Disorders Final Flashcards
(105 cards)
1
Q
Where do Retrocochlear Disorders occur?
A
beyond the cochlea, where the nerve connects to the CANS
2
Q
What are the most common retrocochlear disorders?
A
genetic/congential, auditory processing, intracranial neoplasms, trains to the nerve/temporal lobe, strokes, and cans dysfunction
3
Q
What is a neoplasm?
A
- “new growth” that abnormally grow from the disordered cell cycle
- grows in the same manner after the stimuli stops, competes with normal cells for nutrition, and grows from the host while the host wastes away
- Purposeless, prey on the host, and almost autonomous
4
Q
What are Intracranial Neoplasms?
A
Brain tumors
benign and malignant, meningiomas, and cysts on the parenchyma (brain tissue)
Incidence: 4-12 per 100,000 ppl in the US
5
Q
What are Neuroglial cells?
A
- 45% of intracranial tumors are from these cells
- these are the non-excitable cells of the CANS system, are smaller than neurons, don’t have axons, and don’t synapse
- there are way more of them than neurons (10:1), and make up half the volume of the CNS
6
Q
What are the 4 types of neuroglial cells?
A
astrocytes, oligodendrocytes, microglia, and ependymal
7
Q
What are Astrocytes?
A
Astrocytes: star shaped electrical insulators that provide a barrier at synapses and form the blood-brain barrier (star insulation)
8
Q
What are Oligodendrocytes?
A
form the myelin sheath for central nerve fibers (myelin)
9
Q
What are Microglia?
A
mall glial cells that inflame and degenerate the CNS, they also ingest/remove residue (trash can)
10
Q
What are ependymal?
A
Ependymal: line the CSF cavities, produce CSF, and move CSF (CSF)
11
Q
what are the tumor classifications?
A
Benign: slow growth, defined borders, don’t spread, not life-threatening unless they are local to a life-sustaining area of the organ
Malignant: different cell structure, hard to remove, grow and spread easily, life threatening
12
Q
Intraaxial vs extraaxial tumors
A
Intra-axial: originates within the brain tissue (ex: astrocytoma)
Extra-axial: originates outside of the brain (ex: pituitary gland, meninges, nerve sheaths)
13
Q
What are the 4 segments of the temporal bone?
A
petrous (hardest part that houses inner ear), squamous, tympanic (not fully developed until age 3), and mastoid
14
Q
What are vascular tumors?
A
most in the temporal bone are benign, and very hard to tell apart..
2 types - hemangiomas & vascular malformations
15
Q
What are hemangiomas?
A
Hemangiomas: mostly due to the malformations of angioplasties fetal tissue (present in 1st month of life)
Initial rapid growth followed by a slow period of decreasing size
16
Q
what are vasular malformations?
A
-more common, and always present at birth… although you may not see it
-Grow very fast and don’t ever regress
-In the temporal bone, mostly found in the IAC or ganglion of the 7th cranial nerve (lots of blood in these areas)
17
Q
what are the signs and symptoms of vascular tumors?
A
-Present with symptoms in their 30’s
-When it’s involving the 7th nerve: they experience facial weakness or twitches
-Tinnitus, CHL, facial spasms on one side, vertigo, progressive SNHL (if in the IAC) can also occur
18
Q
how do you diagnose vascular tumors?
A
- case hx and symptoms help get a CT scan, or an MRI with contrast (very intense on a T2 weighted MRI)
- with the MRI, geniculate lesions on the 7th nerve can be hard to see because of their location, but you can still see intracranial calcification with a CT
19
Q
What is the differential diagnosis for vascular tumors?
A
meningiomas (more irregular)
7th nerve schwannomas (less localized, later symptoms, no facial involvement)
cholesteatomas (in the ME cavity)
20
Q
what is the treatment for vascular tumors?
A
surgical removal, low levels of reoccurrence
21
Q
what is a schwannoma?
A
-most common benign tumor in temporal bone
-in CNS, myelin sheath is formed by oligodendrocytes
-In PNS, myelin sheath is formed by Schwann cells
-Often slow growing, unilateral, and are benign extra-axial tumors
22
Q
what are the anatomical locations for schwannomas?
