Autoimmune and Systemic Disorders affecting the auditory system Flashcards
Lectures 12 to 13
what does the immune system protect the body from?
Disease
a healthy immune system has remarkable ability to distinguish between?
bodys own cells (self)
foreign cells (non self)
When does autoimmunity occur?
when bodies powerful immune system that protects the body from invading microorganisms goes away and attacks the body itself
Instead of protecting the body from external pathogens the immune system produce
autoantibodies or T lymphocytes reacting with the hosts own antigens
Cause of autoimmunity possibly interactions of various
immunologic, hormonal, genetic and viral factors
Autoimmune diseases can be cause spectrum of human illnesses and affect: gender?
Women
Autoimmune responses can be limited to a single organ
Thyroid in Hashimotos disease
Autoimmune diseases can cause systemic damage
systemic lupus
multiple sclerosis
The endothelial cells of the stria are connected by tight junctions to establish the blood labyrinth barrier that controls movement of
circulating inflammatory and other cells/proteins
What is an important determinant for the immune response of the inner ear?
blood labyrinth barrier
Immune responses can occur in the inner ear activated by several immunologic mechanisms making the inner ear
susceptible to autoimmune conditions
Inner ear vasculature: What do blood vessels carry?
Immune cells, inflammatory cells, and hormones that affect inner ear function
What is inner ear vasculature responsible for ?
delivery of systemic drugs and steroids for inner ear treatment
The inner ear has extremely high metabolic demands requiring ?
A fully functional vascular system
What has unique homeostatic function that requires uncompromised blood flow?
stria vascularis and spiral ligament
blood labyrinth barrier allows for the endolymph to maintain:
a high K+ level required for production and maintenance of the endocochlear potential and normal cochlear function
Disruption of the blood labyrinth barrier due to vascular leakage can lead to ?
Immediate hearing loss
Normal vascular reactions to inflammatory factors that would be harmless for most organs can be be quite harmful for the inner ear and lead to:
breakdown of strial integrity
decreased endolymph production
reduced EP levels
Vascular functions in the ear disease(systemic)
- vasculature carries hormones responsible for
normal organ function
Vascular functions in the ear disease (systemic)
- vasculature carries immune factors from
systemic infections and inflammatory disease
Vascular functions in the ear disease (systemic)
- endothelial cells are active participants in tissue response to
circulating inflammatory
Vascular functions in the ear disease (systemic)
- endothelial cell tight junctions are opened for
extracapillary movement of serum factors
Vascular functions in the ear disease (inner ear)
- vasculature is the connection between
the body and ear
Vascular functions in the ear disease (inner ear)
- vascular endothelial cells are the
gatekeepers to the ear
Vascular functions in the ear disease (inner ear)
- nothing enters the ear without passing through
endothelial cells
Vascular functions in the ear disease (inner ear)
- what is commonly seen in numerous hearing disorders?
Serum inflammatory factors
Vascular functions in the ear disease (inner ear)
- breakdown of the BBB is the
first vascular reaction to inflammation
Vascular functions in the ear disease (inner ear)
- steroids cause BBB restoration by
regulating tight junction genes
What is the first line of treatment in autoimmune, inflammatory and infectious conditions of the inner ear?
Steroids (glucocorticoids)
steroids can suppress the immune system and can suppress
production of inflammatory cells that cause apoptosis (cell death) of existing cells
Pathologies that affect the general metabolic system or biochemical balance of body can affect
the auditory system
diseases/disorders that can involve the auditory system include
autoimmune disorders
- ms/SSNHL
Vascular disorders
- wegner granulomatosis
Metabolic disorders
- diabetes/thyroid
What is autoimmune inner ear disease characterized by?
