Microstructural integrity of brain white matter in different substance using populations: Diffusion Tensor Imaging analysis of 4 Tesla MRI data
- Author(s): Zou, Yukai
- Advisor(s): Meyerhoff, Dieter J
- et al.
Many individuals with alcohol use disorders (AUD) are chronic cigarette smokers, and the specific contributions of both chronic drinking and smoking to brain injury need to be better understood. A previous analysis of 1.5T diffusion tensor imaging data by Tract-Based Spatial Statistics (TBSS) found significant microstructural injury of brain white matter in 11 smoking alcoholics at 1 week of abstinence. The objectives of this study are to reproduce the 1.5T study with corresponding 4T MRI data from a larger sample of alcoholics (ALC) in recovery and to test the effects of cigarette smoking on microstructural integrity of brain white matter. Corpus callosum, cingulum bundle, fornix, and medial forebrain bundle were chosen as a priori regions of interest (ROIs). After TBSS analyses, family-wise error (FWE)-corrected t-statistics showed significant fractional anisotropy (FA) deficits in smoking ALC (sALC) at 1 week of abstinence compared with nonsmoking healthy controls within corpus callosum (body, genu, and splenium), fornix, and medial forebrain bundle, largely replicating the findings at 1.5T. Exploratory uncorrected t-statistics found significant FA deficits in sALC at 1 month of abstinence compared with smoking controls within cingulum bundle, body of corpus callosum, fornix, and medial forebrain bundle; no regional FA difference remained significant after FWE correction. Exploratory uncorrected t-statistics found significant FA decreases and increases in smoking versus non-smoking alcoholics, as well as regional FA decreases in smoking versus non-smoking healthy controls; none of these smoking effects, however, remained significant after FWE correction. The analyses suggest that white matter microstructural integrity in alcoholics is compromised at 1 week of abstinence and may have recovered after 1 month of abstinence, and chronic cigarette smoking may reduce microstructural integrity in both alcoholics and healthy controls.