The information for this review was identified by searches of PubMed (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi) with the terms “perinatal stroke”, “stroke-infant”, “cerebral infarction-infant”, “thrombosis-infant”, “thrombosis-neonate”, “stroke-neonate”, “thrombophilia-pregnancy”, “coagulation-pregnancy”, “congenital hemiparesis”, “stroke-infant-risk factors”, “stroke-infant-imaging”, and “stroke-infant-outcome”. Articles published until August 2003 were included. Only papers
ReviewStroke in newborn infants
Section snippets
Definition
Perinatal ischaemic stroke is a cerebrovascular event around the time of birth with pathological or radiological evidence of focal arterial infarction. Haemorrhagic lesions, generalised ischaemic lesions involving arterial border zones, and cerebral venous thromboses are not discussed in this review. Most studies have combined both perinatal (from 28 weeks into the pregnancy to 7 days old) and neonatal (under 28 days old) events. As currently understood, perinatal stroke is chiefly, although
Incidence
Most population-based studies of paediatric stroke have excluded the first months or first year of life, and many studies of perinatal systemic thromboembolic events have excluded stroke. Ultrasonography, the neuroimaging modality in most general use in the neonatal nursery, is not a sensitive indicator of perinatal stroke.12 Early imaging studies may be unrevealing in neonates with cerebral infarction,13 and early hospital discharge may preclude in-hospital diagnosis of perinatal stroke in
Perinatal stroke recognised in the neonatal period
Some newborns with perinatal stroke have neurological or general illness leading to neuroimaging and thereby to the identification of the perinatal stroke. Neonatal seizures are most commonly the clinical finding that triggers assessment, but in autopsy studies of infants who had ischaemic cerebral infarcts, neonatal seizures were noted in 25–40%.11, 16 Many neonatal seizures in infants with arterial stroke are focal and may occur in the absence of other signs of neonatal encephalopathy—such as
Pathophysiology
Clot formation is influenced, as Virchow pointed out almost 150 years ago,27 by hypercoagulable blood constituents, injury to vessel walls, and stasis of blood flow. All these may be relevant in perinatal stroke. Many factors that are associated with risk of stroke in older children, and some factors associated with stroke in adults, are also relevant in the perinatal period. In addition, there are risk factors unique to this developmental stage.
Features of the perinatal period that influence
Risk factors
Risk factors for perinatal stroke have been assessed on limited evidence from selected case series and case reports. Epidemiological investigations of infants with perinatal stroke have observed an association with maternal and placental disorders, perinatal asphyxia, blood disorders, cardiac disorders, infection, trauma, and drugs. More than one risk factor is identified in many cases (panel 1).
Assessment and neuroimaging
The assessment of neonatal patients with stroke should include a detailed history with questions regarding maternal disorders, pregnancy disorders (pre-eclampsia, history of fetal loss, placental abruption, haemorrhage), birth history, placental pathology, and family histories of neurological disorders, premature vascular disease (early myocardial infarction or stroke, deep venous thrombosis), and haematological disease (panel 2).93
Cranial imaging procedures for neonatal stroke include MRI, CT,
Management
Few studies and no randomised trials have addressed the issue of treatment, either acutely or for primary or secondary prevention of perinatal stroke. On the basis of adult and animal studies, infection, fever, and seizures should be treated aggressively. The recurrence risk for neonatal stroke is low in the first year and it is unclear whether long-term medical therapy is useful. Further studies are needed to determine the best treatment for neonatal stroke and whether prophylactic measures in
Outcome
The outcome after neonatal stroke varies among studies because of differences in functional measures, stroke type, length of follow-up, and clinical sample studied. Outcome measures used include gross and fine motor development, visual, speech and language function, IQ and behaviour abnormalities, and recurrent seizures. Children with perinatal stroke are typically diagnosed with congenital hemiplegic cerebral palsy, and it seems likely that bilateral lesions cause some spastic quadriplegic
Perinatal stroke is different
Perinatal stroke shares many features with strokes occurring later in childhood or indeed in adult years; however, there are also important differences. The neonatal coagulation system is immature and more susceptible to clot formation. The fetus with a stroke is, and the newborn recently was, attached to the mother and a placenta, and pathology arising in these may be relevant to stroke in the infant. The placenta interface is a unique environment with its own regulation of coagulant
Conclusion
In the study of perinatal stroke, much is uncertain—including the best case definition for neonatal and for delayed diagnosis, neuroimaging criteria for different procedures at different ages, what haematological tests are best at what ages, and whether effective safe preventive treatment is feasible. We still have no evidence-based approach to prevention or management.
The care of children with perinatal stroke is dispersed over several medical specialties. Obstetricians care for women with
Search strategy and selection criteria
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