The frontal/subcortical dementias: common dementing illnesses associated with prominent and disturbing behavioral changes.

Although the most common cause of dementia is Alzheimer's disease, many other common dementing illnesses in the elderly affect the frontal cortex and associated subcortical structures and present with very different symptoms. In general, these illnesses are not detected with typical bedside screening or with conventional dementia assessment tools, such as the Mini Mental State Exam. These illnesses are associated with prominent and disturbing behavioral changes, as well as difficulties with "higher-order" cognitive functions, such as planning and judgment. Common causes of frontal/subcortical dementia include vascular dementia, frontotemporal dementia, alcoholic dementia, dementia due to AIDS, and a number of movement disorders. Familiarity with this clinical picture is essential for recognition, diagnosis, and management of these illnesses, and for working with families and caregivers.