Miscellaneous Otology Flashcards
Tumors of the Internal Auditory Canal/Cerebellopontine Angle
1) Acoustic Schwannoma - 90%
2) Meningioma, Arachnoid Cysts, Cholesteatoma, Facial nerve neuroma, Metastatic lesions - 10%
Acoustic Schwannoma - Growth Rate
1-4mm/year
Effect of Smoking on Tympanoplasty
Smoking is associated with a 3-fold increase in long-term tympanoplasty graft failure.
Constant Landmarks in Middle Ear Surgery
1) Jacobsen’s nerve
2) The Cochleariform process
3) Eustachian tube orifice
4) Round Window niche
5) Stapedius tendon/pyramidal process
Note: if the surgeon should become disoriented, stop working in unknown area, then identify a region of known anatomy, and proceed from known to unknown
Absolute Contraindications for Tympanoplasty
1) Poor general health
2) Malignant tumor of the outer or middle ear
3) Uncontrolled cholesteatoma
4) Unusual infections - malignant otitis externa
5) Complications of chronic ear disease: meningitis, brain abscess, lateral sinus thrombosis
6) Tympanoplasty is contraindicated in the only or significantly better hearing ear to avoid risk of irreversible SNHL
- Operating on the better hearing ear in pts who can use a hearing aid in the opposite ear may be considered in select cases
7) A non-functioning eustachian tube is a relative contraindication to tympanoplasty (hard to determine preop)
8) Repeated surgical failures - leave the ear alone (secondary to middle ear fibrosis, ET dysfunction, recurrent perforations, prosthesis extrusion)
How is stereotactic radiotherapy given for vestibular schwannomas?
1) Given in 1-3 fractionated doses
2) 13 Gray to 21 Gray are given in total
3) Given with a Cyber knife or Gamma knife
Follow-Up of patients with vestibular schwannoma following stereotactic radiotherapy.
1) Follow-up of at least 5 years of no growth would capture around 80% of non controlled tumors
2) A follow-up period of 9 years would capture almost all non controlled tumors
3) Very late tumor progression of vestibular schwannomas has been reported following stereotactic radiotherapy (SRS).
- Post SRS tumors that are not growing still retain proliferative capacity
Source:
Tumor Control Following Stereotactic Radiosurgery in Patients with Vestibular Schwannomas - A Retrospective Cohort Study; Santa Maria, et al, Otology & Neurotology, Vol. 42, No. xx, 2021
Vestibular Schwannoma (VS) tumor control rates following stereotactic radio surgery (SRS).
1) Not all VS grow.
2) Some VS go through periods of quiescence before resuming growth
3) VS control rates are worse following SRS in tumors that have documented pre-SRS growth.
- The degree of growth rate prior to SRS may also influence treatment response.
4) Salvage SRS is less likely to control VS tumor growth
Source:
Tumor Control Following Stereotactic Radiosurgery in Patients with Vestibular Schwannomas - A Retrospective Cohort Study, Santa Maria, et al; Otology & Neurotology, Vol. 42, No xx, 2021
Risk Factors for poor tumor control rates in Vestibular Schwannoma following stereotactic radiosurgery.
1) Tumors with documented growth prior to SRS have worse control rates with SRS
2) Patients with NF2 have reduced tumor control with SRS
- There is also a small increase in risk of radiation-induced malignancy in NF2 patients following SRS
3) Larger tumors have reduced control rates with SRS
- Note: Only 17% of intracanalicular VSs are likely to grow with observation
4) Other factors associated with decreased tumor control
- Female gender: women are 50% more likely to experience non control
Source:
Tumor Control Following Stereotactic Radiosurgery in Patients with Vestibular Schwannomas - A Retrospective Cohort Study; Santa Maria; Otology & Neurotology, Vol. 42, No. xx, 2021
Salvage therapy for vestibular schwannoma following stereotactic radiosurgery.
When VSs are not controlled by SRS, these authors recommend salvage surgery in most patients.
