Cerebrovascular imaging and neurocognitive outcomes in children with moyamoya.

AIM: To study the relationship between brain and cerebrovascular imaging and neurocognitive metrics in children with moyamoya.

METHOD: This was a retrospective observational study of 34 children with moyamoya. Intellectual function was assessed using the Wechsler scales. Neuroimaging variables included the Suzuki stage, ivy sign score, paediatric moyamoya MRI score (PMMS), and a novel angiogram score.

RESULTS

Intellectual function was significantly below average (mean IQ = 86.6). Ivy sign and PMMS were negatively associated with all indices of intellectual function (r = -0.32 to 0.5, p < 0.05). The angiogram score was negatively correlated with non-verbal reasoning, full-scale IQ (FSIQ), and working memory (r = -0.32 to -0.4, p < 0.05). Children with posterior circulation involvement had significantly lower mean IQ scores in the mild-moderate impairment range compared to the average range for children without. The posterior cerebral artery (PCA) ivy sign score and PMMS together significantly explain 35% of the variance in FSIQ (p < 0.001), and accurately classified children with moyamoya who had weak cognitive ability (FSIQ <85), with area under the curve of 0.76 (p = 0.01) and 0.735 (p = 0.02) respectively.

INTERPRETATION: This study reliably identified a relationship between simple, routine neuroradiology sequences and neuropsychological outcomes in paediatric moyamoya. PMMS and/or PCA ivy sign score can be used to identify those children most at risk of cognitive impairment.