Alcohol-related dementia: an update of the evidence

Nicole J Ridley,Adrienne Withall,Brian Draper

doi:10.1186/alzrt157

Abstract

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.

Highlights

The characteristics of dementia relating to excessive alcohol use have received increased research interest in recent times
There is little consensus on the characteristics of a dementia syndrome related to sustained alcohol abuse or its relationship to Wernicke-Korsakoff syndrome (WKS)
We aim to review the neuropathology, nosology, epidemiology, clinical features, and neuropsychology of alcohol-related dementia (ARD) and WKS

Summary

Introduction

The characteristics of dementia relating to excessive alcohol use have received increased research interest in recent times. Much of the debate surrounding ARD encompasses whether it is possible to have a dementia that is the direct result of ethanol neurotoxicity – a primary alcoholic dementia – or whether the clinical presentation of dementia represents another underlying pathology (that is, thiamine deficiency) or multiple factors (for example, neurotoxicity in combination with nutritional deficiencies) Attempts to clarify this have been hindered by confounding factors that often accompany the lifestyles of alcohol abusers, such as head injury, psychiatric and other substance abuse co-morbidities, and a higher rate of vascular risk factors [6]. Harper [1] concludes that the brain pathology of abusers of alcohol likely has two components: one of permanent change, the other transient While these findings reflect general structural changes in chronic abusers of alcohol, what lesions characterize a clinically identifiable dementia and the neuropathological process that underlies this process remain in dispute. The permanence of such changes, and whether they relate to neurotoxicity in isolation, remains to be established [1]

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