To describe a series of toddler aged children with iron deficiency anemia, cerebral venous sinus thrombosis (CVST), and no other significant risk factors for thrombosis.

Up to 5% of toddlers (age 1-3) in the United States have iron deficiency anemia, a known risk factor for thrombosis.  Childhood CVST has been reported in the setting of iron deficiency anemia due to excessive cow’s milk intake. 

We performed a retrospective study of all children seen at Seattle Children’s Hospital between 2009 and 2021 with CVST. Charts and imaging reports of patients identified using diagnostic codes for CVST were reviewed to confirm diagnosis. Chart review was used to extract data about clinical presentation, neuroimaging and outcome.

Six children (15, 33 and 42 month-old boys, and 18, 24 and 38 month-old girls) had CVST, iron deficiency anemia, and apart from some degree of dehydration, no other significant CVST risk factors. They had a negative thrombophilia workup and no documented infection or cerebrovascular abnormalities. Milk intake ranged from 30 to 80 oz/day. Hemoglobin ranged from 2.4-7.5 (median 5.4) g/dL and ferritin from 3.0-4.0 (median 3.2) ng/mL. The deep venous system was involved in all patients, including straight sinus in all 6, and bilateral internal cerebral vein involvement in 5.  Five patients suffered venous infarcts, including thalamic infarcts and deep white matter infarcts.  All 5 of these children required rehabilitation services and have neurocognitive sequelae. 

In our series, CVST in the setting of cow’s milk anemia was associated with deep venous system involvement and deep venous infarcts. Neurocognitive sequelae were present in most patients.  Cow’s milk anemia may result in a more severe form of CVST due to deep venous system involvement and associated anemic hypoxia. Similar to adults, anemia may be an independent risk factor for poor outcome following childhood CVST.