tensor imaging studies of white-matter abnormalities in alcoholics highlight a disruption of myelin microstructure in prefrontal areas and the corpus callosum52 that appears distinct from callosal atrophy seen with Alzheimer’s disease29. In its most severe form, chronic alcohol abuse can lead to Marchiafava-Bignami disease, a neurologic disorder with corpus callosum demyelination84. The commissural fibers of the corpus callosum play a dominant role in the maintenance of interhemispheric connectivity, which was assessed in our study by EEG coherence. Although further evidence is needed to support the link between corpus callosum measures and EEG coherence, these findings may suggest that the variability in interhemispheric connectivity in AUD results from a specific loss of interhemispheric commissural fibers that enable communication between the cerebral hemispheres projecting through the corpus callosum. Given the intriguing associations among variants in 18q23, EEG coherences and AUD, large, comprehensive in-depth studies, are needed to evaluate the associations of EEG coherences, structural brain imaging phenotypes, and neuropsychiatric disorders.
