New Update: GOSH Approved to Join the BLT CPA Consortium Study!
As of 15 January 2026, Great Ormond Street Hospital has been officially approved to join the BLT Consortium Study focused on pediatric cerebral proliferative angiopathy (CPA)—an exciting step forward in global collaboration.
This approval means GOSH can now consent patients and share anonymized imaging and clinical data with Boston Children’s Hospital and The Hospital for Sick Children (SickKids) in Toronto. Together, the three centers will review cases, compare findings, and work as a team to better understand CPA.
Families who are interested in taking part can speak with their GOSH clinician or care team, or reach out to the CPA Research Foundation for connection. Participation involves sharing imaging and clinical information already collected during regular care. All data will be fully anonymized before being shared.
Because CPA is so rare, every case matters. The more information the consortium can gather, the more researchers and clinicians can learn about how CPA develops, how it behaves, and how treatments can be improved in the future. Families who choose to participate will be making a meaningful contribution to research that may help children with CPA worldwide. Please contact us with any questions!
BLT Paediatric Neurovascular Collaboration 2025: Meeting Highlights
On 14 November 2025, teams from Boston, London, and Toronto came together at Great Ormond Street Hospital (GOSH) for the annual BLT Paediatric Neurovascular Collaboration meeting. Each year, this event brings together clinicians, researchers, and trainees who share one goal: improving care for children with neurovascular conditions.
A major focus of this year’s meeting was cerebral proliferative angiopathy (CPA).
Dr. Alfred Pokmeng See shared new insights that are helping teams more confidently recognize CPA, understand how it changes over time, and decide which children may benefit from closer monitoring or specific interventions. His talk emphasized how important careful imaging review and thoughtful, team‑based decision‑making are when caring for children with CPA. As more experts compare their experiences, the field is gaining a clearer picture of what makes CPA unique and how to best support each child.
In the afternoon, case discussions walked through several complex real‑world examples of neurovascular disease, sparking great conversation across specialties. These discussions showed how combining different perspectives leads to stronger, more confident care plans for children and families.
By the end of the day, the group had agreed on several shared goals for the coming year—especially expanding CPA‑focused research, continuing joint case reviews, and working together on new biological targets that may guide future treatments. The day wrapped up with closing remarks from Mr. Greg James and an evening gathering that gave teams a chance to connect informally and strengthen international partnerships.
This year’s meeting highlighted just how powerful collaboration can be in improving care for children with rare neurovascular conditions—especially when it comes to deepening our understanding of CPA. The teams from Boston, London, and Toronto continue to move the field forward together, creating brighter possibilities for families.
Check out our new website! BLTconsortium.org
The study is underway!
September 2023
Greetings to all of those affected by and interested in the treatment of CPA. It is very encouraging to see the CPA Foundation gain traction. For a very rare condition like CPA, an associated charity will never be a huge affair in terms of numbers, but having worked with other rare disease charities and patient associations I firmly believe that quality beats quantity and that the most important resource are interested and engaged patients, families and their advocates. The CPA Foundation certainly has that.
I was fortunate enough to be invited, along with colleagues from Great Ormond Street Hospital, to the Boston-London-Toronto (BLT) group meeting in Boston, Massachusetts, USA this spring for an international forum. We use this opportunity to discuss clinical and research matters and the theme of this particular meeting was CPA.
It was very exciting to hear developments from both side of the Atlantic which will hopefully bring future benefits for children and adults with CPA. We heard from both basic vascular biologists and clinical scientists about research on the condition from the gene and cell to the patient level.
Perhaps most excitingly, we are very near to establishing a trilateral database which will allow anonymised data (with consent from patients) such as scans, blood tests and genetic information to be shared across the three sites.
One of the main problems with studying rare conditions like CPA is that it can be difficult to draw conclusions from small numbers of cases. Collaborations like this allow much more powerful and definitive studies to be undertaken. I am confident that this approach will increase our knowledge and understanding of CPA, allow us to inform patients and families better, and in time will lead to better treatments of this difficult disease.
As well as the busy academic programme, our hosts Dr Smith and Dr Orbach at the Boston Children’s Hospital Cerebrovascular Surgery and Intervention Centre kept us busy on the social side, with a lovely seafood dinner followed next morning by paintballing, at which attendance was unforutnately not optional! I managed to get a hit on my GOSH neurovascular surgery colleague Mr Silva but he soon replied in kind. A sore afternoon all round!
Greg James, Paediatric Neurosurgeon, Great Ormond Street Hospital, London, UK
A clinician’s view
A clinician’s view
August 2021
Cerebral proliferative angiopathy (CPA) was first described in 2008 as a distinct condition – before then, patients were told that they had large, untreatable arterio-venous malformations (AVMs). Even now, many patients and families are told that they have a big AVM rather than a CPA.
We are beginning to understand that CPA is quite different in its presentation, clinical symptoms, radiographic appearance and behaviour to AVMs. One of the problems is the definition remains difficult – where do ‘big AVMs’ finish and ‘CPAs’ begin?
Our Neurovascular Team at Great Ormond Street Hospital is working with colleagues in the USA (Boston Children’s) and Canada (Sick Kids Toronto) to build a database of CPA cases (which are rare). Our first aim is to develop clear guidelines for diagnosis, to help doctors correctly identify CPA. We are also interested in developing treatments for this condition. It is clear that the traditional neurosurgical strategies for treating AVMs, such as surgical excision or embolization, are not suitable for the majority of CPA patients. We need to understand the role of medical treatment, Gamma Knife, and bypass surgery – are these helpful or not for people with CPA? Research is the only way to answer these important questions.
I am very pleased that people and families affected by CPA now have access to their own, excellent charity in the form of the CPA Research Foundation, and I am looking forward to a future where patients, families, doctors and scientists can work together to answer the important questions about this condition.
Greg James, Paediatric Neurosurgeon, Great Ormond Street Hospital, London, UK
Click here for Greg’s GOSH Bio.