Autoimmune and Systemic Disorders Flashcards
What is autoimmunity?
When the body goes awry and attacks the body itself
Produces autoantibodies or T lymphocytes reacting with the host’s antigens
What is the cause of autoimmunity?
Not well understood
Seen as possibly an interaction of various immunologic, hormonal, genetic, and viral factors
What is the incidence of autoimmune diseases?
5-8% of the population
Higher in women (have to be due to some hormonal influence or x-inactivation)
Are autoimmune diseases the 3rd most common category of diseases in the US?
Yes
After cancer and cardiovascular disease
Can damage done by some autoimmune responses be limited to a single organ?
Yes
Thyroid in Hashimoto’s disease
Can some autoimmune diseases cause systemic damage?
Yes
Lupus, rheumatoid arthritis, and MS
Does the inner ear have a blood-labyrinth barrier?
Yes, it is very important for the immune response of the inner ear
What was originally believed about the blood-labyrinth barrier?
That it protected the inner ear from systemic immune responses like the blood brain barrier
What is known now about the blood-labyrinth barrier?
Immune responses can occur in the inner ear activated by several immunologic mechanisms, making the inner ear susceptible to autoimmune conditions
Is little known about the inner ear vasculature and its role in inner ear disorders and treatment?
Yes
Does the blood-labyrinth barrier allow for the endolymph to maintain a high potassium level?
Yes
Required for production and maintenance of the EP
Disruption of the blood-labyrinth barrier due to vascular leakage can lead to an immediate hearing loss
Can normal vascular reactions to inflammatory factors be harmful to the inner ear?
Yes
Can cause breakdown of strial integrity, decreased endolymph production, and reduced EP levels
Is vasculature the connection between the body and the ear?
Yes
What tends to be the first vascular reaction to inflammation?
Breakdown of the blood-labyrinth barrier
Can steroids cause blood-labyrinth barrier restoration?
Yes by un-regulating tight junction genes
Are steroids the first line of treatment in autoimmune, inflammatory, and infectious conditions of the inner ear?
Yes because they suppress the immune system
What else do steroids do?
They suppress the production of inflammatory cells that produce cell death
Suppress the production of cytokines resulting in reduced inflammatory reaction
Suppress production of antibodies against foreign antigens and body’s own proteins
Stimulate the production of inhibitory factors that can inhibit the inflammatory cascade
Increase production of junctional proteins to seal the capillary lining restoring the blood-labyrinth barrier
What are some autoimmune disorders that affect the auditory system?
Systemic demyelinating conditions (MS)
Sudden-onset SNHL
What is a vascular disorder than affects the auditory system?
Vasculitis such as Wegener granulomatosis
What are metabolic disorders?
Diabetes
Thyroid disorders
What is autoimmune inner ear disease (AIED)?
Progressive bilateral SNHL occurring over a period of weeks to months
Responsive to immunosuppressive agents
Is it important to determine the underlying immune pathology for AIED?
Yes
Because AIED is one of the few cases of SNHL that is reversible
What are the two types of AIED?
Primary AIED and secondary AIED
What is primary AIED?
Diseases that are restricted to the ear
What is secondary AIED?
Coming from the rest of the body
Multisystemic
Cogan syndrome and Wegener granulomatosis
What is the incidence of AIED?
Rare disorder
1% of reported HL or dizziness
More common in females
Symptoms appear between 20 and 50 years of age
What is the clinical presentation of AIED?
Bilaterally SNHL progressive over weeks to months (although some present with unilateral fluctuating SNHL)
Aural fullness and/or tinnitus
Vestibular symptoms (imbalance, ataxia, vertigo)
How is AIED diagnosed?
Normal physical examination
May have manifestation of systemic autoimmune disease (effusion of the ME, EAC, and cough (Wegener), skin lesions, and vision loss (cogan’s)
Lab tests and imaging may be helpful in diagnosis
What is the treatment for AIED?
Corticosteroids (standard of care for 4 weeks)
Must begin as soon as possible, irreversible damage occurs within 3 months of onset
Steroids can be given longer than 4 weeks or repeated
What is the differential diagnosis for AIED?
Sudden SNHL (typically unilateral and not progressive)
Meniere’s disease (fluctuating SNHL, tinnitus, aural fullness, and vertigo)
Vestibular schwannoma, MS, and otosyphilis (need to rule out)
What is sudden SNHL?
Greater or equal to 30 dB HL SNHL occurring in at least 3 contiguous frequencies within 3 days
Is sudden SNHL typically unilateral?
Yes
If bilateral, probably not sudden SNHL (could be AIED)
If one ear is affected by sudden SNHL, what is the risk of the other ear being affected during a patient’s lifetime?
