Introduction: Symptomatic infantile spasms (SIS) constitute a debilitating epileptic encephalopathy due to an identifiable lesion in the developing brain. Perinatal and infantile arterial ischemic stroke (AIS) result in a large spectrum of developmental outcomes. Risk factors for worse outcome are not well understood, with epilepsy diagnosis being a poor prognostic factor. As a focal injury in an otherwise healthy brain, early stroke provides unique insight into the developmental effects of epileptic encephalopathy.
Hypothesis: SIS are a rare complication of AIS in infancy/early childhood. Additional neurological comorbidities are seen in stroke patients with SIS.
Methods: A population-based cohort of pediatric stroke (Calgary Pediatric Stroke Program) was screened. Inclusion criteria were: (1) MRI-confirmed AIS (2) age at stroke <2 years (3) EEG with hypsarrhythmia, and (4) clinical diagnosis of infantile spasms. Pediatric Stroke Outcome Measure (PSOM) was used to determine neurological outcome at follow up. Poor outcomes included total PSOM >2 and non-motor outcomes >1.
Results: One hundred and sixty-three children with AIS at <2 years of age were screened. EEGs were available for 92 (56%). Five (3%) of all patients had SIS (3 symptomatic neonatal, 1 presumed perinatal, 1 childhood AIS). Four patients (80%) were male. Strokes were unilateral and involving MCA (4) and PCA (1) territories. Median age at diagnosis was 7 months (range 2-22). Four responded to either vigabatrin and/or ACTH/steroids. One was refractory to several treatments. Compared to 28/158 (18%) in the non-SIS group, 4/5 with SIS (80%) had comorbid neurological diagnoses including genetic syndromes (2), premature brain injury (1), or hypoxic ischemic encephalopathy (1). At a median follow-up of 29 months (range 6-56), all but one patient had poor neurological outcome. One patient with good outcome had no comorbidities. One patient died of causes unrelated to stroke.
Conclusions: Early AIS can be complicated by infantile spasms but usually only in the context of additional neurological comrobidity. Neurological outcomes are poor but discerning the contribution of the epileptic encephlapathy is challenging as in other IS populations.