Convexity subarachnoid haemorrhage secondary to internal carotid stenosis: an indication for revascularisation

With increasing prevalence due to an ageing population, carotid artery stenosis is a significant cause of stroke morbidity and mortality. The indication for revascularisation treatment in symptomatic carotid stenosis is widely documented and accepted in the scientific community. However, treatment of asymptomatic carotid stenosis remains controversial. We report a case of a 78-year-old woman who was admitted with a convexity subarachnoid haemorrhage (cSAH) secondary to an asymptomatic high-grade carotid artery stenosis. Two months later, she suffered an atherothrombotic ischaemic stroke and was referred to surgery. Transcranial Doppler studies showed impaired cerebral vasoreactivity and, after endarterectomy, the patient developed a reperfusion syndrome; both findings consisting of exhausted collaterals as the underlying mechanism. We propose that cSAH secondary to a high-grade internal carotid artery stenosis is a high risk marker for stroke, and revascularisation therapy should be considered.