Multi-center study of long-term evolution of neuroimaging findings in PHACE syndrome

Background: Posterior fossa anomalies, Hemangioma, Arterial anomalies, Cardiac anomalies and Eye anomalies (PHACE) is a neurocutaneous disorder characterized by various neuroimaging abnormalities, including cranio-cervical arterial anomalies. The purpose of this multi-center study is to assess the long-term evolution of neuroimaging findings in PHACE, with focus on progressive arteriopathy and intracranial hemangioma. Methods: Patients with definite PHACE who were ≥10 years of age were recruited from 16 sites. A pediatric neuroradiologist retrospectively reviewed clinical MRI/MRA or CTA reports collected from two timepoints: neuroimaging performed closest to 1 year of life and the latest available neuroimaging at the time of recruitment. Brain structural abnormalities (including intracranial hemangiomas), infarcts, cerebrovascular anomalies (including vascular risk score) and evidence of progressive arteriopathy were identified. Results: Study included 83 patients with definite PHACE (median age at recruitment: 14 years (IQR: 12-18)) with a median of 9 years (IQR: 6-12) between scans. Progression of arteriopathy was identified in 20/68 (29.4%), including 5/68 (7%) with Moyamoya arteriopathy. The vascular risk score at initial imaging was not associated with progressive arteriopathy. Two children (2%) had infarcts; one of whom had a progressive arteriopathy. The presence of intracranial hemangioma was associated with Meckel's cave enlargement and follow-up imaging suggests Meckel's cave enlargement may at least partly be related to involution of an intracranial hemangioma. Conclusion: Almost one third of children with PHACE had a progressive cerebrovascular arteriopathy on long term follow-up imaging, but infarcts were rare. Further research is necessary to guide recommendations on duration and frequency of imaging surveillance.