IAPA Summer School 2008 Neonatal Hearing Screening and

Auditory Neuropathy Berlin, Germany

April 10th and 11th

UPDATING THE UPDATING THE ELECTROPHYSIOLOGY IN ELECTROPHYSIOLOGY IN

NEONATAL HEARING NEONATAL HEARING EVALUATIONEVALUATION

José J. Barajas de José J. Barajas de PratPrat

WHAT SHOULD THE IDEAL INFANT HEARING WHAT SHOULD THE IDEAL INFANT HEARING ASSESSMENT?ASSESSMENT?

Must be applicable to neonates and Must be applicable to neonates and childrenchildren

Measure Hearing sensitivity from Measure Hearing sensitivity from 250-8 kHz250-8 kHz

Assess hearing sensitivity for mild to Assess hearing sensitivity for mild to severe- profound hearing losssevere- profound hearing loss

Objectively detect an infant´s Objectively detect an infant´s response to soundresponse to sound

ELECTROPHYSIOLOGIC TECHNIQUESELECTROPHYSIOLOGIC TECHNIQUES

Click and tone- burst evoked ABRClick and tone- burst evoked ABR Evoked potentials for tones that are Evoked potentials for tones that are

amplitude and/or frequency amplitude and/or frequency modulatedmodulated Auditory-steady state responses (ASSR)Auditory-steady state responses (ASSR)

AMLR and 40 Hz AMLR and 40 Hz Cortical AEPsCortical AEPs

LIMITATIONS OF CONVENTIONAL EVOKED LIMITATIONS OF CONVENTIONAL EVOKED POTENTIAL TESTSPOTENTIAL TESTS

Click ABR:Click ABR: Cannot be used to estimate the 4 frequency Cannot be used to estimate the 4 frequency

(500-4000 Hz) audiogram(500-4000 Hz) audiogram TB-ABR:TB-ABR:

Lenghtly procedure, relies on subjective Lenghtly procedure, relies on subjective analysis of waveformsanalysis of waveforms

AMLR, 40 Hz and CAEP:AMLR, 40 Hz and CAEP: Unreliable during natural or sedated sleep on Unreliable during natural or sedated sleep on

infants and childreninfants and children CAEP methods with quietly awake infants may CAEP methods with quietly awake infants may

hold promise for estimates of thresholds and hold promise for estimates of thresholds and speech feature discrimination abilitiesspeech feature discrimination abilities

AUDITORY STEADY STATE RESPONSE (ASSR)AUDITORY STEADY STATE RESPONSE (ASSR)

Can be recorded in neonates and Can be recorded in neonates and childrenchildren

Are evoked by frequency –specific Are evoked by frequency –specific tonal stimulitonal stimuli

Correlate with elevation in the Correlate with elevation in the hearing thresholdshearing thresholds

Can be objectively evaluatedCan be objectively evaluated Are used to estimate an audiogramAre used to estimate an audiogram

Jose J. Barajas. (1985). Auditory Brainstem and Middle Latency Jose J. Barajas. (1985). Auditory Brainstem and Middle Latency Response in Early Detection of Hearing Loss in Infants. New Response in Early Detection of Hearing Loss in Infants. New dimensions in otorhinolaryngology – head and neck surgery (1); pp dimensions in otorhinolaryngology – head and neck surgery (1); pp 289-292.289-292.

40 Hz40 Hz

Jose J. Barajas. (1988). Middle Latency and 40 Hz Auditory Evoked Jose J. Barajas. (1988). Middle Latency and 40 Hz Auditory Evoked Responses in normal hearing children: 500 Hz thresholds.Scand Audiol Responses in normal hearing children: 500 Hz thresholds.Scand Audiol Supp 30:99-104Supp 30:99-104

Picton TW, John MS, Dimitrijevic A, Purcell D. Human auditory Picton TW, John MS, Dimitrijevic A, Purcell D. Human auditory steady-state responses. Int J Audiol. 2003 Jun;42(4):177-219.steady-state responses. Int J Audiol. 2003 Jun;42(4):177-219.

