OP25 – 2821: Arterial tortuosity: An imaging biomarker of childhood stroke pathogenesis?

Abstract

Objective Arteriopathy is the leading cause of childhood arterial ischemic stroke (AIS). Mechanisms are poorly understood but may include inherent abnormalities of arterial structure. Extracranial dissection is common while intracranial dissection may explain a prevalent, idiopathic focal cerebral arteriopathy (FCA) associated with high recurrence and poor outcome. We aimed to quantify cerebral arterial tortuosity, hypothesizing that increased tortuosity would be associated with extracranial dissection. Methods Children with AIS were identified within the Vascular Effects of Infection in Pediatric Stroke (VIPS) study with healthy controls from the Calgary Pediatric Stroke Program. A validated imaging software method calculated mean arterial tortuosity of the major cerebral arteries using 3D time-of-flight MR angiography (MRA) source images. Objective, multi-investigator expert reviews defined stroke etiology diagnostic categories. Tortuosity scores were compared between definitive dissection (spontaneous and traumatic), FCA, moyamoya, meningitis, and cardioembolic (disease controls) and healthy controls (ANOVA, post-hoc pair-wise Tukey). Results A total of 116 children were studied (median age 10.1 years, 57% male). Age and gender were comparable across groups. Software-generated tortuosity score means and variances were consistent with previous adult validation studies and intra-rater reliability was excellent (intraclass correlation >0.97). Tortuosity scores in healthy controls (1.333±0.039, n=15) were comparable to moyamoya (1.324±0.038, p=0.998, n=15), meningitis (1.348±0.052, p=0.989, n=12) and cardioembolic (1.379±0.056, p=0.190, n=27) cases. Tortuosity was higher in both dissection (1.398±0.072, p=0.021, n=22) and FCA (1.421±0.076, p=0.001, n=25) children. Tortuosity scores did not differ between traumatic (1.391±0.036, n=9) and atraumatic (1.403±0.090, p=0.671, n=13) dissection cases. Conclusion Children with dissection have more tortuous arteries. An association between FCA and increased tortuosity may suggest an inherent difference in vascular biology. Quantified arterial tortuosity may represent a clinically relevant imaging biomarker of pathophysiology in pediatric stroke.