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Scientists find the brain’s hidden pulse that may predict Alzheimer’s

Scientists have captured the brain’s hidden heartbeat, offering a new key to understanding aging and Alzheimer’s.

Date:
October 14, 2025
Source:
Keck School of Medicine of USC
Summary:
Researchers at USC have created the first method to noninvasively measure microscopic blood vessel pulses in the human brain. Using advanced 7T MRI, they found these tiny pulsations grow stronger with age and vascular risk, disrupting the brain’s waste-clearing systems. The discovery may explain how circulation changes contribute to Alzheimer’s and other neurodegenerative diseases.
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Scientists at the Mark and Mary Stevens Neuroimaging and Informatics Institute (Stevens INI) at the Keck School of Medicine of USC have created a pioneering brain imaging method that captures how the brain's smallest blood vessels pulse in time with each heartbeat. These subtle movements may offer vital insights into aging and conditions such as Alzheimer's disease.

Published in Nature Cardiovascular Research, the study presents the first noninvasive approach for measuring "microvascular volumetric pulsatility" -- the rhythmic swelling and shrinking of tiny blood vessels -- in living humans. Using ultra-high field 7T magnetic resonance imaging (MRI), the researchers found that these microvessel pulses become stronger with age, particularly in the brain's deep white matter. This region is essential for communication between brain networks but is also vulnerable to reduced blood flow from distal arteries, which carry blood from the heart to the outermost parts of the body. As these pulses intensify, they may interfere with brain function and contribute to memory decline and Alzheimer's progression.

"Arterial pulsation is like the brain's natural pump, helping to move fluids and clear waste," said Danny JJ Wang, PhD, professor of neurology and radiology at the Keck School of Medicine and senior author of the study. "Our new method allows us to see, for the first time in people, how the volumes of those tiny blood vessels change with aging and vascular risk factors. This opens new avenues for studying brain health, dementia, and small vessel disease."

Scientists have long recognized that stiffness and excessive pulsation in large arteries are linked to stroke, dementia, and small vessel disease. However, until now, it has been nearly impossible to observe these rhythmic changes in the brain's smallest vessels without using invasive procedures limited to animal studies.

To overcome this, the USC team combined two advanced MRI techniques -- vascular space occupancy (VASO) and arterial spin labeling (ASL) -- to monitor subtle shifts in microvessel volume throughout the cardiac cycle. Their results revealed that older adults exhibit stronger microvascular pulsations in deep white matter compared to younger individuals, and that hypertension further intensifies these effects. "These findings provide a missing link between what we see in large vessel imaging and the microvascular damage we observe in aging and Alzheimer's disease," said lead author Fanhua Guo, PhD, a postdoctoral researcher in Wang's lab.

Excessive vascular pulsation may also disrupt the brain's "glymphatic system," a recently discovered network that removes waste substances such as beta-amyloid, a protein that accumulates in Alzheimer's disease. Over time, interference with this fluid circulation could hasten cognitive decline.

"Being able to measure these tiny vascular pulses in vivo is a critical step forward," said Arthur W. Toga, PhD, director of the Stevens INI. "This technology not only advances our understanding of brain aging but also holds promise for early diagnosis and monitoring of neurodegenerative disorders."

The researchers are exploring how the method could be adapted for wider clinical use, including on more commonly available 3T MRI scanners. Future studies will test whether microvascular volumetric pulsatility predicts cognitive outcomes and whether it can serve as a biomarker for early intervention in Alzheimer's disease and related conditions.

"This is just the beginning," Wang said. "Our goal is to bring this from research labs into clinical practice, where it could guide diagnosis, prevention, and treatment strategies for millions at risk of dementia."

About the study

In addition to Wang, the study's other authors are Fanhua Guo, Chenyang Zhao, Qinyang Shou, Kay Jann, and Xingfeng Shao from the Stevens INI, and Ning Jin from Siemens Healthcare.

This research was supported by the National Institutes of Health (NIH) grants UF1-NS100614, S10-OD025312, R01-600 NS114382, R01-EB032169, RF1AG084072, R01-EB028297, R01-NS134712, and R01-NS121040.


Story Source:

Materials provided by Keck School of Medicine of USC. Note: Content may be edited for style and length.


Journal Reference:

  1. Fanhua Guo, Chenyang Zhao, Qinyang Shou, Ning Jin, Kay Jann, Xingfeng Shao, Danny JJ Wang. Assessing cerebral microvascular volumetric with high-resolution 4D cerebral blood volume MRI at 7 T. Nature Cardiovascular Research, 2025; DOI: 10.1038/s44161-025-00722-1

Cite This Page:

Keck School of Medicine of USC. "Scientists find the brain’s hidden pulse that may predict Alzheimer’s." ScienceDaily. ScienceDaily, 14 October 2025. <www.sciencedaily.com/releases/2025/10/251014014418.htm>.
Keck School of Medicine of USC. (2025, October 14). Scientists find the brain’s hidden pulse that may predict Alzheimer’s. ScienceDaily. Retrieved October 14, 2025 from www.sciencedaily.com/releases/2025/10/251014014418.htm
Keck School of Medicine of USC. "Scientists find the brain’s hidden pulse that may predict Alzheimer’s." ScienceDaily. www.sciencedaily.com/releases/2025/10/251014014418.htm (accessed October 14, 2025).

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