SHS 401 Exam 3 Terms

Dizziness

General term for unsteadiness

Vertigo

Illusion of motion (room spinning)

Sensory component of balance

eyes, inner ear, feet

• if one is fails, balance is off

motor component of balance

muscles + reflexes to maintain posture

Vestibular System Functions

• Sends info to CNS for posture and spatial orientation

• Stabilizes vision during head movement

Semicircular Canals (SCC)

detect spinning/head rotation (angular acceleration)

utricle

horizontal movement (ex: car driving foward)

Saccule

vertical movement (ex: elevator up/down)

macula

contains sensory cells

otolithic membrane

gel w/ otoconia (tiny crystals) for weight

otoconia

tiny crystals that helps detect change in motion

ampulla

where sensory cells are in SCC

cupula

gel where hair cells sit (like otolith membrane but in SCC)

Vestibulo-ocular reflex (VOR)

• Keeps eyes steady during head movement

• Turn head right → eyes move left

disorder

general term for something not working right

lesion

damage or abnormal change in tissue

gross/macroscopic

you can see it (e.g. big tumor)

microscopic

you need a microscope to see

ex: hair cell damage

molecular

cell-level changes

ex: genetic mutation

focal

localized tumor (ex: nerve tumor)

diffuse

widespread

systemic

affects whole system

(ex: oxygen loss to brain)

structural

anatomical change

(ex: otosclerosis)

traumatic

injury (e.g. blow to the head, loud noise)

vascular etiology

blood flow issues (e.g., autoimmune)

metabolic

nutritional or fluid imbalance (e.g., Meniere’s)

idiopathic

unknown cause

hereditary

genetic, from birth or later onset

acquired

hearing was normal, then declined

Conductive Hearing Loss

• caused by issues in outer or middle ear

• max CHL 50-60 dB

• excellent speech understanding

• usually treatable

anotia

absence of the pinna

• treatment: cosmetic reconstruction

microtia

abnormal pinna shape

• treatment: cosmetic reconstruction

Stenosis

narrow ear canal

• usually does not affect hearing

Atresia

Closed ear canal

• Surgical treatment, BAHA for hearing

Excessive Cerumen

ear wax buildup

• treatment: removal

Foreign Objects

common in children, may block ear canal

• treatment: removal

Collapsing Ear Canal

pinna pressure causes canal closure

• affects high-frequency hearing

ostemas

unilateral bone growth

• treatment: removal if necessary

Exostoses

bilateral growths (common in swimmers and surfers)

• treatment: surgical removal

Otitis Externa (swimmer’s ear)

infection of the ear canal

• treatment: medications

TM perforation

hole in the eardrum

• treatment: natural healing or surgery

Tympanosclerosis

Scarring on eardrum

• may cause minimal hearing loss

Otitis Media

inflammation of the middle ear, often due to eustachian tube dysfunction

• symptoms: pain, fever, hearing loss

• treatment: antibiotics, PE tubes for chronic cases

otitis media with effusion (OME)

fluid in the ear without infection

chronic otitis media

persistent, may require surgery or PE tubes

cholesteatoma

skin growth in the middle ear that can damage ear structures

• treatment: surgery (mastoidectomy)

ossicular discontinuity

trauma to the ossicles (middle ear bones)

• treatment: surgical repair

otosclerosis

Abnormal bone growth around the stapes (middle ear bone), leading to progressive hearing loss.

• treatment: stapedectomy (removal of stapes), hearing aids, or BAHA implants

Sensorineural Hearing Loss (SNHL):

affects the inner ear (cochlea) or the auditory nerve. It often leads to permanent hearing loss

Noise Induced Hearing Loss (NIHL)

Caused by exposure to loud sounds. It can be temporary or permanent.

Presbycusis

Age-related hearing loss, which usually affects higher frequencies.

Meniere’s Disease

Characterized by vertigo, hearing loss, and tinnitus (ringing in the ears). It’s due to fluid buildup in the inner ear.

Ototoxicity

Damage to the inner ear caused by medications, such as certain antibiotics or chemotherapy drugs.

Auditory Neuropathy Spectrum Disorder (ANSD)

A condition where sound enters the ear but doesn’t get transmitted clearly to the brain.

Tests for Inner Ear Disorders:

• pure-tone audiometry

• OAE’s

• ABRs

Auditory Nerve Disorders

Issues with the auditory nerve can result in difficulties with sound transmission from the inner ear to the brain.

Acoustic Neuroma

A benign tumor that grows on the auditory nerve, causing hearing loss, tinnitus, and balance issues

Presbycusis

• A type of sensorineural hearing loss (SNHL) caused by aging.

• It involves gradual degeneration of structures in the cochlea.

Sensory Presbycusis

Loss of outer hair cells, high-frequency SNHL, good word recognition.

