Delirium: presentation, epidemiology, and diagnostic evaluation (part 1).

Delirium is a highly prevalent and complex neuro- psychiatric disorder marked by attentional dysfunction, disturbances in multiple cognitive domains, and changes in motor behavior, perception, sleep, and thought process. Delirium results from diverse toxic, metabolic, infectious, and structural etiologies and is associated with a number of adverse outcomes. Delirium pathophysiology involves perturbation of multiple neurotransmitter systems. Behavioral presentations of delirium are common and are often misattributed to primary psychiatric processes. Diagnostic assessment of delirium includes thorough physical examination, careful cognitive testing, appropriate metabolic and infectious studies, review of medications, and structural brain imaging and electroencephalography as indicated. Pharmacologic and non-pharmacologic interventions have been documented to reduce the incidence and severity of delirium. Anti- psychotics are the treatment of choice for delirium-related agitation and psychosis.