Researchers at the RIKEN Center for Biosystems Dynamics Research (BDR) in Japan have identified changes in the aging brain related to blood circulation. Published in the scientific journal Brain, the study found that natural age-related enlargement of the ventricles—a condition called ventriculomegaly—was associated with a lag in blood drainage from a specific deep region of the brain. The lag can be detected easily with MRI, making it a potential biomarker for predicting ventriculomegaly and the aging brain, which can then be treated quickly.

Ventriculomegaly is an abnormal condition in which fluid accumulates in the ventricles of the brain without properly draining, making them enlarged. Although ventricular enlargement within normal range is not itself considered a disease, when left unchecked it can lead to ventriculomegaly and dementia resulting from normal pressure hydrocephalus. In their study, the team found that ventriculomegaly was associated with changes in blood circulation of the brain. “We found an age-related perfusion timing shift in the brain’s venous systems whose lifespan profile was very similar to, but slightly preceded that of ventricular enlargement,” explains first author Toshihiko Aso.

After blood circulates through the brain providing necessary oxygen, the deoxygenated blood must return to the heart though our veins. This happens through two pathways, one draining blood from regions close to the surface of the brain, and the other from areas deep in the brain. By using MRI to measure changes in blood flow, the team at BDR recently found that as we age, the time it takes for blood to drain through these two pathways becomes out of sync. The result is a time lag between the deep drainage pathway and the surface pathway, which increases with age.

Scientists at Sanford Burnham Prebys Medical Discovery Institute and Loma Linda University Health have demonstrated the promise of applying magnetic resonance imaging (MRI) to predict the efficacy of using human neural stem cells to treat a brain injury—a first-ever “biomarker” for regenerative medicine that could help personalize stem cell treatments for neurological disorders and improve efficacy. The researchers expect to test the findings in a clinical trial evaluating the stem cell therapy in newborns who experience a brain injury during birth called perinatal hypoxic-ischemic brain injury (HII). The study was published in Cell Reports.

“In order for stem cell therapies to benefit patients, we need to be thoughtful and scientific about who receives these treatments,” says Evan Y. Snyder, M.D., Ph.D., professor and director of the Center for Stem Cells and Regenerative Medicine at Sanford Burnham Prebys, and corresponding study author. “I am hopeful that MRI, which is already used during the course of care for these newborns, will help ensure that infants who experience HII get the best, most appropriate treatment possible. In the future, MRI could help guide the use of stem cells to treat—or in some instances, not treat—additional brain disorders such as spinal cord injury and stroke.”

Scientists now understand that, in many instances, human neural stem cells are therapeutic because they can protect living cells—in contrast to “re-animating” or replacing nerve cells that are already dead. As a result, understanding the health of brain tissue prior to a stem cell transplant is critical to the treatment’s potential success. Tools that help predict the efficacy of neural stem cell therapy could increase the success of clinical trials, which are ongoing in people with Parkinson’s disease, spinal cord injury and additional neurological conditions, while also sparing people who will not respond to treatment from an invasive procedure that offers false hope.