final exam comprehensive Flashcards
ABR findings with conductive HL
an increase with absolute latencies
ABR findings with SNHL
higher wave latencies with early waves disappearing as the intensity decreases
ABR findings with retrocochlear pathologies
presence of wave 1 only
ABR findings with ANSD
a flattened sum curve, flipped condensation and rarefaction curves
ABR findings with a schwannoma
wave 5 increases and therefore interwave latency also increases
OAE findings with PE tubes
reduced or obliterated
OAE findings with negative ME pressure
variable responses
OAE findings with ANSD
present unless blood supply is impacted
neuroglial cells
the supporting cells of the brain
-astrocytes : nerve cells and functions as an insulator
-oligodendrocytes : myelin sheath for central nerve fibers
-microglia : activated with inflammation/degeneration in CNA
-ependymal cells : line CSF filled cavities and spinal cord
neoplasms
abnormal mass of tissue, can be benign or malignant
-a disorder of the cell cycle in which they prey on the host
classification of neoplasms
intracranial, benign, malignant, intra-axial and extra-axial
intracranial neoplasms
brain tumor that includes :
-benign and malignant tumors
-masses within brian
-tumors of meninges
-tumors from structures near brain tissue
benign neoplasm
slow growing with well defined borders
-generally not life threatening
-does not metastasize
malignant neoplasms
tends to grow faster and causes invasion and destruction of structures
-can become life threatening
-able to metastasize to other areas of the body
intra-axial tumors
originating within the brain tissue
extra-axial tumors
originating from tissue that is not originated from the brain
vascular tumors
most found within the temporal bone and are benign
-messy and difficulty to remove due to them becoming involved with blood supply
-typically presenting with symptoms in the 3rd decade of life
two types of vascular tumors
hemangiomas and vascular malformations
hemangiomas
initial rapid growth with decreasing growth rate
vascular malformations
grows in proportion with the body growth without regression
-more common than hemangiomas
site of lesion for vascular tumors
IAC or the geniculate ganglion of the 7th nerve
-can also arise from ME cavity
symptoms of vascular tumors
CN 7 dysfunction, hemifacial spasm, tinnitus and vertigo (occurs when CN 8 is impacted)
diagnosis of vascular tumors
case Hx and presentation of symptoms, high resolution CT scan, MRI with contrast (geniculate lesions may be difficult to view)
what type of MRI is useful with vascular tumors?
T2 weighted image as the fluid is brighter
management of vascular tumors
surgical removal
differential diagnosis of vascular tumors
meningioma, CN 7 schwannoma and cholesteatoma
schwannoma
benign tumor of the temporal bone and CPA that is produced by abnormalities of schwann cells and are slow growing
-extra-axial tumors
site of lesions for schwannomas
IAC from the 8th nerve, jugular foramen of 10th nerve or the fallopian cavity of the 7th nerve
explain the common growth pattern of a schwannoma
grows into the CPA involving the 7th and 8th nerve, it can grow large within the CPA, while in the CPA it can creep into the IAC and with further enlargement it can cause brainstem compression and 5th nerve involvement
symptoms of schwannomas
headache, tinnitus, unsteady gait, imbalance/vertigo, facial paralysis, nystagmus and if 4th ventricle compression occurs it can cause hydrocephalus, coma or death
schwannoma symptoms will typically present _________
ipsilaterally
audiologic findings of a schwannoma
unilateral HF SNHL, normal OAE with not significant HL, OAE suppression is decreased, poor WRS, abnormal ARTs, varied reflex decay (none seen with normal nerve, decay with affected nerve), abnormal ABR in most cases
diagnosis of a schwannoma
T1 contrast MRI
-a CT scan is not sensitive
management of a schwannoma
observation, radiosurgery or surgery
meningioma
the most common benign brain tumor of the CNS that are circumscribes, lobulated and white masses
-extra axial
-appears within middle to late decades of life
meningiomas can be …..
