Disorders Final Flashcards
What is hearing loss resulting from overexposure to loud noise?
- This is the 2nd most common type of acquired hearing loss
- 30 million Americans are exposed daily to dangerous noise conditions (includes children)
- often occupational; regulation of workplace noise by Occupational Safety & Health Association (OSHA)
Noise Induced Hearing Loss
What are the three types of NIHL?
Noise Induced Permanent Threshold Shift (NIPTS), Acoustic trauma, Noise Induced Temporary Threshold Shift (TTS)
Repeated exposure (over the years) to SPLs lower than those that produce acoustic trauma
-Long-term; Usually occupational (ONIHL)
Noise Induced Permanent Threshold Shift (NIPTS)
- Permanent cochlear damage after one exposure to very high SPLs (firecracker, gunfire, jackhammer)
- Physical trauma & acoustic have similar and may occur together
- Hearing loss “muffled”
- Tinnitus
- Disequilibrium (rare)
- Hemotympanum
- Perforation, otorrhea
- Ossicular disarticulation
Acoustic Trauma
Exposure to loud sounds for a few hours
-“buzzy” ears, muffled hearing, decline in thresholds but recovery within hours or days
- not temporary, IHC most affected; long-term effects are initially hidden but progress over time
- the greater the SPL the greater the shift
- max threshold shift occurs 0.5 - 1 octave above the center frequency exposure
- when the max shift in this reaches its maximum, it will lead to a maximum permanent threshold shift
Noise Induced Temporary Threshold Shift (TTS)
- No stereocilia disarray, but decrease in stiffness
- Strial swelling – Excitotoxicity
- Loss of some spiral ligament fibrocytes
- Space of Nuel Collapse (then recovers)
- Synaptic terminal swelling/retraction
- Steriocelia often damages regardless of hair cell survival
- Threshold recovery, ABR & DPOAE thresholds recover from initial shift, but ABR amplitudes decline
- Loss of synapses, terminals after noise
- Delayed loss of afferents
This pathophysiology is indicative of…
TTS
The condition where nerve fibers become permanently disconnected from IHC. Not revelaved by any tests of threshold sensitivity
Hidden Hearing Loss (HHL)
What is the formula for noise exposure?
For every 3 dB increase cut exposure time by half (ex: 85 dBA: 8 hr exposure limit, 88 dBA 4 hr exposure limit, 91 dBA: 2 hr exposure limit…)
Definition: Equal amounts of sound energy will produce equal amounts of hearing impairment regardless of how sound energy is distributed in time
Equal Energy Hypothesis
How much (loudness, annoyance)
Duration (continuous, intermittent, impulse, impact, for how long)
These define…
Characteristics of Noise
Duration of exposure, level of exposure, frequency spectrum of noise, distance from source
These are…
Contributing factors of NIHL
Dehydration, heart disease, smoking, alcohol, diabetes
Health and Lifestyle risk factors that may interact with noise
Public health issues, educate parents and families, discuss hearing loss prevention versus hearing conservation to help patients identify sources of noise in his/her environment, provide appropriate hearing protection
The role of an audiologist
Measure noise exposure levels, document compliance with OSHA guidelines, obtain baseline hearing measures, administer ongoing testing of employees, educate, provide, and monitor the use of hearing protection, may be involved in litigation
the role of an audiologist in the industry
- Information about what sounds can cause damage
- Wear hearing protection
- Be alert to hazardous noise in the workplace
- Protect children (who can’t protect themselves)
- Baseline audiogram
- Public Awareness
NIHL Prevention
- Typically attenuates high frequencies to greater extent than low frequencies
- Rated approx.. 10 dB more effective than reality (likely due to usage)
- Flat attenuation earplugs
- Special Earplugs for musicians, specific needs
Hearing Protection
- 140 dBA impulse (Impulse/impact noise – less than 0.2 seconds)
- Immediate Hearing loss; Both temporary & permanent conditions
- Often accompanied by head trauma
- May be otoscopic evidence of damage to TM
- May be ossicular damage
- May be oval/round window fistula
- Pure Tone thresholds range from mild to severe (in rare case – complete loss)
- May have poor speech discrimination
- May have spontaneous nystagmus and/or reduced caloric response
- Hearing will often improve for a few days/weeks after acute trauma
- Complete recovery depends on the extent of damage
This is indicative of…
Acoustic Trauma
- Direct Damage to stereocilia/hair cells
- Mixing of perilymph and endolymph
- Casacade
- ROS
- If recovery, usually see change within 1 month or 3-6 mos
Pathophysiology of Acoustic Trauma
What is indicative of central & peripheral auditory system changes
Age-related hearing loss (Presbycusis)
65 – 75 years: 30 -35%
75 years +: 40 – 50%
90 years +: > 90%
Incidence/Prevalence of Presbycusis
- Bilateral, symmetric, SNHL (high frequencies most affected)
- Progressive hearing loss with age
- Progressively poorer word recognition scores
- Gradual onset
- Negative history of noise exposure
- Normal otologic exam
Clinical Characteristics of Presbycusis
- DPOAES: decline independently from thresholds in aging
- SRT: increase w/age; greater difficulty understanding comfortably loud speech (esp. in noise)
