A 62-year-old lady presented to hospital with thunderclap headache and was found to have a grade 1 subarachnoid haemorrhage due to ruptured anterior communicating artery (ACoA) aneurysm, treated by endovascular coiling. Two small coincidental left middle cerebral artery (MCA) aneurysms were managed conservatively.
Follow-up imaging at 6 months showed only minor ischaemic changes. Routine 2 year follow up magnetic resonance angiography (MRA) showed the coiled aneurysm to be secure with unchanged coincidental MCA aneurysms but multiple new right cerebral hemisphere lesions with extensive perilesional oedema. These lesions showed punctate enhancement on contrast MRI. 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) imaging showed normal brain FDG update.
The patient developed focal left-sided motor seizures, prompting readmission, and empirical treatment with corticosteroids, antibiotics and aspirin in addition to levetiracetam. Cerebral spinal fluid constituents were normal. Routine bloods, inflammatory markers and blood cultures were normal or negative, as was an echocardiogram. There were no further seizures, and subsequent improvement was noted in the right cerebral hemisphere imaging appearances.
Foreign material emboli following endovascular coiling is described in the literature but, to our knowledge, its presentation in this manner with this latency has not been reported.