aggressive and locally invasive
-can invade nerves
-can become involved with vascular structures
site of lesions with meningiomas
meninges
-originating within the CPA and may grow into the IAC
risk factors for a meningioma
being an NF2 patient, having radiation therapy to the head and certain chromosomal abnormalities
symptoms of a meningioma
vertigo, tinnitus, nausea/vomiting
audiologic findings with a meningioma
progressive unilateral SNHL, abnormal ARTs on affected side, normal tymp, positive reflex decay, positive roll over and poor WRS in noise
treatment of meningiomas
surgical excision followed by radiation
-hearing preservation is more likely for CPA meningiomas rather than CN 8 tumors
-with old or ill patients the approach is more conservative with symptomatic management
differential diagnosis for meningiomas
osteoma, paraganlgioma, NF2 and facial nerve schwannoma
cortical tumors
tumors that are affecting the auditory cortex which may show normal results for peripheral auditory tests however poor WRS will occur
symptoms of cortical tumors
normal ABR if the periphery is normal, headaches, dizziness/unsteadiness
with cortical tumors, the symptoms will be seen _________
contralaterally
malignant tumors
often diagnoses at late stages with a dismal prognosis
-might show symptoms similar to chronic otitis media
symptoms of a malignant tumor
aural discharge, otalgia, HL, tinnitus, facial paralysis, headaches and cochleovestibular deficits (SNHL or vestib issues)
metastatic tumors
malignant tumors that are from other site of origins than the brain
-such as breast cancer, lung cancer, renal carcinoma, thyroid cancer, melanoma or osteoblastoma
autoimmunity
occurs when the body’s immune system attacks the body itself
-instead of the body protecting itself from disease, it attacks the body’s own cells
-more common within females
immunology of the inner ear
cells are connected by the blood labyrinth barrier that controls the movements of circulating inflammatory and other proteins/cells
-this is of importance for the immune response of the inner ear
-this barrier is not immunopriveleged
-this barrier is made of endothelial cells through a tight junction and it affects the EP
inner ear vasculature
responsible for the delivery of systemic drugs and steroids for inner ear treatment
-stria vascularis and spiral ligament have homestatic function that requires uncompromised blood flow
-barrier allows for endolymph to maintain high potassium levels required for production and maintenance of the EP and normal cochlear function
-disruption can lead to immediate HL
what can occur to the inner ear in response to a vascular reaction to inflammatory factors
breakdown of strial integrity, decreased endolymph production and reduced EP levels
-leading to SNHL
how can steroids negatively impact the immune system
suppress the production of inflammatory cells, suppress the production of cytokinesis, suppress the production of antibodies, stimulates production of inhibitory factors and increase production of junctional proteins
autoimmune inner ear disease (AIED)
autoimmune disorder that is characterized by progressive bilateral SNHL and its responsiveness to immunosuppressive agents
-reversible SNHL if treated early
-females are affected more with symptoms appears between 20 and 50 years of age
primary AIED vs. secondary AIED
condition of the inner ear vs. condition coming from another part of the body
symptoms of AIED
bilateral progressive SNHL, aural fullness, tinnitus, imbalance/ataxia and positional/episodic vertigo
diagnosis of AIED
lab tests and imaging studies
-physical exams are usually normal
treatment of AIED
corticosteroids remain the standard and lasting for around 4 weeks
-can be given longer for repeated or for relapses
differential diagnosis of AIED
sudden SNHL, menieres disease, vestibular schwannoma, MS, otosyphillis
sudden sensorineural hearing loss (SSHL)
greater than 30 dB SNHL occurring in at least 3 continuous frequencies within 3 days
-typically unilateral
-increased incidence with age and is seen with patients with previous viral infections
what is SSHL associated with
viral infections, ototoxic drugs, trauma, tumors, autoimmune diseases, menieres disease, drug abuse, nonorganic HL and vascular pathology
