Middle Meningeal Artery Collateralization Patterns and Influencing Factors in Pediatric Moyamoya

The middle meningeal artery (MMArt) is considered to be an important collateral in moyamoya angiopathy; however, an in-depth analysis of the underlying mechanisms directing this collateral formation is missing. The aim of this study was to analyze patterns of activation of MMArt in pediatric patients along with identifying factors influencing these collateral pathways.

Retrospective clinical and angiographic data of a pediatric moyamoya cohort managed at a single center were analyzed. Angiographic staging, MMArt activation, and collateral supply via posterior cerebral artery (PCA) were evaluated on cerebral angiograms. Stroke burden was evaluated using cerebral MRI. Associations with angiographic staging, stroke burden, and PCA collateral supply were determined.

MMArt activation was observed in 49% of patients (n = 101). MMArt anterior division was activated more frequently (31% of all hemispheres). MMArt formed collaterals mostly to the frontal brain. Higher odds of activation of MMArt were observed in advanced anterior angiographic stages (stages 4-5) (OR 4.22, p < 0.001), higher posterior angiographic stages (stages 1-2) (OR 5.75, p < 0.001), longer duration of disease (OR 1.33, p = 0.014), and in cases showing collateral supply from the PCA (OR 3.39, p < 0.003). Age at symptom onset, stroke burden, and type of angiopathy (moyamoya disease/syndrome) were not associated with MMArt activation.

The MMArt serves as a crucial collateral in pediatric moyamoya, particularly to the frontal lobes. Increased MMArt activation is seen in advanced angiopathy with prolonged disease duration and PCA-derived collaterals. Stroke burden and angiopathy subtype do not appear to influence MMArt activation.