete removal of AN Mortality: 10%
Early 1960s Dr. William House
Translabyrinthine approach using surgical
drill and operating microscope
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
Neither Neuroma or Acoustic (auditory) Schwannoma arising from vestibular nerve Benign tumor. Malignant degeneration
Majority originate within the IAC Equal frequency on Superior and Inferior
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
Jackler RK. 2000, p. 180: Tumors of the Ear and Temporal Bone Intracanalicular Cisternal Compressive Hydrocephalic
Most frequent initial symptom Most common symptom ~ 95% AN patients Asymmetric SNHL Down-sloping / High Frequency Decreased Speech Discrimination
100 70 50 30 50
P T T (dB) SDS (%)
Myrseth: Neurosurgery, Volume 59(1).July 2006.67-76
Exact etiology is unknown Compressive effect on cochlear nerve Vascular occlusion of internal auditory
Biochemical alterations inner ear fluids
(1-3 cm)
Lustig LR. Am J Otology 1998: 19; 212-8
Lack of conclusive correlation between tumor
< 20 mm > 20 mm
Stipkovits EM et al. Am. J. Otology 1998: 19; 834-9
Battaglia et al. Otol Neurotol. 2006 Aug;27(5):705-712
A D B A B D
Massick DD. Laryngoscope 2000: 110; 1843-9
Change in Tumor Volume (mm3) Change in Tumor Volume (mm3)
PTA SDS
Herwadker A. Otology and Neurotology 2005: 26; 86-92
Side Gender Initial Volume Age
Serial MRI with and without GAD The only reliable study to
O’ Reilly BF et al. Otol Neurotoloty 2000: 25; 791-6
O’ Reilly BF et al. Otol Neurotoloty 2000: 25; 791-6
Jackler RK. 2000. Tumors of the Ear and Temporal Bone
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)
Hearing Loss
Vertigo
Dysequilibrium
Tinnitus
Facial nerve
Trigeminal nerve
Headache
Visual symptoms
Lower cranial nerves: Dysphagia, Hoarseness, Aspiration,
Shoulder weakness (Jugular foramen syndrome)
Jackler RK. 2000, p. 182: Tumors of the Ear and Temporal Bone
Lustig LR. Am J Otology 1998: 19; 212-8
Idiopathic 1-2 % SSNHL patients have AN 10- 26 % AN patients have a history of SSNHL Most experts advocate obtaining MRI in all
History and Physical Exam Audiology testing:
Audiogram ABR OAE
Vestibular testings (eg. ENG, rotary chair,
Radiography
MRI
Gold Standard
CT
Increased interpeak intervals
I-to-III interval of 2.5 ms, III-to-V interval of 2.3 ms,
Interaural wave V latency difference (IT5)
Greater than 0.2 ms
Poor waveform morphology ie. only some of the
Absent waveform
10-20 % with only
40-60 % with wave V
10-15 % have normal
Fraysse B et al. First International Conf. on Acoustic Neuroma. 1992
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)
33 % (5/15) for Intracanalicular Tumor
False positive Rate:
> 80 % (Jackler 2005)
Positive predictive value:
15 % (Weiss 1990 – 4/26) 12 % (Walsted 1992 – 23/185)
Gordon ML. American Journal of Otology. 1995; 16: 136-9
Chandrasekhar SS et al. Am J Otol 1995;16:63-7
Attempt to improve
“Stacking” of derived
Out of 25 ANs, 5
Don M et al. Am J. Otology; 1997: 21; 148-151
Reflect cochlear/ OHC / sensory hearing Not primarily used as screening tool Presence of OAE in SNHL ↔ Retrocochlear However, 50 % AN demonstrate both cochlear and
Risk stratification for hearing preservation surgery Kim AH. Otol Neurotol. 2006 Apr;27(3):372-9
Preoperative TEOAE
T1:
Isointense to brain, hyperintense to CSF
T2:
Hyperintense to brain, hypointense to CSF
T1+Gad: Enhancing
T1 pre-Gad T1 post-Gad T2
Heterogeneous
Rare calcification Contraindication to MRI
May not be able to detect
Radiation
Observation Surgery
Translabyrinthine Retrosigmoid Middle fossa
Radiotherapy
Conventional Stereotactic
Advanced age (> 65 ) Short life expectancy (< 10 years) Slow growth rate Poor surgical candidate / poor general health Minimal symptoms Only hearing ear Patience preference
Prospective cohort study of 72 patients
Age at presentation: 60.8 years Mean follow-up: 80 months
Mean tumor size at diagnosis: 9.4 mm Mean tumor growth rate: 1 mm/ year 87% growth rate < 2 mm/ year Tumor growth
+ : 39 % 0: 42% - : 19%
No correlation between growth and age, gender,
32 % failed conservative management Raut V et a.: Clin Otolaryngol 29:505–514, 2004.
Rohit MS et al. Ann. Oto. Rhino. Laryng. 2006: 115 (1); 41-6
Walsh RM et al. Laryngoscope 2000: 110; 250-5
Tumor size has no correlation with
Understanding tumor growth rate is important
The study-of-choice to estimate tumor growth