Rises by 4 to 17%
What is the incidence of sudden SNHL?
4000 new cases in the US and 15000 in the world (annually)
No gender difference
Increased incidence with age (most common during 5th and 6th decade of life)
Patient may report a cold or viral infection one to three weeks prior to symptoms
Can sudden SNHL happen if they already have a preexisting SNHL?
Yes
What are some possible causes of sudden SNHL?
Idiopathic
Viral infections
Ototoxic drugs
Trauma
Tumor
Autoimmune diseases
Meniere’s diseases
Perilymphatic fistula
Non-organic HL
Vascular pathology (diabetes, renal disease, leukemia, strokes, surgery causing embolus, etc.)
What are some histopathologic findings of sudden SNHL?
Atrophy of the organ of corti
Atrophy of the stria vascularis
Atrophy of the tectorial membrane
Most of the damage is observed at the cochlear basal turn but can occur anywhere along the cochlea
Degeneration of neural structures is significantly less than the cochlear structures
Vascular channels normal unless vascular etiology
Closely resemble those with viral hearing loss (mumps, rubella, measles, CMV)
What are the audiologic findings for sudden SNHL?
Unilateral sudden SNHL of any severity
Typically high frequency or flat mild to profound SNHL
WRS is much worse than predicted by pure tone thresholds
Vestibular system may be affected too (dizziness or severe vertigo in early stages, long symptom-free periods, long term oscillopsia and ataxia)
Normal tymps
ARTs consistent with degree of loss
What is needed to evaluate sudden SNHL?
A good case history and an audiologic evaluation
How can MRIs be helpful in sudden SNHL?
Useful in ruling out trauma, tumors, or MS
Can lab tests be useful in diagnosing sudden SNHL?
If the etiology is related to hormone levels, a autoimmune condition, or diabetes
When should treatment for sudden SNHL begin?
Within one week of onset
Steroids
What are some consequences of long-term steroid therapy?
Increased appetite and weight gain
Increased susceptibility to infection
Organ damage (blurred vision, upset stomach, gastric ulcers)
Bone loss
Increased hyperglycemia, a major concern for diabetic patients
Fluid retention and increased blood pressure
Can intratympanic steroids be used?
Yes, such as dexamethasone
Can be given in higher concentration with less of the side effects of systemic administration
Injection
What is the prognosis for sudden SNHL?
Variable
30-60% of patients improve without treatment
The SNHL will be permanent in about half the patients even with treatment
What are some indications of a good prognosis for sudden SNHL?
Mild low frequency SNHL
Symptoms persisting for a shorter time
Even with recovery of thresholds, WRS may not fully recover
What are some indications for a poor prognosis for sudden SNHL?
Age; the very old and very young
High frequency or flat SNHL
Greater severity of the SNHL
Accompanying vertigo
Diabetes
What are demyelinating diseases?
Diseases that results in damage (demyelination) of the myelin sheath that surrounds nerve fibers in the brain and spinal cord
What do demyelinated diseases result in?
Impaired sensation, movement, cognition, and other functions are affected depending on the nerves involved
Is demyelination the effect or the cause?
The effect
What are some causes of demyelination?
Genetics
Infectious agents
Autoimmune disease
Idiopathic
Is there a cure for demyelinating diseases?
No
Generally progressive
What is the most common demyelinating disease?
Multiple sclerosis (MS)
Who was credited with describing MS?
Jean-Marie Charcot
1868
Is MS a progressive neurological autoimmune disorder?
Yes
Affects the white matter pathways in the CNS
Immune cells from the blood vessels enter the brain, spinal cord, or optic and other nerves, and cause multiple focal areas of inflammation, demyelination, and nerve damage
What are the focal damaged areas of MS called?
Plagues (sclerosis or scars)
Hallmark of MS
Can be various sizes, develop at different times, and at different locations
Where are plaques more typical for MS?
In the white matter, sparing the axons
Show a preference for the optic nerve and chiasm
What structures can MS involve?
Cerebrum
Cerebellum
Brainstem
Spinal cord
Peripheral nerves (including CN VIII)
Can remyelination and remission occur during the course of MS?
Yes
What is the etiology for MS?
Remains unknown
Probably combination of factors
Both intrinsic (genetic) and extrinsic (environmental) factors may be at play, especially viral infections
Who is MS most common in?
Caucasians in the northern hemisphere
Initially symptoms manifest between 10 to 60 years
Extremely rare in children (progression and severity greater in middle age)
More common in females (2:1)
Can you live with MS for a long time?
