Patient-Specific Modeling Could Predict Occurrence of Pediatric Stroke

Area of Science:

• Biomedical Engineering
• Neurology
• Medical Imaging

Background:

• Moyamoya disease (MMD) is a progressive cerebrovascular condition causing recurrent strokes.
• Current biomarkers are insufficient for predicting contralateral stroke risk in unilateral MMD patients.
• Understanding local hemodynamics is crucial for assessing stroke progression.

Purpose of the Study:

• To noninvasively assess stroke risk in pediatric MMD patients using hemodynamic analysis.
• To identify reliable biomarkers for predicting contralateral stroke in MMD.
• To evaluate the predictive value of wall shear rate (WSR) metrics for future stroke events.

Main Methods:

• Patient-specific circle of Willis models were created from MR and X-ray angiography.
• Navier-Stokes blood flow simulations were performed using an isogeometric analysis framework.
• Wall shear rate (WSR) metrics, including critical WSR coverage and WSR score, were derived and compared with clinical outcomes.

Main Results:

• High WSR (>5,000 s⁻¹) regions indicated increased thrombus formation probability.
• Critical WSR coverage >50% and WSR score >6x control predicted early contralateral stroke in two patients.
• WSR metrics showed less clear prediction for strokes occurring 3-5 years later, but longitudinal analysis suggested predictive value.

Conclusions:

• WSR-based metrics show potential for predicting future stroke risk in pediatric MMD patients post-initial stroke.
• Patient-specific hemodynamic analysis at multiple timepoints may enhance stroke risk prediction.
• Regular follow-up and hemodynamic monitoring are warranted for secondary stroke prevention in MMD.