Research has shown that hypertension (high blood pressure), a common condition in older adults, affects cardiovascular function and, by extension, increases the risk of cerebrovascular disease. While previous studies have identified hypertension as a risk factor for cognitive decline and dementia, a new NIA-funded study was the first to use a brain imaging technology called continuous arterial spin-labeled magnetic resonance imaging (CASL-MRI) to look at the effect of hypertension on cognitively normal people.
Researchers at the University of Pittsburgh School of Medicine studied 41 cognitively normal elderly people, 19 with hypertension and 22 without it, to compare regional cerebral blood flow (rCBF). The study participants, who ranged in age from 75 to 92, had noninvasive CASL-MRI, which measured rCBF rates over the entire brain. All of the individuals with hypertension controlled their blood pressure with medication.
The CASL-MRI results showed that the people with hypertension had reduced cerebral blood flow in many subcortical regions of the brain, including the bilateral putamen, globus pallidus, and left hippocampus, as well as in the limbic and paralimbic structures. These results are consistent with those of previous studies that used other imaging methods.
The authors suggest that, with further development, CASL-MRI might be used to predict dementia by identifying patterns of blood flow in the brains of hypertensive, cognitively healthy individuals and that better blood pressure control may help reduce the risk of AD.
Reference: Weiying, Dai, et al. Abnormal regional cerebral blood flow in cognitively normal elderly subjects with hypertension. Stroke. 2008. 39:349-54.
