quiz 1 Flashcards
horizontal (axial)
divides the brain into superior and inferior parts
sagittal
divides the body into left and right parts
coronal (frontal)
divides the body into front and back
what are some reason that results may be outside of the normal range
race, diet, age, gender, menstrual cycle, degree of physical activity, human error with the specimen, use of prescription or non-prescription drugs, alcohol intake and illnesses
what are the 5 main types of lab tests
blood, genetic, urine, radiographic or biopsy
what are some uses of blood tests
-blood sugar, cholesterol, hemoglobin levels
-cardiac, renal and hepatic functions through the use of looking for enzymes
-finding infections
-electrolyte imbalances
-minerals
-markers for some diseases are present within the blood
what are some uses of genetic testing
-diagnose/rule out a genetic condition
-diagnose/rule out viral infection
-presymptomatic or predictive testing
-establish risk factors
-establish paternity
-prenatal diagnosis of genetic conditions
what is the purpose of a urine test or analysis
used to detect UTI, kidney or bladder diseases
-can show drug use/abuse
what are the types of radiographic or magnetic imaging
x-rays, CT and MRI
what is a biopsy
the examination of tissue, such as liver, bone or tumors, removed from the body to discover the presence, cause or extent of a disease
x-ray
a form of electromagnetic radiation with a higher energy and can pass through most objects including the body
-used to generate images of tissues or structures inside the body
-not great for soft tissues
CT scan
computerized tomography scan that combines a series of x-ray images taken from different angles around the body
-creates cross sectional images of the bones, blood vessels and soft tissues inside the body
explain the densities within a CT scan
-air is black
-fat is the most dark
-fluid/blood/muscle/soft tissue are shades of gray
-bone is white
magnetic resonance imagine (MRI)
powerful magnets combined with electromagnetic fields and coils which produce radio waves, to produce detailed images of organs and tissues in the body
-there are two different contrast images
T-1 weighted MRI
enhances fatty tissue and suppresses the signal of the water
-CSF is darker
two different contrast images
T-1 weighted MRI and T-2 weighted MRI
T-2 weighted MRI
enhances the signal of the water
-ideal for the use of edema
-CSF is brighter
_______ is good for soft tissue contrast, _______ is poor at soft tissue contrast
MRI ; CT scan
audiologic applications for CT and MRI
-acoustic neruoma
-nerve visualization
-congenital bony anomalies
-cholesteatoma and me tumors
-preoperative evaluation for CI
-trauma such as skull fractures
electrophysiologic test
a measure that can record and analyzes the auditory physiologic responses
-within audiology these are immittance tests, OAEs and AERs
auditory evoked responses (AERs)
an activity/response within the auditory system that is produced or stimulated by sounds
-neurons in the brain communicate with rapid electrical impulses that allow the brain to coordinate behavior, sensation, thoughts and emotions
what is used to record the activity of an AER
scalp electrodes
within an AER, where can the activity be
cochlea, auditory nerve or the central auditory nervous system
auditory brainstem response (ABR)
a sequential series of 5-7 peaks/responses following a stimulus
-usually occurs around 5-10 ms after the onset of the stimulus
-also called the BEAR test
what peaks do we typically focus on in an ABR
1-5 in general
-1, 3, and 5 in particular
what is the ABR threshold
the lowest intensity that wave 5 can be recognized
clinical applications of the ABR
-can provide a close estimate of hearing threshold for specific frequencies
-can predict a conductive, sensory or neural site of lesion
-is aa screening tool for retrocochlear pathologies
-measuring neural synchrony
ABR is a measure of _____________
neural synchrony
-ability to fire all the nerves in their set synchronous pattern
generation site of wave 1
distal CN 8 in the cochlea
-farther from the brain
generation site of wave 3
cochlear nucleus, trapezoid body, superior olivary complex
generation site of wave 5
lateral lemniscus
what is the blood supply related to an ABR
labyrinthe artery (in cochlear) and vertebrobasilar artery (in brainstem)
what are the normative peak latency values at 80 dB nHL
wave 1 : 1.5 ms
wave 2 : 2.6 ms
wave 3 : 3.7 ms
wave 4 : 4.7 ms
wave 5 : 5.5 ms
nHL
normal hearing level
what are the normative interpeak latency values at 80 db nHL
waves 1-3 : 2.25 ms
waves 3-5 : 2.0 ms
waves 1-5 : 4.0 ms
what are the stimulus parameters for an ABR
-inserts
-clicks, chirp, tone burst or speech stimuli
-polarity (how it goes in, either rarefaction, condensation or alternating)
-greater than 20/second for a typical ABR
-variable intensity in dB nHL
