Dementia vs Delirium Online version Choose which characteristic goes to which condition. by Lisa Schilling-Kauten 1 Dementia 2 Delirium Rarely alters consciousness Irreversible Unknown cause Chronic - Progressive Gradual (indefinite/insidious) onset Affects mainly memory Hallucinations not common Language: sometimes difficulty finding the right word Fluctuating consciousness Reversible Organic cause Acute – Not progressive Rapid (definite) onset Affects mainly attention Hallucinations common Language: slow, often incoherent, & inappropriate