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OPA1-related auditory neuropathy: site of lesion and outcome of cochlear implantation.

Santarelli R, Rossi R, Scimemi P, Cama E, Valentino ML, La Morgia C, Caporali L, Liguori R, Magnavita V, Monteleone A, Biscaro A, Arslan E, Carelli V - Brain (2015)

Bottom Line: In this study we characterized the hearing dysfunction in OPA1-linked disorders and provided effective rehabilitative options to improve speech perception.The use of cochlear implant improved speech perception in all but one patient.Cochlear implantation improves speech perception and synchronous activation of auditory pathways by bypassing the site of lesion.

View Article: PubMed Central - PubMed

Affiliation: 1 Department of Neurosciences, University of Padova, Via Giustiniani 2, 35128 Padova, Italy 2 Audiology and Phoniatrics Service, Treviso Regional Hospital, Piazza Ospedale 1, 31100 Treviso, Italy rosamaria.santarelli@unipd.it.

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Adaptation of ECochG potentials in OPA1-M patients. ECochG recordings obtained at 100 dB SPL from one control with normal hearing and two OPA1-M patients in response to the stimulus sequence reported at the bottom are illustrated in the left panel. In the right panel the means and standard errors of normalized summating potential–compound action potential (SP-CAP) amplitudes are reported as a function of click position in the stimulus sequence for normally-hearing controls and OPA1-M patients superimposed on mean summating potential amplitudes calculated for controls. In OPA1-M patients the size of attenuation of cochlear potentials during adaptation was within the range of compound action potential attenuation calculated for controls. The vertical dashed lines indicate the summating potential and compound action potential peak in the control and the peak of the prolonged response in OPA1-M patients. Time ‘0’ refers to cochlear microphonic onset. In each recording the horizontal dashed line refers to baseline.
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awu378-F5: Adaptation of ECochG potentials in OPA1-M patients. ECochG recordings obtained at 100 dB SPL from one control with normal hearing and two OPA1-M patients in response to the stimulus sequence reported at the bottom are illustrated in the left panel. In the right panel the means and standard errors of normalized summating potential–compound action potential (SP-CAP) amplitudes are reported as a function of click position in the stimulus sequence for normally-hearing controls and OPA1-M patients superimposed on mean summating potential amplitudes calculated for controls. In OPA1-M patients the size of attenuation of cochlear potentials during adaptation was within the range of compound action potential attenuation calculated for controls. The vertical dashed lines indicate the summating potential and compound action potential peak in the control and the peak of the prolonged response in OPA1-M patients. Time ‘0’ refers to cochlear microphonic onset. In each recording the horizontal dashed line refers to baseline.

Mentions: To clarify whether the prolonged potentials originate from neural or from receptor activation, we used an adaptation procedure that preferentially attenuates neural responses with minor changes in summating potential amplitude (Eggermont and Odenthal, 1974; Santarelli et al., 2008). Figure 5 shows the recordings obtained at 100 dB SPL from one control subject with normal hearing and two representative OPA1-M patients in response to the click stimulation sequence reported at the bottom of the graph. Mean values of normalized amplitudes are reported in the right panel as a function of click position in the stimulus sequence for both controls with normal hearing and OPA1-M patients, superimposed on mean normalized summating potential amplitudes calculated for controls. In the normal controls, compound action potential amplitude was markedly attenuated after adaptation (61%), whereas summating potential attenuation was much lower (17%). Moreover, response duration as measured from summating potential onset to return to baseline was almost unchanged after adaptation. In OPA1-M patients, the prolonged response was markedly attenuated after adaptation, and the amount of peak amplitude attenuation was comparable with that of the normal compound action potential (52%). Moreover, a high stimulation rate reduced the duration of the response evoked by the last click in the stimulus sequence (range 2.1–3.5 ms) to the values seen in controls (range 1.9–3.4 ms) (Santarelli et al., 2008). These findings point to a neural rather than a receptor origin for the generation of the prolonged negative potentials recorded from OPA1-M patients.Figure 5


OPA1-related auditory neuropathy: site of lesion and outcome of cochlear implantation.

