Pathways of neonatal stroke and subclavian steal syndrome

Case report of a central venous access device-associated thrombosis with aortic embolism in a preterm infant

Background

Thrombosis in neonates is commonly a central venous access device (CVAD) associated complication. Furthermore, a patent foramen ovale (PFO) is frequently seen in preterm infants. Even though a coincidence of both is not unusual, detaching of the thrombus and organisation of an aortic embolism has not been described until now. Treatment recommendations of CVAD-associated thrombosis in neonates do not consider frequently seen complications of preterm infants e.g. intraventricular haemorrhage.

This is the first case of a very preterm infant with pre-existing intraventricular haemorrhage, who developed a CVAD-associated thrombosis and thromboembolic complications.

Case presentation

The authors report on a very preterm girl with a pre-existing intraventricular haemorrhage and a CVAD-associated thrombus that, after removal of the CVAD, led to assumed pulmonary embolism and to an extended aortic embolism with consequent cerebral stroke. The girl was treated with unfractionated heparin (UFH) for about 50 days. During the further in-hospital stay the girl developed a mild bronchopulmonary dysplasia. Follow-up revealed clinical signs of cerebral palsy.

Conclusion

Even though preterm infants are often diagnosed with a PFO which constitutes the risk for paradoxical embolism, such complications do not occur frequently due to the physiological heart pressure proportion. Nevertheless, it is important to monitor vital parameters and cerebral perfusion after removing a CVAD with confirmed associated thrombosis, because thromboembolic complications are possible. If practicable, patients with a confirmed CVAD-associated thrombosis should be anticoagulated before removing the CVAD. However, in our patient it was rational to remove the CVAD without prior anticoagulation due to the pre-existing intraventricular haemorrhage.

There are various treatment recommendations for thrombosis or embolism in infants. However, there are no clear recommendations in very preterm infants with a high risk of cerebral bleeding respectively a pre-existing intraventricular haemorrhage. We decided to treat our patient with unfractionated heparin until the affected vessels were recanalised.

Finally, it remains a case-by-case decision how to treat CVAD-associated thrombosis and consequent embolism depending on the patient’s medical history.

Clinical presentations and neurodevelopmental outcomes of perinatal stroke in preterm and term neonates: a case series

Perinatal stroke in neonates can lead to disability in later life. However, its etiology and prognosis are poorly understood. The aim of this study was to describe clinical presentations and neurodevelopmental outcomes of our case series of perinatal stroke in Korea. Thirteen term and preterm neonates who were diagnosed with perinatal stroke in two university hospitals from March 2003 to March 2007 were enrolled. Seven term and 6 preterm neonates were diagnosed with perinatal stroke, based on the brain MRI findings. Perinatal stroke presented with seizure (4/13), perinatal distress (3/13) in term neonates, whereas stroke in preterm neonates did not present with noticeable clinical symptoms. Only one neonate had positive thrombophilic test (homozygous C677T polymorphism for MTHFR). Ten neonates had infarctions in the territory of the middle cerebral artery (MCA), and 3 neonates had borderzone infarctions between the anterior cerebral artery and MCA. Neurodevelopmental outcome was abnormal in 4 neonates. Infarction in MCA main branch or posterior limb of internal capsule showed an abnormal neurodevelopmental outcome. Our study is the first systematic study of perinatal stroke in Korea, and shows its clinical presentations and neurodevelopmental outcomes. The population-based study on incidence and prognosis of perinatal stroke in Korea is required in the future.

Diagnosis of perinatal stroke II: mechanisms and clinical phenotypes

INTRODUCTION

Here (and in an accompanying article dealing with definitions, differential diagnosis and registration), a structured sequential diagnostic flow is proposed to discern clinical phenotypes for perinatal stroke, including arterial ischaemic stroke (AIS), cerebral sinovenous thrombosis (CSVT) and haemorrhagic stroke.

MATERIAL AND RESULTS

For neonatal AIS, the diagnostic sequence is infection, trauma, embolism, arteriopathy, other, primary thrombosis and unclassifiable; for neonatal CSVT, the sequence is infection, trauma, venopathy, other, primary thrombosis and unclassifiable. The proposed hierarchical diagnostic flows are an initial step towards a standard for registration of the causes of neonatal stroke. Such standardization should guide attempts at prevention and intervention. An extensive literature search and study of a retrospective cohort of 134 newborn infants with stroke suggest that embolism is the most common identifiable cause for stroke in general (25%), preceding trauma (10%) and infection (8%). Other causes, such as asphyxia, acute blood loss, extracorporeal membrane oxygenation, genetic disorders or prothrombotic conditions, are seen in <5% of cases. For neonatal AIS, the presence of an embolic phenotype is 33% in this cohort. The designation unclassifiable scored 34% for the entire stroke group and 25% for neonatal AIS. Complex arterial stroke with multiple arteries involved is often seen when the underlying cause is infection, cranial trauma or embolism. One important conclusion is that a means of prevention is avoidance of embolism from thrombosis outside the brain.

CONCLUSION

To prevent the occurrence and recurrence of neonatal ischaemic stroke, clinicians must develop a standardized diagnostic approach that results in characterization of the clinical phenotype.

Diagnostic management of neonatal stroke

In this paper the clinical presentation of neonatal arterial ischaemic stroke (NAIS) and neonatal cerebral sinovenous thrombosis (NCSVT) is briefly summarised; then a structured hierarchical diagnostic flow is proposed to discern clinical phenotypes underlying neonatal (ischaemic as well as haemorrhagic) stroke. The diagnostic flow proposed following clinical detection or chance imaging finding is an initial step towards standardisation of the mechanisms leading to stroke. For NAIS the sequence is: infection, trauma, embolism, arteriopathy, other, primary thrombosis and unclassified; for NCSVT the sequence is: infection, trauma, venopathy, other, primary thrombosis and unclassified. Such standardisation should guide attempts at prevention and treatment. The analysis of a retrospective personal cohort of 134 newborn infants with stroke, suggest that-for stroke in general-embolism is the most common identifiable mechanism (25%), preceding trauma (10%) and infection (8%). For NAIS the presence of an embolic phenotype is 33% in this cohort. The designation unclassifiable scored 34% for the entire stroke group, 25% for neonatal arterial ischaemic stroke. Complex arterial stroke, with multiple arteries involved-is regularly seen following embolism, infection and cranial trauma.

Ischemic perinatal stroke: summary of a workshop sponsored by the National Institute of Child Health and Human Development and the National Institute of Neurological Disorders and Stroke

Ischemic perinatal stroke is a disorder associated with significant long-term neurologic morbidity. With an estimated incidence of 1 in 2300 to 5000 births, stroke is more likely to occur in the perinatal period than at any time in childhood. The incidence of ischemic perinatal stroke ranks second only to that of strokes in the elderly population. Although ischemic perinatal stroke is a well-recognized disorder, many aspects remain to be studied. There is no consensus on its terminology, definition, or classification. Several risk factors have been identified, but their precise roles in causing stroke are not well understood. There are no reliable predictors of ischemic perinatal stroke on which to base prevention or treatment strategies. To review these important issues and propose a research agenda, the National Institute of Child Health and Human Development and the National Institute of Neurological Disorders and Stroke convened a workshop in August 2006. This article provides a summary of the workshop.