Voxelwise and skeleton‐based region of interest analysis of fetal alcohol syndrome and fetal alcohol spectrum disorders in young adults

Abstract

Though fetal alcohol syndrome and fetal alcohol spectrum disorders are among the most common developmental disorders, their understanding is incomplete. Diffusion tensor imaging, which is sensitive to microstructural organization in white matter, may provide a relevant measure in this population demonstrating incompletely characterized white matter pathology. In this study, tractbased spatial statistics routine and a skeleton-based region of interest analyses were employed to detect differences in diffusion tensor imaging derived metrics between young adults who were alcohol exposed and an unexposed control group. Participants include twenty-eight with dysmorphic features associated with fetal alcohol syndrome, twenty-nine who were prenatally exposed but do not show physical effects, and twenty-five with the same low socioeconomic status but unexposed. The tract-based spatial statistics analysis revealed a statistically significant decrease in fractional anisotropy at the isthmus of the corpus callosum and its connected callosal fibers in dysmorphic individuals relative to controls (cluster-wise p FWE < 0.05). This finding was consistent with that of the follow-up skeleton-based region of interest analysis (F (2,79) =3.256, p=0.044). In addition, the patterns in axial and radial diffusivity changes suggest that demyelination may be associated with the degraded white matter integrity observed in the dysmorphic group.

Diffusion Tensor Imaging Correlates of Saccadic Reaction Time in Children with Fetal Alcohol Spectrum Disorder

“…To date, only a few studies have evaluated the correlation between saccadic eye movement control and DTI parameters in healthy controls (Neggers et al, 2012;de Weijer et al, 2010) and in clinical populations (Kloppel et al, 2008;Manoach et al, 2007;Thakkar et al, 2008). Although DTI has been used in previous studies to evaluate microstructural integrity (Fryer et al, 2009;Lebel et al, 2008a;Li et al, 2009;Ma et al, 2005;Sowell et al, 2008a;Wozniak et al, 2006Wozniak et al, , 2009, the functional significance of these abnormalities is not clear. By providing support for the utility of correlating saccade and DTI measures to evaluate the functional and structural organization of the eye movement network, these studies (Kloppel et al, 2008;Manoach et al, 2007;Neggers et al, 2012;Thakkar et al, 2008;de Weijer et al, 2010) provide compelling evidence for determining the relationship between DTI parameters and oculomotor control in gaining further insight into FASD pathophysiology.…”

“…Quantitative DTI measurements have revealed lower FA and higher MD in white matter in children, adolescents, and adults with FASD compared to controls (Fryer et al, 2009;Lebel et al, 2008a;Li et al, 2009;Ma et al, 2005;Sowell et al, 2008a;Wozniak et al, 2006Wozniak et al, , 2009. Collectively, these DTI studies consistently implicate the corpus callosum, long known from pathological specimens and conventional MRI as a major target for alcohol teratogenicity.…”

What Does Diffusion Tensor Imaging Reveal About the Brain and Cognition in Fetal Alcohol Spectrum Disorders?

“…In another study employing a TBSS examination of the corpus callosum among adults with FASD (ages 19 to 27), Li et al (2009) reported lower FA, higher MD, and higher radial diffusivity (RD) in the isthmus for individuals with dysmorphic facial features compared with controls. Significant group differences in FA were also seen in the splenium.…”

Brain Microstructure Is Related to Math Ability in Children With Fetal Alcohol Spectrum Disorder

“…DTI yields a quantitative diffusion parameter, fractional anisotropy (FA), that is related to axonal packing and myelination (Beaulieu, 2002). DTI has been used to study brain abnormalities in children with FASD (Fryer et al, 2009;Lebel et al, 2008;Li et al, 2009;Sowell et al, 2008a;Wozniak et al, 2006Wozniak et al, , 2009, but only 2 studies reported correlations between cognitive tests and brain structure. Sowell and colleagues (2008a) observed a relationship between white matter integrity in the splenium of the corpus callosum and scores on a visuomotor integration task.…”