what do histiopathic findings show with SSHL
atrophy of organ of corti, stria vascularis or tectorial membrane
-most damage seen on the basal turn of the cochlea
-results in a more narrow spiral ganglion than the normal cochlea
audiologic findings with SSHL
unilateral sudden SNHL, rapid deteriorating speech understanding, may present with dizziness or vertigo, normal tymp and ARTs are consistent with HL
diagnosis of SSHL
case Hx, test battery, MRI to help rule out other disorders and lab tests (hormone levels, autoimmune conditions or diabetes)
treatment of SSHL
oral corticosteroids for around 4 weeks is typical but can be intratympanic steroids in higher concentration
-should begin within one week of onset
what are some consequences of long term steroid usage
increased appetite and weight gain, increased susceptibility to infection, organ damage, bone loss, increased hyperglycemia, fluid retention or increased blood pressure
prognosis of AIED
-good prognosis with mild low frequency SNHL or short term symptoms
-poor prognosis with old and young patients, high frequency or flat SNHL, vertigo or patients with diabetes
what are demyelinating diseases
resulting in damage of the myelin sheath that surrounds nerve fibers within the brain and spinal cord
-results in impaired conduction of signals and neurological problems in affected nerves
multiple sclerosis (MS)
progressive neurological autoimmune disease that is multifactorial
-affects the white matter pathways within the CNS
-causing focal areas of inflammation (plaques)
-unknown cause but is believed to have both intrinsic (genetic) and extrinsic (environmental) factors
what is the hallmark of MS
plaques (sclerosis or scars)
-more typical within white matter showing preference for the optic nerve and optic chiasm
symptoms of MS
visual problems (diplopia meaning double vision is seen first), fatigue/malaise, spinal cord issues leading to abnormal reflexes and poor coordination, numbness, dysarthric speech and ataxia
audiologic findings with MS
SNHL, variable ARTs, poor WRS and may show central auditory processing deficits
diagnosis of MS
history, periods of intensified symptoms and periods of diminished symptoms, high levels of immunoglobin found in CSF and imaging (CT or MRI)
how many plaques are present within an MS patient
over two must be seen
treatment of MS
no cure but is manageable
-immunosuppressive agents are recommended but not goo long term
-symptomatic treatment
differential diagnosis of MS
susacs, schilders, diabetes, stroke, SSHL
susac syndrome
self limiting syndrome characterized by encephalopathy (cerebral problems), retinal artery occlusion (vision problems) and asymmetric fluctuating SNHL
-more common in women between 20 and 40 years
why is susac often diagnoses as MS
due to the presence of white matter defects in the corpus callosum
-high rates within women 20-40 years of age
-fluctuating disease
-asymmetric SNHL that is often low frequency and fluctuating
-associated with dizziness/vertigo
schilder’s disease
progressive, degenerative demyelinating disorder of the CNS
-begins within childhood/young adulthood however is present in any age
-course in unpredictable
-often bilateral
symptoms of schilder’s disease
personality changes, poor attention, irreversible and progressive loss of intellectual function, vision and hearing impairments, headaches, seizure, muscle weakness, paralysis and atrophy of adrenal glands
diagnosis of schilder’s disease
MRI with plaques, no other lesions present and PNS is normal
treatment of schilder’s
corticosteroids are used and symptomatic treatment
cogan syndrome
rare chronic autoimmune inflammatory disorder
-impacts young adults with peak incidences in the third decade of life
pathology findings of cogan syndrome
cell infiltration of spiral ligament, endolymphatic hydrops, degenerative changes in the organ of corti, extensive new bone formation in the inner ear and demyelination of the vestibular and cochlear branches of the 8th nerves
symptoms of cogan
interstital keratitis (red, painful, light sensitive eyes), SNHL, nausea, ataxia, oscillopsia, tinnitus, progressive, musculoskeletal symptoms, fever, weight gain and fatigue
testing of cogan
