401 final

two components of balance system

sensory : what body tells us about our surroudings (vestibular-eyes, somatasensory- feet)

motor: to keep your body balanced and not fall (legs and core)

Vestibular system

stabalizes visulal environment during movement

provides spatial info to CNS for linear and angular acceleration

6 total - 3 on each side semicircular canals 

* anterior or supiror, posterior or inferior, lateral/horizonatal

Utricle

horizontal acceleration (front to back)

Saccule

Verticle acceleration (up and down)

Macula

vestbule of sensory cells

* is the yolk if the utricle

otolithic membrane

Gelatinous membrane covered in calcium carbonate crystals (otoconia-little crystals)

* crystals give the jelly weight so it can jiggle
* hair cells are embeded in it
* weight of jell from crystal, bends stericillia, firing that head is moving down

even at rest they are still giving off a steady base firing rate

utiricle and saccule hairs have their own____

Pair

* when one side is firing the other side is saying no its not (inhibitory)
* each hair likes to move in one direction

yaw

roll

pitch

(shaking head)

whole body rolling

nodding head

Semicurcular canal (ralp and larp)

for angular motion

Right Anterior → Left Posterior

Left Anterior → Right Posterior

Peripheral vestibular system has a direct connection to the eyes via the ___

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* brianstem

VOR vestubulo-ocular reflex

helps our eyes maintain visual field

eyes can hold a spot as your head turns

Horizontal SCC

* endolyph flows to opposite side head turns\\
* capula deflects away from utricle
* other side decreases firing rate

nystagmus

eyes wiggle

**Videonystagmography (VNG) Testing**

Vestibular test

* tests eyes
* positional testing (crystals)
* caloric testing (hot cold air in ears)

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**Whole-Body Rotational Chair Test**

vestibular test

* examining nystagmus by rotating chair
* confirming vestibular weakness

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**Video Head-Impulse Test & deficits**

vestibular test

* goggles with camera
* eyes on ones spot
* moves head to test scc

If have a peripheral vestibular deficit, the eyes will move with the head instead of staying fixed on the target.

* “catch-up saccades”(head will turn and then eyes will lock on)

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**Vestibular-Evoked Myogenic Potentials (VEMPs)**

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* sound in ear and measure responses from electrodes on the sternocleidomastoid muscle **(cVEMPs)** or extraocular eye muscles **(oVEMPS)**

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**Computerized Dynamic Posturography (CDP)**

* plate on their feet shift and moves or the walls move
* eyes will be open and closed
* 6differnent conditions
* will tell you how they use their feet eyes and ears

* **a disorder is ?**

* a less than specific term that refers, generally to functional abnormality 

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A lesion is?

any pathology or traumatic discontinuity of tissue or loss of function

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**Gross or macroscopic lesions** 

**Histologic or microscopic lesions** 

**Molecular lesions**

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* **visible, can be seen**
* **visible under a microscope**
* visible with an operating microscope or high- powered magnification

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Size

* Focal lesions
* Diffuse lesions
* Systemic lesions
* Structural lesions

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* **– limited to a small area (Viii nerve tumor)**
* **– cover a wide area (multiple sclerosis)**
* **– affects the entire system or organ as opposed to individual parts (anoxia- lose oxygen supply)**
* **– change in the anatomical construct (otosclerosis- stapes footplate fusing to )**

prognosis

* **Depressive lesions**
* Destructive lesions
* Degenerative lesions
* Irritative lesions

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* **– result in a decrease of function (hearing loss)**
* **– normally lead to obliteration of an organ or abolishment of function (autoimmune disease)**
* **– involve deterioration of a mechanism or function over time (aging)**
* **- stimulate the function of the involved area (meniere’s disease)**

eitiology

* Traumatic lesions
* Vascular lesions
* Trophic or metabolic disorder
* Idiopathic lesions

