Objective: Children with sickle cell disease (SCD) are at risk of developing cerebral vasculopathies, increasing the risk of stroke. While some vasculopathies are medically managed, surgical revascularization might be needed in patients who also have moyamoya arteriopathy (MMA). The aim of this study was to characterize stroke timing and phenotype between children with homozygous SCD (HbSS) alone and those with HbSS and concurrent MMA.
Methods: A retrospective review of clinical and radiological information for pediatric patients (age < 21 years) with HbSS and cerebrovascular sequelae at a single institution (1997-2021) was conducted. Cerebrovascular sequelae included stroke, transient ischemic attack, elevated transcranial Doppler velocities, MMA, or other cerebral vessel stenosis. Patients with HbSS and MMA (HbSS/MMA group) were compared with patients with HbSS alone (HbSS group).
Results: Sixty-one children with HbSS were included; 35 had HbSS and MMA. Thirty-one patients in the HbSS/MMA group underwent surgical revascularization. The remaining patients were medically managed with chronic transfusion, hydroxyurea, and/or stem cell transplant. The incidence of first stroke detected on surveillance imaging peaked at 4-9 years of age for the HbSS group and 3-8 years for the HbSS/MMA group (p = 0.47). Children with concurrent MMA presented more often with symptomatic strokes (p < 0.05) and were diagnosed with MMA several years after their initial stroke (median 4.4, IQR 2.0-7.8). Although the HbSS and HbSS/MMA groups had a similar window of risk, children with HbSS and MMA had a higher stroke rate per person per year (0.15 vs 0.10).
Conclusions: Children with HbSS and concurrent MMA have increased risk of stroke during early childhood relative to children with HbSS alone. Additionally, those with HbSS and MMA are at risk of delayed diagnosis after experiencing neurological deficit from symptomatic stroke. These findings represent an opportunity to optimize stroke prevention screening, targeting children as young as 3-8 years of age.
Keywords: moyamoya disease; pediatrics; revascularization; sickle cell disease; stroke; transcranial Doppler; vascular disorders.