Editor—The study by Govaertet al of ultrasonography in newborn infants with perinatal cortical infarctions1 did not find a cause in 25% of cases. They also confirmed an association between stroke and pulmonary hypertension requiring assisted ventilation.2

We have previously published observations on artificially ventilated newborn piglets with pneumothorax and pulmonary hypertension, showing cerebral arterial air microembolisations.3 ,4 In the case of artificial ventilation, which is often accompanied by pulmonary air leak syndrome (pulmonary interstitial emphysema, pneumomediastinum, pneumothorax), air can easily reach the cerebral vasculature, especially when there is persistent pulmonary hypertension and right to left intracardiac shunts.

In the light of our observations, as air microemboli could not be detected by ultrasound, I suspect that the perinatal cortical infarction may have been due to cerebral arterial air embolisation in some patients in the study by Govaert et al.