Download OtOlOgy, NeurOtOlOgy, aNd Skull BaSe Surgery

Otology, Neurotology,
and Skull Base SURGERY
Clinical Reference Guide
Theodore R. McRackan, MD
Derald E. Brackmann, MD
Contents
Foreword by Harold C. Pillsbury, MD
xi
Introduction
xiii
Acknowledgmentsxv
About the Editors
xvi
Contributors
xvii
Section I
History of Neurotology
1
Chapter 1
History of Neurotology and Skull Base Surgery
Lawrence R. Lustig
3
Section II
Embryology Anatomy Physiology
13
Chapter 2
Embryological Development of the Ear
Theodore R. McRackan and George B. Wanna
15
Chapter 3
Anatomy and Physiology of the Auditory System
Gregory J. Basura and Steven A. Telian
23
Chapter 4
Anatomy and Physiology of the Vestibular System
Gregory T. Whitman and Timothy C. Hain
33
Section III
Evaluation
45
Chapter 5
The Neurotologic Examination
Stanley Pelosi
47
Chapter 6
Hearing Assessment
René H. Gifford
55
Chapter 7
Vestibular Testing
Yuri Agrawal
67
Chapter 8
Intraoperative Monitoring
Christopher K. Giardina and Oliver F. Adunka
75
Section IV
Common Otologic Symptoms
83
Chapter 9
Tinnitus
Theodore R. McRackan and John C. Goddard
85
v
vi Otology, Neurotology, and Skull Base Surgery: Clinical Reference Guide
Chapter 10
Otalgia and Temporomandibular Joint Disorders
Jason A. Beyea and Aaron C. Moberly
93
Section V
Hearing Loss
99
Chapter 11
Congenital and Genetic Hearing Loss
Seiji B. Shibata and Richard J. Smith
101
Chapter 12
Otosclerosis
Felipe Santos and Michael J. McKenna
111
Chapter 13
Presbycusis
Simon I. Angeli
119
Chapter 14
Noise-Induced Hearing Loss
Brian S. Chen and William M. Luxford
125
Chapter 15
Traumatic Injuries to the Ear
Bradley W. Kesser
131
Chapter 16
Autoimmune Inner Ear Disease
M. Jennifer Derebery
141
Chapter 17
Sudden Sensorineural Hearing Loss
David S. Haynes and Jacob B. Hunter
149
Chapter 18
Ototoxicity
Joseph T. Breen and Jeffrey T. Vrabec
157
Chapter 19
Rare Causes of Hearing Loss
Oliver F. Adunka and Craig A. Buchman
169
Section VI
Otologic Infections
177
Chapter 20
Otitis Externa
Theodore R. McRackan and Marc L. Bennett
179
Chapter 21
Otitis Media
Sujana S. Chandrasekhar
187
Chapter 22
Cholesteatoma
Brendan P. O’Connell and Ted A. Meyer
197
Chapter 23
Petrous Apicitis and Intracranial Infection
Anthony Myint, Joel Lavinsky, John L. Go, and
Rick A. Friedman
209
CONTENTS vii
Section VII
Hearing Rehabilitation
221
Chapter 24
Hearing Aids
Monica M. Andriacchi and John W. House
223
Chapter 25
Implantable Hearing Devices
Sohit Kanotra and Moises A. Arriaga
233
Chapter 26
Cochlear Implants
Robert F. Labadie
247
Chapter 27
Auditory Brainstem Implants
Daniel S. Roberts and Eric P. Wilkinson
259
Section VIII Skull Base Disorders
267
Chapter 28
Skull Base and Intracranial Anatomy
C. Eduardo Corrales and Robert K. Jackler
269
Chapter 29
Vestibular Schwannoma
Theodore R. McRackan and Derald E. Brackmann
281
Chapter 30
Meningiomas
Colin L. W. Driscoll
291
Chapter 31
Neurofibromatosis Type II
Brian S. Chen and William H. Slattery III
301
Chapter 32
Stereotactic Radiosurgery in Neurotology
P. Ashley Wackym, Andrew Y. Kee, and
Norman Jed Schroeder
309
Chapter 33
Temporal Bone Malignancy
Paul W. Gidley
321
Chapter 34
