Neonatal Perforator Stroke: Timing, Risk Factors, and Neurological Outcome from a Single-Center Experience

<b>Background and purpose:</b> Perforator stroke (PS) is a subtype of perinatal arterial ischemic stroke (PAIS), in which injuries occur in the territory of the perforator branches of the main cerebral arteries. This study aims to explore the incidence, timing, risk factors, and clinical presentation of PS in both preterm and full-term neonates. <b>Material and methods:</b> We retrospectively analyzed data about all the neonatal brain MRIs carried out in our hospital from March 2012 to March 2023. Criterium of inclusion was the radiologically confirmed diagnosis of perforator stroke involving one or more arterial districts. <b>Results:</b> A total of 1928 patients underwent brain MRIs during the period considered. PAIS was present in 50 patients, of which 19 had PS (38%). Among the patients with PS, nine were preterm babies (47%), and six suffered from perinatal asphyxia (31.5%). PS cUS diagnosis preceded MRI diagnosis in 88% of preterm babies. The mean age at cUS diagnosis was 20 ± 7 days. Preterm babies were often asymptomatic, whereas term babies showed neurological symptoms (mainly seizures). The outcome was favorable as long as PS was isolated. <b>Conclusions:</b> PS is surprisingly frequent among PAIS. It represents the most common form of PAIS in preterm babies and in babies suffering from birth asphyxia. Prenatal and perinatal factors suggesting a possible thromboembolic etiology leading to PAIS are rare in our population of preterm babies, in which the diagnosis was always preceded by negative cUS. These assumptions suggest a postnatal development of PS in premature babies more than a perinatal one.