An introduction to alcohol-induced brain damage and its causes.

The aim of the symposium on alcohol-induced brain damage is to review current opinion and recent advances concerning factors which are thought to play a significant role in this disorder. The three principal factors are: alcohol specific neurotoxicity, associated vitamin B1 (thiamine) deficiency (the Wernicke-Korsakoff syndrome) and liver failure secondary to alcoholic cirrhosis. There is a complex interaction of these and other factors and it is difficult to dissect out the relative importance of each in the pathogenesis of alcohol-related brain damage. Moreover recent molecular and biochemical studies suggest that several of these factors may have pathogenetic mechanisms in common-for example, excitotoxicity, mitric oxide and free radicals. The application of new technologies in neuropathological studies of carefully selected groups of alcoholic cases is beginning to reveal a far more complex pattern of damage than current view holds. Quantitative morphometry and immunohistochemistry can be combined to create three dimensional images of various anatomical regions of the brain together with detailed analyses of neuronal counts, sizes and neurochemical type. In the Wernicke-Korsakoff syndrome (WKS) there is good evidence (in support of neuropsychological and neuroradiological data) to suggest that specific populations of neurons are damaged in cortical and subcortical regions. In those cases with the WKS there is also evidence of pathological damage in cortical and subcortical regions other than the well described periventricular distributions. These more detailed studies provide us with a more comprehensive understanding of alcohol-related brain damage.