Brain synergistic effects: cochlear implant and contralateral hearing aid A positron emission tomography activation study Arnaud Coez 1,2, Evelyne Ferrary 3,4,5, Didier Bouccara 3,4,5, Isabelle Mosnier 3,4,5, Eric Bizaguet 2, Jean-Luc Martinot 1, Olivier Sterkers 3,4,5 1 :INSERM U 1000, psychiatry and neuro-imaging unit, Orsay, France 2 :Laboratoire de Correction Auditive, Bizaguet, Paris, France 3 :INSERM UMR-S 1159, réhabilitation chirurgicale mini-invasive et robotisée de l audition, Paris, France 4 :AP-HP, Hôpital Pitié Salpétrière, Otologie et implants auditifs et chirurgie de la base du crâne, Paris France 5 :Institut Fédératif de Recherche Claude Bernard Physiologie et Pathologie, IFR02, Paris, 75018 France, NO DISCLOSURES
R R Regional cerebral blood flow (rcbf) increase in temporal voice brain area (TVA) is linked to the intelligibility score L Voice versus Non-voice comparison R L Controls R CI (i>80%) L CI (i<20%) (Coez et al., J Nucl Med. 2008; 49:60-7)
A selective human Temporal Voice Area (TVA) Passive listening to sounds No active participation No specific language knowledges First step of intelligibility (Samson Y et al., Rev Neurol,2001;157:837-46, Zatorre RJ et al., trendscognsci, 2002; 6:37-46) L NON VOICE VOICE L R fmri Belin P et al, Nature, 2000; 403:309-12 in bilateral regions of the superior temporal sulcus (STS).
Monaural or binaural CI stimulation: a same pattern of activation? (Voice + Non-Voice) versus silence B R L Bilateral Stimulation R B L Controls versus bilateral CI R Unilateral Stimulation P<0.001 Controls versus unilateral CI Coez et al, 2011, 2014
Evaluation of cochlear implant + contralateral hearing aid - Patients group (n=12) Bilateral Stimulation 12Patients * 4 acquisitions Right CI Stimulation 8 patients * 4 acquisitions Left CI Stimulation 4 Patients * 4 acquisitions PET (H 2 O 15 ), measure of rcbf increase 3 passive conditions : Voice, Non-Voice, Silence 4 acquisitions per condition (voice, non voice): 2 with bilateral stimulation, 2 with unilateral stimulation 2 acquisitions in silence Statistical Parametric Mapping (SPM8), p<0,001 Intelligibility score (IS) 91%[±9] 75% [±16] 71% [±17] - Controls group (n=6+6) 100%
Temporal voice area activation (voice versus non voice) rcbf increase in TVA is linked to the intelligibility score Binaural hearing (HA +IC) L R Monaural hearing (IC) Figure 6: Areas activated by voice stimuli compared to non voice stimuli in each listening condition: binaural, monaural (p<0,0005, k>31).
Binaural, right and left EAR stimulation in the Normal hearing group Subgroup L Subgroup R Binaural hearing
Binaural, right and left EAR stimulation in the Normal hearing group Subgroup L Subgroup R Binaural hearing Left monaural hearing
Binaural, right and left EAR stimulation in the Normal hearing group Subgroup L Subgroup R Binaural hearing Left monaural hearing Binaural to left
Binaural, right and left EAR stimulation in the Normal hearing group Subgroup L Subgroup R Binaural hearing Left monaural hearing Right monaural hearing Binaural to left
Binaural, right and left EAR stimulation in the Normal hearing group Subgroup L Subgroup R Binaural hearing Left monaural hearing Right monaural hearing Binaural to left Binaural to right
Binaural, right and left EAR stimulation in the CI group Subgroup L Subgroup R Binaural hearing Subgroup L CI (n=4) Subgroup R CI (n=8) Left monaural Right monaural Binaural to left Binaural to right
Binaural, right and left EAR stimulation in the CI group Subgroup L Subgroup R Binaural hearing Subgroup L CI (n=4) Subgroup R CI (n=8) Left monaural Right monaural Binaural to left Binaural to right
Binaural, right and left EAR stimulation in the CI group Subgroup L Subgroup R Binaural hearing Subgroup L CI Subgroup R CI (n=8) (n=4) Left monaural Right monaural Left monaural CI hearing Right monaural CI hearing Binaural to left Binaural to right
Binaural, right and left EAR stimulation in the CI group Subgroup L Subgroup R Binaural hearing Subgroup L CI Subgroup R CI (n=8) (n=4) Left monaural Right monaural Left monaural CI hearing Right monaural CI hearing Binaural to left Binaural to right
Binaural, right and left EAR stimulation in the CI group Subgroup L Subgroup R Binaural hearing Subgroup L CI Subgroup R CI (n=8) (n=4) Left monaural Right monaural Left monaural CI hearing Right monaural CI hearing Binaural to left Binaural to right Binaural to left Binaural to right
Conclusion The rcbf response in the TVA paralleled the subject intelligibility score Bilateral stimulation in deafness rehabilitation allowed bilateral rcbf increases similar to controls Unilateral stimulation lead to temporal rcbf increases especially in contralateral temporal regions Synergistic effects of sound information from both sides Auditory thresholds : + 6 db Sound localisation: Inter-aural level difference (ILD) PET TVA activations studies are a good forecasting tools to compare devices effectiveness (evidence based medicine) and to evaluate benefits of future devices developments.