Mechanism of delirium/ elderly encephalopathy : a neuro–geriatric approach

Abstract

Delirium occurs by a) acute brain diseases or b) acute systemic diseases in older subjects with premorbid age–related brain diseases, e.g., Alzheimer's disease, white matter disease, dementia with Lewy bodies, or alcoholic dementia (who had dementia and/or walking difficulty). The ratio of a) vs b) is estimated as 15% : 85%, the latter being more common. Systemic inflammatory encephalopathy, the most common cause of b), is the condition in which systemic cytokines (tumor necrosis factor–alpha, etc.) might penetrate the blood–brain barrier and lead to neural dysfunction. When we encounter delirium, we should evaluate/ treat acute brain/ systemic diseases and premorbid age–related brain diseases together.