Case 319: Multisystemic Smooth Muscle Dysfunction Syndrome

A 7-year-old Chinese girl presented to a local hospital with a 5-day history of progressive right-sided hemiplegia, expressive aphasia, mild bulbar palsy, and reduced general responsiveness. At presentation, her Glasgow Coma Scale was 11/15 (E4 V1M6). Notably, she had two strokelike episodes approximately 7 and 3 months prior to the current episode, with headache, reduced movement, and numbness in the left hand. She also had an extensive medical history at a young age, including congenital mydriasis, patent ductus arteriosus with ligation, dysautonomia, low blood pressure, hypotonic bladder requiring intermittent catheterization, poor bowel transit, and gallstones. Her immunization record was up to date, and her development was otherwise unremarkable. Her parents and younger sibling were healthy. Her blood tests revealed a mildly increased venous lactate level at 2.3 mmol/L (normal range, 0.7-2.1 mmol/L), without acidosis. Results of a coagulopathy work-up (clotting profile and protein C, protein S, antithrombin 3, and fibrinogen levels) were normal. MRI and MR angiography of the brain were performed at presentation.