MEASUREMENTS OF SIGNAL AND NOISE AT MEASUREMENTS OF SIGNAL AND NOISE AT DIFFERENT RATESDIFFERENT RATES

UPDATING THE ELECTROPHYSIOLOGY IN UPDATING THE ELECTROPHYSIOLOGY IN NEONATAL HEARING NEONATAL HEARING

ASSR in newbornsASSR in newborns AEP and early hearing aid fitting and AEP and early hearing aid fitting and

validation validation ASSRASSR CAEP (Obligatory Cortical Auditory Evoked CAEP (Obligatory Cortical Auditory Evoked

Potentials)Potentials)

AEP: Cochlear Implants validationAEP: Cochlear Implants validation

ASSR IN NEWBORNSASSR IN NEWBORNS

ASSR characteristics in newborns:ASSR characteristics in newborns: The neonatal ASSRThe neonatal ASSR Amplitude Development in InfantsAmplitude Development in Infants Detection of ASSR in the neonatal Detection of ASSR in the neonatal

infant periodinfant period ASSR threshold in babiesASSR threshold in babies

THE NEONATAL ASSRTHE NEONATAL ASSRAVERAGED AMPLITUDE FOR NORMAL- HEARING AVERAGED AMPLITUDE FOR NORMAL- HEARING

INFANTS AND ADULTSINFANTS AND ADULTS

Luts H, Desloovere C, Wouters J.2006. Clinical application of dichotic Luts H, Desloovere C, Wouters J.2006. Clinical application of dichotic multiple-stimulus auditory steady-state responses in high-risk newborns multiple-stimulus auditory steady-state responses in high-risk newborns and young children. Audiol Neurootol.;11(1):24-37. and young children. Audiol Neurootol.;11(1):24-37.

AMPLITUDE DEVELOPMENTAMPLITUDE DEVELOPMENT

Johns MS, Brown DK, Muir PJ, Picton TW (2004) . Recording Auditory Johns MS, Brown DK, Muir PJ, Picton TW (2004) . Recording Auditory Steady State responses in young infants. Ear Hear Dec, 25 (6) 539-53. Steady State responses in young infants. Ear Hear Dec, 25 (6) 539-53.

DETECTION OF ASSR IN THE NEWBORNDETECTION OF ASSR IN THE NEWBORN

Is determine by:Is determine by: Amplitude of the response:Amplitude of the response:

Stimulus typeStimulus type Modulation rateModulation rate Carrier frequencyCarrier frequency Electrode configurationElectrode configuration

Amplitude of the background noise:Amplitude of the background noise: State of arousalState of arousal EEG frequency rangeEEG frequency range Test durationTest duration

OPTIMAL MODULATION RATE FOR EACH OPTIMAL MODULATION RATE FOR EACH CARRIERCARRIER

Rickards FW, Tan LE, Cohen LT, Wilson OJ, Drew JH, Clark GM. (1994). Rickards FW, Tan LE, Cohen LT, Wilson OJ, Drew JH, Clark GM. (1994). Auditory steady-state evoked potential in newborns. Br J Auditory steady-state evoked potential in newborns. Br J Audiol.;28(6):327-37. Audiol.;28(6):327-37.

500 Hz

1500 Hz

4000 Hz

ASSR THRESHOLDS IN BABIESASSR THRESHOLDS IN BABIES

Threshold values Threshold values Threshold changes in infancyThreshold changes in infancy Development mechanism affecting Development mechanism affecting

ASSRASSR ASSR vs Tone burst ABR in neonatesASSR vs Tone burst ABR in neonates

ASSR THRESHOLD IN BABIESASSR THRESHOLD IN BABIES

Luts, H. “Diagnosis of Hearing Loss in Newborns. Clinical Application Luts, H. “Diagnosis of Hearing Loss in Newborns. Clinical Application of Auditory Steady- State responses”. Director: Prof. Dr. J. Wouters . of Auditory Steady- State responses”. Director: Prof. Dr. J. Wouters . Katholieke Universiteit Leuven, Faculty of Medicine, 2005Katholieke Universiteit Leuven, Faculty of Medicine, 2005

ASSR THRESHOLD CHANGES IN INFANCYASSR THRESHOLD CHANGES IN INFANCY

Rance, G. & Tomlin, D. (2006). Maturation of ASSR in nomal Rance, G. & Tomlin, D. (2006). Maturation of ASSR in nomal babies. Ear & Hearing, 27, 20-29.babies. Ear & Hearing, 27, 20-29.

