ABR pitfalls, quality, etc. Karsten Plotz Professor for ENT, Phoniatrics and Pedaudiology Dpt. Technology and Human Health TGM Institute for Hearing Technology and Audiology IHA Jade-University of Applied Sciences Oldenburg Germany karsten.plotz@jade-hs.de - tgm.jade-hs.de
pitfalls electrodes movements of the eyes potentials from other parts of the body, neck, chewing, heart beat, brain, electric currency, AC-components, mobile phone failure in the setup All this makes low signal or high noise and degrades the signal to noise-ratio S/N
epidemiology The rate of hard hearing in newborn childs is round about 2 to 6 out of 1.000 healthy babies. This rate differes a bit between countries and depends on the health system and health care in each country round about a mean of 3-4 hard hearing children in 1.000 healthy newborn children. Phonak Pedaudiology Conference, Berlin, 17 th June 2016 3
hearing diagnostics There is a special program for hearing screening and hearing diagnostics. It is nesessary to maintain a step-by-step program to obtain an early hearing threshold within the first 6 month of life. Usually we start at day two with OAEmeasurements But for closer details see the important site: NHS Screening Programmes Newborn Hearing http://www.nhs.uk 4
TEOAE Transitorisch Evozierte OAE Lautsprecher Stapes Click/Chirp Basilarmembran Trommelfell Mikrofon Trennung von Stimulus und Antwort im Zeitbereich 5
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TEOAE Prävalenz If you want a 70% degree the threshold is between 0 to 25 db SNHL In screening procedures additional 5 to 10dB worser that means PASS is still possible with a Hearing loss (SNHL ) of 30 to 35 db 7
hearing diagnostics If the answer is FAIL, than additional sreening with OAE or ABR ist nessesary within the next 2 to 6 weeks. 8
hearing diagnostics Auditory brainstem response An other screening method looks to the neural response to acoustic stimuli. This ist an screening with auditory brainstem responses. The sreening shows again PASS or in the worse case FAIL, but not looking to the response of the OHC instead of analysing a signal received from skull electrodes like an EEG-measure. 9
Imdedence of the electrodes 1 kω 2 kω 5 kω > 5-10 kω Should be lower than 5 kω But more important: no or lowest differences between the used four electrodes (diff << 1 kω) otherwise high probability of strong ACcomponents
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i/o function, level to latency of Wave V
Morphology of recordings with different chirps 13
Morphology of recordings with different notch noise stimuli
i/o-function for NN-recordings
Morphology of low-chirp-recording
BERA-Film 17
Measurement puzzle The task ist: Look for middle ear problems OME and/or CHL Measuring the threshold at least in two or three fequency-regions or better at 500 Hz, 1, 2 and 4 khz Differentiation of CHL, SNHL or mixed types Latency detection of JI, JIII and JV Maturation or central processing IPL interpeak latencies, in I-III and III-V-differences 18
auditory system Short glimpse to the auditory system Phonak Pedaudiology Conference, Berlin, 17 th June 2016 19
1.1.1 The outer Ear- middle ear sound goes through the ear canal to the tympanic membran to the ossicular chain and to the Cochlea Quelle: http://www.dasp.uni-wuppertal.de/ars_auditus/physiologie/ Plotz WS08_09
1.1.1 travelling wave Inpedance air to water Pressure differences between scala vestibuli an scala tympani Travelling wave on the basal membrane goes from basis to apex Quelle: http://www.dasp.uni-wuppertal.de/ars_auditus/physiologie/ Plotz WS 2007/08
