Central Nervous System Alterations in Alcohol Abuse

Abstract

Alcohol abuse and dependence is a serious medical and economic problem in the Western countries as its effects on the central nervous system (CNS) are wide-ranging. The main factors contributing to alcohol-induced brain damage are associated with nutritional deficiencies and repeated withdrawal syndrome. CNS lesions associated with alcoholism include brain atrophy and central pontine myelinolysis. At least four distinct conditions leading to dementia, i.e. Wernicke-Korsakoff syndrome, hepatocerebral degeneration, Marchiafava-Bignami disease, and pellagrous encephalopathy, have a close association with chronic alcoholism, whereby the role of alcohol in their causation is secondary. A disproportionate loss of cerebral white matter relative to cerebral cortex suggests that a major neurotoxic effect of chronic alcohol consumption affects the white matter. Brain atrophy in alcoholics has been demonstrated in various studies. There is a regional selectivity, with the frontal lobes being particularly affected, which might explain the high incidence of cognitive dysfunction observed in alcoholics. In functional genomic studies reported so far, the identity and the number of dysregulated genes, the specific pathways involved and the direction of change show profound interstudy variations and, thus, remain inconclusive.