- This uses a different modality to control tumor and provides a histological diagnosis
- When SRS fails to control VS tumor growth, repeat radio therapy does not reliably control tumor growth
Source:
Tumor Control Following Stereotactic Radiosurgery in Patients with Vestibular Schwannomas - A Retrospective Cohort Study; Santa Maria, et al, Otology & Neurotology, Vol. 42, No. xx, 2021
Surgery After Stereotactic Radio Surgery For Vestibular Schwannomas - What Are The Issues?
1) Cranial nerve injuries are more likely
2) There is a reduced completeness of resection
3) There are higher rates of postoperative complications
4) VS tumors that fail SRS are likely to be more biologically aggressive
- Subtotal resection of these tumors improves facial nerve outcomes, but the patients are at higher risk for continued growth after subtotal resection
Source:
Tumor Control Following Stereotactic Radiosurgery in Patients with Vestibular Schwannomas - A Retrospective Cohort Study, Santa Maria et al., Otology & Neurotology, 2021
Malignant Vestibular Schwannomas - What is the Risk?
1) 1/1041 Vestibular Schwannomas are malignant
2) About half of malignant Vestibular Schwannomas present as benign vestibular schwannomas
3) Malignant transformation of VS following a single treatment of SRS is about 0.3%
- Malignant transformation rate is higher with single dose SRS as opposed to fractionated treatment
- Patients with NF2 are at higher risk for malignant degeneration of a VS
4) Pathology of malignant VS
- Malignant peripheral nerve sheath tumor, triton tumor, or sarcoma
5) Malignancy in VSs following SRS is rare - most reported cases are associated with single-fraction SRS as opposed to fractionated therapy
What are the control rates for Vestibular Schwannoma following Stereotactic Radiotherapy?
1) Sporadic VS = 89% at 3 years
2) NF2 VS = 43% at 3 years
What is the main concern on a vestibular schwannoma that changes from typical to atypical behavior following stereotactic radiotherapy?
Any VS that changes behavior following SRS should be considered for malignant change.
Lesions of the Petrous Apex
1) Primary lesions of the petrous apex:
- Cholesterol granuloma
- Cholesteatoma/Epidermoid cyst
- Mucocele
- Trapped fluid/effusion
- Eosinophilic granuloma
- Mesenchymal tumor (chondroma, chondrosarcoma, osteoclastoma, fibrous dysplasia)
- Petrous apex encehalocele
2) Secondary lesions of the Petrous Apex:
- Direct spread of neoplasm (nasopharyngeal carcinoma, vestibular or jugular foramen schwannoma, trigeminal neuroma, glomus tumor, clival chordoma, meningioma)
- Metastasis or hematogenous spread (metastatic tumor, lymphoma)
- Infection (osteomyelitis, necrotizing external otitis)
- Other (arachnoid cyst, aneurysm or internal carotid artery, sphenoid mucocele)
Cystic lesions of the Petrous Apex - Differential diagnosis
99% of primary cystic lesions of the Petrous Apex are one of the following:
1) Cholesterol granuloma
2) Cholesteatoma/epidermoid cyst
3) Mucocele
What is a cholesterol granuloma of the petrous apex?
A cholesterol granuloma of the petrous apex is a foreign body giant cell reaction to cholesterol deposits, with chronic inflammation, fibrosis, and vascular proliferation that is contained within a fibrous capsule.
- Cholesterol granulomas are 10 times more common than a cholesteatoma
- Cholesterol granulomas are 40 times more common than mucoceles
What causes a petrous apex cholesterol granuloma?
1) The obstruction/vacuum theory: obstruction of a previously aerated space leads to gas trapping and resorption, vacuum formation, hemorrhage into the mucosal surface, inflammation, breakdown of red blood cells, and formation of cholesterol crystals. With the formation of cholesterol crystals, the inflammation cascade is initiated with bony resorption and foreign body reaction.
2) The exposed marrow theory: during development aggressive pneumitization of the apex forms pathologic communications between the mucosa lined air cells and the marrow they gradually replace, creating hemorrhage into the apical air cells. Red blood cells break down, cholesterol crystals form, and the inflammatory cascade begins.