- Tymps: usually normal (woman – decreased compliance)
Test results for Presbycusis
- Loss of tissue elasticity of pinna and ear canal
- Stiffening of tympanic membrane
- Degeneration of middle ear musculature
- Calcification of ligaments
- Ossification of ossicles
- Inner Ear: Major structures degenerate independently
Pathophysiology of aging on the Outer and Middle ear
According to the Schuknecht Study, impact to this part will result in a bilateral precipitous high-freq SNHL and will initially commensurate speech discrimination ability
Sensory
- Degeneration of hair cells & supporting cells @ base of the cochlea (more OHC)
- Atrophy of the organ of Corti (affects auditory nerve)
- Abruptly sloping, high-frequency loss
- Starts at middle age & progresses slowly
Pathophysiology of Cochlear damage (sensory - Schuknecht)
According to the Schuknecht Study, impact to this part will result in a high-freq hearing loss; mild; poor speech discrim scores (early on); progresses rapidly with aging
Neural
- Loss of dendrites & then cochlear neurons
- Audiogram: loss of neurons prior to loss of IHC may not affect hearing sensitivity until up to 90% of radial afferent neurons have degenerated (Expect speech understanding to be worse than anticipated from audiogram)
- Primary: neuropathy
- Secondary: hair cells die, no input, nerve cells die
- Can cut ½ nerve with out changing thresholds
- Can lose up to 90% without threshold change
Pathophysiology of Neural damage (neural - Schuknecht)
According to the Schuknecht Study, impact to this part will result in flat SNHL with good preservation of speech understanding
Strial/Metabolic
- Degeneration of stria vascularis (Disruption of nutrient supply & changes in cochlear electrical potentials)
- Audiogram: flat; reasonable speech discrim scores
- Decrease in endocochlear potential correlated with poorer thresholds
- Larger genetic effect for this pattern
Pathophysiology of Strial/Metabolic damage (Strial/Metabolic - Schuknecht)
According to the Schuknecht Study, impact to this part will result in a sloping SNHL, including low freq, speech understanding good
Mechanical (Cochlear Conductive)
- Changes due to mass/stiffness changes/atrophy of the spiral ligament
Pathophysiology of Strial/Metabolic damage (Mechanic - Schuknecht)
Not Schuknecht category - Hearing loss has a significant effect but may occur in the absence of hearing loss
- “Can’t hear in background noise”
Central damage
Age overall impacts…
Working memory, speed of processing, attention & the brain, senses (touch, vision as well as hearing, central auditory processing)
- Diabetes
- Hypertension
- Hypercholesterolaemia
- Surgeries (anaesthesia)
- Prescription drug ototoxicity
- Hormones, sex
- Cardio/microvascular
- Diet (antioxidants good)
These are all ___________
Risk factors for hearing
This ability deteriorates with age, especially from the seventh decade on
Speech-in-noise
This increasingly affects speech understanding as listeners age
Reverberation
This ability is highly correlated with their ability to understand speech in babble and reverberation
The ability of elderly listeners to segregate non-speech streams using only envelope information
hearing loss matters a lot….
low context
hearing loss matters less….
high context
- Changes with aging
- Estrogen seems to be protective (thresholds, word rec decline with menopause)
- Women aon Hormone replacement therapy do better postmenopausal than those not on HRT
- Aldosterone levels associated with better thresholds
Hormones
- Early identification is important (social, psychological, economic consequences)
- Increased success with HAs
- Disuse atrophy/plasticity (Cortical reorganization)
Presbycusis Identification
A screening tool for Presbycusis
Hearing Handicap Inventory for the Elderly – screening version (HHIE-S)
- Depression
- Confusion
- Inattentiveness
- Increased tension
- Negativism
Is often confused with….
Hearing Impairment in Elderly
- Poor general health
- Reduced mobility
- Reduced interpersonal communication
Is often confused with….
Hearing Impairment in Elderly
Counseling, alleviation of symptoms, HAs, ALDs, and Group Rehab are all ….
Presbycusis Treatment & Rehabilitation Options
- Lifestyle
- Hearing aids and/or assistive listening devices
- Financial constraints
- Measuring hearing aid benefit
- Quality of life
- Family involvement
Should all be considerations for….
Rehab
Anything beyon the cochlea is defined as…
Retrocochlear
- 80 -85% of CPA tumors (MOST COMMON)
- 5 – 10% of intracranial tumors
- 3:2 female to male
- About 50 yrs old, mostly White (black, Hispanic, & Asian populations were more likely to present with large tumors)
- Affects schwann cells on vestibular part of VIII nerve
- Cellular transformation/proliferation of schwann cells
This is the epidemiology of….
Vestibular Schwannoma
Where is the nerve of origin for Vestibular Schwannoma?
Obersteiner – Redlich Zone (where Schwann cells & oligodendrocytes meet)
- Nerves 5 (trigeminal), 7(facial), 8
- AICA artery
- Contains CSF
This describes….
Cerebellopontine Angle (CPA)
- 8.5mm in length
- Lined w/dura & filled w/spinal fluid
- CN7 & CN8
- Where the peripheral & central systems meet
This describes….
