[Delirium and dementia]

Delirium and dementia are highly prevalent neurocognitive syndromes in the elderly. These syndromes are defined by level of consciousness, clinical onset, and potential reversibility, etc. Frequently, both syndromes coincide in the elderly patient and share many epidemiologic, pathogenic and clinical features, which are reviewed in this article. There is no solid scientific evidence that explains the association between delirium and dementia. The present article proposes a change of paradigm in the diagnostic, preventive and therapeutic approach to delirium in the elderly that recognizes the inherent complexity of this geriatric syndrome and, unlike dichotomic models, explores the complex interrelations between both geriatric syndromes. Delirium is viewed as an important model to investigate cognitive disorders and dementia.