Widespread effects of alcohol on white matter microstructure.

Abstract

Evidence suggests that chronic misuse of alcohol may preferentially affect the integrity of frontal white matter (WM) tracts, which can impact executive functions important to achieve and maintain abstinence. Global and regional WM microstructure was assessed using diffusion magnetic resonance measures of fractional anisotropy (FA) for 31 abstinent alcoholics (ALC) with an average of 25years of abuse and approximately 5years of sobriety and 20 nonalcoholic control (NC) participants. Data processing was conducted with FreeSurfer and FSL processing streams. Voxelwise processing of the FA data was carried out using tract-based spatial statistics. Clusters of significance were created to provide a quantitative summary of highly significant regions within the voxelwise analysis. Widespread, bilateral reductions in FA were observed in ALC as compared to NC participants in multiple frontal, temporal, parietal, and cerebellar WM tracts. FA in the left inferior frontal gyrus was associated with drinking severity. This study found widespread reductions in WM integrity in a group of ALC compared to NC participants, with most pronounced effects in frontal and superior tracts. Decreased FA throughout the frontostriatal circuits that mediate inhibitory control may result in impulsive behavior and inability to maintain sobriety.