Internal auditory Canal (IAC)
- Benign; Often characterized by slow growth
- 5% are NF2 patients (less than 30 yrs, bilateral)
- 95% sporadic
- Idiopathic
This is…
The natural history of Vestibular Schwannoma
- Unilateral/Asymmetric hearing loss (most common symptom)
- Usually high freq/can be mid-freq
- Sudden/fluctuating 5-15%
- Unilateral Tinnitus
- Headache
- Balance disturbance/imbalance/dizziness
- Episodic vertigo
- Facial weakness/facial numbness/facial palsy
- Aural fullness
- Ataxia (loss of control of bodily movements)
- Otalgia/jaw pain
- Hyperacusis
These are…
Signs and symptoms of Vestibular Schwannoma
- Pure tone: asymmetry
- Speech Discrim tests: asymmetry
- Poor discrim for thresholds
Will decline even if no/little tumor growth - PI/PB function (rollover)
- Immittance audiometry
- AR ~60% sensitivity if present
- Tone decay – rarely
- ABR, stacked ABR I-III & I –V intervals, Wave V latency difference, ABR peaks absent, misses small tumors
- Vestibular testing (ENG) - tells about superior vestibular nerve (SSC, utricle)
- VEMPS - tell about inferior vestibular nerve (saccule)
- DPOAEs decreased in some cases
This is…
Diagnostic Results for Vestibular Schwannoma
- Potential effect of tumor on nerve – compression
- Effect on blood flow
- Change in gene expression secretion
This is…
The pathophysiology of a Vestibular Schwannoma
- MRI for diagnosis (gold standard)
- Observation
- Surgery
- Gamma knife treatment - radiosurgery noninvasive treatment option (delayed hearing loss)
- Wait & see - for elderly patients, small tumors, refusal of treatment, tumor on side of only hearing ear
- If you take it out —> higher likelihood of preserving hearing
This is…
Management for Vestibular Schwannoma
This is a surgical approach for VS where hearing is sacrificed but it is a good identification of CN VII and there is less risk of CSF leak
Translabyrinthine
This is a surgical approach for VS where hearing preservation is possible; it’s excellent for intracanalicular tumors but there is lack of access to CPA (need to retract temporal bone)
Middle Fossa Approach
This is a surgical approach for VS where hearing preservation possible; there’s access to CPA, limited access to IAC, difficulty repairing CN VII
Retrosigmoid/Suboccipital
Advantages: Decreased length of stay, decreased cost, rapid return to full employment, lower immediate post-treatment morbidity & mortality
Disadvantages: Necessity for regular monitor & frequency re-scanning, does not eliminate the tumor & has higher recurrence rates, higher incidence of trigeminal nerve injury
Gamma Knife Intervention
- Hearing loss, Facial nerve injury, Cerebellar damage, Arterial occlusion/hemorrhage, Meningitis, CSF leaks, headache
Complications of surgery
- Medical Referral & support
- Monitoring
- Rehabilitation
HA, CROS, BAHA, CI, ABI, Vestibular Rehab
Audiologist’s Role
- Nothing to do with VS
- Peripheral tumors
- Café au lait spots >6
- AD
Neurofibromatosis 1 (NF1)
- 15% of Intracranial tumors & 3% of CPA tumors
- Benign & do not metastasize
- Locally aggressive because they invade bone
- Put pressure on nerves, brain vascular
Has a characteristic shape on imaging: close to brain tissue with a “tail”
Which CPA tumor is this?
Meningiomas
- If bilateral VS/young (<30 yrs.)
- This gene on chromosome 22 (22q11-13.1)
Autosomal dominant
Bilateral VS or Eye tumors
Genetic testing to detect mutations
Café au lait spots < 6
-Faster growing vs. VS
What does this describe?
Neurofibromatosis 2 (NF2)
- ~20% of all vertigo, 2% lifetime prevalence
- Brief mild to intense vertigo Triggered by changes in head position (getting out of bed, reaching up to a high shelf)
- Episodes usually less than 30 seconds (Otoconia/otoliths out of the utricle)
- Peak incidence in the 50s; Rare < 35 yrs unless head injury
- Associated with head injury & vestibular neuronitis
- May be present with VS***
- Nystagmus with Dix/Hallpike diagnostic
- Treated with Epley, Semont
Do maneuver to get everything right in back semi-circular canal - HEARING LOSS MIGHT NOT BE PRESENT
BPPV: Benign Paroxysmal positional vertigo
a disorder of the inner ear characterized by dysfunction in the fluid balance regulating system
MENIERE DISEASE
- Incidence 0.2 – 2%
- Slightly more common in those of European descent
- Women > Men
- Incidence highest in 40s and 50s (has been reported in children)
- Associated with a history of allergies, smoking, virus, or respiratory infection, aspirin, stress, ETOH, fatigue, autonomic nerve disease
What is this?
Epidemiology of Meniere Disease
- Stage 1: <=25
- Stage 2: 26 – 40 dB
- Stage 3: 41 – 70 dB
- Stage 4: > 70 dB
What does this desribe?
