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. 2019:24:102006.
doi: 10.1016/j.nicl.2019.102006. Epub 2019 Sep 16.

Altered white matter structure in auditory tracts following early monocular enucleation

Nikita A Wong  1 , Sara A Rafique  1 , Stefania S Moro  2 , Krista R Kelly  3 , Jennifer K E Steeves  4
Affiliations

Altered white matter structure in auditory tracts following early monocular enucleation

Nikita A Wong et al. Neuroimage Clin. 2019.

Abstract

Purpose: Similar to early blindness, monocular enucleation (the removal of one eye) early in life results in crossmodal behavioral and morphological adaptations. Previously it has been shown that partial visual deprivation from early monocular enucleation results in structural white matter changes throughout the visual system (Wong et al., 2018). The current study investigated structural white matter of the auditory system in adults who have undergone early monocular enucleation compared to binocular control participants.

Methods: We reconstructed four auditory and audiovisual tracts of interest using probabilistic tractography and compared microstructural properties of these tracts to binocularly intact controls using standard diffusion indices.

Results: Although both groups demonstrated asymmetries in indices in intrahemispheric tracts, monocular enucleation participants showed asymmetries opposite to control participants in the auditory and A1-V1 tracts. Monocular enucleation participants also demonstrated significantly lower fractional anisotropy in the audiovisual projections contralateral to the enucleated eye relative to control participants.

Conclusions: Partial vision loss from early monocular enucleation results in altered structural connectivity that extends into the auditory system, beyond tracts primarily dedicated to vision.

Keywords: Development; Diffusion tensor imaging; Magnetic resonance imaging; Monocular enucleation; Morphology; Multisensory; Vision.

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Conflict of interest statement

The authors have no conflicts of interest to declare.

Figures

Fig. 1
Fig. 1
Mean values of the diffusion parameters (AD [× 10−3 mm2/s], FA, MD [× 10−3 mm2/s], and RD [× 10−3 mm2/s]) in the ipsilateral (to the enucleated or non-dominant eye) and contralateral tracts of interest for controls (BC) and monocular enucleation participants (ME). Error bars represent ± SEM. Examples of the probabilistic tractography reconstructions of the auditory radiations (MGB-A1 projections), A1-MGB projections, A1-V1 projections, and V1-A1 projections are shown under the associated graphs for a single control participant and monocular enucleation participant. AD = axial diffusivity; FA = fractional anisotropy; MD = mean diffusivity; RD = radial diffusivity. ⁎p < .05; ⁎⁎p < .01; ⁎⁎⁎p < .001.
See this image and copyright information in PMC

References

    1. Andersson J.L., Jenkinson M., Smith S. University of Oxford FMRIB Centre; Oxford, UK: 2007. Non-linear Optimisation. FMRIB Technical Report TR07JA1.
    1. Andersson J.L., Jenkinson M., Smith S. University of Oxford FMRIB Centre; Oxford, UK: 2007. Non-linear Registration, Aka Spatial Normalisation. FMRIB Technical Report TR07JA2.
    1. Beer A.L., Plank T., Greenlee M.W. Diffusion tensor imaging shows white matter tracts between human auditory and visual cortex. Exp. Brain Res. 2011:299–308. - PubMed
    1. Beer A.L., Plank T., Meyer G., Greenlee M.W. Combined diffusion-weighted and functional magnetic resonance imaging reveals a temporal-occipital network involved in auditory-visual object processing. Front. Integr. Neurosci. 2013:1–20. - PMC - PubMed
    1. Behrens T.E.J., Woolrich M.W., Jenkinson M., Johansen-Berg H., Nunes R.G., Clare S., Matthews P.M., Brady J.M., Smith S.M. Characterization and propagation of uncertainty in diffusion-weighted MRimaging. Magn. Reson. Med. 2003;50:1077–1088. - PubMed