Brain failure in older patients. Uncovering treatable causes of a diminished ability to think.

The term "brain failure" implies only dysfunction of a major organ system, not that an exact diagnosis has been made. Assessment and treatment of older patients with diminished cognitive ability can be challenging; however, the experience can also be extremely rewarding when a reversible condition is alleviated and the patient is given added years of productive life. The first step in patient evaluation is to rule out delirium. The presence of delirium is a medical emergency in a patient of any age. Abrupt onset of cognitive deficit, waxing and waning of symptoms, and worsening of symptoms at night are the hallmarks of delirium. The second step is careful history taking and physical examination to rule out "apparent dementia," a potentially reversible form of brain failure that can mimic irreversible dementia. The third step is to treat what is treatable. Finally, extreme care must be taken in making the diagnosis of true dementia. Diagnosis of such a condition (eg, Alzheimer's disease, multi-infarct dementia, dementia of Parkinson's disease) has a profound effect on the patient and the family. These conditions are largely nontreatable, but physicians still have an important role in helping caregivers find appropriate assistance and support.