Medullary arteries in aging and dementia.

We examined sclerotic changes of the medullary arteries in 110 nonneuropsychiatric patients ranging in age from the second to the ninth decades, in 20 patients with subcortical arteriosclerotic encephalopathy (Binswanger's disease), and in 20 patients with dementia of the Alzheimer type. The principal sclerotic change was fibrohyaline thickening of the wall, which began to appear during the late fourth decade, increased in incidence gradually with age, and was most severe in patients with subcortical arteriosclerotic encephalopathy. Morphometry showed that the sclerotic changes of the medullary arteries were most prominent in the frontal lobe, followed by the parietal, occipital, and temporal lobes, in both the nonneuropsychiatric and demented groups. The sclerotic rate in the frontal lobe of patients with dementia of the Alzheimer type was slightly higher than that in the nonneuropsychiatric patients (p less than 0.05) but far less than that in the patients with subcortical arteriosclerotic encephalopathy (p less than 0.001). The sclerotic rate correlated well with the degree of ischemic white matter changes as well as with blood pressure.