Thrombosed brainstem developmental venous anomaly
Developmental venous anomaly (DVA), also known as venous angioma, represent a dilated cerebral vein which is a collector for other smaller veins; it is considered a persistent embryonal vein.
Most authors agree than DVAs are normal veins but in an unusual location, so they are required for normal venous outflow and resection of them should be avoided, because in most cases this would lead to venous infarction.
This case represents combined subarachnoid hemorrhage (SAH) and venous infarction due to thrombosis of DVA in the hindbrain. Coexistence of SAH and venous infarction of such etiology are rare, to our knowledge, this is the first case, because we could not identify similar cases in the English literature.
Since this case demonstrates the development of venous infarction after DVA thrombosis, one may consider this a proof for the requirement of DVA patency for normal venous outflow and the need for avoiding DVA resection.
The differential diagnosis for the case is pontine arterial infarction due to vasospasm and delayed cerebral ischemia, that is frequent after 3-10 days in patients with SAH, but the lack of restricted diffusion in the brainstem lesions makes arterial stroke unlikely.