Rance G, Tomlin D. (2006). Maturation of auditory steady-state Rance G, Tomlin D. (2006). Maturation of auditory steady-state responses in normal babies. Ear Hear.;27(1):20-9.responses in normal babies. Ear Hear.;27(1):20-9.

DEVELOPMENTAL MECHANISMS AFFECTING DEVELOPMENTAL MECHANISMS AFFECTING ASSR THRESHOLD IN INFANCYASSR THRESHOLD IN INFANCY

ASSR & TONE-BURST ABRs IN NEONATESASSR & TONE-BURST ABRs IN NEONATES

Rance G (2008). Assr in Neonates & Infants. In Auditory Steady-Rance G (2008). Assr in Neonates & Infants. In Auditory Steady-State ResponseState Response

Generation, Recording, and Clinical Applications. Gary Rance Generation, Recording, and Clinical Applications. Gary Rance

HEARING LEVEL PREDICTIONHEARING LEVEL PREDICTION

Sensation levelSensation level Regresion formula describing ASS Regresion formula describing ASS

behavioral regressionbehavioral regression

ASSRs IN HEARING IMPAIRED BABIESASSRs IN HEARING IMPAIRED BABIES

Rance G (2008). ASSR in Neonates & Infants. In The Auditory Rance G (2008). ASSR in Neonates & Infants. In The Auditory Steady-State Response: Generation, Recording, and Clinical Steady-State Response: Generation, Recording, and Clinical Applications. Edited by Gary Rance. In review. Applications. Edited by Gary Rance. In review.

For older children and adult subjects For older children and adult subjects ASSR/behavioral threshold ASSR/behavioral threshold correlation has been empirically correlation has been empirically establishedestablished

In normally developing babies this In normally developing babies this relationship is NOT well defined. relationship is NOT well defined.

ASSR threshold variance in babies is ASSR threshold variance in babies is higher than for adults (> 30 dB)higher than for adults (> 30 dB) Ear canal differences.Ear canal differences. Neural development.Neural development.

HEARING LEVEL PREDICTIONHEARING LEVEL PREDICTION

CONCLUSIONCONCLUSION

Maturation factors affect ASSR.Maturation factors affect ASSR. Normally hearing babies present Normally hearing babies present

lower amplitudes than adults and lower amplitudes than adults and older children.older children.

Neonatal period threshold higher and Neonatal period threshold higher and more variable.more variable.

Need to determine typical response Need to determine typical response levels for babies of different ages and levels for babies of different ages and developmental stages. developmental stages.

UPDATING THE ELECTROPHYSIOLOGY IN UPDATING THE ELECTROPHYSIOLOGY IN NEONATAL HEARING EVALUATIONNEONATAL HEARING EVALUATION

ASSR in newbornsASSR in newborns AEP and early hearing aid fitting and AEP and early hearing aid fitting and

validation validation ASSRASSR CAEP (Obligatory Cortical Auditory Evoked CAEP (Obligatory Cortical Auditory Evoked

Potentials)Potentials)

AEP: Cochlear Implants EvaluationAEP: Cochlear Implants Evaluation

LOUDNESS AND ASSRLOUDNESS AND ASSR

Zenker Castro F., Barajas de Prat JJ & Larumbe Zabala E. (2008): Zenker Castro F., Barajas de Prat JJ & Larumbe Zabala E. (2008): Loudness and Auditory Steady State responses in normal hearing Loudness and Auditory Steady State responses in normal hearing subjects. International Journal of Audiology. In press. subjects. International Journal of Audiology. In press.

HEARING AID PRESCRIPTION FROM ASSRHEARING AID PRESCRIPTION FROM ASSR

Zenker F. & Barajas J.J.(2008) ASSRs: Their role in hearing Zenker F. & Barajas J.J.(2008) ASSRs: Their role in hearing device fitting. In: The Auditory Steady State response: device fitting. In: The Auditory Steady State response: generation, recording and clinical application. Edited by Gary generation, recording and clinical application. Edited by Gary Rance. Rance.