positive ECochG, caloric testing shows absent peripheral vestibular function, and generally high frequency slopping SNHL
diagnosis of cogan
based on presence of inflammatory eye disease and vestibulocochlear dysfunction
treatment of cogan
collaborative medical approach, corticosteroids for hearing and ocular symptoms, amplification (CIs are more successful) and vestibular rehabilitation
wegener’s syndrome
autoimmune vasculitis that affects the upper and lower respiratory tracts, ear and kidneys with variable expressivity
-swelling of pinna may occur
-conductive HL associated with OM due to infection of nasopharynx
treatment of wegener’s
immunosuppressive drugs, cytotoxic drugs
-without treatment it can be fatal
diabetes and HL
due to vascular changes that affect the stria vascularis and spiral ganglion
-low frequency HL is common
-high frequency SNHL and fluctuating HL can also be seen
-WRS not affected unless neuropathy is present
hypertension and HL
blood supply is affected and therefor reduced blood and oxygen supply to the cochlea
-increased incidence of high frequency SNHL
vestibular system
the somatosensory portion of the nervous system that provides awareness of the spatial position of the head and body
-provides proprioception and kinesthesia
-peripheral sensory apparatus, vestibular system and motor ouput
peripheral sensory apparatus (vestibular labyrinth)
located within the inner ear and is comprised of the following :
-semicircular canals that are sensory for angular or rotational acceleration
-otolith organs (utricle and saccule) that sense gravitational changes in which the utricle is linear and saccular is vertical
central vestibular system (structures within the brainstem and cerebellum)
receives input from the peripheral vestibular mechanisms by the vestibular divisions of CN 8
-input from labyrinth is processed alongside visual sensory and somatosensory input
-influences eye movement, truncal stability and spatial orientation
motor output (connection to motor nuclei and muscles)
comprised of vestibulo-ocular reflex (VOR), vestibulospinal reflex (VSR) and vestibulocollic reflex (VCR)
VOR
gaze stabilizing reflex that helps keep the environment steady and stable
-when the head rotates one way, the eyes are rotated the opposite direction within the same axis to keep the visual field steady
-oscillopsia occurs when this is not working properly
VSR
stabilizes posture
-maintaining posture, the back is involved
VCR
stabilizes the head
-head is involved
common symptoms of vestibular disorders
sense of imbalance, dizziness, nystagmus and vertigo
nystagmus
disturbances of ocular movement characterized by nonvoluntary rhythmic oscillations or rapid jerky movements of one or both eyes
-either idiopathic or associated with disorders
-can occur spontaneously in response to vestibular upsets
-detection through ENG or VNG
vertigo
a type of dizziness that is specific to vestibular system disorders
-subjective (self) or objective (environment)
-episodic vertigo occurs with sudden onset in distinct episodes
vestibular compensation
typically vestibular symptoms are unilateral however over time symptoms may improve due to compensatory mechanisms
-this process involves changes in the central vestibular nucleus that lead to partial restoration of lost neural activity within affected nuclei
what will not show vestibular compensation
bilateral peripheral deficits and central vestibular pathologies
vestibular labyrinthitis
inflammation of the inner ear labyrinth
-shows both cochlear and vestibular symptoms
vestibular neuritis
inflammation of the vestibular nerve
-shows only vestibular symptoms
what causes vestibular labyrinthitis/neuritis
can occur after infections such as a cold, OM, measles/mumps, meningitis or infection mononucleosis
symptoms of vestibular labyrinthitis/neuritis
cochlear : aural fullness, tinnitus and high frequency SNHL
vestibular : acute vertigo, nausea/vomiting, nystagmus
treatment of vestibular labyrinthitis/neuritis
antibiotics or antiviral drugs, symptomatic treatment with vestibular suppressant drugs and steroids have been used for anti-inflammatory effects or to revere HL
vascular occlusion of the labyrinth artery
occlusion of this artery causes sudden and profound SNHL as well as vestibular dysfunction
-most common within older adults
