Pediatric and fetal stroke

What pediatric and fetal stroke is

A stroke is a sudden interruption of blood supply (ischaemic stroke) or a sudden bleed (haemorrhagic stroke) in the brain. In children the picture splits into three broad time windows, each with its own causes, presentation and prognosis.

Fetal stroke happens before birth, usually in the second or third trimester. It is sometimes seen on prenatal ultrasound or MRI as a porencephalic cyst or asymmetric ventricular enlargement, but is more often diagnosed retrospectively when an infant or older child is investigated for hemiplegia, seizures or developmental difficulties.

Perinatal stroke includes events occurring between 20 weeks of gestation and 28 days after birth. It encompasses perinatal arterial ischaemic stroke (PAIS), neonatal haemorrhagic stroke and neonatal cerebral sinovenous thrombosis. PAIS is the most common type and accounts for the majority of unilateral cerebral palsy.

Childhood arterial ischaemic stroke is stroke occurring between 29 days and 18 years of age. The causes, presentation and acute management overlap with — but are not identical to — adult stroke.

Causes (etiology)

Stroke in children almost always has an underlying cause that should be searched for systematically — finding it changes acute management, recurrence risk, and family counselling.

• Perinatal arterial ischaemic stroke (PAIS): often multifactorial — placental thrombosis or chorioamnionitis, maternal infection or pre-eclampsia, congenital heart disease, thrombophilia in mother or baby, complicated delivery; in many cases no clear single cause is identified
• Neonatal cerebral sinovenous thrombosis: dehydration, infection (meningitis, mastoiditis), prothrombotic states, congenital heart disease
• Focal cerebral arteriopathy (FCA) — the single most common cause of arterial ischaemic stroke in previously healthy children — often follows recent infection (varicella, herpes, mycoplasma) and produces a characteristic unilateral arteriopathy on imaging
• Cardiac causes: cyanotic congenital heart disease, post-cardiac-surgery, infective endocarditis, cardiomyopathy
• Sickle cell disease — preventable with transcranial Doppler screening and chronic transfusion when indicated
• Moyamoya disease and syndrome (often with neurofibromatosis 1, Down syndrome, post-radiation, or sickle cell)
• Inherited prothrombotic conditions, antiphospholipid antibodies, MELAS and other mitochondrial disorders, COL4A1/COL4A2 small-vessel disease, CADASIL precursors
• In adolescents: arterial dissection (often after minor neck trauma), oral contraceptives, drug use, vasculitis

How it presents

Presentation depends on the time window. Many perinatal strokes are silent at birth: the baby's only sign may be focal seizures in the first 72 hours of life, or it may go unnoticed and only become apparent months later, when the family notices an early hand preference, asymmetric crawling or delayed walking.

Older children present more like adults — sudden hemiparesis, dysarthria, facial droop, speech disturbance, ataxia, severe headache — but symptoms are more often subtle, atypical, or attributed to migraine, postictal hemiparesis, or functional causes. Median time from symptom onset to diagnosis in children is still around 24 hours, far longer than in adults, and this delay is one of the most important barriers to acute treatment.

Investigations

Imaging is the first step. MRI with diffusion-weighted imaging is the best diagnostic test; CT is faster and may be used first in the acute setting to exclude haemorrhage. Vessel imaging (MRA, CTA or formal angiography) is essential to characterise the arteriopathy, look for dissection, and decide on thrombectomy. MR venography is needed when CSVT is suspected.

After imaging, the work-up looks for cause: echocardiography (often with bubble study), 24-hour ECG, thrombophilia screen, sickle cell status, lactate and aminoacids if metabolic disease is possible, varicella/herpes/mycoplasma serology in FCA, and — in fetal/perinatal strokes — placental histology when available.

Acute treatment

Acute management has converged with adult practice in the last decade, but with important paediatric caveats: trials are smaller, the evidence base is built on cohort studies and registries rather than randomised trials, and treatment is concentrated in specialised centres.