describe the latency relationship with intensity
best ABR is the result of a high intensity click stimulus
-as intensity increases, latency gets shorter (increases)
-as intensity decreases, latency spreads out (decreases)
-as intensity decreases, the earlier waveforms will disappear
-morphology decreases with the increase in intensity
describe the relationship between an ABR threshold and an actual threshold
the ABR threshold is typically within 10 dB of the actual threshold
normal bone conducted ABR
it can help differentiate the type of loss in addition to an air ABR
-resembles an AC ABR but has poorer morphology and typically wave 5 will be the only one visible
-dynamic range is smaller as there are limits just like with BC thresholds
ABR cautions
-affected by neuromaturation (how the brain matures/grows)
-does not rule out all auditory abnormalities
-sedation is generally required for children between ~6 months and 4 years
how does changing the stimulus rate impact the ABR
higher rates can increase the latency of the ABR waveforms and decrease the amplitude
-increasing the latency above 90/second can be useful for diagnosing the neuropathology
describe how an ABR relates to ANSD
the response will be revered because it is not a true ABR
-meaning we will receive a flat alternating polarity line due to both condensation and rarefaction being inverses
-response is referred to as cochlear microphonic and as we flip polarity, it flips itself
what are some guidelines for ANSD ABR testing
-perform one run with rarefaction and one for condensation
-if the waveforms reverse, stop ANSD diagnoses
-if waveforms do not reverse, proceed to a threshold search by decreasing intensity and using any polarity
-do NOT use alternating polarity initially because this will give a sum resulting is the incorrect diagnosis of SNHL
what occurs to the latency within a ANSD patient
-with the decrease in intensity, there is not change in wave 5
-poor morphology occurs
otoacoustic emissions (OAEs)
produced spontaneously or in response to acoustic simulation based on the outer hair cell function
-absent or damaged OHCs are associated with the absence of OAEs
limitations of OAEs
patient must sit still/be quiet for a couple of minutes for completion, only allows for prediction of a HL, and they cannot determine severity of the HL
absent OAE
anything from a mild to severe SNHL or middle ear disorder
present OAE
does not rule out a mild SNHL, auditory processing disorder or CN 8 disorder
spontaneous OAEs (SOAEs)
elicited without external stimulation
-measured by placing a microphone in the ear canal
transient evoked OAEs (TEOAEs)
occurs in response to a brief acoustic stimulus using a clock or tone burst
-appear age dependent (decreasing in amplitude with age)
distortion product otoacoustic emissions (DPOAEs)
generated from the cochlea by simultaneously presenting pure tones at two frequencies at two levels
2F1-F2 is what we are graphing
clinical applications of OAEs
-NBHS
-hereditary HL
-monitoring cochlear status (such as noise exposure or ototoxicity)
-difficult to test populations
-site of lesion testing
-diagnosing ANSD
-confirmation of behavioral testing
microtia
underdevelopment of the outer ear
-there is a range from absence of the pinna to small ears with atresic canals
-rarely bilateral
-if bilateral, will be seen with treacher-collins syndrome
constricted ear
tight helix seen in two different forms
-loop ear which is bending of the superior helix
-cup ear which is a flare of the superior ear
auricular appendages
accessory auricular hillocks from which the auricular hillocks form which the auricle develops
-can be a problem or cannot cause any problems
-usually bilateral
-may contain skin alone or skin with cartilage
-may present with associated HL
auricular sinuses/pits
pit like depression anterior to the auricle
-usually are harmless
-may result of failed closure of part of the first branchial groove
-may become blocked with debris or secondarily infection
auricular trauma
can result from a thermal injury, penetrating injury or a blunt injury
-due to location, it is susceptible to trauma
-requires antibiotics and tenatus prophylaxis but also may require surgical reconstruction
auricular hematoma
blood vessels in the perichondrium get separated from the underlying cartilage
-can result in devitalization of the avascular cartilage and can occur in scarring
-can result in cauliflower ear if left untreated
penetrating injuries
seen with knife wounds, human and animal bites, and motor vehicle accidents
-complete or partial avulsion of the auricle
-reattachment can occur within 5 hours of injury
perichondritis
inflammation of the perichondrium and cartilaginous layer that can be categorized as suppurative (infectious) or relapsing (noninfectious)
-caused by injury, burns, insect bites ear piercing, boils, etc.