-patients may complain of episodic vertigo causing a transient ischemic attack prior to occlusion
migraine headaches
severe, episodic and disabling neurological condition
-activation and sensitization of the pain pathway of trigeminal and cervical nerves
-more common in females with a genetic component
-throbbing unilateral head pain with sensitivity to movement
-triggers for episodes
-associated with aura (sensory disturbance)
migraine associated vertigo (MAV)
dizziness/vertigo is the aura of the headache and in most they present with true vertigo and no headache
-diagnosis is based on case history and subjective symptoms
treatment for MAV
medication prescribed for migraines, migraine diet and avoid trigger, low dose of vestibular suppressant medicines for acute attacks, vestibular rehabilitation and prophylactic migraines for severe cases
benign proximal positional vertigo (BPPV)
most common cause of vertigo of peripheral origin and can become triggered by certain head positions or movements
-false sensation of rotational movement
-average age is 55 but can occur at any age and is generally idiopathic
risk factors for BPPV
head trauma, vestibular neuritis, stapes surgery, menieres disease, migraines, diabetes and osteoporisis
symptoms of BPPV
brief episodes of mild to intense dizziness/vertigo that is triggered by head positioning
-involves posterior semicircular canal
types of BPPV
acute (resolves over 3 months), intermittent (active and inactive periods) and chronic (continuous symptoms)
what causes BPPV to occur
otolith organs (sensitive to gravity) become dislodges and migrate to the SCC which do not move with gravity
-when the otoliths are triggered to move, they move the fluid within the SCCs which causes the inner ear to send false signals to the brain that the head is moving on gravity
diagnosis of BPPV
audiogram and MRI is typically normal so testing through dix-hallpike test (head maneuver that moves the head into a position which makes the otoliths move within the SCC)
-this signal will cause nystagmus that can be observed and assessed
nystagmus occurs due to ……
a mismatch of information going to the brain
management of BPPV
most are corrected mechanically by maneuvers such as the epley maneuver
-vestibular suppressants are not typically helpful
-surgery can help with vertigo in rare cases
meniere’s disease
idiopathic syndrome characterized by the histopathological finding of endolymphatic hydrops
-a multifactorial condition
-equal incidence between gender with a peak occurring between 30 and 60 years
symptoms of menieres
intermittent episodes of vertigo lasting from minutes to house, fluctuating SNHL, tinnitus and aural fullness/pressure
diagnosis of meniere’s
two or more definitive episodes lasting 20 minutes or longer and at least 2 of the characteristics present
hearing loss with meniere’s
SNHL that progresses as time goes on
-acoustic distortion initially with speech understanding affected
-loudness recruitment with low UCL as a result
-low frequency or flat to reverse cookie bite to flat severe SNHL
acute cases of meniere’s
often will present the same across all patient’s
-unilateral aural fullness, vertigo, tinnitus and SNHL
-hearing can return to normal after the episode
-lasts for a couple of hours to a day
as meniere’s progresses ….
attack becomes more frequent and severe
-HL does not return to normal
-vertigo stops but patients may still feel dizzy
-diplacusis (perceiving the sound as the same despite it being different)
audiologic findings with meniere’s
normal tymp, reflexes present but low, abnormal ECochG (large)
management of meniere’s
symptomatic treatment to control vertigo and nausea, low sodium diet and diuretics to decrease endolymph, corticosteroids are recommended for patients unresponsive to vestivular suppressants and CIs have been found helpful
differential diagnosis for meniere’s
acoustic neurome, labyrinth viral infections, idiopathic vertigo, perilymphatic fistula and cogan
superior semicircular canal dehiscence (SSSCD)
typically a unilateral condition that is the absence of the bone overlying the SCC facing towards the dura and middle cranial fossa
-not every patient will show symptoms, more uncommon to show them
-relating to pressure!
