Type

Journal Article

Authors

Gianpiero L Cavalleri
Colin P Doherty
Norman Delanty
Gerard Boyle
Andrew J Fagan
James F Meaney
Parames M Iyer
Maria Cheung
Erik O'Hanlon
Saud Alhusaini
and 1 others

Subjects

Psychiatry

Topics
brain epilepsy temporal lobe white matter patients mri corpus callosum siblings magnetic resonance imaging mri

White matter alterations in patients with MRI-negative temporal lobe epilepsy and their asymptomatic siblings. (2015)

Abstract The identification of "endophenotypes"-measurable variations along the pathways between genes and distal disease state-may help deconstruct focal epilepsies into more sensitive phenomena and improve future efforts to map the genetic underpinnings of the disorder. In this study, we set out to determine if diffusion tensor imaging (DTI)-inferred white matter (WM) alterations represent a suitable structural endophenotype for focal epilepsy. We recruited 25 patients with sporadic mesial temporal lobe epilepsy (MTLE) with normal magnetic resonance imaging (MRI) findings, 25 of their gender-matched, asymptomatic siblings, and 60 control subjects. Whole-brain, voxelwise statistics were conducted to identify regions of microstructural degeneration in patients with MTLE and/or their asymptomatic siblings. WM tracts exhibiting evidence of microstructural disruption were then reconstructed using deterministic tractography. Diffusion metrics including fractional anisotropy (FA) and mean diffusivity (MD) were compared across groups using a series of one-way multivariate analyses of covariance (MANCOVAs). Voxelwise statistics revealed significant FA reductions in the corpus callosum (CC), bilateral superior longitudinal fasciculi (SLF), bilateral inferior longitudinal fasciculi (ILF), and left corticospinal tract (CST) in MTLE patients only. MD increases were observed in MTLE patients and their asymptomatic siblings in the left SLF and left CST. Deterministic tractography supported the voxelwise results, revealing significant FA alterations in the left SLF and CST in patients only and significant MD alterations in MTLE patients and their unaffected siblings. The diffusion scalars of MTLE patients and their asymptomatic siblings were highly correlated in the SLF and CST ipsilateral to patients' sides of seizure onset. These findings confirm the presence of microstructural WM alterations in patients with MRI-negative MTLE and provide preliminary support for a diffusion-based endophenotype in the disorder. Further studies of narrow-sense heritability in larger cohorts of first-degree relatives of MTLE patients are required to confirm these results.
Collections Ireland -> Royal College of Surgeons in Ireland -> PubMed

Full list of authors on original publication

Gianpiero L Cavalleri, Colin P Doherty, Norman Delanty, Gerard Boyle, Andrew J Fagan, James F Meaney, Parames M Iyer, Maria Cheung, Erik O'Hanlon, Saud Alhusaini and 1 others

Experts in our system

1
Gianpiero L Cavalleri
Royal College of Surgeons in Ireland
Total Publications: 35
 
2
Colin P Doherty
Trinity College Dublin
Total Publications: 35
 
3
Norman Delanty
Royal College of Surgeons in Ireland
Total Publications: 41
 
4
Gerard Boyle
Royal College of Surgeons in Ireland
Total Publications: 4
 
5
Andrew John Fagan
Trinity College Dublin
Total Publications: 72
 
6
James Meaney
Trinity College Dublin
Total Publications: 28
 
7
Erik O'Hanlon
Royal College of Surgeons in Ireland
Total Publications: 16
 
8
Saud Alhusaini
Royal College of Surgeons in Ireland
Total Publications: 10