Changes in carotid blood flow after unilateral perinatal arterial ischemic stroke

INTRODUCTION: Little is known about changes in carotid blood flow after perinatal arterial ischemic stroke (PAIS). The aim of this study was to assess the blood flow in the internal carotid arteries (ICAs) after unilateral PAIS. METHODS:The carotid flow (ml/min) was measured noninvasively by means of two-dimensional phase-contrast magnetic resonance angiography (2D PC-MRA) in 25 full-term infants who had unilateral PAIS within 10 d after birth. In 17 infants a second 2D PC-MRA was carried out at the age of 3 mo. Asymmetry of carotid blood flow was calculated at both time points, and the circle of Willis (CoW) was assessed with a three-dimensional (3D) time-of-flight MRA. RESULTS: On the early magnetic resonance imaging (MRI), a significant increase in ipsilateral blood flow was observed (7.7%, 95% confidence interval (Cl) 3.0-14.9%), which persisted after correcting for CoW configuration. At 3 mo, this asymmetry was no longer observed. No relationship was found between the asymmetry in blood flow and either stroke size or postnatal age at scan. DISCUSSION: A higher blood flow in the ipsilateral ICA was observed during the acute phase after unilateral PAIS, and this disappeared after 3 mo. Further research into the role of hyperperfusion after PAIS may suggest new approaches to neuroprotection.