Progressive bilateral SNHL
responsive to immunosuppressive agents (corticosteroids)
AIED is one of the few cases of SNHL that is
reversible
Primary autoimmune inner ear disease
diseases restricted to the ear
Secondary autoimmune inner ear disease
multisystemic autoimmune diseases that also involve inner ear
EX: Cogan syndrome or WG
Autoimmune inner ear disease epidemiology
female preponderance
symptoms 25-50
Clinical presentation of AIED is
bilateral SNHL
aural fullness
tinniutus
vestibular symptoms
Diagnosis of AIED
normal physical examination
manifestations of systemic autoimmune disease such as:
- effusion in ME and EAC and cough (Wegner)
- skin lesions
- visual loss (cogans)
Treatment of AIED is
corticosteroids
how many weeks of corticosteroids and irreversiable damage how many months of onset
~4 weeks
~3 months
differential diagnosis of AIED
SSNHL
Menieres
CN VIII schwannoma
MS
AIED is typically ____ & _______
While SSNHL is ____ & ____
AIED = progressive and bilateral
SSHL = unilateral and not progressive
SSHL is defined as
> 30 dB HL SNHL occurring in at least three contiguous frequencies within <3 days
SSHL is typically unilateral or bilateral ?
UNILATERAL
if bi lateral look for different cause
For SSNHL if one ear has been affected the other being affected during lifetime increases
4 to 17%
SSNHL no gender difference typically in what decade of life?
5th to 6th
Etiology of SSNHL
idiopathic hearing loss
viral infections
tumor
ototoxic drugs
trauma
autoimmune disease
meineres
drug abuse
perilymphatic fistula
Histopathologic findings of SSNHL
atrophy of
- organ of corti
- stria vascularis
- tectorial membrane
damage at cochlear basal turn
Audiologic findings of SSNHL
- no specific audiometric configuration or degree of loss
high frequency or flat mild to profound SNHL
POOR WRS
Vestibular findings of SSNHL
diziness or vertigo
SSNHL Immittance
normal tympanogram
ARTS consistent with degree of HL
Evaluation of SSNHL
case history/ audiologic evaluation
for SSNHL MRI is useful to rule out
trauma
tumors
multiple sclerosis
Treatment of SSNHL
Oral corticosteroid therapy for 4 weeks
What are consequences of long term corticosteroid therapy
increased appetite and weight gain
susceptibility to infection
organ damage (blurred vision/upset stomach)
bone loss
increased hyperglycemia
fluid retention/increased blood pressure
Prognosis of SSNHL
variable because multifactorial
SSNHL can be permenant
pts improve with no treatment
Indications for good Prognosis of SSNHL
Mild to low frequency SNHL
Symptoms persisting for shorter time
WRS may not recover
Indications for BAD prognosis of SSNHL
Age; very old/young
high frequency or flat SNHL
vertigo
diabetes
demyelinating disease =
disease results in damage of of myelin sheath that surrounds nerve fibers in brain and spinal cord
demyelinating disease result in
impaired conduction of signals and neurological problems in affected nerves such as impaired
- sensation
- movement
-cognition
Some causes of demyelination include
genetics
infectous agents
autoimmune disease
idiopathic
Multiple sclerosis is a progressive
neurological autoimmune disorder
MS affects the ___ matter pathways
white matter pathways of CNS
What enters the brain, spinal cord, or optic and other nerves causing multiple focal areas of inflammation, demyelination, and nerve damage?
Immune cells form blood vessels
The focal damaged areas of MS are called
Plaques
In MS where are plaques more typical
white matter sparing axons
In MS where do plaques show preference ?
