Alcohol-related dementia: An update of the evidence

The characteristics of dementia relating to excessive alcohol use have received increased research interest in recent times. In this paper, the neuropathology, nosology, epidemiology, clinical features, and neuropsychology of alcohol-related dementia (ARD) and alcohol-induced persisting amnestic syndrome (Wernicke-Korsakoff syndrome, or WKS) are reviewed. Neuropathological and imaging studies suggest that excessive and prolonged use of alcohol may lead to structural and functional damage that is permanent in nature; however, there is debate about the relative contributions of the direct toxic effect of alcohol (neurotoxicity hypothesis), and the impact of thiamine deficiency, to lasting damage. Investigation of alcohol-related cognitive impairment has been further complicated by differing definitions of patterns of alcohol use and associated lifestyle factors related to the abuse of alcohol. Present diagnostic systems identify two main syndromes of alcohol-related cognitive impairment: ARD and WKS. However, 'alcohol-related brain damage' is increasingly used as an umbrella term to encompass the heterogeneity of these disorders. It is unclear what level of drinking may pose a risk for the development of brain damage or, in fact, whether lower levels of alcohol may protect against other forms of dementia. Epidemiological studies suggest that individuals with ARD typically have a younger age of onset than those with other forms of dementia, are more likely to be male, and often are socially isolated. The cognitive profile of ARD appears to involve both cortical and subcortical pathology, and deficits are most frequently observed on tasks of visuospatial function as well as memory and higher-order (executive) tasks. The WKS appears more heterogeneous in nature than originally documented, and deficits on executive tasks commonly are reported in conjunction with characteristic memory deficits. Individuals with alcohol-related disorders have the potential to at least partially recover - both structurally and functionally - if abstinence is maintained. In this review, considerations in a clinical setting and recommendations for diagnosis and management are discussed. It is well established that excessive and prolonged alcohol use can lead to permanent damage to the structure and function of the brain [1]. Despite this, there is little consensus on the characteristics of a dementia syndrome related to sustained alcohol abuse or its relationship to Wernicke-Korsakoff syndrome (WKS). After a long period of neglect, research interest has increased in recent years and has been spurred on by clinical demand, increased reported rates of alcohol abuse in older people, and increasing alcohol consumption by women [2, 3]. In this paper, we aim to review the neuropathology, nosology, epidemiology, clinical features, and neuropsychology of alcohol-related dementia (ARD) and WKS. To retrieve papers for the purpose of this review, the search terms (alcohol OR alcoholism) AND (dementia OR brain damage OR brain injury OR cognitive impairment) were used as keywords in the Medline and PsycINFO databases. Additional terms included Wernicke's encephalopathy, Korsakoff, and Alcohol Amnestic Disorder. Reference lists were also scanned for relevant papers.