Supplementary Material for: Mineralizing Microangiopathy Presenting as Pediatric Stroke: A Case Report

Introduction:
Mineralizing angiopathy is a rare cause of pediatric stroke and has not previously been described in a Nordic European country. This case highlights the diagnostic value of CT imaging and the potential underdiagnosis of this condition in high-income countries.

Case presentation:
An 11-month-old previously healthy boy presented with acute left-sided hemiparesis, with a pediatric National Institutes of Health Stroke (pedNIHSS) score of nine. Initial CT revealed bilateral basal ganglia calcifications and tortuous internal carotid arteries. MRI confirmed an acute infarction in the right basal ganglia. The diagnosis of mineralizing angiopathy was made based on the neuroimaging findings, with sagittal CT views visualizing calcifications following the contours of deep perforating vessels. An extensive stroke workup, including cardiac and metabolic evaluations, was unremarkable. The patient received supportive care, was discharged with a pedNIHSS of five, and is under neurological follow-up.

Conclusion:
Mineralizing angiopathy may be underrecognized in pediatric stroke, particularly in settings where MRI is preferred over CT. Early CT imaging can aid diagnosis. Longitudinal follow-up may offer novel insights into the pathophysiology of vascular calcifications.