Positron Emission Tomography in Deaf Patients at Rest

Deggouj, N; Devolder, A; Catalán, Miguel; Michel, Christian; Gersdorff, Michel; Veraart, Claude

doi:10.1159/000424431

Cited by 8 publications

(4 citation statements)

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“…Brain imaging studies have revealed abnormal metabolic levels [120], [121] and activations of the auditory cortex of deaf patients by visual or tactile stimuli [122], [123] that could originate from a direct functional impact of the non-auditory projections presently described. However, given the paucity of such abnormal projections, additional mechanisms should be considered to fully account for the crossmodal reorganization of the deafened auditory cortex.…”

Section: Discussionmentioning

confidence: 99%

Reorganization of the Connectivity of Cortical Field DZ in Congenitally Deaf Cat

2013

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Psychophysics and brain imaging studies in deaf patients have revealed a functional crossmodal reorganization that affects the remaining sensory modalities. Similarly, the congenital deaf cat (CDC) shows supra-normal visual skills that are supported by specific auditory fields (DZ-dorsal zone and P-posterior auditory cortex) but not the primary auditory cortex (A1). To assess the functional reorganization observed in deafness we analyzed the connectivity pattern of the auditory cortex by means of injections of anatomical tracers in DZ and A1 in both congenital deaf and normally hearing cats. A quantitative analysis of the distribution of the projecting neurons revealed the presence of non-auditory inputs to both A1 and DZ of the CDC which were not observed in the hearing cats. Firstly, some visual (areas 19/20) and somatosensory (SIV) areas were projecting toward DZ of the CDC but not in the control. Secondly, A1 of the deaf cat received a weak projection from the visual lateral posterior nuclei (LP). Most of these abnormal projections to A1 and DZ represent only a small fraction of the normal inputs to these areas. In addition, most of the afferents to DZ and A1 appeared normal in terms of areal specificity and strength of projection, with preserved but smeared nucleotopic gradient of A1 in CDCs. In conclusion, while the abnormal projections revealed in the CDC can participate in the crossmodal compensatory mechanisms, the observation of a limited reorganization of the connectivity pattern of the CDC implies that functional reorganization in congenital deafness is further supported also by normal cortico-cortical connectivity.

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Section: Discussionmentioning

confidence: 99%

Reorganization of the Connectivity of Cortical Field DZ in Congenitally Deaf Cat

2013

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“…Recent evidence from functional magnetic resonance imaging (fMRI) showed that brain intrinsic activity can predict both task-induced activity and behavioral performance (Mennes et al 2010(Mennes et al , 2011Koyama et al 2011). Some previous studies using positron emission tomography have explored glucose metabolism at rest in cochlear-implanted deaf individuals (Catalan- Ahumada et al 1993;Deggouj et al 1995;Hirano et al 2000;Lee et al 2001Lee et al , 2003Strelnikov et al 2010). These results suggest that the function of auditory cortex in deaf people dynamically changes after cochlear implanting.…”

Section: Introductionmentioning

confidence: 98%

Altered Intra- and Inter-Regional Synchronization of Superior Temporal Cortex in Deaf People

Booth

Peng

et al. 2012

Cerebral Cortex

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Functional organization of the brain can be fundamentally altered by auditory deprivation. Previous studies found that the superior temporal cortex in deaf people is reorganized to process non-auditory stimuli, as revealed by the extrinsic task-induced brain activities. However, it is unknown how the intrinsic activities of this region are impacted by deafness. This study explored this issue using resting-state functional magnetic resonance imaging. We examined 60 congenitally deaf (CD) individuals, 39 acquired deaf (AD) individuals, and 38 hearing controls (HC), and focused on the effect of deafness on the intra- and inter-regional synchronization of different parts of superior temporal sulcus (STS). We found that intra-regional synchronization or regional homogeneity (ReHo) of the middle STS (mSTS) was decreased in AD compared with HC or CD, while the CD had preserved ReHo in mSTS. Greater connectivity was observed between mSTS and posterior STS in CD and HC than in AD, while both CD and AD had weaker connectivity of mSTS with the anterior STS (aSTS) compared with HC. Moreover, the connectivity of mSTS-aSTS in CD and AD was associated with their language skills. These findings confirmed our hypothesis that the intrinsic function of different parts of STS is distinctly impacted by deafness.

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“…Previous studies have suggested that auditory areas presented high accumulation of FDG with deafness of early onset, and plastic changes in auditory cortices were strongly affected by the duration of auditory deprivation [1,5,6,19,20]. Since low activation of the auditory cortices with visual stimuli suggests the subject's lesser dependence on visual communication methods and substantial residual plasticity in his auditory cortices, case 2 with an SLC26A4 mutation may be determined to be an appropriate candidate for cochlear implantation.…”

Section: Discussionmentioning

confidence: 99%

Different cortical metabolic activation by visual stimuli possibly due to different time courses of hearing loss in patients withGJB2andSLC26A4mutations

Moteki

Naito

Fujiwara

et al. 2011

Acta Oto-Laryngologica

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Conclusion.We have demonstrated differences in cortical activation with language-related visual stimuli in patients who were profoundly deafened due to genetic mutations in GJB2 and SLC26A4. The differences in cortical processing patterns between these two cases may have been influenced by the differing clinical courses and pathogenesis of hearing loss due to genetic mutations. Our results suggest the importance of hearing during early childhood for the development of a normal cortical language network.Objectives.To investigate the cortical activation with language-related visual stimuli in patients who were profoundly deafened due to genetic mutations in GJB2 and SLC26A4.Methods:The cortical activity of two adult patients with known genetic mutations (GJB2, SLC26A4) was evaluated with fluorodeoxyglucose-positron emission tomography (FDG-PET) with a visual language task and compared with that of normal-hearing controls.Results:A patient with a GJB2 mutation showed activation in the right auditory association area [BA21, BA22], and the left auditory association area [BA42] even with visual language task; in contrast, a patient with an SLC26A4 mutation showed no significant activation in the corresponding area.

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Positron Emission Tomography in Deaf Patients at Rest

Cited by 8 publications

References 0 publications

Reorganization of the Connectivity of Cortical Field DZ in Congenitally Deaf Cat

Reorganization of the Connectivity of Cortical Field DZ in Congenitally Deaf Cat

Altered Intra- and Inter-Regional Synchronization of Superior Temporal Cortex in Deaf People

Different cortical metabolic activation by visual stimuli possibly due to different time courses of hearing loss in patients withGJB2andSLC26A4mutations

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