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* **– resulting from an external insult (head injury, noise exposure)**
* **– resulting from disorders of the blood stream (autoimmune disease)** 
* **– resulting from disruptions or disorders of nutrition to some area (meniere’s disease)**
* **– dysfunction for which there is no known etiology (dont know what it is)**

what is

* Etiology 
* **Diagnostic Test Results Classified by**
* Site of Lesion 

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* Classified by the thing that caused the hearing loss. But, the etiology must be known.
* **type, degree, configuration of loss.** 
* **Classified by location (outer, middle, inner, brainstem,ect)**

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Malformations (disorders of outer ear)

* anotia
* microtia
* tag/pit
* stenosis
* astresia

* absent pinn
* abnormal shape of pinna
* limps/little holes
* narrowing of ear canal (does not nesesarlit cause hearing loss)
* closed ear canal

what is a BAHA

bone anchored hearing aid

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excessive cerumen (disorders of outer ear)

* most common outer ear disorder
* Visible with otoscopy


* __Type B tymp with volume <0.2 mL (small ear canal volume)__
* Can cause CHL, otalgia, dizziness/vertigo

collapsing ear canal (disorders of outer ear)

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* Presents as high frequency CHL w/ normal tymps\*\*\*
* stick probe tip in ear and run pressure sweep, will get a normal type A tymp

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* **Osteomas**
* Exostoses

* __**True bony growths**__
* **Typically** __**unilateral**__

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* **Multiple bony growths**
* **Typically** __**bilateral**__

Can be seen in swimmers who are frequently in cold water

Otitis externa

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* Infection of the outer ear (pinna and/or ear canal)
* itching, redness, swelling, otalgia, otorrhea (ear drainage)
* May not cause hearing loss

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**Tympanosclerosis**

* Formation of whitish plaques on the tympanic membrane

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* Can come from frequent infections, trauma, etc.

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* Degree of CHL depends on amount of sclerotic tissue (scar tissue)– often causes little-to-no hearing loss

Otitis Media (middle ear disorder)

* **Definition – Inflammation, or infection, of the middle ear.**

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* **Etiology**
* **Not fully defined**
* __**Associated with eustachian tube dysfunction.**__ 
* Absorption of oxygenated air causing …(vacuum)
* Build up of negative pressure causing…(negative tymp type c)
* Secretion of fluid from mucous membrane – OTITIS MEDIA

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type of otitis media

* Otitis media with __effusion__


* __Serous__
* __Secretory__
* __Suppurative__ (purulent)

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* thin, clear, and watery fluid without infection

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* \
* thicker fluid, may\* contain infection

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* \
* thick, infected (like glue)

STage 1 of otitis media

hypermia

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* **presence of an abnormally large blood supply**
* **increase in blood supply**

STage 1 of otitis media

Exudation

* **- gradual increase of liquid in the middle ear space**

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* Tympanic membrane __becomes thickened, red, and bulging__.

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* Pain, fever, and temporary hearing loss are often present.

Stage 2 (treatment) of otitis media

Suppuration

or PE tube

Antibiotics for otitis media

* **- Rupture of the tympanic membrane and discharge of infected liquid through the perforation**
* **(surgery) pe tube helps drain fluid**

More commone is children cause eustachian tube is more horizonatal

* **Only effective during the infectious stage**

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**Cholesteatoma (middle ear disorder)**

* can smell 
* one of the layers of the ™ separates and creates puss and a mass
* mass cause damage to the mastoid

Ossicular Discontinuity (middle ear disorder)

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* truma /breakage of chain causing ear drum to move around
* Flat 50-60 dB CHL
* Tymps may show high admittance (Ad)

Otosclerosis

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* bone of stapes and cochlea softening and hardening repeatedly 
* **Results in a progressive, conductive hearing loss**

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* Starts in one ear and then becomes bilateral

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**Diagnostic Signs of otosclerosis**

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* Otoscopy
* WNL
* Schwartze Sign- red hue in the region of the promontory

tympanometry

* tpp in normal range
* low acoustic emmitance type As 
* ossicular chain is not moving enough then ™ can not move as much

Acoustic Reflexes

* Reflexes are typically absent.

