This key symptom can make Alzheimer’s disease worse

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In a new study, researchers found that impaired blood flow in the brain is linked to the buildup of tau tangles, a hallmark indicator of cognitive decline.

The finding suggests that treatments targeting vascular health in the brain — as well as amyloid plaques and tau tangles — may be more effective in preserving memory and cognitive function than single-target therapies.

This study confirms that doctors should carefully consider vascular health and associated risk factors — like high blood pressure, smoking, and physical inactivity — in the course of Alzheimer’s prevention.

The research was conducted by a team at USC.

In the study, the team wanted to understand how restricted blood flow in the brain relates to the buildup of the tau proteins characteristic of Alzheimer’s disease.

To do so, they examined MRI and PET images, as well as cerebrospinal fluid, among two groups: cognitively normal individuals and those at various stages of dementia, including mild cognitive impairment and Alzheimer’s disease.

They found that those with strong overlap between vascular dysfunction and tau pathology in key Alzheimer’s brain regions had the worst cognitive symptoms.

This connection was most pronounced among those in more advanced stages of the disease, suggesting that the pathway corresponds to cognitive decline over time.

That finding is particularly important because it suggests the pathway could be a useful biological marker for measuring Alzheimer’s progression in patients.

The effect was also most pronounced in amyloid-positive individuals, pointing to a relationship between cerebrovascular, tau, and amyloid pathologies.

The team says they are now starting to fully appreciate the role of vascular dysfunction in Alzheimer’s disease.

Controlling risk factors like smoking and high blood pressure are accessible lifestyle modifications that offer hope for those at risk.

Future steps include evaluating how the synergy between these pathologies relates to cognitive decline over time.

One author of the study is Judy Pa, an associate professor of neurology.

The study is published in The Journal of Neuroscience.

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