SPA 4302 Exam 2 Comprehensive Review - University of Florida

General Exam Logistics and Foundations

Tympanic Peak Pressure (TPP): Students will not be asked to calculate the TPP. It will either be provided as a value or must be identified on an actual tympanogram. The clinical emphasis is on understanding what the TPP value signifies.
Ototoxicity:
* Knowledge of general risk factors is required.
* Because most ototoxic events result in sensorineural hearing loss, students are not required to identify or produce specific examples.
Embryology:
* Emphasis is placed on the general timeline of development and key events in that timeline.
* Identification of specific structures or detailed development of the pinna is not expected.
Genetics:
* Students must know the key features of genetic conditions.
* Understanding of basic inheritance patterns is required.
Definitions of Otitis:
* Otitis Externa: Inflammation or infection of the external (outer) ear.
* Otitis Media: Inflammation or infection of the middle ear.
Infection Control: Gloves can be used at any time during a procedure. They are mandatory if there are any external signs of infection present.
Evidence-Based Practice (EBP): There will be no questions on EBP on the exam.
Normative Data: Tables for tympanogram normative values will be provided during the exam; students must be familiar with how to navigate and interpret these tables.
Categorization of Symptoms:
* Syndromic: A condition where many symptoms arise from a single common cause.
* Non-Syndromic: A condition characterized by one symptom in isolation or several symptoms that do not originate from a common cause.

Auditory Brainstem Response (ABR) Stimuli and Pathways

The ABR Waveform: ABR testing creates a series of waves relating to the specific structures of the auditory neural pathway when a loud stimulus (like a click) is used.
The Neural Pathway (Waves I–VI):
    * Wave I: Cochlea
    * Wave II: 8th Cranial Nerve ( $CN$ )
    * Wave III: Cochlear Nucleus
    * Wave IV: Superior Olivary Complex
    * Wave V: Lateral Lemniscus
    * Wave VI: Inferior Colliculus
Comparison of Tone Bursts vs. Clicks:
    * Tone Bursts:
        * Primary Use: Hearing assessment.
        * Nature: They are not technically tones but filtered noise that mimics the effects of a specific tone.
        * Assessment Goal: Work to identify the 5th wave ( $Wave\,V$ ) of the auditory pathway.
        * Procedure: Trace the 5th wave down to the lowest intensity level where a response can still be visualized (finding the threshold).
        * Loudness Consistency: Tests are often run at varying frequencies (e.g., $500\,Hz$ , $1000\,Hz$ , $2000\,Hz$ , and $4000\,Hz$ ) but all at the same level of loudness for comparison.
    * Clicks:
        * Primary Use: Neural assessment.
        * Nature: Broadband noises that include a wide range of frequencies.
        * Assessment Goal: Stimulate a large portion of the organ of hearing to generate a very large response.
        * Outcome: Identify the six major waves created by the auditory pathway.

Immittance Testing and Tympanometry

Definition: Immittance is an umbrella term for a variety of tests, including:
    * Tympanometry
    * Acoustic Reflex Testing (also known as Middle Ear Muscle Reflex testing)
    * Reflex Decay
Tympanometry Mechanics:
* When the ear canal is pressurized, the eardrum is pushed toward the middle ear.
* When the ear canal is depressurized, the eardrum is pulled toward the probe (toward the outer ear).
Clinical Indicators for Ear Canal Volume (ECV):
    * ECV measurements are helpful for identifying Atresia (closure or absence of the ear canal opening) or Stenosis (an abnormally narrow but open ear canal).
    * Microtia is identified through visual inspection rather than immittance testing.
    * Acoustic Equivalent Ear Canal Volume: This is an automated value provided in the results table representing the ECV.
Probe Tones for Tympanometry:
* $226\,Hz$ : Used for patients older than 6 months.
* $1000\,Hz$ : Used for infants younger than 6 months due to the hyper-flexibility of the infant ear canal. This helps differentiate changes in admittance caused by eardrum movement from those caused by the expansion and contraction of the canal wall itself.

