Recurrent strokes secondary to moyamoya phenomenon in a child with Down's syndrome

A 6 year-old girl with Down's syndrome presented to the paedriatic emergency department with sudden onset weakness of the left half of body. Evaluation leads to the eventual diagnosis of stroke secondary to Moyamoya syndrome. This is an unusual presentation of stroke and highlights the need to expand the differential diagnosis to include rare diseases in children with predisposing conditions. This case highlights the relationship between trisomy 21 and Moyamoya syndrome