Stages of hearing loss in Definite/Certain Meniere’s
- Endolymphatic hydrops leads to distortion of scala media (membranous labyrinth)
- Idiopathic
What does this describe?
Etiology of Meniere’s Disease
- Fluid imbalance
- Perilymph —> similar to CSF, High Na+, Low K+
- Endolymph (in stria vascularis) —> similar to Intracellular fluid (ICF), Low Na+, High K+
- Membranous labyrinth separates the two (difference of 80 mV in charge & no pressure difference) - Hydrops
- Obstruction of endolymphatic duct/sac? (No evidence in animals)
- Alteration of endolymph absorption?
- Autoimmune?
- Small endolymphatic aqueduct or sac?
- Build-up in pressure may lead to micro-ruptures of membranous labyrinth
- May explain episodic nature of attacks
- Healing of ruptures may account for return of hearing
- Apex wound more rightly than base, bigger effect?
- Hydrops alone do not seem to cause this…
Pathophysiology of Meniere’s Disease
may include symptoms of tinnitus, fullness & fluctuating hearing loss WITHOUT vertigo
“Cochlear hydrops”
- hearing loss fluctuates, low freq SN initially, but declines with time across frequencies
- May not be most disturbing symptom
unless interferes w/work - Reduced discrimination, tinny
- Recruitment, dipaclusis (ears perceive
different pitch) - Usually begins unilaterally, but 40% will
become bilateral - Distortion & fluctuation
- May not be most disturbing symptom
- Tinnitus,
- Episodes of vertigo —> you or your environment is moving/ illusion of movement
- Subjective: patient moving
- Objective: environment moving
- Drop attacks (vertigo so disabling they
collapse) - Can be resolution of vestibular symptoms
(burn out)
- Aural Fullness,
- Fluctuation
- Symptom-free periods
- VARIABILITY
What are these symptoms of?
Meniere’s Disease
vertigo at least 20 min, usually last 1-2 hours, can be up to 24 hours
- nausea, vomiting
- feel tired, unsteady & nauseated for hours –
days
- Interim- symptom free, but may deteriorate
- timing & freq variable, may be able to
predict
Triggers: diet, menstrual cycle, stress
What does this describe?
Vertigo attack associated with MD
- Episodic vertigo w/out documented hearing loss
- SNHL fluctuating or fixed with disequilibrium but w/out definitive episodes
- Other causes ruled out —> always there
What does this describe?
Possible MD
- One definitive episode of vertigo
- Audiometrically documented hearing loss on at least one occasion
- Tinnitus or aural fullness in the treated ear
- Other causes excluded
What does this describe?
Probable MD
- 2+ spontaneous episodes of vertigo 20mins or longer
- Audiometrically documented hearing loss on at least one occasion
- Tinnitus or fullness in the affected ear
What does this describe?
Definite MD
Definite MD + histopathologic confirmation (Temporal bone pathology)
What does this describe?
Certain MD
- Can have resolution of vestibular symptoms with no surgical treatment (8-10 years = burn out)
- Study found: Long term PTA in affected ear ~50 dB; Speech discrim 53%; Caloric response reduction 50%
- Hearing loss: Early stage unilateral SNHL low freq rising to normal
- Hearing loss: Late stage bilateral HL, one worse than other, flat across freq
- Hearing loss doesn’t get worse with vertigo
What does this describe?
The natural history of MD
- Case history
- Complete hearing test including LDLs (reduced dynamic range)
- Vestibular, especially for bilateral
- C-VEMP – (Saccule, ipsi, IVN) likely absent in symptomatic ears
- O-VEMP – (utricle, SVN, complex) likely absent in symptomatic
- ENG – SVN
- Dix-Hallpike BPPV
- Possibly, ECOG, ABR< EEG, DPOAES, glycerol (rare)
- ECOG —>SP/AP ratio > 0.5
- Glycerol reduces hydrops
- RULE OUT tests: blood tests, allergy tests, MRI
This describes…
Diagnostic testing for MD
- Conservative treatment – acceptable results (control of vertigo)
- Lifestyle changes
- Regular meals; avoid triggers
- Low salt, No MSG, caffeine, smoking,
ETOH
- Medical treatment: decreasing the amount of fluid in the inner ear
- Low salt diet salt believed to alter fluid
balance in inner ear leading to depletion of
endolymph - Diuretic not great research suggesting
this works - Vasodilators —> allow the blood to flow
more freely
- Low salt diet salt believed to alter fluid
- Acute therapy —> Meclizine, Benzodiazepines, Corticosteroids
- Maintenance therapy —> no conclusive studies show efficacy of drugs intended to alter disease course of Meniere’s
- Other management: placebo effect?
- PE tubes, Antiviral drugs, Anti-nausa,
Homeopathy, Herbal gingko, Chiropractic,
Acupuncture —> positive case studies
What does this describe?
