Microvascular brain pathology and late-life motor impairment.

OBJECTIVE: To test the hypothesis that microvascular brain pathology is associated with late-life motor impairment.
METHODS: More than 2,500 persons participating in the Religious Orders Study or the Memory and Aging Project agreed to annual motor assessment and autopsy. Brains from 850 deceased participants were assessed for microvascular pathology including microinfarcts, cerebral amyloid angiopathy, and arteriolosclerosis, and we examined their association with global motor scores proximate to death.
RESULTS: Mean age at death was 88.5 years. More than 60% of cases had evidence of 1 or more microvascular pathologies and of these more than half did not have observed macroinfarcts. In separate regression models adjusted for age, sex, and education, microinfarcts and arteriolosclerosis were associated with level of motor function proximate to death (arteriolosclerosis, estimate, -0.027, SE 0.005, p < 0.001; microinfarcts, estimate, -0.017, SE 0.008, p = 0.026). These associations were not attenuated when controlling for vascular risk factors and diseases, postmortem interval, or interval from last clinical examination, and did not vary with level of cognition or presence of dementia proximate to death. When the 3 microvascular pathologies, macroinfarcts, and atherosclerosis were considered together in a single model, more severe arteriolosclerosis (estimate, -0.021, SE 0.005, p < 0.001) and macroinfarcts (estimate, -0.019, SE 0.006, p < 0.001) showed separate effects with the level of motor function proximate to death.
CONCLUSIONS: Microvascular brain pathology is common in older adults and may represent an under-recognized, independent cause of late-life motor impairment.