Brain Blood Flow and Posture

Abnormal blood flow to the brain during changes in posture may lead to a higher risk of falling. This project is important because it investigates blood flow and blood pressure during posture transitions.

Project Status: Complete

Project Description

More than one third of older adults fall each year. There may be a relationship between falls and reduced brain blood flow when a person changes positions (e.g., going from laying down to standing up). The brain cannot store energy and needs constant blood flow to function and meet its energy needs. Younger people’s cardiovascular systems can maintain a constant amount of blood flow to the brain by adjusting blood pressure. However, as the body ages, there are several changes (e.g., stiffer arterial walls) that change the cardiovascular system’s ability to control blood pressure effectively. As a result, older adults are at greater risk of developing hypotension (i.e., low blood pressure) for a period during and after changes in posture. This period of low blood pressure (called “postural hypotension”) may be experienced by an older adult as light-headedness and/or dizziness and in some cases, may lead to a fall.

Participants were asked to wear a special headband that measures oxygen levels in the brain and a finger-cuff to measure blood pressure. They were asked to complete three posture changes: (1) going from laying down to standing up, (2) going from laying down, to sitting down, to standing up, and (3) going from sitting down, to standing up. The researchers were able to view changes in brain blood flow and blood pressure during each of these transitions. They looked at participants with and without a history of falling. The balance data collected 2-minutes after standing demonstrates that those who have a history of falling sway more in the side-to-side and forwards-to-backwards directions compared to those who don’t have a history of falls. These findings suggest that those more likely to fall are more unstable following a posture transition.

Project Lead

Project Team

Richard Hughson - Principal Investigator
Laura Fitzgibbon-Collins - Co-investigator

Research Topics