- PE tubes, Antiviral drugs, Anti-nausa,
Management of MD
Dietary modification
1st Level Management of MD
Meniett, Intratympanic corticosteroids, Endolymphatic shunt, Intratympanic gentamycin, Endolymphatic sac vein decompression
2nd Level Management of MD
pressure pulses delivered via probe in ear canal, portable low intensity alternating generator – “ promotes the flow of endolymph out the cochlea, alleviating the hydrops & relieving the symptoms”
Menniett
preferred because of gentamicin’s vestibuloselectivity, side effects = temporary imbalance or nystagmus, & hearing loss; relieves symptoms but not always
Intratympanic gentamycin
supported to address the site of obstruction causing hydrops. Types = decompression, shunting, drainage, removal, damage; debate on if effective or not
Endolymphatic sac vein decompression
- Vertigo is usually the initial concern
- Short and midterm very disruptive
- Control is usually successful long term
- Hearing loss and tinnitus
- No treatment shown success for
preventing decline of hearing & decreasing
tinnitus
- No treatment shown success for
- Long term expect far more effect on QOL
- Functional Level Scale (completed by the patient)
- How Meniere’s disease function is
assessed
- How Meniere’s disease function is
- Rehabilitation
*Physical/audiological issues
-Fluctuating HL —>hearing aids
w/multiple memories (best hearing &
worst hearing)
-Emotional Issues- Stress of illness
- Restriction of activities
- Vestibular rehabilitation
What does this describe?
Audiologic Management of MD
- Etiology
- Diagnosis
- Role of genetics, autoimmunity, viruses, environment
- Fluid dynamics
- Changes at the molecular, cellular and organ level
What does this describe?
What remains unresolved about MD
- Recognize emotional & social aspects
- Reasonable expectations
- Support for identifying triggers
- Use of earplugs to protect from noxious noise
- Support use of amplification
- Support groups
What does this describe?
The essentials of counseling for MD
- Recurrent episodes of headache with light/sound sensitivity
- Nausea, vomiting
- Unilateral
What does this describe?
Migraine
- Intense rocking swaying sensation
- Usually after cruise
- More common in women
- Etiology unknown
- May not resolve
- May resolve with vestibulo-ocular reflex reset
What does this describe?
MAL DE DEBARQUEMENT
- Vertigo, imbalance, dizziness, unsteadiness, motion sensitivity (may last > 24 hours)
- Muffled hearing, tinnitus, fullness
- Hearing loss very uncommon, if present usually low freq, rarely progressive
What does this describe?
Vestibular Mirgaine
vertigo lasts up to 24 hrs, SNHL nearly always progressive/most often unilateral/fluctuation common, tinnitus may be unilateral or bilateral and often significant intensity, photophobia never present
The main differentials for…
MD
vertigo may last longer than 24 hrs., SNHL very uncommon, tinnitus may be unilateral or bilateral but rarely obtrusive, photophobia is often present and may be associated with dizziness
Vestibular Migraine
- 1/1000 Clinically: when cerebellar tonsils extend through foreman magnum
- Type 1, may not be diagnosed
- Dizziness, muscle weakness, numbness, vision problems, headache, progressive SNHL, tinnitus & problems w/coordination
- Occipital headache with valsalva
- Post surgery tinnitus
What does this describe?
CHIARI MALFORMATION
- Abnormal connection between inner and middle ear that allows leakage of perilymph
- Like MD also a fluid imbalance (in both too much endolymph relative to perilymph theory)
- Prevalence, diagnosis, treatment all controversial
What does this describe?
PERILYMPHATIC FISTULA
- Hearing loss (83% - 90%)
- Fluctuating SNHL, sudden or progressive and/or fluctuating word discrimination
- Vestibular symptoms
- Vertigo with or without head position
changes- Dysequilibrium (off-balance), nausea, and
vomiting
- Dysequilibrium (off-balance), nausea, and
- Tullio & Hennebert signs
- Vertigo with or without head position
- Tinnitus may be roaring
- Aural fullness
What does this describe?
Signs & Symptoms of Perilymph Fistula
- Physical trauma (including temporal bone fracture)
- Acoustic trauma (18 inches from fire engine siren)
- Barotrauma
- Spontaneous
- Ear surgery, esp. stapes surgeries
- Neoplasms, cholestomas
- Congenital especially cochlear abnormalities
What does this describe?
Etiology of Perilymph Fistula
sensation of self-motion when no self-motion is occurring or the sensation of distorted self-motion during an otherwise normal head movement
Vertigo
“sensation of disturbed spatial orientation without false or distorted sense of motion”
Dizziness
- Case history
- Battery of test:
- Fistula test – pressure to ear
- Look for nystagmus
- Tymp
- ECOG – elevated SP/AP
- ENG
- VEMP
- Exploratory surgery
- MRI w/intrathecal gadolinium (AIR IN COCHLEA BAD!)
- NO GOLD STANDARD
What does this describe?
Diagnostics & Testing for Perilymph Fistula
- Bed rest
- Avoidance of straining
- Reoccurs 21 – 47% of patients
- Exploratory tympanostomy & repair
What does this describe?
Treatment for Perilymph Fistula
- Vestibular neuritits
- Vestibular, vision & concentration
- Viral/bacterial infection of the vestibular
nerve
*May have long recovery or be chronic
- BPPV
- Ototoxicity
What does this describe?
