Higher Cerebrovascular Impedance Found in Adults with Mild Cognitive Impairment

Older adults with mild cognitive impairment showed greater resistance to brain blood flow compared to those without cognitive impediments, according to a first-of-its-kind study in the Journal of Applied Physiology.

Brain blood flow resistance (also called cerebrovascular impedance) is linked to cognitive problems, which can manifest in several ways, including:

• Difficulty remembering recent events
• Difficulty finding the right word or remembering a name
• Difficulty focusing on a task
• Disorientation in time and space

The purpose of the study was to determine if mild cognitive impairment affects the brain’s blood vessels’ ability to transport blood. Using blood pressure instruments and ultrasound imaging to measure impedance in the brain’s blood vessels, the research team studied 58 older adults with mild cognitive impairment who have a higher risk for developing Alzheimer disease. The researchers compared these participants to 25 age-matched volunteers with normal cognition.

The research team found the volunteers with mild cognitive impairment had higher cerebrovascular impedance and, in turn, decreased blood flow (hypoperfusion) through the brain. Hypoperfusion can lead to cognitive problems in older adults. “These findings shed light on the pathophysiological mechanisms of brain hypoperfusion in older adults who have a high risk of [Alzheimer disease],” the researchers wrote.

“This study highlights the importance of brain vascular function in brain health in older adults,” said Rong Zhang, PhD, a professor of neurology and senior author of the study.