Patent foramen ovale and wake-up stroke

Abstract

A 53-year-old male patient with no medical history except for overweight (body mass index 29.1 kg/m) presented to the emergency room with an altered mental state. The patient had gone to bed in normal state and was found by his wife snoring and unable to wake. At arrival, his Glasgow Coma Scale was 9 (E2M5V2), and he demonstrated severe agitation upon further physical examination. The latter showed no clinical signs of venous thrombo-embolism. Emergency computed tomography (CT) angiography showed normal anatomy of the cerebral arteries without significant carotid artery disease. Additional perfusion CT showed recent ischaemia of the thalamus extending into the mesencephalon. Due to delay, the patient was ineligible for thrombolysis and was treated with platelet inhibition and admitted to the stroke unit. Prolonged monitoring demonstrated no arrhythmias and a normal transthoracic echocardiogram. The patient was referred for transoesophageal echocardiography to rule out a cardiac source of embolism which was performed under sedation due to the heavy gag reflex of the patient. In resting conditions, the inter-atrial septum seemed to be intact. However, upon snoring the inter-atrial septum became increasingly mobile revealing a patent foramen ovale (PFO, Figure 1; Video 1). Right to left shunting was confirmed with the administration of agitated saline (Figure 2; Video 2). Hence, snoring (essentially the combination of the Müller and Valsalva manoeuvre) may lead to a right to left shunt in case of PFO. Our patient had an uneventful recovery with medical treatment consisting of antiplatelet therapy, a statin and referral for polysomnography. Although conflicting and scant clinical information is available on the association between obstructive sleep apnoea and wake-up stroke, the combination should trigger healthcare providers to search for a possible PFO. Transoesophageal echocardiography is a valuable diagnostic tool and should be considered in these cases.