Ischaemic stroke is associated with dynamic and regional changes in PVS volume and count, with stroke survivors showing significant longitudinal reductions in perivascular space volume and cluster counts over 36 months, contrary to age-related PVS enlargement observed in healthy controls.
Key Findings
Results
At 3 months post-stroke, whole-brain PVS metrics were significantly greater in stroke survivors compared to healthy controls.
Stroke survivor group: n=124; 39 women; median age=70 [62, 76] years
Healthy control group: n=39; 15 women; median age=69 [66, 72.5] years
MRI scans were acquired at 3 months, 12 months, and 36 months post-stroke
PVS were automatically segmented from T1-weighted MRI using a validated deep learning algorithm (nnU-Net)
Generalised linear mixed-effects models were used, adjusting for baseline age, sex, total intracranial volume, and body mass index
Results
By 36 months post-stroke, stroke patients demonstrated significant PVS reductions relative to controls specifically in the frontal lobe.
These reductions were region-specific, with the frontal lobe being explicitly identified as the site of significant change
Results
Stroke survivors showed significant longitudinal reductions in PVS volume and cluster counts over 36 months, contrary to the age-related PVS enlargement observed in healthy controls.
Healthy controls exhibited age-related PVS enlargement over the same follow-up period
Stroke survivors demonstrated the opposite trajectory, with PVS volume and cluster counts decreasing over time
This divergence suggests that post-stroke PVS trajectories are dynamic rather than static
Discussion
MRI-visible PVS trajectories after ischaemic stroke are dynamic and region-specific, challenging the interpretation of PVS enlargement as a simple marker of cerebrovascular disease burden.
PVS are described as an emerging marker of cerebral small vessel disease with potential prognostic value in stroke
The study challenges a straightforward interpretation of PVS as a unidirectional marker of disease burden
The findings indicate that stroke-related PVS changes do not follow the same trajectory as normal aging-related PVS changes
What This Means
This research tracked changes in tiny fluid-filled spaces surrounding brain blood vessels—called perivascular spaces (PVS)—in people who had suffered a stroke, comparing them to healthy individuals over a period of three years. These spaces can be detected using MRI brain scans and are thought to reflect the health of small blood vessels in the brain. The study followed 124 stroke survivors and 39 healthy controls, scanning their brains at 3, 12, and 36 months after the stroke occurred.
The study found that shortly after stroke (at 3 months), stroke survivors had noticeably larger and more numerous perivascular spaces throughout the brain compared to healthy controls. However, over the following three years, stroke survivors actually showed a decrease in these spaces—particularly in the frontal lobe—while healthy controls showed the opposite pattern, with perivascular spaces gradually enlarging as part of normal aging. This suggests that the brain undergoes distinct and region-specific changes in these fluid spaces following a stroke.
These findings matter because perivascular spaces have been proposed as a useful marker to monitor brain blood vessel health and disease progression. This research suggests that the relationship between perivascular spaces and brain health after stroke is more complex than previously thought—perivascular spaces do not simply grow larger as disease worsens. Instead, they can shrink following stroke in ways that differ from normal aging, which means scientists and clinicians may need to reconsider how they use PVS measurements as indicators of cerebrovascular disease after stroke.
Pham W, Khlif M, Chen Z, Jarema A, Henderson L, Macefield V, et al.. (2026). Tracking the changes in longitudinal MRI-detected perivascular spaces following ischaemic stroke.. European stroke journal. https://doi.org/10.1093/esj/aakag108