Midline corpus callosum is a neuroanatomical focus of fetal alcohol damage

Abstract

Prenatal exposure to high levels of alcohol often induces birth defects that combine morphological stigmata with neurological or neuropsychological deficits. But it has proved problematic to diagnose these syndromes in adolescents and adults, in whom the morphological signs are absent or attenuated, the behavioral deficits nonspecific, and the exposure history often difficult to reconstruct. Localizing the associated brain abnormalities might circumvent most of these difficulties. To this end, three-dimensional (3D) locations were recorded for 67 homologous points on or near the corpus callosum in magnetic resonance (MR) brain images from 60 adolescents and adults who were normal, 60 diagnosed with fetal alcohol syndrome, and 60 diagnosed with fetal alcohol effects. We combined the standard statistical approach to this type of geometric data, Procrustes analysis, with a multivariate strategy focusing on differences in variability. In this data set, the shape of the corpus callosum and its vicinity proves systematically much more variable in the alcohol-affected brains than in those of the normal subjects. From this excess variability follows a promising classification rule, having both high sensitivity (100 out of 117) and high specificity (49 out of 60) in this sample. The discrimination uses four landmark points and two summary scores of callosal outline shape. The information from the corpus callosum and vicinity, as viewed in MR brain images of full-grown subjects, may serve as a permanent record of the prenatal effects of alcohol, even in patients who are first suspected of these syndromes relatively late in life or who lack the facial signs of prenatal alcohol damage. The statistical pattern underlying the callosal diagnosis also leads to speculations on mechanisms of the prenatal damage. Anat Rec (New Anat) 269:162-174, 2002.

Neuroimaging and fetal alcohol spectrum disorders

“…Rather than compare area, volume, or location, other studies have described the shape of the corpus callosum in FAS and other FASD individuals (Bookstein et al, 2001(Bookstein et al, , 2002a. Using novel shape-based representations of callosal morphology, alcohol-exposed subjects exhibited increased variability in the shape of the CC (Bookstein et al, 2001(Bookstein et al, , 2002a.…”

“…Using novel shape-based representations of callosal morphology, alcohol-exposed subjects exhibited increased variability in the shape of the CC (Bookstein et al, 2001(Bookstein et al, , 2002a. According to Bookstein et al (2001), the shape-based analytic technique may be more valid than previously used techniques as it requires no spatial correction for microcephaly commonly found in alcohol-exposed groups.…”

Hominin lower second premolar morphology: evolutionary inferences through geometric morphometric analysis

“…''Sliding techniques'' can be used to minimize the effects of the arbitrary placement along the curve (Bookstein, 1996(Bookstein, , 1997Bookstein et al, 2002;Gunz et al, 2005). In applying these methods, a ''semilandmark'' is converted into a ''sliding semilandmark.''…”

“…Actually, and for reasons of optimizing the shape information, the semilandmark slides along its tangent to the outline until its final position minimizes one of several possible criteria, such as the bending energy (Bookstein, 1997;Bookstein et al, 2002Bookstein et al, , 2003Mitteroecker et al, 2004;Bastir et al, in press), the distances between semi-landmarks between reference and target , or the Procrustes distance between reference and target (Rohlf, 1998a). Each of these criteria have different advantages and disadvantages Zelditch et al, 2004;Bastir et al, in press).…”

“…Because the use of sliding semi-landmarks is relatively new, few studies have been published to date dealing differently with this issue (Bookstein, 1997;Rohlf, 1998a;Bookstein et al, 1999Bookstein et al, , 2002Mitteroecker et al, 2004;Sheets et al, 2004;Bastir et al, in press). In its favor, the sliding technique provides non-arbitrary criteria (Zelditch et al, 2004;Gunz et al, 2005) and allows curves or outlines to be analyzed within the Procrustes scheme of shape analysis (Rohlf and Slice, 1990;Slice, 2001;Rohlf, 2003).…”