Jugular Foramen Lesions
Theodore R. McRackan and James L. Netterville
331
Chapter 35
Lesions of the Cerebellopontine Angle and Petrous Apex
David R. Friedmann, J. Thomas Roland, Jr., and
Sean O. McMenomey
341
Chapter 36
Cerebrospinal Fluid Leaks and Encephaloceles
Jeffrey D. Sharon and Howard W. Francis
351
viii Otology, Neurotology, and Skull Base Surgery: Clinical Reference Guide
Chapter 37
Complications from Neurotologic Surgery
Marc S. Schwartz
361
Section IX
Vestibular Disorders
371
Chapter 38
Bedside Vestibular Evaluation
Evan Graboyes and Joel Goebel
373
Chapter 39
Ménière’s Disease
Cameron C. Wick, Maroun T. Semaan, and
Cliff A. Megerian
389
Chapter 40
Benign Paroxysmal Positional Vertigo
Judith A. White
401
Chapter 41
Superior Semicircular Canal Dehiscence Syndrome 409
Heather M. Weinreich and John P. Carey
Chapter 42
Labyrinthitis and Vestibular Neuronitis
Edward I. Cho
419
Chapter 43
Vestibular Migraine
Michael Thomas Teixido
427
Chapter 44
Nonotologic Causes of Dizziness
Timothy C. Hain and Marcello Cherchi
439
Chapter 45
Vestibular Therapy
Elizabeth Grace Georgelos
449
Section X
Facial Nerve
459
Chapter 46
Embryology and Anatomy of the Facial Nerve
Matthew L. Carlson and Alex D. Sweeney
461
Chapter 47
Electrodiagnostic Testing of the Facial Nerve
Joseph P. Roche and Marlan R. Hansen
473
Chapter 48
Acute Facial Nerve Palsy
Joseph P. Roche and Bruce J. Gantz
481
Chapter 49
Primary Facial Nerve Tumors
Alejandro Rivas and Theodore R. McRackan
493
Chapter 50
Facial Nerve Rehabilitation
Caroline A. Banks and Tessa A. Hadlock
501
CONTENTS ix
Section XI
Pediatric Otology
511
Chapter 51
Hearing Loss Syndromes
Lourdes Quintanilla-Dieck and Steven Goudy
513
Chapter 52
Congenital Aural Atresia
Paul R. Lambert
525
Section XII Other Otologic Considerations
531
Chapter 53
Otologic Manifestations of Systemic Disorders
J. Eric Lupo
533
Chapter 54
External Auditory Canal Lesions
Elliott D. Kozin and Daniel J. Lee
545
Chapter 55
On the Horizon
Justin S. Golub and Ravi N. Samy
553
Index
563
Foreword
This remarkable text, edited by Drs. McRackan and Brackmann, is a significant addition to our armamentarium of references in the field of otology, neurotology, and skull base surgery. The chapters are well-written and
encompass the scope of the subspecialty. Each author is a well-recognized
expert in their field and the format of the chapters by outline is extremely
easy to follow. It is an outstanding reference for residents, fellows, and
practicing otolaryngologists as well as neurotologists. The text is simplistic and easily addresses any question that may arise in the mind of the
reader. This is clearly a reference guide. No attempts have been made to
increase the prose to describe the topics, but that is not to say that the
key issues are hard to assess using the format. The editors are to be commended in formulating a text that is extremely user-friendly to the reader.
In these days where the majority of information we seek is available on the
Internet, this particular book will be a completely different offering that
will be a welcome addition to anyone’s library. I look forward to receiving
my copy!!!
