Delayed Cerebral Hyperperfusion with Subarachnoid Haemorrhage after Carotid Artery Stenting

Cerebral hyperperfusion syndrome is a rare but serious complication after carotid revascularisation procedures that manifests as ipsilateral migraine-like headache, seizure, and transient focal neurological deficits in the absence of cerebral ischaemia. Cerebral hyperperfusion syndrome may lead to cerebral oedema and haemorrhage, and imaging findings of hyperperfusion may be seen. Cerebral hyperperfusion syndrome and haemorrhage after carotid artery stenting occurs most often in the first postoperative day and rarely after the first week. We report a case of a patient with delayed subarachnoid haemorrhage 16 days after carotid artery stenting, presenting with headache and focal neurological deficit, with associated imaging findings of hyperperfusion. Given the short hospital stays associated with carotid artery stenting, the present case highlights the need for vigilance by patients, carers, and clinicians for this serious complication.