Abstract
Background Scalp arteriovenous malformations (AVM) are rare vascular malformations that are predominantly congenital and asymptomatic. We report a novel case of an ischaemic stroke associated with a scalp AVM, in a 44-year-old man presenting with a cerebellar infarct.
Presentation A 44-year-old previously healthy man presented with nausea, vomiting, headache and dizziness. He has had a soft, painless mass on the right posterior scalp for over 20 years, which gradually increased in size in the last few months. CT brain and angiogram showed an evolving right posterior inferior cerebellar artery infarct and a right occipital scalp AVM measuring 7cm in diameter. Digital subtraction angiography confirmed arterial feeding from the right occipital and V3 vertebral arteries. Work up for other young stroke causes only revealed hypercholesterolaemia. On day 3, repeat CT brain showed progressive hydrocephalus and new tonsillar herniation. Posterior fossa decompression was contemplated but avoided due to the difficult access to the posterior fossa and high risk of bleeding. Urgent AVM resection/embolisation were discussed but not enacted due to the possibility of scalp necrosis or cerebellum compression from a partially-resected AVM haematoma. Fortunately, the patient remained stable. The AVM was devascularised endovascularly on day 10.
Conclusions We hypothesise that the infarct was caused by a steal phenomenon from the scalp AVM, which has not been previously associated with ischaemic strokes. The position of the AVM posed treatment dilemmas, where the natural history of the cerebellar infarct was weighed against numerous risks of posterior fossa decompression with an overlying scalp AVM.