Santarelli R, Rossi R, Scimemi P, Cama E, Valentino ML, La Morgia C, Caporali L, Liguori R, Magnavita V, Monteleone A, Biscaro A, Arslan E, Carelli V - Brain (2015)

Adaptation of ECochG potentials in OPA1-M patients. ECochG recordings obtained at 100 dB SPL from one control with normal hearing and two OPA1-M patients in response to the stimulus sequence reported at the bottom are illustrated in the left panel. In the right panel the means and standard errors of normalized summating potential–compound action potential (SP-CAP) amplitudes are reported as a function of click position in the stimulus sequence for normally-hearing controls and OPA1-M patients superimposed on mean summating potential amplitudes calculated for controls. In OPA1-M patients the size of attenuation of cochlear potentials during adaptation was within the range of compound action potential attenuation calculated for controls. The vertical dashed lines indicate the summating potential and compound action potential peak in the control and the peak of the prolonged response in OPA1-M patients. Time ‘0’ refers to cochlear microphonic onset. In each recording the horizontal dashed line refers to baseline.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4339771&req=5

awu378-F5: Adaptation of ECochG potentials in OPA1-M patients. ECochG recordings obtained at 100 dB SPL from one control with normal hearing and two OPA1-M patients in response to the stimulus sequence reported at the bottom are illustrated in the left panel. In the right panel the means and standard errors of normalized summating potential–compound action potential (SP-CAP) amplitudes are reported as a function of click position in the stimulus sequence for normally-hearing controls and OPA1-M patients superimposed on mean summating potential amplitudes calculated for controls. In OPA1-M patients the size of attenuation of cochlear potentials during adaptation was within the range of compound action potential attenuation calculated for controls. The vertical dashed lines indicate the summating potential and compound action potential peak in the control and the peak of the prolonged response in OPA1-M patients. Time ‘0’ refers to cochlear microphonic onset. In each recording the horizontal dashed line refers to baseline.
Mentions: To clarify whether the prolonged potentials originate from neural or from receptor activation, we used an adaptation procedure that preferentially attenuates neural responses with minor changes in summating potential amplitude (Eggermont and Odenthal, 1974; Santarelli et al., 2008). Figure 5 shows the recordings obtained at 100 dB SPL from one control subject with normal hearing and two representative OPA1-M patients in response to the click stimulation sequence reported at the bottom of the graph. Mean values of normalized amplitudes are reported in the right panel as a function of click position in the stimulus sequence for both controls with normal hearing and OPA1-M patients, superimposed on mean normalized summating potential amplitudes calculated for controls. In the normal controls, compound action potential amplitude was markedly attenuated after adaptation (61%), whereas summating potential attenuation was much lower (17%). Moreover, response duration as measured from summating potential onset to return to baseline was almost unchanged after adaptation. In OPA1-M patients, the prolonged response was markedly attenuated after adaptation, and the amount of peak amplitude attenuation was comparable with that of the normal compound action potential (52%). Moreover, a high stimulation rate reduced the duration of the response evoked by the last click in the stimulus sequence (range 2.1–3.5 ms) to the values seen in controls (range 1.9–3.4 ms) (Santarelli et al., 2008). These findings point to a neural rather than a receptor origin for the generation of the prolonged negative potentials recorded from OPA1-M patients.Figure 5

Bottom Line: In this study we characterized the hearing dysfunction in OPA1-linked disorders and provided effective rehabilitative options to improve speech perception.The use of cochlear implant improved speech perception in all but one patient.Cochlear implantation improves speech perception and synchronous activation of auditory pathways by bypassing the site of lesion.

View Article: PubMed Central - PubMed

Affiliation: 1 Department of Neurosciences, University of Padova, Via Giustiniani 2, 35128 Padova, Italy 2 Audiology and Phoniatrics Service, Treviso Regional Hospital, Piazza Ospedale 1, 31100 Treviso, Italy rosamaria.santarelli@unipd.it.

Show MeSH
Related in: MedlinePlus