Innovative fMRI Technique Reveals Brain Health Improvements in Aging Women

A research group at Children's Hospital Los Angeles has developed a novel functional magnetic resonance imaging (fMRI) analysis approach that assesses cerebrovascular health in older adults. Unexpectedly, findings indicate that postmenopausal women exhibit improvements in brain health, particularly in regions linked to movement, memory, and overall connectivity within the brain. This discovery challenges previous assumptions about vascular aging, which typically predict decline with age.

The study involved measuring cerebrovascular reactivity (CVR)—the capacity of brain blood vessels to expand in response to stimuli—in 53 participants aged 51 to 83. Using blood oxygen level dependent (BOLD-CVR) imaging, researchers evaluated the ability of brain vessels to regulate blood flow amid changes in carbon dioxide levels. Dr. Bethany Sussman, the lead author, explained that this measure is crucial in understanding overall brain health, as impaired vessel response can increase susceptibility to stroke.

Interestingly, instead of a decline, the study found an increase in CVR among postmenopausal women. This was particularly evident in regions associated with movement, memory, and connectivity. The team had anticipated no change or a decrease in CVR with age, especially given prior research linking reduced reactivity with cognitive impairment.

This unexpected result may be linked to hormonal changes after menopause, such as the cessation of cyclical anemia caused by menstruation, which might impact vascular health. Future investigations aim to analyze blood hemoglobin levels to explore this further.

The research is part of the larger MASBI study, embedded within the ongoing HABS-HD project, which investigates aging and health disparities across populations. The findings not only provide insights into vascular aging in adults but also pave the way for applying this methodology to pediatric populations, as many childhood diseases involve rapid vascular changes.

Dr. Borzage emphasized the significance of the validation of this imaging approach, which could serve as a predictive tool for stroke risk and overall brain health across the lifespan. The team is planning pediatric studies to understand circulation issues from birth through adolescence, potentially benefiting conditions like diabetes, tumors, and Moyamoya disease.

The full study, "Sex Differences in the Neurovascular Health of Aging Adults," was published in the journal Stroke and presented at the International Society for Magnetic Resonance in Medicine conference. This research underscores the importance of vascular health as a key component of brain integrity and highlights the ongoing efforts at CHLA to explore vascular mechanisms in both pediatric and adult populations.