No etiology

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**Carhart’s Notch** – (otoschlorosis)

Elevated bone conduction thresholds at \~ 2000 Hz.

Treatment for (otoschlorosis)

* **Stapedectomy**
* **Stapes is removed**
* **A clean bony surround is created at the oval window**
* **The stapes is replaced with a prosthetic implant**

Ototoxicity

caused by drugs in blood supply and stia vascularis traveling to endo and parylinph

* Cochleotoxic – just cochlea
* Vestibulotoxic – just vestibular

SOme ototoxic meds are nesseary (chemo)

ALL MEDS ENDING in MYCIN

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**Aminoglycoside Antibiotics (infections)**

ototoxic

* Hearing loss is sensorineural and permanent in 2-5% of patients. (goes up if through an IV)

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* Prolonged administration causes programmed cell death (apoptosis). 
* affects:
* Outer hair cells
* Supporting cells
* Stria vascularis
* Spiral ganglion cells
* Basilar membrane collapses
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**Loop Diuretics (kidney failure/pulmonary edema)**

Edematous – too much fluid so gets rid of it

* can get rid of the fluid in the cochlea
* Hearing loss is sensorineural, immediate, drop of spectogram, and usually temporary. 
* Loop diuretics wipe out the positive endocochlear potentials (EP).

(constant voltage difference)

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* No direct damage to the hair cells or spiral ganglion. 
* Edema (swelling)in the epithelium (outer layer)of the stria vascularis and cochlear wall. 
* \
* But the **timing is off**. __Swelling__ of the stria vasularis occurs __after hearing loss.__ 
* Diuretics rapidly reduce the blood flow to the stria vascularis (ischemia) but __not to the basilar membrane or hair cells__.

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**Salicylates (pain) ototoxic**

* toxic in high doses (6-8 pills per day)
* Patients with severe arthritis may take up to 24 aspirin tablets a day
* Hearing loss is sensorineural and almost always temporary 

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* Salicylate affects the OHC’s electro-motility response by binding to the prestin layer of the cells which suppresses the amplification properties of the cochlea.

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**Anti-Neoplastic Drugs (cancer)**

* Chemotherapy
* Prevents the development, growth, or proliferation of tumor cells.

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* Cochleotoxic Anti-neoplastic Drugs
* Cisplatin 

\n Hearing loss is sensorineural and **permanent**

* Toxin enters all cells in the cochlea and destroy them at the level of the organelles causing premature cell death. 

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* Hair cells are most affected but so are:
* Spiral ganglion cells
* Spiral ligament
* Stria vascularis
* Supporting cells

symptoms of ototoxicity

* Cochleotoxic
* typically high pitched tinnitus
* tinnitus may precede hearing loss

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* Vestibulotoxic- vertigo/ dizziness/unsteadiness
* Otoscopy- WNL

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* Tympanometry- WNL

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* Acoustic Reflexes - consistent with degree of hearing loss >50
* high frequency heairng losss

cochlear disorders: Presbycusis

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* Hearing loss caused by the degenerative effects of aging.
* PTA >25
* more prevelant in men
* There is a strong association between noise exposure and increased hearing loss.  

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* treatment : heairn aid or cochlear implant

Sensory presbycusis

gradual loss of outer hair cells due to high frequencies

* bilateral
* high-frequency sensorineural hearing loss

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* Good word recognition WRS (consistent with loss)

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Neural Presbycusis

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* __Loss of auditory nerve fibers__ 
* __Greatest loss in the basal turn of the cochlear but may also be diffuse.__
* Bilateral, high-frequency sensorineural hearing loss

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* Poorer than expected word recognition

Strial Presbycusis

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* Damage or atrophy of the stria vascularis. 

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* Atrophy of the stria vascularis and __nerve fiber loss__ are the major causes of presbycusis, not so much hair cell loss.


