Quantitative Arterial Tortuosity Suggests Arteriopathy in Children With Cryptogenic Stroke

Background and Purpose— Quantitative arterial tortuosity (QAT) is a ratio of vessel length between 2 points to the shortest linear distance between same points. QAT has been reported as an imaging biomarker of arteriopathy in pediatric arterial ischemic stroke (AIS) because of dissection and transient cerebral arteriopathy. We sought to determine whether QAT abnormalities are present in other subtypes of pediatric AIS. Methods— Children with AIS-absent conventional biomarkers of arteriopathy and case–controls who underwent magnetic resonance angiography were classified by stroke mechanism. The primary study population consisted of cryptogenic AIS cases. AIS with bow hunter physiology and cardiogenic emboli were also evaluated. AIS because of nontraumatic dissection served as positive controls. Patients without vascular risk factors served as negative controls. Segmental QAT of cervicocerebral arteries were measured using automated image processing and differences between groups analyzed. Results— In negative controls, QAT showed significant age-related variability for most arterial segments. Positive controls showed significantly increased QAT of the distal extracranial vertebral arteries (VAs) and decreased QAT of the intracranial VA relative to negative controls. Cryptogenic stroke and bow hunter physiology cases were similar to positive controls showing increased QAT of the distal extracranial VA and decreased QAT of the intracranial VA relative to negative controls. Cardioembolic stroke cases were similar to negative controls showing decreased QAT of the distal extracranial VA and increased QAT of the intracranial VA relative to positive controls. Conclusions— Pediatric cryptogenic stroke is frequently associated with cervicocerebral arteriopathies expressing altered QAT. QAT may be a diagnostic biomarker of arteriopathy in pediatric AIS.