What is Gradenigo’s Triad?
1) Otorrhea
2) Deep retroocular pain
3) Abducens nerve palsy
Note: Gradenigo’s triad is associated with petrous apicitis
What viruses are known to cause audio vestibular symptoms?
1) Herpes Viruses: CMV, HSV, VZV, EBV
2) Paramyxoviradae: Parainfluenza, mumps, measles
3) Polio virus
4) Rubella virus
5) Influenza virus
6) HIV
7) Hepatitis viruses
8) Flaviviruses: Zika virus, Dengue virus
What Audiovestibular Symptoms Occur in Patients with COVID-19 Infections?
1) 90% common COVID-19 symptoms: Fever, cough, dyspnea and/or fatigue 21 days before and 14 days after onset of hearing loss, tinnitus, or vertigo
2) 70% of patients developed audiovestibular symptoms after other COVID-19 symptoms
3) Audiovestibular symptoms can be the presenting symptoms of a COVID-19 infection
What audiovestibular symptoms do patients have after a COVID-19 infection?
1) Tinnitus - 23%
2) Dizziness/Vertigo - 18%
3) Dizziness/Vertigo improves with time after COVID infection
What are the symptoms of ‘Long COVID?’
1) General: Fatigue, muscular weakness, joint pain
2) Lungs: Dyspnea, cough, persistent 0xygen requirement
3) Brain: Anxiety, Depression, PTSD, Brain Fog, Headaches
4) Heart: Palpitations, Chest Pain
5) Blood Vessels: Thromboembolism
6) Kidneys: Chronic kidney disease
7) Skin: Hair loss
COVID-19 Vaccines and Sudden Hearing Loss
1) Most studies have found that COVID-19 vaccination does not significantly increase the risk of SSNHL.
- One study reported an increased risk of SSNHL (Yanir et al, 2022, JAMA OHNS), but the effect was small
2) The benefits of COVID-19 vaccine outweigh its risk for causing SSNHL
Vaccine Adverse Event Reporting System (VAERS) - What is this and when is it used?
1) Healthcare providers are required by law to report:
- Serious adverse events (AEs) regardless of causality (e.g., death, birth defect, hospitalization)
- Cases of multisystem inflammatory syndrome
- Cases of myocarditis or pericarditis
2) Healthcare providers are encouraged to report:
- Any AEs
- Vaccine administration errors, whether or not associated with an AE
What causes presbycusis?
Age related hearing loss correlates with hair cell loss more than strial degeneration.
Source:
Age-Related Hearing Loss Is Dominated by Damage to Inner Ear Sensory Cells, Not the Cellular Battery That Posers Them
Wu, et al
What are the complications of Otitis Media and Mastoiditis?
1) Intratemporal Complications:
- Hearing Loss: CHL or SNHL
- Vestibular dysfunction
- Tympanic membrane perforation
- Mastoiditis
- Acquired cholesteatoma
- Facial nerve dysfunction
- Labyrinthine Fistula: in 10% of pts with COM with cholesteatoma
- Petrous Apicitis
2) Extratemporal Complications:
- Typically, extension of acute mastoiditis: Subperiosteal abscess, Citelli abscess, Bezold abscess, Luc abscess, Zygomatic root abscess
3) Intracranial Complications:
- Meningitis
- Lateral sinus thrombosis
- Subdural empyema
- Intraparenchymal brain abscess
- Otitis hydrocephalus
What are the goals of surgery in chronic otitis media?
1) To create a safe, clean, and dry ear
2) To preserve hearing
How can you improve eustachian tube function?
1) Treat Sino nasal disease: Eustachian tuboplasty, allergy treatment
2) Treat laryngopharyngeal reflux
3) Stop tobacco/marijuana use
4) Clear obstruction of the nasopharynx and protympanum
5) PE tube placement
6) Can you separate the mastoid/middle ear and indirectly improve eustachian tube function?
