Inaugural cerebral sinovenous thrombosis revealing homocystinuria in a 2-year-old boy.

Cerebral sinovenous thrombosis is unusual during childhood and requires early and accurate management because of its detrimental consequences. We report on the case of a 2-year-old boy with mild psychomotor delay, who presented with nonfebrile acute ataxia. A brain computed tomographic (CT) scan showed complete thrombosis of the superior sagittal sinus, confirmed by magnetic resonance angiography and associated with a right frontal hemorrhagic infarction. Systematic screening for thrombophilia revealed homocystinuria linked to cystathionine β-synthase deficiency with underlying compound heterozygosity. The evolution was favorable after anticoagulant therapy, specific diet, and vitamin supplementation. This case is of interest because of the unusual clinical presentation as a pediatric cerebral sinovenous thrombosis. Furthermore, homocystinuria is rarely revealed by cerebral sinovenous thrombosis at the onset of the disease and should systematically be ruled out in pediatric stroke.