SSCD is the lack of ________ of the bone covering the superior semicircular canal
thickening
how does SSCD alter fluid mechanics
it creates a third window into the inner ear in which energy then can de transmitted out to the cranial vault of from the cranial vault into the endolymph
-this alters the circulation of pressure
-signs are due to this third window
etiology of SSCD
congneital (poor development of temporal bone), head trauma and idiopathic
how do symptoms present in SSCD
presents with either vestibular or auditory symptoms, presents with both symptoms or no symptoms
vestibular symptoms of SSCD
vertigo/dizzinrss, nystagmus, tulio’s (sound induced vertigo)or oscillopsia
auditory symptoms of SSCD
conductive or fluctuating HL with low frequency ABGs and normal ARTs
why do bone threshold get better in the low frequencies with SSCD
vibration of the skull from the transducer and with the pressure being altered in a different way it improves these thresholds
diagnosis of SSCD
vestibular assessment, high resolution CT scan, ECochG (abnormal SP/AP ratio)
management of SSCD
mild to moderate symptoms have a conservative approach and with debilitating symptoms surgical repair with bony cement or a soft tissue plug occurs
differential diagnosis of SSCD
patulous ET and otosclerosis
mal de debarquement
sickness of disembarquement
-illusion of movement experienced after traveling
-unknown case, more common in women
-diagnosis through subjective history
symptoms of mal de debarquement
rocking or disqeuallibrium after return to land, anxiety and depression, worse when in enclosed spaces or when motionless and it often improves during continuous movement
management of mal de debarquement
drugs for motion sickness, vestibular rehabilitation may help along with avoidance of trigger
why are vestibular disorders often underdiagnosed in children
it is often compensated and they do not have the vocabulary to express the symptoms and
more often than not, vestibular dysfunction in children often accompanies by ___________
hearing loss
what are some disorders that can affect the pediatric vestibular system
genetic conditions, neurological conditions, trauma/infection and other conditions including ANSD and SSCD
OM is a common cause of vestibular symptoms in children, what are two explanations for this
invasion of bacterial toxins in the inner ear and formation of cholesteatoma that causes labyrinthitits or perilymphatic fistula
a good case history is a critical diagnosis for children, what should be focused on
identifying provoking movements or activities such as motion sensitivity
you should suspect a vestibular dysfunction in children if what occurs
if a child has a HL greater than 60 dB HL and has not walked by 14.5 months
hearing level cutoffs for hearing loss
shift of greater than or equal to 15 dB HL for the average thresholds 500, 1000, 2000 and 3000 Hz
WRS change to be significant
shift of 15-20% or greater
what is an ECochG
electrophysiological test that reflects elevation of the inner ear pressure
-sensitive to pressure changes within the cochlea
-records a summating potential (from organ or corti) and a action potential (from the nerve)
what is the action potential in an ECochG in terms of the ABR
wave 1
ECochG levels to be significant
greater than 0.42 or 42% SP/Ap ratio is positive
examples of disorders where a ECochG would be helpful to diagnosis
meniere’s, SSCD and cogans
type Ad tympanogram associates with
ossicular disarticulation
type B tympanogram associated with
ME fluid (OM) or choelsteatoma
type B high volume tympanogram associated with
perforation or PE tube
type B low volume tympanogram associated with
occlusion within the canal
type C tympanogram associated with
auditory tube dysfuntion or middle ear fluid
unilateral ME pathology will show what reflex pattern
when anything is coming or going from the affected ear
cochlear pathology will show what reflex pattern
affects anything when it is presented to the bad ear
-STIM affects
CN 8 pathology will show what reflex pattern
reflexes affected when the tone is presented to the bad ear
-STIM effect
brainstem lesions will show what reflex pattern
contralateral reflexes are absent
CN 7 pathology will show what reflex pattern
affected when it is measured on the affected side
-PROBE effect