• Intravenous thrombolysis (alteplase, increasingly tenecteplase) is used in selected children >2 years with disabling acute arterial ischaemic stroke within ~4.5 hours of onset, following adapted institutional protocols; multicentre registries since 2019 have reported acceptable safety with appropriate selection
• Mechanical thrombectomy is now considered in children with large-vessel occlusion, often beyond 6 hours when perfusion imaging supports it; case series in 2023–2025 (including from the Save ChildS registry) report favourable outcomes comparable to adults
• Neonatal stroke is treated differently — thrombolysis is not used; care focuses on seizure control, supportive management, and detailed work-up for cause; therapeutic hypothermia is for neonatal encephalopathy from asphyxia, not for perinatal arterial stroke itself
• CSVT is treated with anticoagulation in most children (low-molecular-weight heparin, then oral) following AHA/ESO paediatric guidelines; in neonates, anticoagulation is considered for clot extension or symptomatic CSVT
• Sickle cell stroke is treated acutely with exchange transfusion to lower HbS, and chronically with transfusion or hydroxyurea per STOP and TWiTCH trial data
• Decompressive craniectomy is life-saving in selected children with malignant infarction

Rehabilitation and long-term care

Most children survive their stroke; the medium-term picture is shaped by what happens in the months and years afterwards. The young brain has real but limited plasticity, and the strongest evidence base in paediatric stroke rehabilitation is for intensive, modality-specific, repetitive practice.

• Constraint-Induced Movement Therapy (CIMT) for hemiplegia — strong randomised-trial evidence in perinatal stroke and pediatric stroke survivors; benefit is dose-dependent and is generally given in intensive 1- to 3-week blocks
• Hand–Arm Bimanual Intensive Training (HABIT) and mirror therapy as alternatives or complements to CIMT
• Goal-directed gait training, treadmill training and selective orthotics; functional electrical stimulation in selected children
• Speech and language therapy for aphasia (more common after dominant-hemisphere strokes in older children), feeding therapy if dysphagia is present
• Neuropsychological assessment and educational support — cognitive and behavioural consequences are common and often under-recognised, particularly attention, memory and executive function difficulties
• Post-stroke epilepsy follow-up — about 15–30% of survivors develop epilepsy, often years later
• Mental-health follow-up — anxiety, depression and post-traumatic features are common in children and parents

Prognosis

Mortality in childhood arterial ischaemic stroke is around 5–10%, lower than in adults. About 60–70% of survivors have some long-term motor, cognitive, language, behavioural or epilepsy sequelae; the rest recover well. Outcome is worse with larger infarcts, basal-ganglia involvement, posterior circulation strokes, delayed presentation, and certain causes (cardiac, moyamoya). For perinatal stroke, the dominant long-term picture is unilateral cerebral palsy, sometimes with epilepsy and learning differences — and again, intensive early rehabilitation changes the trajectory.

Recurrence risk is meaningful and underlines the need to find a cause: about 10–25% over 5 years in childhood arterial stroke, much higher in untreated sickle cell, moyamoya and arterial dissection, but very low in perinatal stroke when the cause was a one-off placental event.

The research pipeline

Several promising directions are at trial or near-trial stage. None of these are approved as standard care, and most are being tested in adult or older paediatric cohorts first.

• Erythropoietin and modified erythropoietin analogues for neuroprotection after neonatal stroke (NEAT trial and follow-up studies) — animal data show improved long-term motor and cognitive outcomes, early human safety studies are encouraging
• Allogeneic umbilical cord-blood cells, with or without erythropoietin, for subacute stroke recovery — a 2025 randomised controlled trial reported that adding rhEPO to UCB cells improves neurological recovery in subacute stroke without added safety signals; paediatric extensions are in planning
• Cord blood and mesenchymal stromal cell therapies for perinatal stroke / hemiplegic cerebral palsy — multiple Phase 1 and Phase 2 trials underway in Australia, the US and Europe (including the Hudson Institute's intra-amniotic cord-blood programme for unborn babies)
• Hyperbaric oxygen after stroke thrombectomy — the multicentre NOTICE-1 trial is planned to begin enrolment in 2026 in adults; paediatric protocols are emerging but evidence is still preliminary
• Robotic and virtual-reality enhanced rehabilitation, non-invasive brain stimulation (tDCS and repetitive TMS) as adjuncts to CIMT — small paediatric trials suggest additive benefit; not yet standard
• Patient registries (IPSS — International Pediatric Stroke Study, and national paediatric stroke registries) are powering the trials that will set future guidelines

How an educational review can help

If your child has had — or is suspected of having had — a stroke at any point from fetal life onwards, an educational review can organise the imaging and work-up, explain the likely cause and what it means for recurrence risk, suggest which assessments are still worth pursuing, and outline current rehabilitation options and research pathways relevant to your child's age. It is educational and supports your treating team.