SNHL in a population based sample hearing loss in high frequencies affects development of speech and binaural hearing Cocktail-Party-Effect no impairment according to WHO (grey) Flat shape: 45% High frequency: 19% Ski-slope: 25% Middle Frequency: 0,3% Low Frequency: 0,3% HoerStat, von Gablenz & Holube (2016, in press) HNO I; Plotz; 22
hearing diagnostics detection of ABR-threshold. 23
Conductive hearing loss CHL OME and related CHL leads to FAIL during UNHS. The rate of OME in neonates is about 5% Baldwin&Watkin, Ear Hear 2013 ABR-threshold about 50dB, i/o-function of JV with 30 db-shift and >1 ms longer latencies 24
Definition of ABR threshold and ABR-offset Visually detected ABR-threshold The ABR-offset is the difference between the visually detected ABRthreshold and the true psychoacoustic threshold
hearing diagnostics the frequency-specific ABR measures. 26
Tonotopy of the basilar membrane 500 Hz Basis Apex High stimulus, like Click at 1-4 khz Basis Apex from Promenade `round the cochlea - www.iurc.montp.inserm.fr 27
Mustermessung Tieffrequente Chirp-BERA vs. NN-BERA-500 LChirp-Mask NN-500 Hz
Fallbeispiel: Low-Chirp-BERA vs. Notched- Noise-BERA 500 Tonaudiogramm Erwachsener mit Schrägabfall 29
Estimated hearing loss ehl ehl estimation in regard to: Differences between the stimulus level delivered to a baby compared to an adult. transducer stimulus corrections. These are different for different types of transducer (headphones, insert earphones and bone conductors). Differences between ABR thresholds and true hearing thresholds (defined as 50% detection of the psychoacoustic response) - i.e. ABR offsets. Taken from: Guidelines for the early audiological assessment and management of babies referred from the Newborn Hearing Screening Programme, Version 3.1, www.nhs.uk 30
What kind of hearing loss? 31
Potential sources of the peaks in ABR-recordings J J6 J5 4 J 3 J 2 J 1 Peaks of ABR, Jewitt I to VI: Welle VI: Colliculus inferior Welle V: Lemniscus lateralis (ascending part) Welle IV: upper Olivary complex and inferior part of Lemniscus lateralis Welle III: Nucleus cochlearis ventralis Welle II: auditory nerve Welle I: SGC Spiralganglion 32
Reference: IPL inter peak lantency
BERA child 4;11 years Nice recording Each peak ist visible Threshold at 30dB Ok or not?
BERA child 4;11 years JI o.k. III too late V too late I-III 2,5-2,6ms III-V too long I-V 4,8-5,1 ms
FF- Reaktionsschwelle
proposal We found the most reliable results in the following measures: 1. otoscopy and tymponometry 2. CLICK-ABR for general purposes, neurodiagnostics and threshold in the 1 2 khz-region 3. low-chirp for threshold in the 500 Hz-region 4. and 4kHz notch-noise ABR in the high frequencies 37
The end Many thanks for your attention! and thanks to my colleagues: Manuela Hagen, Petra von Gablenz, Inga Holube and Manfred Mauermann from Oldenburg Izet Baljic from Erfurt 38
Literature NHS Screening Programmes Newborn Hearing http://www.nhs.uk AG-ERA; Empfehlungen der AGERA zur pädaudiologischen Konfirmationsdiagnostik (follow-up) nach nicht bestandenem Neugeborenen- Hörscreening DGPP; Phoniatrisch-pa daudiologischer Konsensus zu einem universellen Neugeborenen-Ho rscreening in Deutschland, http://www.dgpp.de Baldwin, M., & Watkin, P. (2013). Predicting the type of hearing loss using click auditory brainstem response in babies referred from newborn hearing screening. Ear and Hearing, 35(1), 1 9. http://doi.org/10.1097/aud.0b013e31829e0718 Damm, M., Jayme, K. P., & Klimek, L. (2013). Recurrent otitis media with effusion in childhood, 61(10), 843 848. http://doi.org/10.1007/s00106-013-2700-9 Hoth, S., Mühler, R., Neumann, K., & Walger, M. (2015). Objektive Audiometrie im Kindesalter. Springer-Verlag.