Atypical Hemispheric Asymmetry in Fetal Alcohol Spectrum Disorders: A Review of the Effects of Prenatal Alcohol Exposure on Language Lateralization.

Abstract

SUMMARYAtypical lateralization is evident in developmental disorders, including autism spectrum disorders and dyslexia. Moreover, atypical lateralization is linked to language impairments: reduced or reversed lateralization is associated with poorer language outcomes. Fetal alcohol spectrum disorders (FASD) result from the deleterious effects of prenatal alcohol exposure on the brain, resulting in a range of physical, behaviou ral, and cognitive abnormalities, including language impair ments. To date, little is known about lateralization in FASD. This review examines the effects of prenatal alcohol exposure on lateralization in FASD, seeking to determine the degree to which the language deficits associated with FASD can be attributed to aberrant cortical lateralization. The research reviewed indicates that the left temporo-parietal region is par ticularly vulnerable to prenatal alcohol exposure, causing atypicalities in structural and functional lateralization. As this region typically controls language processing, the data imply a direct link between atypical lateralization in FASD and language impairment. Knowledge of patterns of altered structural and functional lateralization in FASD has the potential to improve diagnostic efficacy and may facilitate the development of appropriate management and intervention programmes, improving outcomes for people with FASD.

Evaluation of Brain Alterations and Behavior in Children With Low Levels of Prenatal Alcohol Exposure

“…Interestingly, we observed more group differences in the left hemisphere than the right hemisphere in the present study. Cortical lateralization in white matter has not been widely studied yet in the PAE population, although a previous review found atypical asymmetry in the left temporal-parietal region associated with PAE …”

“…Cortical lateralization in white matter has not been widely studied yet in the PAE population, although a previous review found atypical asymmetry in the left temporal-parietal region associated with PAE. 57 One prior study 29 examined PAE in the full ABCD cohort and reported larger total brain volume and regional cortical volumes in the PAE group compared with unexposed controls. That study included participants who had been exposed to alcohol before awareness of pregnancy only, those with PAE reported by nonbiological parents, and children with other prenatal exposures (eg, cannabis, tobacco).…”

“…Interestingly, we observed more group differences in the left hemisphere than the right hemisphere in the present study. Cortical lateralization in white matter has not been widely studied yet in the PAE population, although a previous review found atypical asymmetry in the left temporal-parietal region associated with PAE 57. One prior study29 examined PAE in the full ABCD cohort and reported larger total brain volume and regional cortical volumes in the PAE group compared with unexposed controls.…”