Asymmetric insular function predicts positional blood pressure in nondemented elderly.

Forty percent of nondemented octogenarians have Braak stages consistent with insular involvement, and may be at risk for "age-related" autonomic dysfunction. The authors examined the association between insular resting cerebral blood flow (rCBF) and cardiovascular functions in 29 nondemented elderly subjects who were highly screened to exclude comorbid cardiovascular disease. Mean insular rCBF was significantly higher on the right than left. However, 35.4% of participants had left dominant rCBF (a high-risk group). Right insular rCBF was significantly lower in the high-risk group. This subset had significantly increased positional drops in systolic blood pressure. While these data cannot address Alzheimer's disease as the specific cause, this possibility is being investigated in other cohorts.