A
- IAC: equally from superior of vestibular division of CN 8 in the medial portion of IAC (rarely in the cochlear division)
- Jugular foramen: CN 9 and 10 superior to the jugular bulb (mistaken for a paraganglioma)
- Fallopian canal: CN 7
23
Q
what is the incidence of schwannomas?
A
rare before 30, diagnosis in 6th decade, more common in females
24
Q
what is the growth pattern for schwannomas?
A
originated in the IAC most often, grows in the CPA, further spreading in the brain can cause Brainstem compression (large ones can cause hydrocephalus and death)
25
what are the signs/symptoms for schwannomas?
- occur when tumor is 1-4cm in size
- Phase 1 (otologic): compressing structures in the IAC, causes HL through blood supply or 8th nerve damage. Mostly HL, can also cause false vertigo, headache, tinnitus, and gait problems
- Phase 2 (neurologic): compressing intracranial structures. Sensory face disturbances, facial twitching, nystagmus
In late stage, it can compress the 4th ventricle causing hydrocephalus, coma, and death
26
what are the pure tone, oae, and speech findings for schwannomas?
Pure tones: unilateral, high freq. SNHL (asymmetrical, positive tone decay)
OAE: usually present if the HL is not too bad, decreased contralateral supports ion
Speech: WRS worse than expected, worse in noise, and positive RI (over 0.45)
27
what are the tymp & ART findings for schwannomas?
Immittance: Tymp is normal, ART can be absent (not sensitive to an 8th nerve schwannoma)
ART: 8th nerve has absent Ipsilateral and contra on the affected side, Brainstem has abnormal contra and normal Ipsilateral
28
what are the acoustic reflex decay findings for schwannomas?
Acoustic reflex decay: contralateral decay at 500 and 1000Hz are positive for decay
Hirsh and Anderson classifications:
RD+++ : over 50% decay at both 500 and 1000Hz (retrocochlear sign)
RD++ : over 50% decay at only 1000Hz (questionable)
RD+ : less than 50% decay (not a retro sign)
29
what are the tone decay & ABR findings for schwannomas?
Tone decay/threshold adaptation: measured in SL above threshold where a tone is heard for 60 seconds (over 30SL is a retrocochlear sign)
Perform on both ears to see comparison, and the more frequencies involved with the decay is more of a retrocochlear sign
ABR: abnormal, increased wave 5 latency, increased interwave latencies, absent wave 5 (compare both ears, +0.3ms ILD between ears is a retrocochlear sign)
ABR won’t match the audiogram, can be absent with normal hearing
30
how to definitvely diagnose a schwannoma?
t1 weighted MRI with gandolinium contrast is the gold standard! (Look for increased lumen of IAC)
31
what is the treatment for schwannomas?
Observation: watch and wait for small and slow growing tumors
Stereotactic radiosurgery: reduce size when removal surgery is not an option (ex: elderly or NF2)
Surgery: alleviate risk of intracranial damage, preserve nerve functions
32
what is a meningioma?
common benign brain tumor in the CNS in adults (very superficial, arriving in the meninges)
Incidence: 2:1 female, later in life appearance
33
what is the etiology for meningiomas?
uncertain
Associated with NF2 (20% also have NF2)
Head radiation therapy increases risk 4x
Genetics: cell changes/loss of chromosomes can cause it (1, 7, 10, 14)
34
what is the size of meningiomas?
- relative to location
- Larger in the CPA than the IAC (rarely stays in the IAC though)
- Can mimic the acoustic neuroma (makes diagnosis difficult)
- They are aggressive and locally invasive (can invade cranial nerves and cause calcification)
35
what are the audiometric signs for meningiomas?
Progressive unilateral SNHL
Vertigo, tinnitus, nausea, 8th CN involvement, abnormal ABR, normal OAE if they have normal hearing
36
what is the treatment for meningiomas?
Locally destructive: surgical removal, radiation, long term follow up (30% reoccurrence rate)
Small: symptomatic treatment, watch and wait
37
what is the differential diagnosis for meningiomas?
