Implementing the Cross-Check Principle in Pediatric Audiology

Transcription

1 Implementing the Cross-Check Principle in Pediatric Audiology A Review for Audiologists, Speech-Language Pathologists, and Graduate Students Elizabeth Musgrave, Au.D., CCC-A Sara Neumann, Au.D., CCC-A

2 The Hearts for Hearing Team Audiologists Additional Team Members Jace Wolfe, Ph.D., CCC-A Kris Hopper Kerri Brumley Pati Burns Krystal Hudgens, Au.D., CCC-A Sherry Edwards Susan LaFleur Rocio Portillo Sara Neumann, Au.D., CCC-A Reyna Romero Kristi Murphy Christian Boone Mila Duke, Au.D., CCC-A Dianne Ward JJ Sanders Verneda Osborne Elizabeth Musgrave, Au.D., CCC-A Jackie Keathly Sabrina Calise Rachael Odor Johnna Wallace, Au.D., CCC-A Kristen Kastner Rachel Magann-Faivre, Au.D., COHC Sarah Cain, Au.D., F-AAA Emily Mills, Au.D., CCC-A Shannon Winters, Au.D. Jarrod Battles, Au.D. Extern Esther Kim, Au.D. Extern Speech-Language Pathologists Joanna T. Smith, M.S., CCC-SLP, LSLS Cert. AVT Tamara Elder, M.S. CCC-SLP, LSLS Cert. AVT Darcy Stowe, M.S. CCC-SLP, LSLS Cert. AVT Lindsay Hannah, M.S., CCC-SLP, LSLS Cert. AVT Jennifer Bryngelson, CCC-SLP, LSLS Cert. AVT Tessa Hixon, M.S., CCC-SLP Parker Wilson, M.S., CCC-SLP Lauren Henry, M.A., CFY-SLP

3 Areas of Concern Pediatric diagnostic testing, including infant auditory brainstem response (ABR) testing, can be some of the hardest for audiologists to master. Currently in the U.S., there is not a cookbook available to guide clinical decision making with a comprehensive test battery. Without using multiple diagnostic measures, the audiologist opens themselves to liability for mistakes when ruling out or diagnosing hearing loss. In turn, this can negatively impact a child s future outcomes. The ABR should not be viewed as the be all, end all in audiologic management. It should be used in combination with a battery of objective measures to ensure proper and timely diagnosis.

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5 Objectives Today s discussion will provide attendees with 1. the rationale and set up of a basic protocol for obtaining ABR measurements, including other objective measures as part of the test battery. 2. the skills to, at a basic-level, label an ABR waveform as present, absent, or inconclusive. 3. opportunities to review and evaluate case studies involving the cross-check principle.

6 Audiologic Test Battery ABR testing is the gold standard for diagnostic evaluation of hearing sensitivity in infants. The ABR, although the gold standard, should not be used in isolation. Cross-Check principle (Jerger & Hayes, 1976) The basic premise of the principle is that no test result is accepted independently without corroborating with results from another objective or behavioral method Each test assess a different part of the hearing system (outer, middle, and inner ear). Additional tests are often completed prior to the ABR, as they can give great insight for what to expect from the ABR. Ensures the results are not inaccurate due to operator error, equipment malfunction, or anatomic and physiologic variables. Increases confidence in diagnosis or rule-out of hearing loss.

7 Audiologic Test Battery Otoscopy Tympanometry Monitors movement of the tympanic membrane Acoustic Reflex Thresholds (ARTs) / Middle Ear Muscle Reflexes (MEMRs) Quickly assesses the integrity of the auditory pathway Distortion Product Otoacoustic Emissions (DPOAEs) Evaluates the integrity of outer hair cells in the cochlea Auditory Brainstem Response (ABR) Tests the response from the hearing nerve to the level of the brainstem

8 Outer Ear Space: Otoscopy

9 Middle Ear Space: Tympanometry & ARTs/MEMRs

10 Tympanometry Factors that may cause abnormal tracings: Fluid and/or congestion behind the tympanic membrane Abnormal middle ear bones Extremely small, near-collapsing ear canals Cerumen build-up Parameters vary based on patient age: 6 months or younger, 1000 Hz probe tone 6 to 9 months, 226 and 1000 Hz probe tones Greater than 9 months, 226 Hz probe tone

