Distinguishing Delirium and Dementia

Delirium and dementia are syndromes with multiple cognitive impairments common to the elderly and to medically ill patients. While strides have been made in recognition of both delirium and dementia, underdiagnosis is common. Delirium and dementia cause great suffering in patients, families and caregivers. Both necessitate further advancement in assessment methods and treatment, especially when they overlap. Differentiating delirium and dementia requires recognizing that both may present with cognitive, behavioral and neuropsychiatric symptoms, but attentional disturbance and acute onset are cardinal discriminators in delirium. Superimposed delirium on dementia presents a particularly vexing problem in terms of recognition, treatment and prognosis. The pathophysiology of delirium results from diffuse cortical dysfunction or impairment in susceptible areas of the cortex and the reticular activating system. The pathophysiology of dementia is varied across dementias although several share histolological features. Treatment for both delirium and dementia includes antipsychotic medications and cholinesterase inhibitors, among others, although the disadvantages of pharmacological treatment are becoming better understood and demand caution. Nevertheless, there is an array of treatments and preventive strategies being explored for dementia, and to a lesser degree for delirium, that hold promise for the future.