- Otitis media (red eardrum, CHL, granular tissue formation)
- Paraganglioma (highly vascular, can be a neck mass)
- Facial nerve involvement (facial paralysis)
- Vestibular schwannoma (difficult to differentiate especially if it’s in the IAC)
38
what are some other benign tumors or the temporal bone?
osteoma, paraganglioma, NF2, facial nerve schwannoma
39
what is a cortical tumor?
signs and symptoms are on the other side of the tumor!may show all normal peripheral hearing tests (reflexes, OAE, pure tones)
worse WRS and inconsistent, especially in noise!!! evoked potentials: ABR normal (if periphery is WNL) and middle and late evoked responses may be absent
Headaches and dizziness are common
40
what is a malignant tumor?
often diagnosed at late stages and present a bad diagnosis
symptoms similar to chronic suppurative OME, delays the diagnosis
Audiologically: Aural discharge, otalgia, and hearing loss often seen as well
Neurologically: facial paralysis, headache, SNHL and vestibular deficits
41
what are some metastatic tumors from sites other than the temporal bone?
breast cancer, lung cancer, leukemia, GI tract tumors, thyroid cancer, and melanoma
42
what is autoimmunity?
occurs when the body's immune system attacks itself. The cause is not well understood. Affects 5-8% of the population, MOSTLY WOMEN. Damage can be done to a single organ (thyroid) or an entire system (rheumatoid arthritis, multiple sclerosis, etc)
43
how common is autoimmunity in the US?
the 3rd most common category of disease
44
what is the immunology of the ear?
the endothelial cells are connected by tight junctions to establish the blood labyrinthine barrier, which has immune cells. Some thought that the ear blocked immune cells from going into the brain, but this is not true
45
what does the inner ear vasculature do?
blood carries drugs to it, inner ear and also carries immune cells and hormones, but we don’t know what role it plays in disorders and treatment.
The inner ear system requires a lot of metabolic functions, so if there’s any compromise of blood, we have a significant problem
46
Normal vascular reactions to inflammatory factors that would be harmless for most organs can be quite detrimental for the inner ear and lead to what?
-Breakdown of strial integrity
-Decrease endolymph production
-Decreased EP level
47
what are the vascular factors in ear diseases?
General Systemic: vasculature carries hormones, immune factors, has tight junctions, and is an active participant in tissue responses to disease
Inner ear: vascular connects body to ear and the endothelial cells are the gatekeepers, serum inflammatory factors are common, breakdown of the blood labyrinthine barrier is the first reaction (steroids can restore the blood-lab barrier)
48
what do steroids do?
first line of treatment for any type of infectious, inflammatory, or autoimmune conditions in the inner ear (they are anti-inflammatory, and they suppress inflammation and cytokines)
Suppress production of antibodies, stimulate inhibitory factors, and increase junction proteins to seal the lining of the blood-lab barrier
49
what are the types of systemic disorders in the auditory system?
autoimmune, vascular, and metabolic
50
what is Autoimmune inner ear disease (AIED)?
progressive bilateral SNHL, responsive to steroids, REVERSIBLE
Primary AIED: restricted to the ear
Secondary AIED: multi system that includes the inner ear (ex: Cogan or Wegener Syndromes)
51
what is the epidemiology of AIED?
rare with 1% reporting HL and dizziness (more females, symptoms start in 2-5th decades)
52
what does AIED look like clinically?
progressive bilateral SNHL, aural fullness and tinnitus, 80% have vestibular symptoms (imbalance or ataxia and episodic vertigo)
53
what is the diagnosis of AIED?
normal physical exam (sometimes you see OME and a cough)
Visual loss: cogan syndrome
Cough and ME effusion: Wegeners
54
what is the treatment of AIED?
steroids for 4 weeks, must begin immediately to prevent irreversible damage
55
what is the differential diagnosis for AIED?
Sudden sensorineural hearing loss (SSHL): typically unilateral and not progressive
Ménière’s disease: mimics with fluctuating progressive SNHL (some that were originally thought to have menieres end up with AIED)
Rule out: 8th nerve schwannoma, MS, and otosyphilis
56
what is Sudden SNHL?
over 30dB SNHL in at least 3 frequencies in a row within 3 days.
always sudden and sensorineural, can occur with previously existing SNHL, typically unilateral.