Episodic vertigo WITHOUT hearing loss
- Labyrinthitis
- Hearing loss, tinnitus, vestibular
- Viral/bacterial infection of the labyrinth
- Serous or Suppurative
- Gradual recovery or chronic
What does this describe?
Episodic Vertigo WITH hearing loss
Clinical syndrome characterized by electrophysiological evidence of normal or near normal cochlear function and absent or abnormal auditory pathway transduction
Some sort of disconnect between OHCs and nerve itself; not necessarily one site of lesion; people will present differently
Auditory Neuropathy
- Normal outer hair cell function as measured by present OAEs or the presence of a cochlear microphonic
- OAEs may be present initially but
disappear over time, or be absent at time
of diagnosis
- OAEs may be present initially but
- Abnormal auditory nerve response as observed by absent or markedly abnormal ABR
- Acoustic reflexes are absent in most cases
What does this describe?
Audiological Findings of Auditory Neuropathy
- PT thresholds ranging from normal to profound
- Disproportionately poor speech recognition abilities for the degree of hearing loss
- Difficulty hearing in noise
- Impaired temporal processing
- Hearing fluctuation
- Some individuals have little or no communication difficulties while others are functionally deaf
- abnormal ABR with present CM
- NOT ALL INDIVIDUALS DIAGNOSED WITH THIS EXPERIENCE THE SAME PROBLEMS OR TO THE SAME DEGREE
What does this describe?
Clinical Characteristics Reported for ANSD
- Disorder initially thought to be rare
- Many published reports since late 90’s describing patients with similar audiologic test findings.
- Estimates range from 7 -10% of children diagnosed with permanent hearing loss
What does this describe?
Prevalence of ANSD
- Genetic:
*Syndromes
Charcot-Marie-Tooth disease; Friedrich’s
Ataxia; Hereditary motor and sensory
neuropathy (HSMN)- Non-syndromic
Recessive genetic mutations: Otoferlin
(OTOF), Pejvakin (PJVK)
Autosomal dominant mutations: AUNA1
(onset of auditory symptoms in late teens)
- Non-syndromic
- Perinatal Conditions
- Hyperbilirubinemia
- Hypoxia
- Low birth weight
- More common in premature infants
- Congenital Condition: Cochlear nerve deficiency (Small nerve or absent nerve)
- Infectious Processes: Viral infections (e.g. mumps, meningitis
- Head injury: E.g. Shaken baby syndrom
Possible Etiologies and Associations for ANSD
- ABR
- Immittance
- Tymps
- AR
- OAEs
- Behavioral Audiometry
- Speech Recognition testing
What does this describe?
Recommended Audiologic Test battery for ANSD
- Pre-neural response (occurs before wave 1 in the ABR)
- Unlike the ABR, this shows a direct phase relationship to the acoustic waveform. When the polarity of the stimulus is changed there is a reversal of this waveform as well
- this is the only one that changes
- Considered to have limited clinical use in past; renewed interest in diagnosis of ANSD
- Can be recorded in normal ears, ears with “typical SNHL” and ears with ANSD
- Significance in ANSD is this is present when neural response is absent or markedly abnormal
- Have to have good recording conditions
- Use single polarity clicks at high-intensity
levels - Must use insert earphones
What is being described?
Cochlear Microphonic
If response remains with sound tube disconnected from transducer, response obtained is __________ and not ________
Stimulus artifact; CM
- Medical history
- Ear exam
- Etiology
- Evaluate for other associated problems
*Seizures, Motor delays, Visual problems,
Ear canal problems, Otitis Media - Radiologic Studies (MRI/CT)
- Inner ear malformations, Cochlear nerve
integrity
- Inner ear malformations, Cochlear nerve
- Other studies as needed
What does this describe?
Otologic Examination
- Child has an auditory disorder but its difficult to know prognosis at time of ABR eval
- Degree of deficit may be mild or severe or even normal hearing thresholds
- Results of behavioral testing are necessary before specific recommendations can be made
- HA use is helpful in some cases but not in others
- CI may be necessary
- Frequency follow up needed
- Enrolled in early intervention
- Communication strategy will need to be determined
- Work together as a team to find a solution
What is being described here?
ANSD counseling for families
- Amplification should be fitted as soon as ear specific elevated pure-tone and speech detection thresholds are demonstrated by conditioned test procedures
- Hearing aid fitting strategies… should follow established guidelines for the fitting of amplification in infants and toddlers
Amplification Guidelines for ANSD
- Evidence of auditory nerve sufficiency should be obtained prior to surgery using appropriate imaging technology
- Children with ANSD who do not demonstrate good progress…
ANSD Guidelines (COMO 2008): Special Considerations for CI
- Parent questionnaires (e.g. PEACH, IT_MAIS, or MAIS)
- Early speech perception test battery
- Standard
*Low verbal
- Standard
- MLNT/LNT words and phonemes
- PB-K words and phonemes
- CNC words
- HINT sentences in quiet and in noise conditions
What is this?
