Final Exam Review Flashcards
What causes tinnitus?
- The cause is unknown
- Usually associated with damage to the auditory pathway
- Tinnitus with normal hearing is less common
What happens on the neural level with tinnitus?
- Change in spontaneous neural activity
- Brain identifies the change and interprets it as sound (tinnitus)
How can cochlear damage contribute to perception of tinnitus?
- Damage to cochlea leads to increased spontaneous firing rate in auditory structures
- If there is hearing loss, you can get increased firing in the ventral cochlear nucleus, dorsal cochlear nucleus, and inferior colliculus
What happens when there’s a decrease in auditory stimulation from the auditory nerve?
- Neurons spontaneously start having oscillations
- Spatial synchrony: across space there are a bunch of neurons firing at the same time
- This produces a phantom sound
What is the role of the nucleus accumbens?
Positive emotions: laughter, reward, reinforcement, learning
Negative emotions: fear, aggression, impulsivity
What is the role of the ventromedial prefrontal cortex?
Location: frontal lobe at bottom of cerebral hemispheres
- Implicated in processing of risk and fear
When should a tinnitus patient be referred to an audiologist?
- Symptoms suggest neural origin of tinnitus (tinnitus does not pulse with heartbeat)
- No ear pain drainage, or malodor
- No vestibular symptoms (dizziness/vertigo)
- No unexplained sudden hearing loss or facial palsy
When should a tinnitus patient be referred to an ENT?
- Symptoms suggest somatic origin of tinnitus
- Ear pain, drainage, or malodor
- Vestibular symptoms (dizziness/vertigo)
- Unilateral tinnitus
- Presentation of symptoms similar to Meniere’s Disease
When should a tinnitus patient be referred to emergency care?
- Facial palsy
- Physical trauma
- Sudden unexplained hearing loss
When should a tinnitus patient be referred to mental health services?
- Suicidal ideation
2. Obvious mental health problems
When can you forego referral to ENT?
- Tinnitus is linked to noise exposure
- Tinnitus symmetrical/non-pulsatile
- Tinnitus stable, long duration (6 months or more)
- Audiogram consistent with diagnosis of symmetrical, sensorineural hearing loss
What are mental health disorders that commonly co-occur with tinnitus?
- Clinical depression
- Anxiety
- PTSD
- Sleep disorders
What is residual inhibition?
Temporary suppression of tinnitus after a masking noise is played in their ear
What is pseudohypacusis?
False hearing loss
What is psychogenic?
Loss/disorder arising from psychological conditions; the patient is not aware that he is simulating deafness
What is nonorganic?
Apparent loss with no known disorder or insufficient evidence to explaint it
What is malingering?
Deliberately faking a loss
Why would a patient present with nonorganic hearing loss?
- Adults seek financial or other gain (predominately male)
- Children (mostly girls) seek medical attention when they really need attention for an issue they cannot express
- Wish to avoid undesirable situation
- Attempt to place blame for inadequate social behavior on psychological disorders
What are some signs of nonorganic hearing loss?
- Disagreement among test results
- SRT vs. PTA, Audiometric vs. AR thresholds, Air-bone gap in the wrong direction - Disagreement between test results and behavior
- Disagreement between test-retest reliability - greater than 10 dB
- No shadow curve in the unmasked results
- Odd repetition of monosyllabic words
- Odd results (repeating half of the spondees)
What are some behaviors associated with nonorganic hearing loss?
- Exaggerated listening behaviors
- Smirking (if a kid)
- Avoiding eye contact
- Unwillingness to use own voice
- Over reliance on lip reading
- Inappropriate repetition of words
- Repeating spondees or monosyllabic words with questioning intonation
- Exaggerated or contradictory statements of difficulty or discomfort
- Vague description of hearing difficulties
- Volunteering of unasked for supplementary information
How can you modify audiometric testing if you suspect malingering?
Use ascending rather than descending thresholds.