Tympanogram Parameters and Interpretation

ECV (Ear Canal Volume): Helps determine if the eardrum has a hole, if the canal is a normal size, or if it is blocked.
Adm (Admittance): Indicates if the eardrum and ossicles are moving properly or if movement is hindered by things like fluid or air pressure.
TPP (Tympanic Peak Pressure): Shows if there is normal pressure in the middle ear and quantifies it. It evaluates if the Eustachian tube is functioning to balance pressure with atmospheric levels.
TW (Tympanometric Width): Determines if middle ear pathology is present even when the eardrum is moving. It may indicate a resolving issue, such as Otitis Media with Effusion.
* Calculation Example: TW is derived from the difference in absolute values on the admittance graph (e.g., $-150\,daPa$ and $-50\,daPa$ results in a width of $100$ ).

Normative Values for Tympanometry

Adults:
    * ECV: $0.80$ to $2.20\,ml$ (or cc)
    * Adm: $0.30$ to $1.70\,mmhos$
    * TPP: $-105$ to $+5\,daPa$
    * TW: < 125\,daPa
Children (18 months to 10 years):
    * ECV: $0.60$ to $1.20\,ml$ (or cc)
    * Adm: $0.30$ to $1.05\,mmhos$
    * TPP: $-75$ to $+25\,daPa$
    * TW: < 200\,daPa
Children (6 months to 18 months):
    * ECV: $0.50$ to $1.00\,ml$ (or cc)
    * Adm: $0.20$ to $0.70\,mmhos$
    * TPP: $-75$ to $+25\,daPa$
    * TW: < 250\,daPa
Infants (< 6 months):
* ECV: N/A
* Adm: $< 0.20\,mmhos$ * TPP: $< -200\,daPa$ * TW: $> 250\,daPa$

Acoustic Reflex Threshold (ART) and Pathological Scenarios

ART Procedure:
    * A tympanogram is performed first to find the TPP.
    * The ear is then pressurized specifically to that TPP value to ensure optimal eardrum movement.
    * Testing is performed using various tones (e.g., $500\,Hz$ ) or noise at loud levels.
    * The goal is to identify the softest sound that elicits a muscle contraction.
Pathologies Indicated by Tympanograms:
    * Low middle ear admittance.
    * Large ear canal volume (often indicating a hole or PE tube).
    * Negative TPP (Negative Middle Ear Pressure).
    * Wide tympanometric width.
    * Suspected Otitis Media with Effusion (OME).
    * Resolving OME.
    * Patent Pressure Equalization (PE) Tube.
    * Perforation in the eardrum.
    * Disarticulation of the Ossicles.

Otoacoustic Emissions (OAEs)

Overview: Although the time to run the tests varies, the primary difference lies in how they assess the auditory system.
DPOAEs (Distortion Product OAEs):
    * Type: Diagnostic.
    * Function: Focuses on individual regions of outer hair cells (OHCs).
    * Utility: Allows for a direct comparison with pure tone behavioral hearing results. For example, if DPOAEs are present at $1000\,Hz$ , expectations for a behavioral pure tone test would be normal or near-normal hearing at $1000\,Hz$ .
TEOAEs (Transient Evoked OAEs):
    * Type: Screening.
    * Function: Tests many regions of the outer hair cells simultaneously.
    * Limitation: If results are abnormal, they cannot specify which region is faulty because results are combined.
    * Strength: This method is more effective at catching mild hearing losses than DPOAEs.

Central Auditory Processing Disorder (CAPD) Profiles

CAPD Assessment Battery: A set of tests designed to overwork the auditory systems to evaluate where a breakdown occurs. Results are compared against age-matched norms.
Goal: To define the specific nature of the problem (e.g., binaural processing) and check for other comorbid disorders.
Three Major CAPD Profiles:
    * 1. Decoding Deficits:
        * Often considered the "True CAPD" because it is a purely auditory-based deficit.
        * Definition: The system is unable to extract pitch, loudness, and timing cues.
        * Nature: A discrimination-based problem located in the left hemisphere and/or high brainstem.
    * 2. Integration Deficits:
        * Definition: A cortical deficit in communication between the right and left hemispheres.
        * Symptoms: The patient is unable to combine information or synthesize meaning (cannot "put it all together").
        * Impact: Systems are easily overwhelmed by large amounts of information and have difficulty processing info quickly.
    * 3. Prosodic Deficits:
        * Also known as Right Hemisphere APD.
        * Definition: Inability to process the rise and fall in pitch and loudness (intonation/syllabic emphasis).
        * Nature: Difficulty with the analysis and synthesis of prosodic features in communication.