Differential diagnosis of dementia syndromes.

Dementia includes a spectrum of clinical features centered on cognitive and behavioral disturbances. The pathophysiologic cascade of events that leads to most forms of dementia is relatively poorly understood. Therefore, criterion-based approaches are used to identify the presence of dementia and to differentiate causes of dementia in the clinical setting. Relatively few cases of reversible dementia exist, but the effort to identify these and treat them appropriately can result in important benefits to patients. Clinical differentiation helps to inform prognosis of permanent forms of dementia and eases communication with patients and their families. Recent research in neurodegenerative disease suggests that improved disease-modifying treatments for the irreversible forms of dementia may become available in the next several years. Because these treatments are likely to be disease-specific, clinical differential diagnosis of dementia will be even more important in the future.