Cerebral venous sinus thrombosis in a neonate due to factor V Leiden deficiency

A case is described of cerebral venous sinus thrombosis due to factor V Leiden deficiency that occurred in the neonatal period, presenting with seizures. Diagnosis was based on ultrasonography, Doppler ultrasound (US) and magnetic resonance imaging (MRI). The aetiology was only recognized after blood-clotting tests, antithrombin III, C and S protein levels and factor V Leiden were studied. This situation was treated with intravenous heparin controlled by activated partial thromboplastin time (APTT). MRI angiography and Doppler US were important in the follow-up. It is important to assess periodically the neurological development of the baby and to prevent situations such as dehydration or severe infection, which can precipitate further thrombotic events. Molecular genetics allowed the identification of this trait in other family members.

In every newborn with a thrombotic episode, coagulation studies must be performed, including testing for activated protein C (APC) resistance. Doppler US flow measurement and the MRI studies provide the best tools for diagnosis and follow-up. Heparin should be given to double the initial individual APTT. It is important to prevent any risk situation such as dehydration or severe infection, which could lead to a recurrence of a thrombotic episode. Regular assessment of the child's neurodevelopment is an important aspect of further care.