Increased Risk of Cryptogenic Stroke Associated with Patent Foramen Ovale in Young Adults

Ischemic stroke is defined as a reduction in blood flow to brain tissue that results in the deterioration and death of neurons in a matter of minutes. While often seen in older patients with a history of atherosclerosis of the major arteries, a subset of ischemic strokes occur in younger individuals with minimal to no prior risk factors. Further evaluation of these unknown, or cryptogenic, strokes has yielded positive findings of a patent foramen ovale (PFO) in a concerning number of cases. Cryptogenic strokes attributable to PFO present an important clinical occurrence because they do not fit the typical template regarding those most at risk for such acutely devastating outcomes, making their identification uniquely important for both immediate and long-term patient care.  A 20-year-old Hispanic female presented to the emergency department for evaluation of neurological symptoms indicating obstruction of a major cerebral vessel. After being placed on stroke alert and found to have an embolus occluding the left middle cerebral artery (MCA) via non-contrast computed tomography (CT), tissue plasminogen activator (tPA) was administered, and mechanical thrombectomy was performed to restore blood flow. Following stabilization, further testing done on the patient revealed a substantial PFO that likely allowed for the crossing of an embolus from venous blood returning to the heart directly into the arterial circulation. The patient opted for cardiac monitor placement and has remained asymptomatic to this point while awaiting surgical repair. This case demonstrates an unusual presentation of ischemic stroke in a young individual with no reported risk factors and highlights the importance of screening for large PFO in patients prior to a serious cerebrovascular accident. It is our hope that highlighting this case may heighten awareness of this condition and allow for timely recognition from medical personnel who may encounter this same medical emergency in the future.

A Rare Case of Spontaneous Pneumothorax Leading to Cerebral Air Embolism

Cerebral arterial air embolism (CAE), a rare subtype of air embolism, carries a 21% mortality rate. We present a unique case involving a 69-year-old female with a history of usual interstitial pneumonia (UIP) who suffered a transient ischemic attack (TIA) due to CAE. Unlike typical cases, CAE in this instance resulted from spontaneous pneumothorax, not the more common iatrogenic causes. Adding complexity, an unexpected discovery emerged during evaluation: a patent foramen ovale, contributing to paradoxical embolism. This underscores the vital need to consider CAE as a differential diagnosis in UIP patients with neurological symptoms, highlighting its rarity and diagnostic challenges.

Eustachian Valve-Enhanced Paradoxical Cerebral Embolism: A Case Report

Cryptogenic stroke includes many suspicious embolic causes that do not fulfill the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification criteria. Atrial fibrillation (AF) is one of the major hidden causes of cryptogenic stroke, and an implantable loop recorder (ILR) is widely used for detecting AF. Herein, we report a case of paradoxical cerebral embolism due to a large Eustachian valve with large PFO under no molecular complete remission (CR) of acute monocytic leukemia (AMoL). A 75-year-old man arrived at our emergency room because of aphasia and right hemiparesis. He had a history of two cryptogenic strokes and implanted ILR. Magnetic resonance imaging showed left middle cerebral artery occlusion with slight acute ischemic lesion. The red clot was retrieved by mechanical thrombectomy, and complete recanalization was achieved. We checked ILR, but there was no AF. Transesophageal echocardiography revealed a large patent foramen ovale (PFO) and the large Eustachian valve in the right atrium. Although obvious deep vein thrombosis (DVT) was not detected in venous ultrasonography of the lower extremities, Wilms' tumor 1 messenger ribonucleic acid (WT1mRNA) expression level was high, and AMoL was considered to be not in molecular CR, suggesting a high risk of thrombosis to the large Eustachian valve. From large PFO and no molecular CR of AMoL, we diagnosed him with paradoxical cerebral embolism. Ruling out of AF by ILR and other etiologies, such as aortic or carotid atherosclerosis and pulmonary shunt, also supported the diagnosis of paradoxical cerebral embolism. Even in the absence of obvious DVT, paradoxical cerebral embolism should be considered in cases of a large Eustachian valve and PFO with a hypercoagulable state.

A Case of Paradoxical Cerebral Embolism Due to Pulmonary Arteriovenous Fistula Mimicking Vertebral Artery Dissection With Wallenberg Syndrome

Pulmonary arteriovenous fistula (PAVF) leads to paradoxical cerebral embolism, which can be fatal if left untreated. We report a rare case of brainstem infarction with acute severe headache and Wallenberg syndrome caused by a PAVF mimicking vertebral artery (VA) dissection. A 40-year-old man presented with a sudden occipital headache accompanied by right hemisensory disturbance. Magnetic resonance imaging revealed left lateral medullary infarction and poor depiction of the left VA. However, it was clearly recanalized on day six, and there were no findings of VA dissection. Whole-body contrast-enhanced computed tomography (CT) revealed a PAVF in the right lung and a thrombus in the feeding artery. The patient was diagnosed with hereditary hemorrhagic telangiectasia due to recurrent epistaxis and peripheral vasodilation of the tongue. An anticoagulant was administered for preventing further ischemic stroke, and a follow-up CT confirmed the disappearance of the thrombus in three months. Thoracoscopic partial lung resection was performed five months after the onset, and no recurrence of ischemic stroke was observed.

[A case of recurrent cerebral infarction in an adult patient with false Taussig-Bing anomaly]

The case was a 53-year-old woman. At birth, she was diagnosed with a false Taussig-Bing anomaly with pulmonary artery stenosis and a single ventricle. However, no cardiac surgery was performed, and conservative treatment was continued by a cardiovascular surgeon even after adulthood. Because of secondary polycythemia and a history of multiple cerebral infarctions, she took anti-platelet drugs and anti-coagulants. However, she was admitted with the diagnosis of cerebral infarction for the fourth time. It was considered that the patient was at high risk of paradoxical cerebral embolism due to cardiac malformation with cyanotic congenital heart disease accompanied by coagulation abnormalities. Considering the pathophysiology, we decided to use aspirin in combination with warfarin.

A Case of Hereditary Hemorrhagic Telangiectasia Suspected due to Anemia during Anticoagulation Therapy after Thrombectomy

Objective

Hereditary hemorrhagic telangiectasia (HHT) may be associated with paradoxical cerebral embolism caused by pulmonary arteriovenous malformation (PAVM). We present a case of HHT diagnosed by progressive anemia during anticoagulant therapy following mechanical thrombectomy.

Case Presentation

The patient was a 59-year-old woman who presented with acute stroke due to intracranial large vessel occlusion. Mechanical thrombectomy was successfully performed and the thrombus was retrieved. Postoperatively, anticoagulant therapy was started; however, she developed progressive anemia, which was associated with marked weakness, although no bleeding source was detected. Thorough postoperative imaging studies revealed PAVMs, which may be a source of cerebral embolism. It was noted that she frequently had episodes of epistaxis and a family history of PAVM. Embolization of PAVMs was performed to prevent the recurrence of embolic disorders. After this procedure, anticoagulant therapy was safely discontinued, which resulted in the improvement of anemia.

Conclusion

Physicians need to consider the possibility of HHT associated with PAVM which can cause paradoxical cerebral embolism.