Evaluation of Speech Perception Following Hearing Aid Fitting or Cochlear Implantation
- Needs to have child awake but quiet
- The shorter the gap detection, the higher the PBK word score (research study)
- evaluates outer ear to auditory cortex
CAEP (Cortical Auditory Evoked Potential)
evaluates outer ear to lower brainstem
ABR
- Not Conductive! Duh
- > 30 dB loss at 3 contiguous frequencies occurring w/in 24 – 72 hours
- Usually unilateral (Bilateral 1-5% of cases)
- Mild – profound, may be upsloping
- Tinnitus ~50%
- 32 – 65% spontaneous recovery
*Trend for older age
to have poorer
recovery - Fullness, much less common
- Vertigo (less common) ~25%
- Age: typically 40 -54 years (can have kids)
SYMPTOMS OF SUDDEN SENSORINEURAL HEARING LOSS
Which disorder excludes * Pre-existing hearing loss
* Bilateral hearing loss
* Low freq hearing loss (M’S D)
* Oscillopsia
* Signs of neurological/optical dysfunction
* Signs of stroke
* Head trauma
* Acoustic Trauma
Sudden Sensorineural HL
- Idiopathic
- Blood supply – vasospasm
- Autoimmune: Cogan syndrome, systemic lupus erythematosus, and other autoimmune rheumatologic disorders
- Intracochlear membrane rupture
- Viral infection (bacterial)
What is described?
Pathophysiology of SSNHL
- Viral (syphilis, meningitis, encephalitis)
- Other infection – toxoplasmosis etc
- Meniere D
- Neoplasms (CPA tumor)
- Vascular abnormalities/ Endocrine abnormalities (Hyothyroidism, Diabetes mellitus)
- Multiple Sclerosis
- Congenital anomalies (Mondini, EVA)
- Trauma, PLF
- Ototoxicity
- Lyme
- Virus —> immune/autoimmune response HL?
Differential Diagnosis for SSNHL
- Genetic polymorphisms
- Endothelial function
- Migraine
- Statin use
- Cardiovascular risk factors
- Periodontal disease?
- Chronic otitis media?
- Smoking, alcohol use
- Diabetes
Are all _____________ for this….
Risk factors for SSNHL
- PT, Speech, immittance including AR
- OAEs (tell you if cochlear or retrocochlear cause)
- ABR
- Vestibular tests usually only if vestibular symptoms
- MRI only if suspicion of tumor
This is what?
Testing for SSNHL
- Considered otologic emergency —> ENT more likely to treat w/corticosteroids & for long time (may add in antivirals)
- High spontaneous recovery rate so hard to demonstrate significant efficacy
- Counseling
- Communication strategies; may become HA candidate
What is being described?
Referral for SSNHL
- Anti-inflammatories steroids
- Hyperbaric oxygen
- Both combined
- Enhanced sound (prevent cortical reorganization)
What is being described?
Tx for SSNHL
- Age younger than 15 yrs or older than 65 yrs
- Elevated ESR inflammation measure
- Vertigo of vestibular change evident on ENG
- Hearing loss in opposite ear
- Severe/profound hearing loss
- Late presentation
- Family history
What is being described here?
Negative prognostic factors for SSNHL
more likely profound, 50% no recovery, more commonly associated with life threatening conditions
Pharmacological —-> speedballing, Imatinib, heroin, cocaine, methadone overdose
What is being described?
Bilateral SSNHL
Bilateral SNHL of at least 30 dB at any frequency with progression in at least one ear, defined as a threshold shift that is greater than 15 dB at any frequency or 10 dB at 2 or more consecutive frequencies or a significant change in discrimination score.
AUTOIMMUNE INNER EAR DISEASE (AIED)
- Progressive, often fluctuating, bilateral (79%) SNHL over a period of weeks to months
- Poor speech discrim
- Vertigo, generalized imbalance, and ataxia
- Tinnitus (roaring, ringing, hissing)
- Aural fullness
- Excludes SSNHL occurring in less than 24 hours
- Existing AI disease —-> lupus, ulcerative colitis, rheumatoid arthritis, scleroderma
Signs & Symptoms of AIED
- 20 – 50 years
- Possibly more woman than men
Epidemiology of AIED
- Immune reaction to inner ear antigens
- Circulating immune complexes
Pathophysiology of AIED
PLF, Meniere’s disease, SSNHL are all ….
Differentials of AIED
- Audiometry, possibly vestibular
- Antigen nonspecific:
- Antigen specific tests
Testing for autoimmune
- Medical emergency —-> refer
- IF under treatment:
- Monitor hearing,
balance - Possible
amplification - Communication
strategies - Counseling
What is being described?
- Monitor hearing,
Audiologist’s role in AIED
- Corticosteriods (response is diagnostic, positive response ~60%)
Others - Cyclophosphamide –
anti-tumor - Methotrexate –anti-inflammatory
- Plasmapheresis
What are these?