If it’s bilaterally, look to diagnosis AIED instead.
If one ear is affected, the other has a 17% chance of other ear being effected
57
what is the incidence of SSNHL?
no gender difference, increases with age, patients sometimes report a cold a few weeks prior
58
what is the etiology of SSNHL?
no cause, viral, drugs, trauma, tumor, autoimmune diseases, memieres, vascular (diabetes, renal disease, leukemia, strokes, etc.)
59
What are the Histopathologic findings of SSNHL?
atrophy of organ of corti, stria vascularis, tectorial membrane, more damage at basal turn, etc. (similar to symptoms with mumps, rubella, CMV)
60
what are the audiologic signs of SSNHL?
unilateral sudden SNHL, no specific audiogram configuration, deteriorating speech abilities (bad WRS), no vestib symptoms, normal tymps, ART’s consistent with HL levels (with a mod severe HL, can still see normal ART’s up to 65dB HL)
61
what does the diagnosis look like for SSNHL?
good case hx,audiology evaluation, MRI to rule out tumors, trauma, and MS, + lab tests (not useful unless etiology is related to hormone levels, diabetes, and autoimmune disease)
62
what is the treatment of SSNHL?
needs to start within 3-7 days, its a medical emergency.
Corticosteroids for 4 weeks is most common! but can cause weight gain, susceptibility to infection, bone loss, organ damage, increased hyperglycemia, fluid retention over long term treatment
Intratympanic steroids can be used in higher concentration with less side effects
63
what is the prognosis for SSNHL?
variable outcomes, 30-60% improve without treatment, 50% patients SNHL becomes permanent even with treatment
Good prognosis: mild low freq. SNHL, shorter duration of symptoms, WRS may not recover when thresholds do
Bad prognosis: age (very young or old), high freq. or flat SNHL, greater severity of SNHL, vertigo, and diabetes
64
what is multiple sclerosis (MS)?
MS is the most common of the demyelinating diseases
MS is a progressive neurological autoimmune disorder,affecting white matter pathways of the CNS
65
what is a demyelinating disease?
remove myelin sheath surrounding nerve fibers in the brain and spinal cord, result in neurological damage (sensation, movement, cognition, and other functions impaired)
The effect not the cause of a disease. Some causes: genetics, infectious agents, autoimmune disease, idiopathic
They are progressive, and have no cure
66
what are the hallmark signs of MS?
Plaques, More typical in the white matter, not the axons…and prefer the optic nerve and chiasm (double vision presents first)
67
what can cause remission during MS?
Re-myelination occurs in the CNS which causes remission phases throughout the progression of the disease
68
what is the etiology of MS?
unknown, prob a lot of factors, may be viral
69
what is the epidemiology of MS?
Caucasian’s in north hemisphere/cold climates, initial symptoms at 10-60years old, peak incidence at 30, extremely rare in kids, 2:1 female ratio, periods of remission and slow progression throughout span of disease (5-20years)
70
what is the disease course for MS?
unpredictable and varies among different people. Visual system is vulnerable and gets symptoms 1st (diplopia and muscle paralysis), fatigue and malaise, spinal cord (reflexes and walking), numbness, tingling, etc, “heat factor” that increase body temp 10C, dysarthria of speech and ataxia, HL, and vestibular dysfunction (Brainstem involved)
71
what are the peripheral audiologic signs of MS?
hl is not an initial compliant, no specific pattern or configuration.
