UPDATING OF THE UPDATING OF THE ELECTROPHYSIOLOGICAL ELECTROPHYSIOLOGICAL

RESPONSE IN THE NEWBORNSRESPONSE IN THE NEWBORNS

José Juan Barajas de Prat

ICA 2010 Sao Paulo, Brazil

March 28 th – April 1 st

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

Must be applicable to neonates Must be applicable to neonates and childrenand children

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

Assess hearing sensitivity for mild Assess hearing sensitivity for mild to severe- profound hearing lossto severe- 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 Evoked potentials for tones that

are amplitude and/or frequency are amplitude and/or frequency modulatedmodulated Auditory-steady state responses Auditory-steady state responses

(ASSR)(ASSR) AMLR and 40 Hz AMLR and 40 Hz Cortical AEPsCortical AEPs

LIMITATIONS OF LIMITATIONS OF CONVENTIONAL EVOKED 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

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.

0 25 50 75 100ms

25 ms, 40 Hz

STIMULI AND GENERATION OF THE MLR 40 HZ

CLICK

PIP (0.25, 0.5, 1, 2, 4 kHz)

V

N0(N10)

Pa

MLR 40Hz

40 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 MEASUREMENTS OF SIGNAL AND NOISE AT DIFFERENT RATESAT DIFFERENT RATES

1

1

3

3

5

7

0 28 0 28 ms ms

ORIGIN SSR (Herdman et al, 2002)Cz

Cz

1

2

3

4

5

6

2

4 6

88 Hz 39 Hz

L R

AUDITORY STEADY STATE AUDITORY STEADY STATE RESPONSE (ASSR)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

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

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.

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.

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.

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.

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. Int J Audiol. 2008 May;47(5):269-7.subjects. Int J Audiol. 2008 May;47(5):269-7.

LOUDNESS MAP ASSR

Zenker F. & Barajas J.J. ASSRs: Their Role in Hearing Device Fitting. In: Gary Rance, editor. The Auditory Steady-State Response: Generation, Recording & Clinical Application. San Diego: Plural Publishing; 2008. p. 241-263.

PREDICTION OF LOUDNESS GROWTH FUNCTION FROM THE ASSR

Predicted Loudness (fo) = B0 + B1 * Intensity + B2 * Amplitude

Y = 0.75X0.4

Zenker Castro, Franz, Juan Barajas de Prat, Jose and Larumbe Zabala, Eneko (2008). Loudness and auditory steady-state responses in normal-hearing subjects. International Journal of Audiology, 47:5, 269 — 275.

Subject TP023 - Right ear

Loudness Perception MapLoudness Perception Mappredicted from ASSRpredicted from ASSR

soft speech

average speech

loud speech

Y = 0.75X0.4

500 1000 2000 4000

dB HL 45 50 60 65

ASSR RecordingASSR Recording

HEARING AID PRESCRIPTION HEARING AID PRESCRIPTION FROM ASSRFROM 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.

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

hearing aid function?hearing aid 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 infants. Reliable present in awake young infants. Can be present in children with auditory Can be present in children with auditory

neuropathy/dys-synchrony. 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

EFECTO OF AGE OVER THE LATE RESPONSES

F Zenker & J J Barajas (1999) Auditory P300 development from an active, passive and single-tone paradigms., 99-111. International Journal of Psychophysiology 33 (2).

Barajas JJ (1990) The effects of age on human P3 latency. Acta Otolaryngol Suppl;476:157-60.

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

D. KURTZBERG 19899

-100.0 0.0 100.0 200.0 300.0 400.0 500.0

Am

plitu

d (µ

V)

0.0

10.0

20.0

-10.0

CAP (P1)

Latencia (mseg)

-100.0 0.0 100.0 200.0 300.0 400.0 500.0

0.0

10.0

20.0

-10.0

Latencia (mseg)

Am

plitu

d (µ

V)

CAP (P1)

-100.0 0.0 100.0 200.0 300.0 400.0 500.0

0.0

10.0

20.0

-10.0

Latencia (mseg)

Am

plitu

d (µ

V)

P1

CAP (P1)

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.

BRASIL

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

Average

Stimuli

EEG

FFT

SSR Recordings

Modulation Frequency (Hz)

Thresholds

Right

Left

CONCLUSION

Maturation factors affect ASSR. Normally hearing babies present

lower amplitudes than adults and older children.

Neonatal period threshold higher and more variable.

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