Moyamoya Syndrome

In brief: Moyamoya syndrome describes characteristic moyamoya vascular changes that occur with another associated disease, genetic disorder, or exposure.

Use in moyamoya disease

The imaging pattern can resemble primary moyamoya disease: narrowing near the terminal internal carotid arteries with abnormal collateral networks. The distinction is based on the broader clinical context, not on the word “syndrome” implying milder disease. Modern Japanese criteria discuss associated conditions while recognizing that terminology has evolved. [1]

Reported associations include sickle cell disease, neurofibromatosis type 1, Down syndrome, autoimmune disorders, some thyroid disorders, meningitis, and prior cranial radiation. The evaluation should confirm the vascular anatomy and assess the associated condition rather than assume causation from a coincidental diagnosis.

Treatment questions remain similar: symptoms, prior stroke or hemorrhage, perfusion, cerebrovascular reserve, anatomy, and the expected role of revascularization. Management also includes the associated disorder. [2]

Clinical detail

Research papers and centers may use moyamoya angiopathy as an umbrella term for disease and syndrome. Readers should check each source’s definition before comparing outcomes.