Date	Event
21 days before presentation	Dental scaling
15 days before presentation	Headache onset
1 day before presentation	Neurological symptoms
Day 0	Emergency department/head computed tomography (CT)
	Suspected intracranial tumours
Day 0	Transfer
Day 1	Head magnetic resonance imaging
	Confirmed intracerebral abscesses
Day 1	Abscess drainage
	Cultivated by bacteria commonly found in the oral flora
Day 2	Transthoracic echocardiography
	Findings of the dilated coronary sinus
Day 4	Transoesophageal echocardiography with agitated saline
	Confirmation of shunt, suspicion of simultaneous extra- and intracardiac shunting
Day 5	Cardiac magnetic resonance and magnetic resonance angiography
	Confirmation of persistent left superior vena cava and right-sided superior vena cava draining into the left atrium. However, intracardiac shunting is not evident
Day 15	Cardiac CT with angiography
	Extracardiac sinus venosus defect discovered