— Harold C. Pillsbury, MD
Professor and Chief
Otolaryngology-Head and Neck Surgery
The University of North Carolina at Chapel Hill
xi
Chapter
29
Vestibular Schwannoma
Theodore R. McRackan and Derald E. Brackmann
Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282
Epidemiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282
Pathophysiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282
Presentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283
Diagnosis and Evaluation . . . . . . . . . . . . . . . . . . . . . . 284
Natural History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285
Treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285
Observation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286
Microsurgery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286
Radiosurgery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289
281
282 Otology, Neurotology, and Skull Base Surgery: Clinical Reference Guide
Nomenclature
• Virchow named lesion neuroma due to parallel fibers on histology
appear to be axons
• Initially thought to be cochlear origin due to associated hearing loss
• Murrey and Stout discovered origin cell to be Schwann cell
• Preferred name is currently vestibular schwannoma (VS) although
acoustic neuroma is still widely used
Epidemiology
• Represent approximately 6% of all intracranial tumors
• Prospective Denmark database estimate approximately 20 VS per 1
million population
• Incidence increasing due to awareness and improved imaging access
and quality
1. 7.8 VS/million 1976 to peak 23 VS/million year 2004
• Tumor size at time of diagnosis has decreased from 30 mm in mid1970s to current 10 mm
• Mean age at diagnosis has also decreased from 58 years to 49 years
Pathophysiology
• Arise from vestibular division of eighth cranial nerve
1. More commonly the inferior vestibular nerve
• VS do not likely arise from Obersteiner-Redlich transition zone (glialschwannian junction) as initially thought
1. Most tumors form lateral to the Obersteiner-Redlich transition
zone; oligodendrocytes produce myelin medial to junction and
Schwann cells lateral
2. Greatest density of Schwann cells lies at Scarpa’s ganglion; VS
likely arise from Schwann cell population associated with the
Scarpa’s (vestibular) ganglion; like VS, Scarpa’s ganglion can lie
near junction but also at various locations
• Understanding of genetic origins of sporadic VS is still
uncertain; tumor biology is mostly understood through studying
Neurofibromatosis type II (see Chapter 31)
• There are two histological patterns; Antoni A are densely packed
cells with an organized whirled appearance (Verocay body); Antoni B
are more loosely packed collection of vacuolated pleomorphic cells;
Antoni B may occur more frequently in large tumors
1. Stain positive for S-100
CHAPTER 29
Vestibular Schwannoma 283
Presentation
• Hearing loss is most common presenting symptom and present in
95% of patients
1. Typically gradual onset unilateral sensorineural hearing loss
2. During clinical course up to 26% of patients report sudden onset
SNHL
3. Normal hearing patients are more likely to have tumors <1 cm
• AAO-HNS has standardized hearing reporting in VS (Table 29–1)
• Vertigo/dysequilibrium is most common presentation in patients with
normal hearing
1. Occurs in 20–50% of patients
2. Vertigo typically occurs relatively early in symptomology due to
peripheral nerve disturbance but can spontaneously resolve
3. Dysequilibrium typically occurs late in course due to cerebellar
involvement
4. Due to slow rate of tumor growth, majority of patients
compensate
• Tinnitus reported in 53–70% of patients
1. Variable in nature
2. Asymmetric tinnitus without hearing loss should warrant
investigation for retrocochlear pathology
• Trigeminal nerve symptoms occur in approximately 20% of patients
1. Most commonly malar hypesthesia or parasthesia
a. Can result in absent or decreased corneal reflexes
b. Very rare in tumors <1 cm, but occurs in 20% of patients with
1–3 cm tumors and 50% in tumors larger than 3 cm
2. Given high prevalence of headache in general popular, hard
to establish association with acoustic neuromas; vestibular
schwannoma-related headaches are likely dull with mild to
moderate intensity
Table 29–1. American Academy of Otolaryngology-Head
and Neck Surgery Hearing Classification after VS Surgery
Hearing Class
PTA
SDS
A
≤30
≥70%
B
31–50
50–71%
C
>50
>50%
D
Any
<50%
Note. PTA = pure-tone average; SDS = speech discrimination score.
