Applications of morphometric and diffusion tensor magnetic resonance imaging to the study of brain abnormalities in the alcoholism spectrum

Broad disruption of brain white matter microstructure and relationship with neuropsychological performance in male patients with severe alcohol dependence

AIMS

In the last years, refined magnetic resonance diffusion tensor imaging (DTI) methods have become available to study microstructural alterations in the human brain. We investigated to what extent white matter tissue abnormalities are present in male patients after chronic, excessive alcohol consumption and if these alterations are correlated with measures of alcohol consumption and neuropsychological performance.

METHODS

Twenty-four detoxified adult male patients with severe alcohol dependence and 23 healthy male control subjects were included in the study. Neuropsychological tests were assessed for executive function, attention, memory and visuospatial function. DTI was acquired and preprocessing of the data was performed using tract-based spatial statistics. Group differences of fractional anisotropy (FA) as well as correlation analyses with neuropsychological measures and drinking history were calculated.

RESULTS

Performance in alcoholic patients was significantly poorer in tests of non-verbal reasoning and attention. In detoxified alcoholic patients, lower FA was primarily found in the body of the corpus callosum, but these findings did not correlate directly with behavioral measures. However, executive and psychomotor performance (Trail-Making Test) correlated significantly with FA in right anterior cingulate and left motor areas.

CONCLUSION

These findings provide further evidence for reduced integrity of interhemispheric connections in male patients with severe alcohol dependence, and neurocognitive performance was in part correlated with FA.

Imaging the addicted human brain

Modern imaging techniques enable researchers to observe drug actions and consequences as they occur and persist in the brains of abusing and addicted individuals. This article presents the five most commonly used techniques, explains how each produces images, and describes how researchers interpret them. The authors give examples of key findings illustrating how each technique has extended and deepened our knowledge of the neurobiological bases of drug abuse and addiction, and they address potential clinical and therapeutic applications.