Hemorrhagic transformation of childhood arterial ischemic stroke

Abstract

Background and purpose: The objective of this study was to describe the occurrence of hemorrhagic transformation (HT) among children with arterial ischemic stroke within 30 days after symptom onset and to describe clinical factors associated with HT.

Methods: Sixty-three children aged 1 month to 18 years with arterial ischemic stroke between January 2005 and November 2008 were identified from a single-center prospective pediatric stroke registry. All neuroimaging studies within 30 days of stroke were reviewed by a study neuroradiologist. Hemorrhage was classified according to the European Cooperative Acute Stroke Study-1 definitions. Association of HT with clinical factors, systemic anticoagulation, stroke volume, and outcome was analyzed.

Results: HT occurred in 19 of 63 children (30%; 95% CI, 19% to 43%), only 2 (3%) of whom were symptomatic. Hemorrhage classification was hemorrhagic infarction (HI)1 in 14, HI2 in 2, parenchymal hematoma (PH)1 in 2, and PH2 in 1. HT was less common in children with vasculopathy (relative risk, 0.27; 95% CI, 0.07 to 1.06; P=0.04) than in those with other stroke mechanisms. HT was not significantly associated with anticoagulation versus antiplatelet therapy (relative risk, 0.6; 95% CI, 0.2 to 1.5; P=0.26) but was associated with larger infarct volumes (P=0.0084). In multivariable analysis, worse Pediatric Stroke Outcome Measure scores were associated with infarct volume ≥5% of total supratentorial brain volume (OR, 4.0; 95% CI, 1.1 to 15; P=0.04), and a trend existed toward association of worse Pediatric Stroke Outcome Measure scores with HT (OR, 4.0; 95% CI, 0.9 to 18; P=0.07).

Conclusions: HT occurred in 30% of children with arterial ischemic stroke within 30 days. Most hemorrhages were petechial and asymptomatic. Infarct volume was associated with HT and worse outcome.

Figure 1. Examples of ECASS Classification of Hemorrhagic Transformation

A. HI1 on head CT with punctate foci of petechial hemorrhage within left frontal infarct (white arrows). B. Diffusion-weighted MRI showing left sided infarcts (left panel). HI1 on gradient recalled echo (GRE) T2* susceptibility MRI from same patient, showing punctate foci of petechial hemorrhage within the left occipital infarct (dark arrows) (right panel). C. Diffusion-weighted MRI showing left frontal infarct (left panel). HI2 on GRE T2* susceptibility MRI from same patient as in D, showing more confluent small foci of hemorrhage without mass effect (white arrows) (right panel). D. PH1 on head CT showing a small hematoma with mild surrounding edema within right basal ganglia infarct (white arrow).

Figure 2

Distribution of Strokes. ACA, Anterior cerebral artery; MCA, Middle cerebral artery; PCA, Posterior cerebral artery

Figure 3. Distribution of Total Pediatric Stroke Outcome Measure Scores at Follow-up according to the Presence or Absence of Hemorrhagic Transformation (HT)

A. Total cohort B. Children with isolated supratentorial infarction