optic nerve and optic chiasm
Etiology of MS
unknown
result of intrinsic (genetics) and extrinsic (environmental factors
Epidemiology of MS
common in Caucasians in the northern hemisphere
- 10 to 60 years
- females
Signs and Symptoms of MS
- visual system
- paralysis of eye muscles
- fatigue and malaise
SPINAL CORD AFFECTED 1st - abnormal reflexes and poor coordination - exhibits heat factor
-dysarthric of speech and ataxia - HL and vestibular problems
Peripheral audiologic signs and symptoms of MS
- high frequency SNHL
- bi lateral
- low frequency rising SNHL
FLUCTUATING HL - in young adults should raise suspicion
Central audiologic signs and symptoms in MS
poorer WRS in speech in noise
auditory processing deficits
- abnormal ABR
what is the largest band of white matter in CNS
Corpus Callosum
Diagnosis of MS
History
high levels of immunoglobulin
Imaging
- >2 lesions (plaques) in white matter pathways w/ history and clinical presentation
Treatment of MS
not cureable
- immunosuppressive agents / oral corticosteroids
Differential diagnosis
Autoimmune diseases :
1)Susacs syndrome
2) Schilders disease
Diabetes
Stroke
SSNHL
Susacs syndrome
Characterized by:
self limiting syndrome
- cerebral disturbances
- visual problems
- asymetirc fluctuating SNHL
Susacs syndrome often misdiagnosed as MS because of presence of
white matter defects in corpus callosum
what are the white matter defects ? Infarcts :
localzied dead tissue due to lack of blood supply
Susacs resembles MS because
affetcs women 20 to 40
fluctuating disease progression
asymetric SNHL low frequency
vertigo and diziness
Schilder Disease is
(considered a childhood variant of MS)
Progressive degenerative demyelinating disorder of CNS
in Schilders disease what is affected
both adrenal gland as well as myelinated nerves and their axons
Clinical presentation of Schilder
- personality changes/ poor attention
- irreversiable, progressive loss of intellectual function
- vision and hearing impairment
- balance
- headaches/ vommiting/ seizures
muscle weakness - atrophy of adrenal glands
Diagnosis of Schilder
on MRI to >2 large often bilateral plaques
treatment of Schilder
corticosteroids
symptomatic treatment
Cogans Syndrome is a rare
chronic autoimmune inflammatory disorder
Cogan Syndrome epidemiology
young adults
3rd decade of life
median age 22
no gender or racial predominance
Pathology of Cogans
lymphocyte and plasma cell infiltration of spiral ligament
- endolymphatic hydrops
- degernative changes organ of corti
- new bone formation in the inner ear
- demyelination and atrophy of vestibualr and cochlear branches
Cogan Syndrome clinical presentation
vestibulocochlear dysfunction and interstitial keratitis
Cogan Syndrome vestibular symptoms
(generally sudden onset)
Imbalance/vertigo
nausea and vommiting
ataxia
oscillopsia (perception of objects jiggling back and forth after turning head to one side)
Cogan Syndrome cochlear symptoms
tinnitus
unilateral/bilateral high frequency sloping SNHL
Cogan Syndrome Occular
Interstitial Keratitis (red/painful/ light sensitive eyes)
- blood vessels grow into cornea
blurred and decreased vision
non specific systemic Cogan Syndrome
musculoskeletal symtpoms
fever
fatigue
weight loss
cardiovascular concerns
Cogan Syndrome Diagnosis
inflammatory eye disease and vestibulocochlear dysfunction
Cogan syndrome treatment
collabrative medical approach
corticosteroids
hearing aids
cochlear implant
vestibular rehabilitation
Cogan Syndrome Differential diagnosis
menieres disease
1) eye symptoms absent
2) CS imbalance an ataxia vs menieres objective vertigo
3) systemic manifestations in CS not in menieres
Labrinthitis/neuronitits
Wegners granulomatosis
Wegeners granulomatosis
autoimmune vasculitis affects upper/lower respiratory tracts/ears/ and kidneys
Wegeners Granulomatosis
audiologic manifestations
swelling of pinna (polychondritits)
conductive HL (otitis media and obstruction of nasopharynx)
patients w/ SSNHL, wegner should be part of differential diagnosis
treatment of wegners granulomatosis
corticosteroids
cytotoxic drugs
can be fatal w/o treatment
Other multisystemic conditions
diabetes
hyper tension
cigarette smoking
chronic alcoholism
Diabetes chronic (carbohydrate metabolism) results in blood
hyperglycemia
Diabetes manifestation of vascualr changes may affect
stria vascularis
spiral ganglion
Hypertension blood pressure is
equal or above 140/90 mm HG