284 Otology, Neurotology, and Skull Base Surgery: Clinical Reference Guide
• Facial nerve (FN) dysfunction is relatively uncommon (<10% of
patients)
1. Can present as facial twitching or paralysis/paresis
2. Either symptom should raise concern for primary facial nerve
tumor
• Late symptoms are much less common today due to early detection
1. Increased intracranial pressure from hydrocephalus can result
in nausea/emesis, diplopia, papilledema, and lethargy to
obtundation
2. Lower cranial nerve symptoms of hoarseness, dysphagia, and
dysarthria are rare in modern era
Diagnosis and Evaluation
• Audiologic evaluation
1. Pure-tone audiogram (PTA) and speech discrimination scores
(SDS) show wide variability from normal to no response
2. Rollover (worsened SDS with increasingly loud presentation)
and acoustic reflex decay (acoustic reflex fades during prolonged
presentation of signal) were once thought to be good markers for
retrocochlear pathology; over time these have been found to be
poorly reliable
• Auditory brainstem response (ABR) testing
1. Attractive as screening tool because it is noninvasive, inexpensive,
and rapid
2. The interaural wave I to V latency difference (IT5) is most
reliable screening measure for VS; latency of 0.2 ms or more is
considered abnormal
3. Sensitivity ranges from 63–95%
a. Highest sensitivity with tumors larger than 2 cm (100%)
b. Decreased to 60% with tumors less than 1 cm
4. Stacked ABR increases sensitivity to 95% for all tumors
• Electronsytagmography
1. Abnormal results in 98% of superior vestibular tumors and 60%
inferior vestibular nerve tumors
2. Reduced ipsilateral caloric response and spontaneous nystagmus
to contralateral side are common findings
3. Wide variety of findings in larger tumors including: abnormal
saccadic pursuit, bilateral horizontal gaze nystagmus, and failed
fixation suppression
4. Can be used to help identify vestibular nerve of origin in
planning for hearing preservation surgery for middle cranial fossa
surgery (discussed later)
CHAPTER 29
Vestibular Schwannoma 285
• Magnetic Resonance Imaging
1. Isotense or hypotense on T1 and T2, but enhance with
gadolinium
2. VS are centered on IAC, have spherical shape without dural
attachment or hyperostotic adjacent bone
3. Up to 100% sensitivity and specificity in modern era with
gadolinium
4. Able to accurately display size, location, depth of penetrance into
IAC (discussed later for hearing preservation surgery)
5. Heavily T2 weighted fast spin-echo series can help identify
location of facial nerve (FN) nerve with regard to the VS
a. This series can also identify VS with 98–100% sensitivity and
99.5–100% specificity without gadolinium
Natural History
• Determination of tumor growth varies based on study; some define
intracanalicular tumor growth as growth to extrameatal tumor
whereas others simply define tumor growth as growth in any
dimension by 2 mm; most precise gauge is volumetric analysis
• Difficult to determine true VS growth rates as larger tumors are
intervened upon and not included in natural history studies;
therefore, there is an inherent bias toward decreased growth rates
• Collected data in meta-analyses show approximately 50% of VS grow
(data ranges from 6–73% in literature)
• Mean growth rates in all VS 1–2 mm/year; this rate increases to
2–4 mm/year in those tumors with proven growth
• Majority of studies show no relationship between gender, age,
duration of symptoms, initial hearing level, and laterality and
likelihood of VS growth
1. Multiple studies have shown that VS larger than 2 cm have
increased propensity to grow
2. Some evidence exists for increased growth rates of extrameatal
compared to intrameatal tumors
Treatment
• Overall goal is to maintain patient quality of life and intervene when
the decrease in quality of life from treatment outweighs the effects of
further tumor growth