Present the monosyllabic word lists at 10 dB SL
Yes-No Test: patient tends to say “no” to tones below stated threshold
How can you test a patient with a unilateral nonorganic hearing loss?
Stenger Test
When a listener is presented with the same type of sound in both ears, s/he will only hearing a single sound and hear it in the ear in which it’s louder
Part 1: Present 2 tones
- A +10 dB SL in good ear
- A -10 dB SL in “bad ear”
- If no response, you’ve caught them
Part 2: Reduce level in “bad” ear until they respond
Inconsistent results may be due to…(non-organic hearing loss)
- Pt. doesn’t understand the test procedure
- Pt. is poorly motivated
- Pt. is physically or mentally incapable of appropriate responses
- Wishes to conceal a handicap
- Is deliberately feigning or exaggerating a hearing loss for personal gain or exemption
- Suffers from some degree of psychological disturbance
What are conditions that mimic nonorganic hearing loss?
- Cortical deafness
- King-Kopetzky Syndrome
- Auditory Neuropathy Spectrum Disorder
Define sensitivity.
Percentage of persons with a disorder who show up on your test as having that disorder.
Define specificity.
Percentage of persons without a disorder who show up on your test as not having that disorder.
List the clinical uses for OAEs.
- Universal newborn screening
- Differential diagnosis
- Monitor effects of treatment
- Selection of treatment
- Surgical options
List the research uses for OAEs.
- Non-invasive window into intracochlear processes
- Insights mechanisms and function of cochlea
- New understanding nature of sensory impairment
Why isn’t an OAE examination a test of hearing?
- The patient can have a hearing loss, but still have present OAEs
- It’s not really hearing unless the patient states that they hear it
- Presentation levels are loud, so OAEs are not a measurement of absolute threshold
When would you expect to find a hearing loss with normal DPOAEs?
- There is damage to the inner hair cells
2. The hearing loss is neural
How can OAEs tell us about the site of lesion?
They can distinguish between sensory and neural hearing losses.
What are the advantages of OAEs?
Fast, simple, inexpensive
What are the disadvantages of OAEs?
High failure rate, does not detect Auditory Neuropathy Spectrum Disorder
What are the effects of the outer ear on OAE generation?
- Wax and debris can block sound delivery tube or microphone
- Leakage from improper fit
- Acoustics of the ear canal (are compensated by calibration prior to measurement)
What are the effects of the middle ear on OAE generation?
- Health of ME influences OAE recordings 2 times- forward and reverse propagation
- Reverse propagation is less efficient than forward- leads to a loss of 30 dB
What are the effects of the inner ear on OAE generation?
- Sensitive to loss of outer hair cells- can pick up dysfunction before audiogram
- Also affected by stria vascularis, which maintains the electrochemical balance necessary for normal OHC function
Why doesn’t middle ear transmission work in reverse?
Mechanisms that aid impedance matching in forward transmission become impediment in reverse transmission.
What happens with negative middle ear pressure?
DPOAE levels reduced below 2 kHz, minimal effects at 2 kHz, variable effects are above 2 kHz
Introducing negative pressure can offset effects
What are the functional differences between OHCs and IHCs?
IHCs: sensory function; mediate conversion of mechanical energy to neural signals
OHCs: mechanical function; amplification for low-input signals
What are spontaneous OAEs?
Recorded without external stimulation.
SOAEs are equally spaced along basilar membrane
What is the relationship of SOAEs to hearing status?
Presence of SOAEs doesn’t guarantee normal hearing
What are 2 possible mechanisms for SOAEs?
- In normal hearing ears, SOAEs are the result of active cochlear mechanisms and global resonance in ear canal
- Isolated, high-level SOAEs are associated w/ cochlear damage- artificial boundaries along the cochlear partition act as barriers or reflectors creating OAEs
What are the 2 types of evoked OAEs?
DPOAEs
TEOAEs