Cognitive decline in ageing

In recent years there have been major advances in the conceptualisation of dementia and cognitive decline in older age. Cognitive decline should be seen as a continuum, with the distinction between dementia and milder degrees of cognitive impairment being somewhat arbitrary and carrying no pathological justification. The co-existence of Alzheimer's disease and small-vessel ischaemic cerebrovascular disease in older people with cognitive impairment has also previously been under-recognised. These pathologies carry a long list of shared genetic and environmental risk factors, and the recognition of the fact that vascular disease and Alzheimer's pathology usually co-exist opens up additional possibilities for treatment and prevention of cognitive decline and dementia in older people. Subjects with a clinical diagnosis of vascular dementia will often have Alzheimer's pathology and may benefit from cognitive enhancers such as cholinest- erase inhibitors. Conversely, subjects with clinical Alzheimer's disease may benefit from the active management of vascular risk factors. The traditional diagnostic labels of Alzheimer's disease and vascular dementia are unhelpful, as they fail to recognise the interaction between these pathologies. Prevention of cerebrovascular disease is likely to play an important role in attenuating cognitive decline in high-risk older patients.