The University of Southampton
University of Southampton Institutional Repository

Identification and interpretation of microstructural abnormalities in motor pathways in adolescents born preterm

Identification and interpretation of microstructural abnormalities in motor pathways in adolescents born preterm
Identification and interpretation of microstructural abnormalities in motor pathways in adolescents born preterm
There has been extensive interest in assessing the long-term effects of preterm birth on brain white matter microstructure using diffusion MRI. Our aim in this study is to explore diffusion MRI differences between adolescents born preterm and term born controls, with a specific interest in characterising how such differences are manifested in white matter regions containing predominantly single or crossing fibre populations. Probabilistic high angular resolution tractography together with large deformation spatial normalisation were used to objectively investigate diffusion tensor parameters at regular intervals along fibre tracts of 45 adolescents born before 33weeks of gestation and 30 term-born typically developing adolescents. Diffusion parameters were significantly different between preterms and controls at several levels along the cortico-spinal, thalamo-cortical and transcallosal pathways. Within the predominantly single fibre regions of the corpus callosum and internal capsule, in the preterms mean diffusivity (MD) was found to be increased while fractional anisotropy (FA) was decreased compared to controls. In contrast, however, where these pathways traversed the centrum semiovale, FA and MD were both significantly increased. The major contributor to reduced FA in preterms in predominantly single fibre regions was the increased radial eigenvalue (i.e. increased radial diffusivity). In predominantly crossing-fibre regions, the tensor eigenvalues are not meaningful, and the observed increase in FA is likely to be due to a decrease in anisotropy in one of the contributing fibre bundles. Similar differences (although less pronounced) were observed after excluding preterms with radiological signs of preterm brain injury from the sample. In summary, white matter microstructure was found to be altered in motor pathways in adolescents born preterm. Disruption of white matter (WM) microstructure in a single fibre region with resulting higher radial diffusivity leads to lower FA, whereas selective disruption of one fibre population in a crossing fibre region is observed to lead to higher FA. These findings challenge the common simplistic interpretation of FA as a measure of WM tract integrity.
preterm, DTI, HARDI, motor system, crossing fibres, fractional anisotropy
209-219
Groeschel, Samuel
2eecc1ae-2cca-4e75-81ef-d906e0e82f93
Tournier, J-Donald
88d38d6d-fbd5-4e9a-b9ff-9c9a7ff13fa0
Northam, Gemma B.
dcdb5be0-d963-4c21-81db-6055317a64aa
Baldeweg, Torsten
e6ba710f-1634-48fe-84b9-84141cc2ad54
Wyatt, John
0413fffa-0db2-4608-91ab-80528b8c5a4d
Vollmer, Brigitte
044f8b55-ba36-4fb2-8e7e-756ab77653ba
Connelly, Alan
b2e15ed0-c70b-4de6-ab5a-4ff6861859de
Groeschel, Samuel
2eecc1ae-2cca-4e75-81ef-d906e0e82f93
Tournier, J-Donald
88d38d6d-fbd5-4e9a-b9ff-9c9a7ff13fa0
Northam, Gemma B.
dcdb5be0-d963-4c21-81db-6055317a64aa
Baldeweg, Torsten
e6ba710f-1634-48fe-84b9-84141cc2ad54
Wyatt, John
0413fffa-0db2-4608-91ab-80528b8c5a4d
Vollmer, Brigitte
044f8b55-ba36-4fb2-8e7e-756ab77653ba
Connelly, Alan
b2e15ed0-c70b-4de6-ab5a-4ff6861859de

Groeschel, Samuel, Tournier, J-Donald, Northam, Gemma B., Baldeweg, Torsten, Wyatt, John, Vollmer, Brigitte and Connelly, Alan (2013) Identification and interpretation of microstructural abnormalities in motor pathways in adolescents born preterm. NeuroImage, 87, 209-219. (doi:10.1016/j.neuroimage.2013.10.034). (PMID:24185027)

Record type: Article

Abstract

There has been extensive interest in assessing the long-term effects of preterm birth on brain white matter microstructure using diffusion MRI. Our aim in this study is to explore diffusion MRI differences between adolescents born preterm and term born controls, with a specific interest in characterising how such differences are manifested in white matter regions containing predominantly single or crossing fibre populations. Probabilistic high angular resolution tractography together with large deformation spatial normalisation were used to objectively investigate diffusion tensor parameters at regular intervals along fibre tracts of 45 adolescents born before 33weeks of gestation and 30 term-born typically developing adolescents. Diffusion parameters were significantly different between preterms and controls at several levels along the cortico-spinal, thalamo-cortical and transcallosal pathways. Within the predominantly single fibre regions of the corpus callosum and internal capsule, in the preterms mean diffusivity (MD) was found to be increased while fractional anisotropy (FA) was decreased compared to controls. In contrast, however, where these pathways traversed the centrum semiovale, FA and MD were both significantly increased. The major contributor to reduced FA in preterms in predominantly single fibre regions was the increased radial eigenvalue (i.e. increased radial diffusivity). In predominantly crossing-fibre regions, the tensor eigenvalues are not meaningful, and the observed increase in FA is likely to be due to a decrease in anisotropy in one of the contributing fibre bundles. Similar differences (although less pronounced) were observed after excluding preterms with radiological signs of preterm brain injury from the sample. In summary, white matter microstructure was found to be altered in motor pathways in adolescents born preterm. Disruption of white matter (WM) microstructure in a single fibre region with resulting higher radial diffusivity leads to lower FA, whereas selective disruption of one fibre population in a crossing fibre region is observed to lead to higher FA. These findings challenge the common simplistic interpretation of FA as a measure of WM tract integrity.

This record has no associated files available for download.

More information

e-pub ahead of print date: 31 October 2013
Keywords: preterm, DTI, HARDI, motor system, crossing fibres, fractional anisotropy
Organisations: Clinical & Experimental Sciences

Identifiers

Local EPrints ID: 359904
URI: http://eprints.soton.ac.uk/id/eprint/359904
PURE UUID: 4ea62774-c107-45db-b7ed-89c8b2e8c077
ORCID for Brigitte Vollmer: ORCID iD orcid.org/0000-0003-4088-5336

Catalogue record

Date deposited: 15 Nov 2013 14:33
Last modified: 15 Mar 2024 03:36

Export record

Altmetrics

Contributors

Author: Samuel Groeschel
Author: J-Donald Tournier
Author: Gemma B. Northam
Author: Torsten Baldeweg
Author: John Wyatt
Author: Alan Connelly

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×