* Bilateral, flat sensorineural hearing loss

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* Good word recognition (consistent with loss)

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**Cochlear Conductive Presbycusis**

* Structural alterations in the basilar membrane and/or spiral ligament.
*  (not conductive hearing loss)


* Bilateral, high-frequency sensorineural hearing loss

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* Good word recognition (consistent with loss)

SSNHL (sudden ) cochlear disorder

* Abrupt, sensorineural hearing loss without apparent cause.
* onset is rapid and may occur in minutes or develop over a few hours or days

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* Sensorineural hearing loss 
* Thresholds 30 dB HL or greater
* 3 continuous frequencies 
* <3 days
* usually unilateral
* tinntus
* aural fullness and or vertigo
* hearing loss can range

__**etiology: Idiopathic**__

SSNHL treatment

Hyperbaric Oxygen Chamber – mixed findings in the literature

Administration of steroids

* __Oral__ - systemic side effects
* __Intratympanic__ – injected directly into the middle ear without side effects
* Combination of oral and intratympanic administration has been shown to be the most effective.

5 SSNHL prognosis

1. early identification
2. severity of hearing loss
3. presence fo veritgo
4. age
5. Shape of the audiogram

* **rising and mid- frequency losses recover more frequently than sloping or flat losses**

ANSD (cochlear disorder)

A condition in which **outer hair cell integrity is normal** but the **afferent auditory pathway is abnormal**.

* inner hiar cells or nerve fibers
* __**etiology: genetic**__ mutation
* aquired: lack of oxygen or jaundice

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how to manage ANSD

people with ANSD are atypical

* **Amplification (i.e. hearing aids)**

**FM system**
* **Improve signal-to-noise ratio**
* **Cochlear Implant** 
* **An option if amplification is ineffective** 

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* **Communication Training** 
* **Listening strategies**
* **Speech reading training**

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* Sign language
* Cued speech

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ANSD audiometric results

* **Audiometry**
* **Normal to Profound SNHL**
* **typically bilaterally, often fluctuating**

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* **Speech Perception**
* **poor performance(quiet and noise that is not consistent with hearing loss)**

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* **Auditory Brainstem Response**
* **no peaks**
* **cochlear microphonic**
* present dpoaes above noise >6
* ABR adds a little wiggle

ANSD subjective characteristics

often in young people

* Fluctuating / progressing HL
* Unable to understand speech, especially in noise
* Strong visual orientation
* Little-to-no benefit from traditional amplification (patient may completely reject)

ANSD objective chractersitics

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* \
* **Otoscopy - WNL**
* **Tympanometry - Type A tymp**
* **Acoustic reflexes** 
* **Absent/elevated (ipsi and contra) that can be inconsistent with pure tone thresholds**

manieres disease (cochlear disorder) chracteristics

A rare disorder of the membranous labyrinth and cochlear fluids.

__**etiology: is etiopathic**__

unilateral can become bi

* Hearing loss
* Hearing can fluctuate – can recover quickly (hours) in early stages. Can take days to months after a severe episode
* Ear eventually “burns out” – flat 50-60 dB HL SNHL
* Tinnitus\*
* Vertigo 
* Aural fullness\*

it can come and go

manieres disease (histology)

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* swelling in the vestibular system and cochlea


* Endolymphatic hydrops may rupture and distort the membranous labyrinth system, particularly in the region of __Reissner's membrane.__
* __leads to damage to hair cells and associated nerve fibers__

manieres diesease treatment

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no cure only can manage

* Dramamine or Meclizine (for nausea caused by the vertigo)


*  Diuretics (reduce the endolymphatic fluid pressure)


* Vasodiolators (to shorten episodes)


* Stress reduction


* Reduced salt intake (<1g per day)


* Limit use of alcohol, caffeine, and nicotine

Surgery:

* endolymphatic shunt
* Gentamicin injection to chemically destroy the vestibular system
* labyrinthectomy (cut vestibular nerve)


* \

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manieres diesease diognostic test results

* toscopy - WNL


* Tympanometry –  WNL


* Acoustic Reflexes – Consistent with the degree of loss


* OAES – consistent with degree of loss
* Pure-tone Audiometry
* Low-frequency SNHL
* Fluctuates with episodes of the disease
* Flat 50-70 dB HL sensorineural hearing loss, after burned out ear

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* Decreases in thresholds >10 dB or speech perception >15% are considered significant for the disease.

