Changes in Cerebrovascular Reactivity within Functional Networks in Older Adults with Long COVID, 2025, Pommy et al

Changes in Cerebrovascular Reactivity within Functional Networks in Older Adults with Long COVID

Jessica Pommy, Alexander Cohen, Amarpreet Mahil, Laura Glass-Umfleet, Sara Jane Swanson, Malgorzata Franczak, Shawn Obarski, Kelly Ristow, Yang Wang

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Abstract
Cognitive symptoms are reported in the vast majority of individuals with long-COVID and there is growing support to suggest neurovascular mechanisms may play a role. Older adults are at increased risk for developing complications associated with COVID-19, including heightened risk for cognitive decline.

Cerebrovascular Reactivity (CVR), a marker of neurovascular health, has been linked to age related cognitive decline and may play a role in long-COVID, however, this has not yet been explored.

The present study examined group differences in CVR in 31 older adults with long-COVID compared to 31 cognitively unimpaired older adults without long-COVID symptoms. Follow up analyses were conducted to examine how CVR was associated with both subjective cognitive Altered Cerebrovascular Reactivity in Long-COVID symptoms and neuropsychological (NP) test performance.

Using a subject specific approach, Distribution-Corrected Z-scores (DisCo-Z), analyses revealed the long-COVID group demonstrated significantly greater incidence of extreme CVR clusters within the brain (>100 voxels) and within functional networks thought to drive attention and executive function. Extreme positive CVR clusters were positively associated with greater number of subjective cognitive symptoms and negatively correlated with NP performance.

These findings are among the first to provide a link between cognitive functioning in long-COVID and neurovascular changes relevant for aging and mechanistic studies of long-COVID.

Link (Frontiers in Neurology) [Provisionally Accepted, Abstract Only]

 

What is a CVR-cluster?

 

As far as I can find out by googling, it's when blood vessels in a certain area of the brain react especially strongly to the vasoactive stimulus used in the scanning process. There can be a positive or negative correlation with the stimulus; in this case it's 'extremely positive'. I can't work out if that means they saw a lot more blood flow in areas associated with executive function and attention, or a lot more change in reactivity (so sometimes more than normal and sometimes less). Hopefully someone with knowledge will come along and explain!