PHACE, Blood Vessels, and Stroke: What Two New Studies Tell Us

When your child has PHACE, it’s understandable to worry about stroke. I wanted to share 2 recent studies of children with PHACE that looked closely at their brain and neck blood vessels over years. The take-home message is this: the vessels often look unusual and can change over time, but strokes in childhood are rare.

The newest PHACE study

The first study is the most recent, just published in February 2026. It’s an extension of the  “10 years of age and older” long‑term outcomes PHACE study that a lot of families in our community participated in.

In this study, researchers focused specifically on the brain and neck imaging scans from a group of children and teens in the 10 years and up study.

• They looked at 83 children with definite PHACE, most in their teens (median age 14), and compared brain imaging scans from around age 1 with scans an average of 9 years later.

• About one‑third (29%) showed some worsening or new changes in their arteries over time (what doctors call “progressive arteriopathy”).

• A small group (5 children or 7%) developed a more concerning pattern called moyamoya, where arteries become more narrowed and the brain grows tiny “backup” or “collateral” vessels to keep blood flowing normally. Three of these children had surgery to help improve their blood flow further. None of them developed stroke.

• Strokes were very uncommon. Only 2 children had signs of stroke on MRI, one at age 1 year and the other at age 14 years. Both were “silent”, meaning they were found on routine imaging and not because of any obvious symptoms at the time.

So, in this large, older PHACE group, over 97% did not have a stroke.

The second study showed similar findings

The other study, published in 2024 from a single children’s hospital, followed 34 children with PHACE from infancy over an average of 7 years, with some followed into their teen years.

• About 29% had “progressive arteriopathy” (definition above) seen on follow‑up imaging, but in most children (71%), the abnormal blood vessels seen on imaging during infancy were stable over time and did not change or get worse.

• Only 3 children (9%) had transient ischemic attacks (TIAs), which are brief stroke‑like episodes. All occurred early in infancy/early childhood and did not recur after 3 years of age. All 3 children completely recovered.

• Only one child had a stroke seen on MRI, which happened around the time of birth, not later in childhood.

• Importantly, no child in this study had a new stroke during follow‑up, even among those considered “high‑risk” (with more severe vessel changes) and followed into adolescence.

So, these authors similarly concluded that the head and neck blood vessel abnormalities seen in PHACE children are usually stable. Even when vessel changes occur, they are typically symptom-free, and the actual risk of stroke during childhood is rare.

What this means for PHACE families

• Stroke in childhood PHACE is rare. Strokes were rare in both studies and were silent on imaging or occurred around birth rather than later in childhood.

• Most vessel changes don’t cause noticeable symptoms. Even when scans showed that arteries had changed over time, most children did not develop stroke or any neurologic problems.

• “High‑risk” on imaging does not equal “certain stroke.” High‑risk features help doctors decide who may need closer monitoring or medication like aspirin, but even in these higher‑risk groups, childhood strokes were still very rare.

Hope this is helpful and at least a little reassuring! Please feel free to post questions or comments 😊