Original Research ARTICLE
WHITE MATTER MICROSTRUCTURAL CHANGES AND EPISODIC MEMORY DISTURBANCES IN LATE-ONSET BIPOLAR DISORDER
- 1Departamento de Medicina Clínica, Universidade Federal do Ceará, Brazil
- 2Psychiatry and Psychosomatics, Goethe-Universität Frankfurt am Main, Germany
- 3Institute of General Medicine, Goethe-Universität Frankfurt am Main, Germany
- 4Psicologia, Pontifícia Universidade Católica de São Paulo, Brazil
- 5Psychiatry, University of Toronto, Canada
Background: Bipolar disorder (BD) has been associated with distributed network disruption, but little is known on how different clinical subtypes, particularly those with an earlier and later onset of disease, are related to connectivity changes in white matter (WM) tracts.
Methods: Diffusion tensor imaging (DTI) and volumetric measures were carried out in early-onset bipolar patients [(EOD)(n=16)], late-onset bipolar disorder [(LOD)(n=14)] and healthy controls (n=32). We also computed ROI analysis of grey matter (GM) and white matter (WM) volumes using the regions with significant group differences in the DTI parameters. Cognitive and behavior measurements were analyzed between groups.
Results: Lower fraction of anisotropy (FA) in the right hemisphere comprising anterior thalamic radiation, fornix, posterior cingulate, internal capsule, splenium of corpus callosum was observed in the LOD in comparison with EOD; additionally, lower FA was also found in the LOD in comparison with healthy controls, mostly in the right hemisphere and comprising fibers of the splenium of the corpus callosum, cingulum, superior frontal gyrus and posterior thalamic radiation; LOD also showed worse episodic memory performance than EOD; no statistical significant differences between mood symptoms, WM and GM volumes were found between BD groups.
Conclusion: Even after correcting for age differences, LOD was associated with more extensive WM microstructural changes and worse episodic memory performance than EOD; these findings suggest that changes in the WM fiber integrity may be associated with a later presentation of BD, possibly due to mechanisms other than neuroprogression. However, these findings deserve replication in larger, prospective, studies.
Keywords: DTI, bipolar disorders, TBSS, White-matter, Aging, Cognition
Received: 31 May 2018;
Accepted: 13 Sep 2018.
Edited by:Elie Cheniaux, Rio de Janeiro State University, Brazil
Reviewed by:Marco Solmi, Dipartimento di Neuroscienze, Università di Padova, Italy
Michele Fornaro, New York State Psychiatric Institute (NYSPI), United States
Copyright: © 2018 ALVES, Reif, Oertel, Reinke, Prvulovic, Knöchel, Paulitsch, Pantel, Sudo and Carvalho. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Prof. GILBERTO S. ALVES, Universidade Federal do Ceará, Departamento de Medicina Clínica, Fortaleza, 60430140, CEARÁ, Brazil, firstname.lastname@example.org