Yes
5 to 20 years
Are the signs and symptoms for MS predictable?
No
Different symptoms in different people
What are some possible signs and symptoms for MS?
Paralysis of the eye muscle (horizontal nystagmus, diplopia, and dizziness)
Fatigue and malaise
Abnormal reflexes and poor coordination/control (spinal cord effected)
Numbness, tingling, itching
“heat factor” increases the body’s temp 1 degree C above baseline (reduces condition of demyelinated fibers)
Dysarthric speech and ataxia and hearing loss and vestibular problems (if the brainstem and midbrain is affected)
What are the peripheral audiologic signs and symptoms for MS?
SNHL is not an initial symptoms or prominent complaint
No single audiometric pattern (some have bilateral sloping SNHL, bilateral reverse slope SNHL, sudden hearing loss, and fluctuating hearing loss)
ARTs are variable (depending on thresholds)
What are the central audiologic signs and symptoms for MS?
Poor WRS including SIN scores than predicted by audiometric thresholds
Possible abnormal auditory evoked responses (ABR)
May show central auditory processing deficits (binaural integration and dichotic listening tasks)
How is MS diagnosed?
History
Disease progression (intensified symptom and diminished/no symptom periods)
High immunoglobin levels in CSF
CT and MRI ( greater than or equal to 2 plaques)
What is the treatment for MS?
Management
Immunosuppressive agents (intravenous and oral corticosteroids)
Symptomatic treatment
No therapy is successful for all patients
What are the differential diagnoses for MS?
Other autoimmune conditions (Susac’s syndrome and Schilder’s disease)
Diabetes (HL, visual problems, disequilibrium, poor WRS)
Stroke (Poor WRS, visual problems, cognitive issues, poor motor skills)
Sudden SNHL (due to other causes including other autoimmune conditions)
What is susac syndrome?
Self-limiting syndrome
An autoimmune disorder of unknown etiology
What is susac syndrome characterized by?
Encephalopathy (cerebral disturbances)
Branch retinal artery occlusions (visual problems)
Asymmetric fluctuating SNHL
Does susac syndrome resolve?
Neurological symptoms do over 2 to 4 years
Patients often show a residual SNHL
Why is susac syndrome often misdiagnosed as MS?
Due to the presence of white matter defects in the corpus callosum viewed on MRI
These defects are infarcts (dead tissue due to lack of blood supply) that atrophy during chronic stage of the disease
Why does susac syndrome clinically resemble MS?
The disease most commonly appears to affect women between 20 to 40 years of age
It presents with a fluctuating disease progression like MS
Asymmetric SNHL that is generally low frequency and fluctuating
Sometimes associated dizziness/vertigo and tinnitus
Vestibular symptoms indicate involvement of the labyrinth
What is schilder’s disease?
Very rare, progressive
Just a handful of definitive diagnosis
When does schilders disease begin?
Childhood and young adulthood
Some consider it as a childhood variant of MS
What is affected in schilders disease?
Adrenal glands and myelinated nerves and axons
Is the demyelination of schilders disease bilateral?
Yes and observed in the CNS
In schilders disease, do motor, sensory, and cognitive problems develop in the first decade of life and progress?
Yes
Is the course of schilders disease predictable?
No
What is the clinical presentation of schilders disease?
Personality changes and poor attention
Irreversible, progressive loss of intellectual function
Vision and hearing impairment and balance problems
Headaches, vomiting, seizures
Muscle weakness, paralysis, incontinence
Atrophy of adrenal glands
How is schilders diagnosed?
Presence of 2 or more large plaques (often bilateral)
No other lesions
Peripheral nervous system normal
What is the treatment for schilders?
Corticosteroids are used but not always beneficial
Symptomatic treatment
What is cogan syndrome?
Rare chronic autoimmune inflammatory disorder
Who does cogan syndrome affect?
Mostly young adults
Peak incidence occurs in the 3rd decade of life
No known gender or racial predominance
What is some autopsy data derived from the temporal bones of patients with cogans?
Lymphocyte and plasma cell infiltration of the spiral ligament
Endolymphatic hydrops
Degenerative changes in the organ of corti
Extensive new bone formation of the inner ear
Demyelination and atrophy of the vestibular and cochlear branches of the eighth cranial nerve
What is the hallmark of cogan?
Vestibulocochlear dysfunction and interstitial keratitis
Both eye and ear symptoms
Why does cogan have inflammation of the eyes and ears?
Patients immune system producing antibodies that attack the inner ear and eye tissues
What is the clinical presentation of cogan?