11 ARTs / MEMRs Factors that may cause abnormal tracings: Abnormal movement of the tympanic membrane Conductive or mixed hearing loss Greater than moderate sensorineural hearing loss Auditory Neuropathy Spectrum Disorder (ANSD) Parameters vary based on patient age: 6 months or younger, 1000 Hz probe tone, broadband noise 6 to 9 months, 226 and 1000 Hz probe tones, broadband noise and tonal stimuli Greater than 9 months, 226 Hz probe tone, tonal stimuli

12 Putting it Together

13 Putting it Together (Hall & Swanepoel, 2010)

14 Inner Ear Space: DPOAEs, & ABR

15 Outer Hair Cells (OHCs)

16 DPOAEs Factors that may cause abnormal responses: Abnormal movement of the tympanic membrane Conductive or mixed hearing loss Greater than slight/mild sensorineural hearing loss Auditory Neuropathy Spectrum Disorder (ANSD) Interpreting: An infant s OAEs should be robust if hearing sensitivity is within normal limits Boy s Town Normative Data, 95% confidence interval Responses can be robust, present, present with reduced amplitude, or absent

17 ABR ABR testing can determine type and degree of hearing loss. Types of ABR testing: Air Conduction Tone burst (frequency-specific) Click (neural synchrony) Bone Conduction Tone burst (frequency-specific)

18 Anatomy & Physiology of the ABR

19 Interpreting the ABR Waveforms should be super-imposed and in the same scale. At suprathreshold levels, waves I, III and V should be present for a child with normal hearing sensitivity or a mild hearing loss. Evaluating waveform morphology: Sweep to artifact ratio (artifact should be less than 10% of sweeps) Residual noise (should be 20 nanovolts or less) Wave V amplitude (should be 3 times the noise) Latency (should shift as intensity decreases) When searching for threshold, obtain waveforms 10 db above and 5-10 db below where threshold is suspected.

20 Interpreting the ABR Response Present Response Inconclusive Response Absent

21 Match feature Superimpose feature Interpreting the ABR This side is not superimposed This side is superimposed

22 Putting it Together Tympanometry Type A good movement of the tympanic membrane Type A S limited movement of the tympanic membrane Type A D excessive movement of the tympanic membrane Type B abnormal movement of the tympanic membrane (normal ECV), cerumen impaction (small ECV), or present PE tube/perforation (large ECV) Type C significant negative middle ear pressure ARTs / MEMRs (in the presence of Type A tymp) Within normal limits normal hearing sensitivity to a mild hearing loss Elevated mild to moderate hearing loss Absent moderately severe to profound hearing loss DPOAEs (in the presence of Type A tymp) Robust normal hearing sensitivity Present with reduced amplitude slight to mild hearing loss Absent mild to profound hearing loss

23 General Rules for Testing Children Factors that may cause interference: Crying Sucking Stirring Indicators that results have been affected by the above factors: Tympanometry & ARTs / MEMRs: spikes or inconsistent tracings DPOAEs: excessive noise floor in the recording ABR: high level of noise in the EEG and/or waveform, poor sweep to artifact ratio, poor waveform morphology (e.g. baseline drift)

24 Why have a protocol? Ensures that the process is the same for each child Ensures all testing has been completed that is necessary to diagnose or rule out hearing loss Ensures that appropriate levels and frequencies are tested Improves efficiency in testing Ensures a timely diagnosis for early intervention Provides standardized correction factors to ensure the child is appropriately managed Gives the clinician confidence in determining type and degree of hearing loss Ensures the cross-check principle is applied in all circumstances

25 Pearls Use preliminary test results (i.e. tympanometry, ARTs / MEMRs, DPOAEs) to guide expectations for ABR testing If ABR testing is not what you expect per preliminary tests, start troubleshooting! The ABR should not be viewed as the be all, end all in audiologic management. It should be used in combination with a battery of objective measures to ensure proper and timely diagnosis. Pay close attention to case history details. Know that the presence or absence of risk factors does not preclude the child from having hearing loss.

26 References Hall, J.W. & Swanepoel, D.W. (2010). Objective Assessment of Hearing. San Diego, CA: Plural Publishing, Inc. Hunter, L. (2013, September). 20Q: Acoustic immittance - what still works & what's new. AudiologyOnline, Article Retrieved from: Sutton, J. & Lightfoot, G. (2013). Guidance for auditory brainstem response testing in babies, version 2.1. Retrieved from: tent/uploads/2014/08/nhsp_abrneonate_2014.pdf Wolfe, J. (2014, October). 20Q: ABR assessment in infants - protocols and tandards. AudiologyOnline, Article Retrieved from:

27 Shoot for the Moon! THANK YOU FOR YOUR ATTENTION