Generally high freq, bilateral SNHL, some have a rare!! low rising SNHL, fluctuating HL (with remission phases), reflexes vary based on the thresholds
72
what are the central audiologic signs of MS?
poor WRS, worse in noise, cochlear synaptopathy (hidden HL), abnormal evoked responses, binaural integration and dichotic listening tasks are abnormal (corpus c. Involvement)
73
what is the diagnosis of MS?
case hx, remission and intensified symptoms, high immunoglobulin levels (in CSF), CT and MRI to observe plaques (+2 in CNS to diagnose)
74
what is the treatment of MS?
no cure, but can be managed… immunosuppressive steroids are recommended, nothing is universally recommended and successful
75
what is the differential diagnosis of MS?
autoimmune diseases like susac’s and schilder’s, diabetes (hl, vision, poor WRS), stroke (poor motor), sudden SNHL
76
what is susac syndrome? what are the triad symptoms?
self limiting, unknown etiology. Neurological symptoms resolve over 2 years, HL remains
triad of symptoms : Encephalopathy (cerebral disturbances), branch retinal artery occlusion (visual problems), and asymmetrical, fluctuating SNHL
77
why is susac syndrome misdiagnosed as MS?
also has white matter defects in the corpus c. (They are infarcts that die during the chronic phase), affects middle aged women, has low frequency, fluctuating HL, some have dizziness and tinnitus. Due to a blocked artery and resolves itself, not the same as MS
78
what is schilder's disease?
considered a childhood variant of MS (very rare).
Begins in childhood and young adulthood, often bilateral, and demyelination of the adrenal glands and myelinated nerves AND AXONS are affected.
Motor, sensory, and cog symptoms are in 1st decade of life and get worse. Course of the disease is unpredictable, just like MS
79
what is the clinical presentation of schilder's disease?
personality change, poor attention, irreversible loss of intellectual ability, vision, hearing, balance impairments, headaches, vomiting, seizures, muscle weakness, atrophy of adrenal glands (on top of kidneys)
80
what is needed to diagnose schilder's disease?
more than 2 large, bilateral plaques, no other lesions, peripheral nervous system is normal
81
what is the treatment for schilder's disease?
steroids are not always beneficial, treat the symptoms
82
what is cogan syndrome?
super rare, autoimmune inflammatory disorder affecting young adults.
83
what is the epidemiology of cogan syndrome?
3rd decade of life, around 22 years, no known gender/race preference
84
what is the pathology of cogan syndrome?
plasma cell infiltration of spiral ligament, endolymphatic hydrops (gives similar symptoms as menieres), degenerative organ or corti, new bone formation in the inner ear, demyelination of 8th nerve and atrophy of the vestibular and cochlear branches off that nerve
85
what is the clinical presentation of cogan syndrome?
vestibulocochlear dysfunction + interstitial keratitis.
85% of patients present with ear and eye symptoms in 2 years (probably caused due to inflammation in the ears and eyes from immune system producing antibodies).
Association between CS and systemic vasculitis (other blood vessels get inflamed and cause organ damage)
Meniere’s-like symptoms that last for days on end:
Vestibular: positive ECochG, oscillopsia, nausea, ataxia, calorics show absent peripheral vestib, function)
Cochlear: tinnitus, high frequencies slipping SNHL that can be fluctuating and can progress to profound HL (unlike menieres)
Ocular: interstitial keratitis (red, painful, light-sensitive eyes) : blood grows into the cornea, causes blurred and decreased vision
Non-systemic: arthritis and myalgia, fever, fatigue, weight loss, cardiovascular (valve deficiencies for example)
86
what is the diagnosis of cogan syndrome?
inflammatory eye disease and vestibulocochlear dysfunction
87
what is the treatment of cogan syndrome?
corticosteroids, hearing aids, CI’s (very successful), vestibular rehab if it is debilitating
88
what are the differential diagnosis for cogan syndrome?
Menieres: symptoms are very similar, look at: eye symptoms, imbalance and ataxia, sudden sensorineural hl, and systemic manifestations that aren’t involved with menieres
Labyrinthitis: no eye symptoms, bad vestib symptoms
Wegener's granulomatosis (again, vestib but not eye)
89
what is Wegener’s Granulomatosis?
autoimmune that affects respiratory tracts, ears, and kidneys
90
what happends in wegener's granulomatosis audiologically?
polychondritis (auricle swelling), CHL from serous/purplent OME (ET dysfunction), otalgic symptoms may present first
91
what is the treatment of wegener's granulomatosis?
immunosuppressive drugs (steroids), cytotoxic drugs (methotrexate), and can be fatal without treatment
92
what is hypertension?