- via either CWD/mastoid obliteration?
What types of surgery can be done on the middle ear/mastoid in chronic otitis media surgery?
1) Tympanoplasty
2) Endaural atticotomy
3) CWU tympanomastoidectomy
4) CWD tympanomastoidectomy
5) Canal wall reconstruction/mastoid obliteration (CWR/MO)
6) Subtotal petrosectomy/blind sac closure
Note: Advances - endoscopic, laser?
Canal Wall down mastoidectomy - what are the advantages and disadvantages?
1) Advantages:
- CWD Mastoidectomy is the gold standard for treatment of COM/Cholesteatoma
- Recidivism rate of 2-5%
- May need just one operation
2) Disadvantages:
- Cosmetic: meatoplasty
- Need for mastoid bowl cleaning
- Not physiologic: persistent otorrhea
- Propensity to caloric stimulus
- Pediatric patients/Mental Retardation Developmental Delay
- Hearing aid difficulties
- Water precautions
What types of otalgia are there?
1) Primary otalgia - pain that arises from pathology of the external, middle, and inner ear
2) Secondary/Referred Otalgia - pain that arises from pathology outside the ear
What is the differential diagnosis of primary otalgia?
1) Infection - most common cause of primary otalgia
- Otitis externa
- Otitis media
- Bullous myringitis
- Cellulitis of the pinna
- Perichondritis
- Herpes zoster oticus
2) Cerumen impaction
3) Foreign bodies
4) Eustachian tube dysfunction
5) Trauma - lacerations, hematoma of the pinna
6) Relapsing polychondritis
7) Cholesteatoma
8) Neoplasm of the ear - BCCA, SCCA, Melanoma
What is the differential diagnosis of secondary/referred otalgia?
1) Dental infection/inflammation
2) TMJ disorders
3) Trigeminal neuralgia
4) Sinonasal patthology
5) Laryngeal/pharyngeal pathology:
- Laryngtitis
- Pharyngitis
- Tonsillitis
- Post tonsillectomy pain
- Peritonsillar abscess
6) Head & Neck cancers
7) Musculoskeletal pathology
- Cervical spine disease
- Myofascial pain syndrome
8) Eagle’s syncrome
9) Temporal arteritis
10) Thyroiditis
11) GERD
12) Cardiac - angina, acute coronary syndrome
What is the Tullio Phenomenon?
1) The Tullio phenomenon is a symptom/physical exam finding in which nystagmus or vertigo are induced in response to sound.
What are the causes of Tullio’s Phenomenon?
1) Superior Semicircular Canal Dehiscence
2) Otosclerosis
3) Congenital syphilis with osteomyelitis of the boney labyrinth.
- Miliary Gummas form on the endosteum leading to labyrinthine fistulae
4) Meniere’s disease
5) Perilymph fistula
6) Cholesteatoma with semicircular canal erosion and fenestration
7) Head trauma
8) Normal patients
9) Post stapedectomy
10) Collapsed canal syndrome
11) Congenital deafness
12) Seronegative Lyme Borreliosis
13) Middle ear osteoma`
What is the incidence of Acoustic Schwannoma in a patient with asymmetrical hearing loss?
The incidence of acoustic schwannoma in a patient with asymmetrical hearing loss is 0.85% to 15.8%.
Reference: Predictors of Abnormal MRI Findings in Patients With Asymmetrical Sensorineural Hearing Loss. Prayuenyong P, Pitathawatchai P, et al: Laryngoscope; 2024; (October 12)
What is the best predictor of an acoustic schwannoma on MRI?
Hearing asymmetry of at least 15dB at 1000Hz is the best predictor of acoustic schwannoma on MRI:
1) Sensitivity = 84%
2) Specificity = 48%
3) Odds ratio = 4.87
Reference: Predictors of Abnormal MRI Findings in Patients With Asymmetrical Sensorineural Hearing Loss. Prayuenyong P, Pitathawatchai P, et al: Laryngoscope; 2024; (October 12)
