Increased prevalence of potential right-to-left shunting in children with sickle cell anaemia and stroke.

'Paradoxical' embolization via intracardiac or intrapulmonary right-to-left shunts (RLS) is an established cause of stroke. Hypercoagulable states and increased right heart pressure, which both occur in sickle cell anaemia (SCA), predispose to paradoxical embolization. We hypothesized that children with SCA and overt stroke (SCA + stroke) have an increased prevalence of potential RLS. We performed contrasted transthoracic echocardiograms on 147 children (aged 2-19 years) with SCA + stroke) mean age 12·7 ± 4·8 years, 54·4% male) and a control group without SCA or stroke (n = 123; mean age 12·1 ± 4·9 years, 53·3% male). RLS was defined as any potential RLS detected by any method, including intrapulmonary shunting. Echocardiograms were masked and adjudicated centrally. The prevalence of potential RLS was significantly higher in the SCA+stroke group than controls (45·6% vs. 23·6%, P < 0·001). The odds ratio for potential RLS in the SCA + stroke group was 2·7 (95% confidence interval: 1·6-4·6) vs controls. In post hoc analyses, the SCA + stroke group had a higher prevalence of intrapulmonary (23·8% vs. 5·7%, P < 0·001) but not intracardiac shunting (21·8% vs. 18·7%, P = 0·533). SCA patients with potential RLS were more likely to report headache at stroke onset than those without. Intrapulmonary and intracardiac shunting may be an overlooked, independent and potentially modifiable risk factor for stroke in SCA.

Brainstem strokes in children: an 11-year series from a tertiary pediatric center.

METHODS: Potential clinical barriers to making a timely diagnosis of pediatric brainstem stroke and pitfalls of noninvasive vascular imaging are presented. METHODS: An institutional review board-approved institutional database query from 2001-2012 yielded 15 patients with brainstem strokes. Medical records were reviewed for symptoms, stroke severity using the Pediatric National Institutes of Health Stroke Scale, and outcomes using the Pediatric Stroke Outcome Measure. Magnetic resonance angiography was compared with digital subtraction angiography. RESULTS: There were 10 boys and five girls; 9 months to 17 years of age (mean 7.83 years). Symptoms were headaches (eight); visual problems (eight), seizure-like activity (seven), motor deficits (six), and decreased level of consciousness in four. Time since last seen well was 12 hours to 5 days. Pediatric National Institutes of Health Stroke Scale was 1-34; <10 in eight; 3 in 1, 10-20 in two, and >20 in four. Strokes were pontine in 13/15 and involved >50% of the pons in six and <50% in seven; 2/15 had medullary strokes. Magnetic resonance angiography showed basilar artery occlusion in 8/13 patients and vertebral artery dissection in two. Digital subtraction angiography done within 9-36 hours of magnetic resonance angiography in 10/15 patients confirmed the basilar artery occlusion seen by magnetic resonance angiography and showed vertebral artery dissection in four patients. Patients were systemically anticoagulated without hemorrhagic complications. One patient died. Pediatric Stroke Outcome Measures at 2-36 months is 0-5.0/10 (mean 1.25). CONCLUSIONS: Vague symptoms contributed to delays in diagnosis. Magnetic resonance angiography was equivalent to digital subtraction angiography for basilar artery occlusion but not for vertebral artery dissection. Even with basilar artery occlusion and high stroke scales, outcome was good when systemic anticoagulation was started promptly.