when blood pressure exceeds 140/90 mm Hg consistently
The heart has to pump harder, and causes vasoconstriction and results in reduced blood and oxygen supply to the cochlea
Increased incidence of high frequency SNHL, correlation with presbycusis
93
what happens when you smoke cigarettes?
affects hearing loss through effects on antioxidative mechanism and vasculature in the cochlea
1.67x more likely to have hearing loss
Middle ear affected due to inflamed nasopharynx
94
what happens when you are a chronic aloholic?
inhibitory effect on the nervous system, affects central auditory processing
also have poor eating habits, and a disease with a lack in vitamin B1 is called Korsakoff’s
Syndrome (memory deficiency)
Greater risk for elderly alcoholics
95
Systemic Conditions +SNHL
only risk factor associated with hearing loss was cardiovascular disease + inflammation, arteriosclerosis, and hypertension. If you improve vascular health, the risk of hearing loss decreases
96
what is diabetes?
chronic, incurable, manageable, metabolic disorder resulting in blood hyperglycemia and glycosuria (elevated glucose in blood and urine). due to inadequate production or utilization of insulin (produced by pancreas)
97
what happens audiologically in diabetes?
No single audiological profile for diabetes, HL might be caused by metabolic pathway, peripheral neuropathy, and impaired vasculature (we do see poor WRS, especially in noise)
Vascular changes can affect the stria and the spiral ganglion: low freq SNHL, low WRS if there is neuropathy, fluctuating HL
Synergistic effects of risk factors are a concern… increase risk of NIHL and reduced recovery rate of TTS from noise
98
what does the vestibular system do?
The vestibular system is a somatosensory portion of the nervous system that provides proprioception (spatial position of the body) and kinesthesia (awareness of limbs movement) cues.
There are 3 omponents that work together to maintain balance by orienting you to your body position in space.
VOR and VSR are monitored by the central vestibular system in the cerebellum (and calibrated). Lesions in the cerebellum would cause nystagmus (involuntary eye movement) and gait ataxia
99
There are 3 primary components of the vestibular system, what happens in the peripheral sensory apparatus?
Peripheral sensory apparatus: in the inner ear, called the vestibular labyrinth. Semicircular canals detect angular or rotational acceleration (3D movement). Otolith organs detect gravity: utricle senses linear movement and saccule detects vertical movement
The peripheral information goes to the central portion via the 8th nerve. The cochlea and vestibular system share blood supply, so the symptoms can be with cochlear symptoms too (ex: dizziness often with hearing loss).
100
There are 3 primary components of the vestibular system, what happens in the central vestibular system?
receives input from the peripheral system via the 8th nerve, and is channeled to the cochlear nuclei in the 4th ventricle and the cerebellum.
Input is processed with vison and somatosensory inputs. The vestibular nuclei output influences eye movements, trunk stability, and spatial orientation
101
There are 3 primary components of the vestibular system, what happens in motor output?
integrated into 3 reflexes:
Vestibulo-ocular reflex (VOR): stabilizes gaze
If it’s not stable, we get oscillopsia (environment bobs up and down with your movement)
Vestibulospinal reflex (VSR): stabilizes posture
Vestibulocollic reflex (VCR): stabilizes the head
102
what are the signs and symptoms of vestibular disorders?
sense of imbalance, dizziness/vertigo, nystagmus. dizziness is nonspecific, and usually short and abrupt if vestibular related with nausea and vomiting
103
what is vertigo?
type of dizziness. True vertigo is very scary, gives an illusion of motion that you don’t have any control over. can be a sense of motion of self (subjective) or environment (objective)
Occurs with sudden onset episodes (called episodic vertigo) . Can be peripheral or central in origin .The clinician needs to probe to dive deeper into dizziness complaint to check for vertigo
104
what conditions can cause episodic vertigo?
menieres, recurrent vestib. Neuritis, BPPV, migraine, post traumatic (peri lymphatic fistula), SSCD, and otitis media
105
what causes vertigo?
Almost always called by deficits in the peripheral labyrinth connecting to the central system.