UPDATING THE ELECTROPHYSIOLOGY IN UPDATING THE ELECTROPHYSIOLOGY IN NEONATAL HEARING NEONATAL HEARING

ASSR in newbornsASSR in newborns AEP and early hearing aid fitting and AEP and early hearing aid fitting and

validationvalidation ASSRASSR CAEP (Obligatory Cortical Auditory Evoked CAEP (Obligatory Cortical Auditory Evoked

Potentials)Potentials)

AEP: Cochlear Implants validationAEP: Cochlear Implants validation

TYPES OF AER THAT HAVE BEEN USED TO TYPES OF AER THAT HAVE BEEN USED TO OBJECTIVELY EVALUATE HEARING AIDS OBJECTIVELY EVALUATE HEARING AIDS

FUNCTIONFUNCTION

Auditory Brainstem Responses (ABR)Auditory Brainstem Responses (ABR) Auditory Steady state Responses Auditory Steady state Responses

(ASSR)(ASSR) Obligatory Cortical Auditory Evoked Obligatory Cortical Auditory Evoked

Potential (CAEP)Potential (CAEP)

Why are we using obligatory cortical Why are we using obligatory cortical responses to evaluate hearing aid responses to evaluate hearing aid

function?function?

More likely to correlate well with More likely to correlate well with perception.perception.

Can be elicited by a range of speech Can be elicited by a range of speech phonemes. phonemes.

Reliable present in awake young Reliable present in awake young infants. infants.

Can be present in children with Can be present in children with auditory neuropathy/dys-synchrony. auditory neuropathy/dys-synchrony.

Suzanne C. Purdy et al. (2004). Aided cortical auditory evoked Suzanne C. Purdy et al. (2004). Aided cortical auditory evoked potentials for hearing instrument evaluation. 3rd Pediatric potentials for hearing instrument evaluation. 3rd Pediatric Conference “A Sound Foundattion through early amplification”. Conference “A Sound Foundattion through early amplification”. Chicago, IllinoisChicago, Illinois

CAEPCAEP

MATURATIONAL EFFECTS ON CORTICAL EVOKED MATURATIONAL EFFECTS ON CORTICAL EVOKED RESPONSERESPONSE

Ponton et al. (2000) Maturation human central auditory system Ponton et al. (2000) Maturation human central auditory system activity: evidence from multi-channel evoked potentials. Clinical activity: evidence from multi-channel evoked potentials. Clinical Neurophysiology 111 (2): 220-236Neurophysiology 111 (2): 220-236

CAEP CAN ELICITED BY DIFFERENT CAEP CAN ELICITED BY DIFFERENT SPEECH PHONEMES IN NEWBORNSSPEECH PHONEMES IN NEWBORNS

D. KURTZBERG 19899

HEARING AID GAINS AND CAEP HEARING AID GAINS AND CAEP AMPLITUDEAMPLITUDE

Suzanne C. Purdy et al. (2004). Aided cortical auditory evoked Suzanne C. Purdy et al. (2004). Aided cortical auditory evoked potentials for hearing instrument evaluation. 3rd Pediatric potentials for hearing instrument evaluation. 3rd Pediatric Conference “A Sound Foundattion through early amplification”. Conference “A Sound Foundattion through early amplification”. Chicago, IllinoisChicago, Illinois

P1 IN HEARING AIDSP1 IN HEARING AIDS

Anu Sharma, Emily Tobey, Michael Dorman, Sneha Bharadwaj, Kathryn Martin, Phillip Gilley, Fereshteh Kunkel. Central Auditory Maturation and Babbling Development in Infants With Cochlear Implants. ARCH OTOLARYNGOL HEAD NECK SURG/VOL 130, MAY 2004.

P1 IN COCHLEAR IMPLANTSP1 IN COCHLEAR IMPLANTS

Anu Sharma, Michael F. Dorman, Andrej Kral. (2005). The Anu Sharma, Michael F. Dorman, Andrej Kral. (2005). The influuence of a sensitive period on central auditory development influuence of a sensitive period on central auditory development in children with unilateral and bilateral cochlear implants. in children with unilateral and bilateral cochlear implants. Hearing Research 203, 134–143.Hearing Research 203, 134–143.

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