Alcohol-related dementia: an update of the evidence

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.

Addressing alcohol-related dementia should involve better detection, not watchful waiting

“…Although Oslin et al refined the diagnostic criteria to improve specificity by including measures of duration and severity of alcohol consumption, excluding characteristic features of Alzheimer's disease and vascular dementia and linking dementia with a minimum abstinence time before onset, 8 these criteria have yet to be validated in methodologically sound prospective studies. 4 …”

“…5 The neuropsychological profile of alcohol-related dementia has not been as well studied, but there is evidence that in comparison with Alzheimer's disease, language impairment is unlikely; with better performance on semantic tasks and on verbal memory recognition, but worse performance on visuospatial tasks. 4 However, as many also have features of WKS, there is often profound anterograde amnesia, impaired recall of past events and impaired executive functioning. 4 A UK cohort study of people with a mean age of 56 found that drinking above 32 UK units of alcohol per week was associated with greater global impairment in cognitive function, as well as in memory and executive function 10 years later.…”

“…4 However, as many also have features of WKS, there is often profound anterograde amnesia, impaired recall of past events and impaired executive functioning. 4 A UK cohort study of people with a mean age of 56 found that drinking above 32 UK units of alcohol per week was associated with greater global impairment in cognitive function, as well as in memory and executive function 10 years later. 6 These global changes in cognitive function go beyond the neuropsychological profile of amnestic syndrome, which does not characteristically affect visuospatial function.…”

“…However, the relationship between heavy alcohol consumption and dementia has been less clear for reasons that include the apparent lack of a specific neuropathology, the role of comorbidities such as cerebrovascular disease and traumatic brain injury, and the difficulties in distinguishing the effects of alcohol from degenerative dementias such as Alzheimer's disease and frontotemporal dementia. 3,4 In spite of this, it is becoming clearer that alcohol-related dementia is emerging as a distinct mental disorder.…”

“…4 However, as many also have features of WKS, there is often profound anterograde amnesia, impaired recall of past events and impaired executive functioning.…”