Background:There is sparse literature on the frequency and clinical significance of intracranial venous variants in children with cerebral sinovenous thrombosis (CSVT).

Methods:We retrospectively reviewed children (term neonates – 18 years), with CSVT from January 2008 to January 2014 and age- and sex-matched controls without CSVT who underwent CT/MR venography. Clinical features studied in CSVT subjects included raised intracranial pressure, presentation and risk factors. Radiological features studied included CSVT location, presence and type of intracranial venous variants, hemorrhagic venous infarction and venous collateralization. Clinical outcome was measured by the paediatric stroke outcome measure (PSOM) and radiological outcome was measured by timing of thrombus recanalization at follow-up.

Results:Fifty-one children with CSVT were identified. Twenty-two (43%) had anatomical venous variants at presentation. These included 19 (86%) children with hypoplasia/absence of a major dural sinus, 5 (23%) with persistent fetal structures, 3 (14%) with duplications/fenestrations and 1 (5%) with disconnected superficial and deep venous systems. Age and sex-matched controls had a slightly higher prevalence of anatomical venous variants 26/51 (51%). There were no significant clinical and radiological difference between children with CSVT and venous variants compared to those with typical venous anatomy. However, children with variants at presentation 3/22 (14%) vs. those with no variants 0/29 demonstrated a trend towards abnormal cognitive and behavioural outcome (p = 0.0616).

Conclusions: Anatomical variants are seen in the majority of children with and without CSVT. The influence of these alterations on the brain’s ability to tolerate venous congestion due to thrombosis merits further study.