Atypical functional lateralization in children with fetal alcohol syndrome

Abstract

In order to explore effects of prenatal alcohol exposure on functional lateralization, item tasks measuring preferences of hand, foot, eye, and ear were administered to a sample of 23 children diagnosed with fetal alcohol syndrome (FAS) compared with typically developing (TD) children. In addition, a dichotic listening task was administered to a subsample of 11 children with FAS and a TD group of comparable age, sex and handedness. The children with FAS were characterized by increased nonright-handedness compared with TD children. No differences were evident for preferential use of foot, eye, or ear. Moreover, children with FAS displayed more right ear extinctions during dichotic listening relative to TD children, indicating a lack of right ear advantage. The results add to findings of decreased manual asymmetry and less left-lateralized speech perception in children with developmental disorders, and are further discussed in relation to the high incidence of callosal abnormalities in alcohol-exposed children.

O que sabemos das alterações auditivas centrais em crianças expostas ao álcool na gestação? Revisão sistemática

“…The six selected studies addressed the diagnostics of individuals exposed to alcohol during pregnancy, four of them (12,13,19,20) exclusively on FAS, one of them (21) on FAS and pFAS, and one (22) on FAS, pFAS and ARND. Of the four studies that addressed diagnostics exclusively on FAS, three were from the 1990s (12,13,19) , and the two studies that used the sub-labels of the FAS/FASD (21,22) were published in the year or after the guiding publications, with guidelines on the theme (23)(24) .…”

“…None of them presented longitudinal and/or cohort characteristics, but four of them (19)(20)(21)(22) used control groups for comparison with the study groups. The cross-sectional study with a control group shows level of evidence "3" and grade of recommendation "B" (19)(20)(21)(22) . The other two papers (12,13) show level of evidence "4" and grade of recommendation "C".…”

“…The other two papers (12,13) show level of evidence "4" and grade of recommendation "C". It is worth mentioning that 66.6% (4/6) of the articles, those with grade of recommendation "B" (19)(20)(21)(22) , presented credible outcomes, that is, their results can be generalized for the studied conditions and should be used for clinical decision making. The studies with grade of recommendation "C" (12,13) suggest that conditions may be clinically different from those used in the study (19) .…”

“…For the other selected works, one article (20) used behavioral evaluation and three papers (13,19,20) applied electrophysiological measurement. There was another only study (22) in which the authors chose magnetoencephalography (MEG) with Oddball paradigm to investigate the cortical activation of auditory stimuli.…”

“…The following behavioral assessments were used: verbal dichotic listening test (VDT) with syllables (20) , competing sentence test (CST) in contralateral mode, and speech-in-noise test (SNT) (12) . Verbal dichotic listening tests are commonly associated with cortical auditory disorders, whereas the SNT is susceptible to both cortical and subcortical disorders (25,26) ; nevertheless, there are signs that noise attenuation begins at the superior olivary complex (27) .…”