Recanalization therapy in pediatric stroke

• stroke is relatively rare in childhood – the incidence is reported in the wide range of 1.2-13/100 000 children < 18 years (both ischemic and hemorrhagic)
  • the highest risk is in newborns – incidence up to 25/100.000 births [Panagopoulos,2021]
  • ischemic stroke accounts for only 55% of all strokes (compared to 80% in adults)
• in adults, occlusion of a major artery is associated with significant morbidity and increased mortality; greater brain plasticity may mitigate the stroke impact in children
• nevertheless, stroke in children often results in substantial motor and/or neurocognitive impairment (up to 60%), which is then managed for several decades [Kinney, 2018]   [DaVeber, 2000]
• the mortality rate of pediatric stroke is lower than that of adults (approximately 3-6%); however, stroke is among the top 10 causes of death in children  [Panagopoulos,2021]

• stroke is often diagnosed later in children than in adults
  • strokes in children are relatively rare, so they are not thought of as much
  • pediatric stroke may have an atypical course resembling other diagnoses (stroke mimics)
  • lack of a stroke protocol for pediatric emergencies
• late diagnosis may delay or hinder the initiation of recanalization therapy

• cardioembolism, dissection, or other focal vasculopathies and hematologic disorders predominate at younger ages
• in approx. 50% of strokes, the exact etiology is not detected (cryptogenic stroke)

→ see Pediatric stroke etiology

• the incidence of stroke mimics in children is relatively high (up to 44% according to the TIPS trial, over 70% according to other sources) [DeLaroche, 2017]]
  • Todd’s hemiparesis after a seizure
  • migraine
  • functional disorders (up to 20%!)  [DeLaroche, 2017]
  • methotrexate toxicity
  • PRES
  • demyelinating diseases
• therefore, clear evidence of ischemic etiology is required for the indication of recanalization therapy (it is optimal to see a lesion on DWI + occlusion on MRA)

• MRI is the optimal and preferred modality
  • it detects early ischemia on DWI + occlusion on MRA and can help to exclude some stroke mimics
  • rapid stroke protocol can be performed in 15-20 minutes (DWI/ADC, FLAIR or T2, GRE/SWI, MRA extra- and intracranial)
  • MR perfusion is optional
• CT (if MRI is not available or the child is unstable)
  • optimally perform NCCT+CTA (+CTP)
  • CTA is excellent for assessing occlusion and collateral circulation
  • disadvantages of CT: poor detection of early ischemia and mimics, radiation exposure, contrast agent toxicity
• relevance of CTP in children is unclear
  • adult cut-off values may not be valid in the pediatric population (especially in very young children)
  • currently, there are no strict rules for the indication of procedures beyond the 4.5 (IVT) or 6h (MT) window based on CTP

→ neuroimaging in pediatric stroke

• there is a lack of randomized data regarding the safety and efficacy of recanalization methods in children; retrospective cohorts conclude the safety and feasibility of IVT and MT in the pediatric population
• consider risk-benefit; high-risk procedures may be less justified in children than in adults (although lower rates of sICH have been reported for both IVT and MT compared with adults)  [Sporns, 2020]
  
• consider the specific causes of stroke in children (e.g., focal cerebral arteriopathy)

• a network of pediatric stroke centers should provide pediatric stroke care
• follow locally approved protocols that take into account the specific causes of a stroke at a young age and the possibility of stroke mimics (confirmation of stroke by imaging is essential)
• the legal aspects of care for minors should also be considered