A previously independent 47-year-old woman presented to the emergency department with left face and upper limb sensorimotor deficits. Her initial National Institutes of Health Stroke Scale (NIHSS) score was 11 points and CT scan of the head excluded a haemorrhagic lesion. Unfortunately, late arrival at hospital contraindicated acute reperfusion therapy. MR scan of the brain showed an ischaemic stroke involving the deep right middle cerebral artery territory with ipsilateral encephalomalacia.
Six years previously she had developed a right hemisphere ischaemic stroke with subsequent complete motor recovery. The event had been deemed cryptogenic after a negative full workup. She was discharged on aspirin 100 mg daily but stopped this herself.
On both occasions, a CT angiogram had been reported as unremarkable. However, review of the sagittal images identified a linear filling defect in the right extracranial internal carotid artery (ICA) (figure 1A). A previous ultrasound scan of the neck…