The results of this study align interestingly with prior evidence for alcohol-related interruption of frontocerebellar circuitry (Sullivan and Pfefferbaum, 2005), involving network nodes pons and thalamus, which exhibit volumetric decrements among adult alcoholics (Sullivan et al., 2003). Although we did not examine the integrity of frontocerebellar white matter connectivity specifically, we did observe lower FA in the superior cerebellar peduncle, a fiber tract that connects the thalamus to deep cerebellar nuclei (Wakana et al., 2004). Thalamic projections also emanate from the posterior limb of the internal capsule, where reduced fiber coherence was detected. These observations of altered white matter microstructure, combined with results from other DTI, morphometric, fMRI, and neuropsychological studies, serve as converging lines of evidence pointing towards a deleterious influence of alcohol on frontocerebellar circuitry (Sullivan and Pfefferbaum, 2005). Unlike the aforementioned studies with samples comprised of mature individuals with years of alcoholism, the sample of this exploratory analysis represents teenagers at the beginning stages of risky alcohol use, and related white matter abnormalities in these pathways detectable as early as 16 years of age.
