Psychology ETDs

Mollie Monnig

Publication Date

6-25-2010

Abstract

The effects of alcohol on white matter integrity were investigated in a sample of 12 individuals with current alcohol dependence or abuse (AUD-C), 9 individuals with alcohol dependence in remission (AUD-R) for at least one year, and 16 healthy control (HC) participants matched to alcohol groups on age, sex, and smoking status. Magnetic resonance imaging (MRI) and neuropsychological data were collected. Diffusion tensor imaging (DTI) data was analyzed using tract-based spatial statistics (TBSS). Using a standard white matter atlas, fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were quantified for three corpus callosum ROIs and eight bilateral ROIs. Repeated measures ANOVAs revealed significant group differences for MD, AD, and RD and a trend for group differences in FA in the bilateral ROIs. Consequently, diffusivity measures for each ROI were tested for group differences using univariate ANOVAs followed by pairwise Tukey tests. Diffusivity was lower in AUD-C compared to HC in anterior limb of internal capsule, anterior corona radiata, cingulate gyrus, and external capsule. AUD-C also had lower diffusivity than AUD-R in cingulum-hippocampal connections and uncinate fasciculus. Furthermore, correlations between frontal and limbic white matter and cognitive measures of executive function, attention, and processing speed were identified. Hypotheses of abnormal diffusion in frontal and limbic ROIs were confirmed, yet the direction of differences was opposite that of previous findings. These results draw attention to the critical issue of duration of abstinence and its possible role in contributing to the different pattern of white matter integrity observed across studies.

Degree Name

Psychology

Level of Degree

Masters

Department Name

Psychology

First Committee Member (Chair)

Thoma, Robert

Second Committee Member

Hutchison, Kent

Language

English

Keywords

Brain--Effect of chemicals on, Myelinated neurofibrils--Physiology, Alcohol--Physiological effect, Alcoholism--Pathophysiology.

Document Type

Thesis

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