Neural Presbycusis

Loss of auditory nerve fibers, poor word recognition, high-frequency SNHL.

Strial Presbycusis

Atrophy of the stria vascularis, flat SNHL, good word recognition.

Cochlear Conductive Presbycusis

Structural changes in cochlea, high-frequency SNHL, good word recognition.

Treatment for Presbycusis

• Hearing Aids: First option for mild to moderate hearing loss.

• Cochlear Implants: For severe cases where hearing aids don't help.

Sudden SNHL (SSNHL)

Rapid-onset SNHL without an obvious cause, defined by a ≥30 dB HL shift in at least 3 frequencies over 72 hours.

• rare

Causes for SSNHL

• Vascular: Disrupted blood flow to cochlea.

• Viral: Infections like pneumonia, herpes, mumps.

• Trauma: Damage from fractures or surgeries.

SSNHL Treatments

• Steroids: Most common treatment for severe cases.

• Other treatments: Diuretics, anticoagulants, hyperbaric oxygen therapy.

Auditory Neuropathy Spectrum Disorder (ANSD)

A disorder where outer hair cells work fine, but there is a disruption in neural transmission from inner hair cells to the auditory nerve.

• symptoms: Fluctuating hearing loss, poor speech understanding, especially in noise.

• Tests: OAEs normal and ABR abnormal

ANSD Causes (etiology):

• Genetic: Single-gene mutations or syndromes causing hearing loss.

• Acquired: Prematurity, jaundice, hypoxia.

ANSD treatment

• Hearing Aids: First step, but only about 50% benefit.

• Cochlear Implants: Effective for some cases.

• FM Systems: Improve signal-to-noise ratio.

Meniere’s Disease

A disorder caused by excess fluid (endolymph) in the cochlea, leading to hearing loss, tinnitus, and vertigo.

• symptoms: hearing loss (low-freq. SNHL), tinnitus (roaring or whooshing), vertigo (lasting hours)

Causes of Meniere’s

• Imbalance in fluid production/absorption in the cochlea.

• Rupture of the membranous labyrinth (e.g., Reissner's membrane).

Merniere’s Treatment Options:

• Medications: Anti-nausea, diuretics, vasodilators.

• Surgical: Shunt or decompression to relieve fluid pressure.

• Lifestyle Adjustments: Reduce salt, caffeine, alcohol, and stress.

Retrocochlear Disorder

A disorder beyond the cochlea, typically affecting the auditory nerve or central auditory pathways

Neoplasm

A tumor resulting from abnormal cell growth

Intra-axial tumor

a tumor occurring within the brainstem

extra-axial tumor

a tumor occurring in the cerebral cortex

What does the brainstem do?

acts as a relay between the brain and the sensory/motor systems

what does the cortex control

higher order functions; interprets sensory input

where can neoplasms develop in the auditory system?

Anywhere from the eighth nerve to the auditory cortex.

Are audiologists usually the first to see patients with brainstem or cortical lesions?

No, because the initial symptoms are usually non-auditory.

Are intra-axial tumors more common in children or adults?

Children

What increases the likelihood of auditory symptoms in brain tumors?

The closer the tumor is to the cochlea.

What is a typical hearing profile for extra-axial tumors?

Normal thresholds and good speech recognition in quiet, but poor in noise or with competing messages.

Can someone have a normal audiogram but poor speech understanding with an extra-axial tumor?

Yes

What is another proper name for 8th nerve tumors?

vestibular schwannomas

are vestibular schwannomas benign or malignant?

benign

What is the most common type of vestibular schwannoma?

Sporadic unilateral vestibular schwannoma.

What percentage of vestibular schwannomas are sporadic and unilateral?

95%

What is the incidence of sporadic unilateral vestibular schwannomas?

 About 10 per 1 million people annually.

• mostly ppl in their 40s and 50s

What are the symptoms of sporadic unilateral vestibular schwannomas?

Unilateral high-frequency hearing loss, tinnitus, imbalance.

What condition is associated with bilateral vestibular schwannomas?

 Neurofibromatosis (Type 1 or 2).

What percentage of vestibular schwannomas are bilateral?

5%.

What are cystic vestibular schwannomas?

Aggressive unilateral tumors with cysts that grow rapidly and may grow back after removal.

 What are complications of cystic vestibular schwannomas?

hearing loss and vertigo

What are the three main priorities in surgical treatment?

1. Preserve facial nerve function
2. Preserve useful hearing
3. Complete tumor removal

What are the outcomes after complete surgical tumor removal of a tumor or vestibular schwannoma?

90% facial nerve preservation, 20–80% hearing loss, 5% regrowth.

 What is the purpose of radiation treatment?

To damage tumor DNA and stop reproduction or shrink/stop growth.

What are possible complications from radiation?

Hearing loss, facial sensory loss, brainstem injury.

What hearing device is used when one ear has no hearing?

CROS hearing aids.