Tx for AIED
autoimmune disorder
* Rare – 200 cases in literature
* Interstititial keratitis (eye inflammation)
* Hearing loss & vestibular impairment
* Hearing loss —> biilateral and permanent
* Meniere like symptoms, starts with vestibular than hearing loss
Cogan’s Syndrome
- Genetic, hemoglobin change
- Some protection from malaria
- 1/500 African – Americans
- Vaso-occlusive episodes (pain, esp. joints), organ damage
- Hemolytic anemia (blood cells fall apart)
- Longer life seeing more ontological complications
- Hearing loss: EVERYTHING – bilateral, unilateral, gradual, sudden
- Other tinnitus and vertigo possible
Sickle Cell Anemia
- Sickled RBCs —-> impaired oxygen supply
- Compression of the auditory canal and auditory nerve by the hyperactive bone marrow in the petrous part of the temporal bone
- More susceptible to bacterial meningitis due to decrease immune function
Pathophysiology of Sickle Cell Anemia
(in womb is damaging to auditory system)
- Brain damage, MR, growth retardation, hearing loss in babies
- Pendred is euthyroid
- Common in adults
* 1.4-2% of women;
0.1-0.2% of men
* Increases with age
* Changes body temperature —-> will affect evoked potential
Hypothyroidism
mitochondrial genetic syndrome
- 2/3 of adults have hearing loss (~2x greater risk of HL)
* Metabolic disease
* Type 1: lack of insulin, often identified in children —-> could cause neuropathy
* Type 2: hyperglycemia, insulin resistance, lifestyle
DIABETES:
MELAS
- Microvascular
- Inflammation
- Hyperglycemia: smoking increases risk
- Glucose control
- Energy source
- Hair cells &
spiral ganglion
cells
(spiral lamina
most
affected) - Chronic
hyperglycemia
can disrupt
function
- Glucose control
- Microangiopathy: the thickening of basement membrane of the capillaries within the stria vascularis
- Neuropathy
- ROS
What is being described?
The Diabetes Mechanism
- Thresholds
- More difficulty in noise
- Epithelial changes may affect earmold comfort
- Danger for malignant otitis externa after EMI or cerumen removal
What is being described?
Audiological Effects of Diabetes
- Cardiac health risk factors —> smoking, waist circumference, cholesterol, BP
- This is related to heart attacks
- Association studies —-> good heart health = good hearing
- Coronary artery disease linked to poorer hearing
- Hypertension Proposed Pathophysiology: Decreased vascular supply to stria vascularis
- Hypothesis: low freq. HL as a predictor of cardiovascular status not the other way around
- Shuknect: strial HL
Hypertension/Cardiovascular
- SSNHL
- Treatment: apheresis (clean out the blood)
Hypercholesterolaemia/hyperlpproteinemia (basically high cholesterol)
- SSNHL
- Microembolisms (particles from ateriosclerotic plaques, fat or air)
- PLF
- Tears in scala
- Risk factors: contributors to presbycusis, factor in decreased hearing in adults
Cardiopulmonary surgery
- Acute (24-48hr), idiopathic, unilateral, peripheral, lower-motor neuron facial nerve paralysis
- Resolves over time in 80 – 90% of cases (especially if mild case, not elderly)
- 20-30/100000
- More common in diabetics, pregnant women
- Treat with corticosteroids & antivirals
What is being described?
Bell’s Palsy (CN VII)
- Facial muscle weakness
- Eyelid closure
- Aching of the ear or mastoid
- Alteration of taste
- Hyperacusis, tinnitus
- Tingling or numbness of cheek/mouth
- Tearing
- Visual signs
- Rarely SSNHL or progressive HL, may be low frequency
- May show up in AR
- Bilateral palsy: Guillain-Barre Syndrome- —> REFER: autoimmune response
What is being described?
Symptoms of Bell’s Palsy (CN VII)
- Twitching (myoclonus)
- Irritation of VII or its nucleus
- 40+, may be a sign of MS in younger age
Hemifacial Spasm
- Neuropathic pain
- 50+
Trigeminal neuralgia V—in Ramsay Hunt Syndrome
- In kids especially – significant symptom: Facial paralysis
- SSNHL – take history look for test for Borrelia burgdorferi
- Not much on gradual hearing loss, but some reports of HF hearing loss
- Tinnitus common
Lyme Disease
- Anterior inferior cerebellar artery (AICA) stroke (2nd most common brainstem stroke:
- Vertigo, tinnitus, hearing loss, alone or with facial weakness, hemiataxia, hypalgesia
- Retrocochlear: middle cerebellar peduncle, cerebellar flocculus, inferolateral tementum of the pons or cochlear
- Vascular loops
- Association of stroke with both increased hearing loss and increased risk of SSNHL
- Ischemic and hemmoragic
Stroke
- Association between CKD and HL
- Dialysis patients especially at risk
Chronic Kidney Disease
- Inflammatory, demyelinating disease of the central nervous system
- Diagnosis is described as definite, probable or possible _____
- Chronic progressive, relapsing remitting
- New treatments may change
- Disease of young adults —> occurs in 20s
Multiple Sclerosis (MS)
- Hearing loss rarely the first sign
- Sudden, usually fluctuates, recovers
- Retrocochlear —> testing
- Vertigo relatively common, initial symptom
- Imbalance and disequilibrium more commong
- Testing: PT, speech (may be poorer) AR pattern, ABR, vestibular, MRI
The auditory system of MS