Positive ECochG more common than seen in Meniere’s
Vestibular symptoms (imbalance, nausea/vomiting, ataxia, oscillopsia (objects jiggling back and forth after abruptly turning the head), absent peripheral vestibular function due to caloric)
Cochlear symptoms (tinnitus, unilateral or bilateral generally sloping SNHL)
Can the hearing loss in cogan be fluctuating?
Yes
And unlike meniere’s can progress to a severe to profound SNHL
What are some ocular presentations for cogan?
Interstitial keratitis with red, painful, light sensitive eyes (blood vessels grow in the cornea)
Blurred and decreased vision due to corneal clouding
What are some other symptoms for cogan?
Musculoskeletal symptoms such as arthritis and myalgia
Fever
Fatigue and weight loss
Cardiovascular concerns such as aortitis (10%), pericarditis, valve deficiencies, and systolic murmur
What is a diagnosis of cogans based on?
The presence of characteristic inflammatory eye disease and vestibulocochlear dysfunction
What is the treatment for cogan?
Collaborative medical approach
Corticosteroids for both hearing loss and ocular symptoms
Hearing aids
CI (better success rate than amplification)
Vestibular rehabilitation if dizziness is disabling
What are the differential diagnosis for cogan?
Menieres (eye symptoms absent in menieres, menieres has vertigo, systematic manifestations not seen in menieres)
Labyrinthitis (no eye symptoms)
Wegener’s (no eye symptoms)
What is wegener’s granulomatosis?
Autoimmune vasculitis that affects the upper and lower respiratory tracts, ears, and kidneys
What are the audiologic manifestations seen in wegeners (20-60% of cases)?
Swelling of the pinna during exacerbations
CHL associated with otitis media because of infection/obstruction of the nasopharynx
10% show a mild to mod SNHL
Are otologic symptoms sometimes the first or the sole manifestation of the early disease process for wegeners?
Yes
For patients presenting with sudden unexplained SNHL, should Wegener’s be part of the differential diagnosis?
Yes
What is the treatment for wegeners?
Immunosuppressive drugs such as corticosteroids
Cytotoxic drugs
Can be fatal without treatment
What is diabetes?
A chronic, incurable, but manageable metabolism disorder
What does diabetes result in?
Blood hyperglycemia and glycosuria
Elevated levels of glucose/sugar in the blood and urine, respectively
Due to inadequate production of insulin by the pancreas or inadequate utilization of insulin by the body cells
What can hearing loss in diabetic patients be caused by?
Impairment of vasculature or metabolic pathways
Peripheral neuropathy
How does hearing loss manifest with diabetes?
Branches of the cochlear arteries become progressively narrower towards apex
Impaired circulation due to diabetes
Low freq hearing loss is quite common
High freq SNHL and fluctuating hearing loss reported
WRS generally not affected
Can microvasculature diseases (diabetes) increase the risk of NIHL or reduce changes of recovery from TTS?
Yes
What is hypertension?
High blood pressure
Consistently equal to or exceeds 140/90 mm Hg
Is high blood pressure a good thing?
No, it can lead to significant problems
The heart must pump harder to overcome hard and narrow arterial walls
How does hypertension affect the cochlea?
Blood supply is negatively affected
Reduced blood and oxygen supply to the cochlea will often result in auditory deficits
Is there increased incidence of high freq SNHL in individuals with hypertension?
Yes
Is there a positive correlation between hypertension and presbycusis?
Yes
Stiffening blood vessels with age
Does cigarette smoking affect hearing?
Yes, through its effects on anti-oxidative mechanisms of the cochlea and cochlear vasculature
What can nicotine and carbon dioxide do?
Can cause vasospasm and thrombotic occlusions of cochlear blood vessels
How much more likely are smokers to have hearing loss than non-smokers?
1.69 times
Does second hand smoke also produce a small negative effect?
Yes
Can smoking also affect the middle ear?
Yes
Due to inflammation of the nasopharynx
Does chronic alcoholism have adverse affects on all body systems?
Yes
What effect does alcohol have on the nervous system?
Inhibitory
Primarily affects the cerebral cortex (primary sensory pathways intact) affects central auditory processing
Increase transmission time in the brainstem
Can poor eating habits that often follows chronic alcoholism also affect the auditory system?
Yes
Leads to nutrition depletion and secondary affects on the body
What is korsakoffs syndrome?
Chronic memory disorder caused by severe deficiency of thiamine
Seen in most alcoholics
Greater risk in elderly alcoholics
What are some issues that arise from korsakoffs syndrome?
Problems with learning new information, inability to remember recent events, and long-term memory gap
Social skills relatively unaffected
Can factors that improve vascular health preserve good hearing?
Yes
