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UPDATING OF THE ELECTROPHYSIOLOGICAL RESPONSE IN THE NEWBORNS José Juan Barajas de Prat ICA 2010 Sao Paulo, Brazil March 28 th – April 1 st.

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Presentation on theme: "UPDATING OF THE ELECTROPHYSIOLOGICAL RESPONSE IN THE NEWBORNS José Juan Barajas de Prat ICA 2010 Sao Paulo, Brazil March 28 th – April 1 st."— Presentation transcript:

1 UPDATING OF THE ELECTROPHYSIOLOGICAL RESPONSE IN THE NEWBORNS José Juan Barajas de Prat ICA 2010 Sao Paulo, Brazil March 28 th – April 1 st

2 WHAT SHOULD THE IDEAL INFANT HEARING ASSESSMENT? Must be applicable to neonates and children Must be applicable to neonates and children Measure Hearing sensitivity from kHz Measure Hearing sensitivity from kHz Assess hearing sensitivity for mild to severe- profound hearing loss Assess hearing sensitivity for mild to severe- profound hearing loss Objectively detect an infant´s response to sound Objectively detect an infant´s response to sound

3 ELECTROPHYSIOLOGIC TECHNIQUES Click and tone- burst evoked ABR Click and tone- burst evoked ABR Evoked potentials for tones that are amplitude and/or frequency modulated Evoked potentials for tones that are amplitude and/or frequency modulated Auditory-steady state responses (ASSR) Auditory-steady state responses (ASSR) AMLR and 40 Hz AMLR and 40 Hz Cortical AEPs Cortical AEPs

4 LIMITATIONS OF CONVENTIONAL EVOKED POTENTIAL TESTS Click ABR: Click ABR: Cannot be used to estimate the 4 frequency ( Hz) audiogram Cannot be used to estimate the 4 frequency ( Hz) audiogram TB-ABR: TB-ABR: Lenghtly procedure, relies on subjective analysis of waveforms Lenghtly procedure, relies on subjective analysis of waveforms AMLR, 40 Hz and CAEP: AMLR, 40 Hz and CAEP: Unreliable during natural or sedated sleep on infants and children Unreliable during natural or sedated sleep on infants and children CAEP methods with quietly awake infants may hold promise for estimates of thresholds and speech feature discrimination abilities CAEP methods with quietly awake infants may hold promise for estimates of thresholds and speech feature discrimination abilities

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

6 ms 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

7 40 Hz Jose J. Barajas. (1988). Middle Latency and 40 Hz Auditory Evoked Responses in normal hearing children: 500 Hz thresholds.Scand Audiol Supp 30:99-104

8 Picton TW, John MS, Dimitrijevic A, Purcell D. Human auditory steady-state responses. Int J Audiol Jun;42(4): MEASUREMENTS OF SIGNAL AND NOISE AT DIFFERENT RATES

9 ms ms ORIGIN SSR (Herdman et al, 2002) Cz Hz39 Hz L R

10 AUDITORY STEADY STATE RESPONSE (ASSR) Can be recorded in neonates and children Can be recorded in neonates and children Are evoked by frequency –specific tonal stimuli Are evoked by frequency –specific tonal stimuli Correlate with elevation in the hearing thresholds Correlate with elevation in the hearing thresholds Can be objectively evaluated Can be objectively evaluated Are used to estimate an audiogram Are used to estimate an audiogram

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14 OPTIMAL MODULATION RATE FOR EACH CARRIER Rickards FW, Tan LE, Cohen LT, Wilson OJ, Drew JH, Clark GM. (1994). Auditory steady-state evoked potential in newborns. Br J Audiol.;28(6): Hz 1500 Hz 4000 Hz

15 THE NEONATAL ASSR AVERAGED AMPLITUDE FOR NORMAL- HEARING INFANTS AND ADULTS Luts H, Desloovere C, Wouters J Clinical application of dichotic multiple-stimulus auditory steady-state responses in high-risk newborns and young children. Audiol Neurootol.;11(1):24-37.

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

17 ASSR THRESHOLD CHANGES IN INFANCY Rance, G. & Tomlin, D. (2006). Maturation of ASSR in nomal babies. Ear & Hearing, 27,

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

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23 CONCLUSION Maturation factors affect ASSR. Maturation factors affect ASSR. Normally hearing babies present lower amplitudes than adults and older children. Normally hearing babies present lower amplitudes than adults and older children. Neonatal period threshold higher and more variable. Neonatal period threshold higher and more variable. Need to determine typical response levels for babies of different ages and developmental stages. Need to determine typical response levels for babies of different ages and developmental stages.

24 AEP and early hearing aid fitting and validation AEP and early hearing aid fitting and validation ASSR ASSR CAEP (Obligatory Cortical Auditory Evoked Potentials) CAEP (Obligatory Cortical Auditory Evoked Potentials) AEP: Cochlear Implants Evaluation AEP: Cochlear Implants Evaluation

25 LOUDNESS AND ASSR Zenker Castro F., Barajas de Prat JJ & Larumbe Zabala E. (2008): Loudness and Auditory Steady State responses in normal hearing subjects. Int J Audiol May;47(5):269-7.

26 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; p

27 PREDICTION OF LOUDNESS GROWTH FUNCTION FROM THE ASSR Predicted Loudness (fo) = B 0 + B 1 * Intensity + B 2 * Amplitude Y = 0.75X 0.4 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.

28 Subject TP023 - Right ear Loudness Perception Map predicted from ASSR soft speech average speech loud speech Y = 0.75X dB HL ASSR Recording

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

30 Why are we using obligatory cortical responses to evaluate hearing aid function? More likely to correlate well with perception. More likely to correlate well with perception. Can be elicited by a range of speech phonemes. Can be elicited by a range of speech phonemes. Reliable present in awake young infants. Reliable present in awake young infants. Can be present in children with auditory neuropathy/dys-synchrony. Can be present in children with auditory neuropathy/dys-synchrony.

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

32 MATURATIONAL EFFECTS ON CORTICAL EVOKED RESPONSE Ponton et al. (2000) Maturation human central auditory system activity: evidence from multi-channel evoked potentials. Clinical Neurophysiology 111 (2):

33 EFECTO OF AGE OVER THE LATE RESPONSES F Zenker & J J Barajas (1999) Auditory P300 development from an active, passive and single-tone paradigms., International Journal of Psychophysiology 33 (2). Barajas JJ (1990) The effects of age on human P3 latency. Acta Otolaryngol Suppl;476:

34 CAEP CAN ELICITED BY DIFFERENT SPEECH PHONEMES IN NEWBORNS 9 D. KURTZBERG 1989

35 Amplitud (µV) CAP (P1) Latencia (mseg)

36 Latencia (mseg) Amplitud (µV) CAP (P1)

37 Latencia (mseg) Amplitud (µV) P1 CAP (P1)

38 P1 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.

39 P1 IN COCHLEAR IMPLANTS Anu Sharma, Michael F. Dorman, Andrej Kral. (2005). The influuence of a sensitive period on central auditory development in children with unilateral and bilateral cochlear implants. Hearing Research 203, 134–143.

40 BRASIL

41 ASSR & TONE-BURST ABRs IN NEONATES Rance G (2008). Assr in Neonates & Infants. In Auditory Steady-State Response Generation, Recording, and Clinical Applications. Gary Rance

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44 Average Stimuli EEG FFT

45 SSR Recordings Modulation Frequency (Hz) Thresholds Right Left

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47 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.


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