-insidious onset
infection of the auricle can be ________ or _________
bacterial ; viral
herpes zoster oticus (shingles) or ramsay hunt syndrome
viral infections that involve CN 7 paralysis
-caused by reactivation of the chicken pox virus within the geniculate, spiral or vestibular ganglion and 8th nerve sheath
-earliest symptoms is pain and a painful rash in the ear canal, concha or below/behind the auricle
-treatment with antiviral drugs and steroids
allergic contact dermatitis
caused by exposure to medicinal and cosmetic products
-auricle becomes red, inflamed and with pain
-treatment with topical antibiotics and steroids
seborrheic dermatitis
believed to be due from an infection by a yeast like organism
-results in scaly superficial dermatitis
-not contagious
-causes otitis externa
-treatment with antimycotic drugs, topical steroid cream and drops
neoplasm
new tissue, can be benign or malignant
benign neoplasms of the auricle
cysts - fluid filled cysts that are generally seen following trauma (treat with antibiotics)
kleoids - outward overgrowth of scar tissue (treat with surgical excision or steroid injections)
malignant neoplams of the auricle
are rare
-squamous cell carcinoma
-basal cell carcinoma
-cutaneous cell carcinoma
-rhabdomyosarcoma (cancer of connective tissue)
ear canal stenosis
very narrow ear canal
-ear canal fails to completely develop during the 7th month in utero
-repaired by canalplasty which is to widen the canal
congenital aural atresia
failure of canalization of the EAC
-sporadic or can occur with known syndromes
-associated with microtia and middle ear anomalies
collapsing ear canals
can collapse when supra aural headphones are placed over the ears
-can result in normal tymp, CHL in higher frequencies with supras, thresholds will be better with inserts
-use inserts for best results
who is at risk for collapsing canals
younger children and older adults due to soft and deteriorating cartilage
inflammatory polyps
abnormal tissue growth that can present as masses in the EAC
-seen with chronic otitis media
-most are painful and respond to topical therapy
otitis externa
inflammatory condition of the skin lining the EAC
-most common to affect the EAC
-can be acute diffuse, acute localized or chronic otitis
acute diffuse otitis externa
typically a bacterial infection throughout the canal
-caused by local trauma, frequent swimming or spontaneously
-severe pain, conductive HL, otorrhea and/or acute swelling may be present
-treat with analgesics for pain, topical antibiotics and steroids and can have the removal of infected debris if needed
acute localized otitis externa
two main forms, within one area of the canal typically
-furuncle (abscess) or bullous myringitis
furuncle (abscess)
staphylococcus aureus infection of a hair follicle on the EaC
-tender and painful, but self remitting in a few days
-symtomatic treatment for pain if needed
bullous myringitis
localized viral or bacterial infection of the TM or deep EAC
-more serious
-blood blisters of varying sizes
-painful but typically self remitting in a few days
chronic otitis externa
generalized condition of the EAC
-seborrheic dermatitis is typically the cause (yeast like organism)
-underlying skin appears red and scaly with lack of cerumen
-treatment of topical steroids
-stenosis of EAC due to inflammation or formation of false membrane across the EAC that may block the TM and result in conductive HL
otomycosis
fungal infection within the EAC
-spontaneous or result of frequent use of topical antibiotics
-extensive debris within the EAC
-patients complain of HL and/or a wet feeling inside the EAC
-treat with topical antifungal medication and removal of debris from the EAC
necrotizing external otitis (NEO)
more aggressive otitis media infection in the immunocompromised patients
-skull based osteomyelitis can occur when the disease involved the temporal bone and skull based
-chronic infection with granulation and inflammatory tissue forming in the EAC replacing a significant portion of the bony EAC
-treat with topical antibiotics
exostosis
bony growth and the most common tumor of the EAC
-caused by localized hyperplasia usually due to irritation
-single or multiple growths
-starts unilaterally
-can lead to a CHL
osteomas
true benign bony tumor
-less common and more laterally based
-usually smooth and singular
-symptoms similar to exostosis
-treat with surgical excision
malignant neoplasms
malignancies of the temporal bone are rare
-all patiens presenting with non-healing granulation tissue in the EAC should be biopsied
osteoradionecrosis (ORN)
rare and most serious complication arising from radiation of the base of skull bones due to cancer, but idiopathic variants do occur
-localized or diffuse
-ear fullness, otalgia, foul odor, HL, discharge and tinnitus
