We describe the pathologic findings in 17 persons with dementia, 12 of whom exhibited leuko-araiosis on computed tomographic scan. The presence of white matter pallor was confirmed on autopsy in 11 of these 12 cases, 9 with Alzheimer's disease and 2 with multi-infarct dementia. Two further patients, 1 with Alzheimer's disease and 1 with multi-infarct dementia, proved to have white matter changes on pathologic examination. White matter pallor coexisted with cerebral amyloid angiopathy in the brains of the patients with Alzheimer's disease. The presence of severe white matter pallor in patients with Alzheimer's disease correlated with early death, while the presence of cortical scars was associated with prolonged survival. Because early death in patients with Alzheimer's disease has been linked with severe pathologic and chemical changes, the presence of white matter pallor may be further evidence of a particularly severe process in patients with early onset of Alzheimer's disease.