Processing of voices in deafness rehabilitation by auditory brainstem implant.
The superior temporal sulcus (STS) is specifically involved in processing the human voice. Profound acquired deafness by post-meningitis ossified cochlea and by bilateral vestibular schwannoma in neurofibromatosis type 2 patients are two indications for auditory brainstem implantation (ABI). In order to objectively measure the cortical voice processing of a group of ABI patients, we studied the activation of the human temporal voice areas (TVA) by PET H(2)(15)O, performed in a group of implanted deaf adults (n=7) with more than two years of auditory brainstem implant experience, with an intelligibility score average of 17%+/-17 [mean+/-SD]. Relative cerebral blood flow (rCBF) was measured in the three following conditions: during silence, while passive listening to human voice, and to non-voice stimuli. Compared to silence, the activations induced by voice and non-voice stimuli were bilaterally located in the superior temporal regions. However, compared to non-voice stimuli, the voice stimuli did not induce specific supplementary activation of the TVA along the STS. The comparison of ABI group with a normal-hearing controls group (n=7) showed that TVA activations were significantly enhanced among controls group. ABI allowed the transmission of sound stimuli to temporal brain regions but lacked transmitting the specific cues of the human voice to the TVA. Moreover, among groups, during silent condition, brain visual regions showed higher rCBF in ABI group, although temporal brain regions had higher rCBF in the controls group. ABI patients had consequently developed enhanced visual strategies to keep interacting with their environment.
Coez
Arnaud
A
CEA-INSERM U797 Research Unit of Neuroimaging and Psychiatry, Service Hospitalier Frédéric Joliot, IFR49, Orsay, France. acoez@noos.fr
Zilbovicius
Monica
M
Ferrary
Evelyne
E
Bouccara
Didier
D
Mosnier
Isabelle
I
Ambert-Dahan
Emmanuèle
E
Kalamarides
Michel
M
Bizaguet
Eric
E
Syrota
André
A
Samson
Yves
Y
Sterkers
Olivier
O
D000328:Adult; D038263:Auditory Brain Stem Implantation / Q000295:instrumentation*; D001303:Auditory Cortex / Q000502:physiology*; D001307:Auditory Perception; D001931:Brain Mapping / Q000379:methods*; D003638:Deafness / Q000503:physiopathology* / Q000534:rehabilitation*; D005072:Evoked Potentials, Auditory; D005260:Female; D006801:Humans; D007802:Language; D008297:Male