* ECochG test

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manieres disease test

If positive, can be a strong diagnostic indicator

* If negative, doesn’t mean that it isn’t Meniere’s
* Not a test with high sensitivity and specificity 

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Neoplasm - tumor arising from the alteration of the normal cells with subsequent uncontrolled growth

* Neoplasms can develop anywhere in the central auditory system from the 8th nerve to the auditory cortex.

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* In many cases of brainstem and cortical lesions, the audiologist is not the first medical professional to see the patient. That is, patients often seek help for symptoms other than hearing loss first.

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Intra-axial tumors-tumor occurring and affecting the brainstem

* Intra-axial tumors are __more common in children__ than adults.


* __The closer the tumor is to the cochlea, the more auditory symptoms are present (intra-axial).__

Symptoms include:

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* Hemiparesis 
* Sensory disorders 
* Tremors
* Hydrocephalus 
* Nystagmus
* Vertigo
* Poor balance, unsteadiness
* Poor reflexes
* Facial paralysis
* Ataxia

Extra-axial tumors- tumors occurring in, and affecting, the cortex

* Neoplasms at the level of the cortex are often associated with normal hearing thresholds and good speech recognition in quiet.  

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* __Speech recognition can break down in noise or with a competing messag__e. 

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* Unilateral tumors are expressed as abnormalities on the side opposite the lesion. 

Symptoms may include:

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* Seizures
* Memory problems
* Emotional problems
* Personality disorders
* Aphasia
* Vertigo
* Poor balance, unsteadiness
* Tinnitus, auditory illusions
* Visual hallucinations

eighth nerve tumors

* Arise from the neural sheath surrounding the vestibular branch of the eighth nerve.  

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* More accurately referred to as “Vestibular Schwannoma”

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* These tumors are benign.

Sporadic unilateral vestibular schwannomas

__(random on one side)__

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* Constitutes 95% of all vestibular schwannomas.
* usually occurs in 4th or 5th decade of life
* If they grow large enough, they can cause __hydrocephalus, brainstem compression, and death__. 

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* Initially, they are __associated with unilateral high-frequency hearing loss, tinnitus, and imbalance.__ 

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Bilateral vestibular schwannomas

* commonly associated with 
* Neurofibromatosis (Type 1 or 2)
* A disease that results in small tumors of the nervous system that occur all over the body including both eighth nerves.

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Cystic vestibular schwannomas

* These are aggressive, unilateral tumors that __contain cysts within, or surrounding, the tumor__.  
* eats away surrounding structures
* rapid regriwth after surgury

eighth cranial nerve tumors treatment

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**Surgery**

* Priorities
* maintaining of facial nerve function
* preservation of hearing (socially useful)
* complete tumor removal
* radiation


* Amplification for patients with complete hearing loss is possible
* __CROS__ (contralateral routing of signal)
* __Bone anchored hearing aid (BAHA)__

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eighth cranial nerve tumors subjective traits

age: 40-50years

main complaint: progressive unilateral hearing loss

duration: over a year

eighth cranial nerve tumors objective traits

* toscopy - WNL
* Tympanometry - Type A- WNL
* Acoustic reflexes - absent in the pathological ear
* abnormal reflex decay (acoustic emmitance lecture)


* OAEs - WNL (only goes to outer hair cells)
* audiometry
* can vary by patient
* unilateral or significantly asymmetric, high frequency SNHL

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* Speech Perception
* poorer than expected

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normal typa A tymp

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SRT (understand word)  is way worse than PTA(heart he sound)

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