Delirium is a form of acute brain dysfunction that manifests as fluctuating attention and impaired cognitive function. It can present with a variety of symptoms, including significant psychomotor agitation, depressed level of consciousness, or both. According to the American Psychiatric Association’s Diagnostic and Statistical Manual—5th edition (DSM-5) guidelines, delirium is an acute confusional state defined by acute disturbances in attention, awareness, or cognition developing over hours to days due to disease or sedation that is not better explained by an alternative diagnosis or a comatose state. Notably, delirium can and often does coexist with underlying neurological disease such as dementia, traumatic brain injury, and stroke and so is not precluded from developing in these patients.
