Neuropathology in older people with disequilibrium of unknown cause.

Abstract

To identify the neuropathologic features associated with disequilibrium in older people. Disequilibrium of unknown cause is common in older people. Postmortem specimens from six patients and four control subjects, who were part of a longitudinal study of older people with disequilibrium, were studied. Cerebral atrophy, ventriculomegaly, and histologic appearance were assessed. Astrocytic hypertrophy, arteriolar sclerotic index (1 - [inner diameter/outer diameter]), and arteriolar density were quantified in the frontal periventricular white matter (FPVWM). In comparison with control subjects, most patients had prominent frontal atrophy and ventriculomegaly. There were no other gross pathologic findings, microscopic infarcts, or areas of necrosis in patients or control subjects. Markedly reactive astrocytes were found in FPVWM of most patients and not in control subjects. Patients tended to have higher mean sclerotic indices compared with control subjects, but arteriolar density was no different in the two groups. Senile plaques and neurofibrillary tangles were no different in patients and control subjects except in one patient, in whom AD developed after entry. One patient had cerebral amyloid angiopathy (CAA) without intraparenchymal hemorrhage. Although there was some overlap between the two groups, the main differences between patients and control subjects were prominent frontal atrophy and ventriculomegaly, reactive astrocytes in FPVWM, and increased arteriolar wall thickness (sclerotic index). These findings suggest an association between subcortical leukoencephalopathy and disequilibrium in older nonhypertensive patients.