46 Acute Ischemic Stroke Secondary to Cardiac Myxoma Embolus
46.1 Case Description
46.1.1 Clinical Presentation
A 28-year-old female initially presented to the emergency department as a code stroke with left-sided deficits. She underwent successful thrombectomy, but sustained residual loss of vision in the left eye. Poststroke workup with echocardiography revealed a left atrial mass, and CT of the abdomen revealed emboli to the liver and spleen. She underwent minimally invasive cardiac surgery 2 days after her initial presentation with pathology, demonstrating a left atrial myxoma. Four years after her initial episode, she presented with headaches, which prompted MRI evaluation.
46.1.2 Imaging Workup and Investigations
MRI at the time of the second presentation revealed a fusiform aneurysm of the distal right M1 and proximal right M2 branches.
46.1.3 Diagnosis
Acute ischemic stroke secondary to cardiac myxoma and subsequent development of myxomatous aneurysm.
46.1.4 Treatment
Acute Management
On the initial presentation, the patient underwent successful thrombectomy.
Subsequent discovery of the fusiform right middle cerebral artery (MCA) aneurysm prompted initiation of acetylsalicylic acid (ASA) to prevent potential future ischemia.
Surgical Treatment
Resection of the cardiac myxoma
Outcomes
From her initial presentation, the patient sustained minimal deficits after a successful thrombectomy and resection of the cardiac myxoma.
Subsequent discovery of the right MCA fusiform aneurysm prompted initiation of ASA treatment. Surveillance MRI imaging over the next three years demonstrated no complications (Fig. 46.1).
Fig. 46.1 Right MCA oncotic aneurysm demonstrating minimal growth over 1.5 years.
46.2 Companion Case
46.2.1 Clinical Presentation
A 25-year-old female presented to the emergency department 5 hours post onset of sudden weakness of the right face and arm. Since initial CT was normal but symptoms persisted, the patient underwent emergency MRI for evaluation of acute ischemic stroke. MR demonstrated acute ischemic infarcts in the left occipital lobe, left midbrain/cerebral peduncle, and left thalamocapsular region (Fig. 46.2). Past medical history was significant for migraines and Crohn disease.
46.2.2 Imaging Workup and Investigations
Intracranial and cervical MRA are normal without any findings for vasculitis or atherosclerosis.
Serum antinuclear antibody is positive. Antiphospholipid antibody is borderline. Coagulation studies are normal.
Transesophageal echocardiogram demonstrates a left atrial mass (Fig. 46.3). This mass went on to be resected, and pathology was consistent with a cardiac myxoma.
Fig. 46.3 (a) Echocardiographic image demonstrates a large pedunculated mass in the left atrium. (b) surgical specimen of the pedunculated soft tissue mass, which was a pathologically proven cardiac myxoma.
46.2.3 Diagnosis
Acute ischemic stroke secondary to cardiac myxoma.
46.2.4 Treatment
Acute Management
The patient was not considered to be a tissue plasminogen activator candidate, as she presented outside the therapeutic window. Additionally, the absence of a large vessel occlusion and the low National Institutes of Health Stroke Scale (NIHSS) score meant she was not a candidate for endovascular treatment.
Surgical Treatment
Resection of the cardiac myxoma.
Outcomes
Two years following treatment, the patient presented with flashing lights in her right eye. MRI was performed, which revealed three hemorrhagic foci in the left occipital lobe (Fig. 46.4). These were thought to possibly represent metastatic lesions.
Diagnostic cerebral angiography was performed which demonstrated distal fusiform aneurysms in the region of these hemorrhagic lesions. These findings were suggestive of oncotic aneurysms secondary to myxomatous emboli (Fig. 46.5). These were treated conservatively with close imaging follow-up.
Fig. 46.4 Two years following her ischemic events, she developed a flashing sensation in her right eye. (a–c) MRI demonstrated three hemorrhagic foci, the largest of which demonstrated marked contrast enhancement on post-gadolinium T1-weighted images. 
Fig. 46.5 (a) Digital subtraction angiography following left vertebral artery injection demonstrates scattered areas of irregular caliber in several mid through distal branches in the left PCA territory. (b) Smaller fusiform aneurysm distal left calcarine branch above tentorium near the calvarium, corresponding to the hemorrhage focus seen in the left occipital lobe (curved arrow). (c) There is a large serpiginous, fusiform aneurysm in the distal left parietooccipital artery at a bifurcation which appears to correlate with the enhancing lesion (straight arrow).
46.3 Discussion
46.3.1 Background
Cardiac myxomas are reported to be the cause of 0.5% of acute ischemic strokes. 1 Furthermore, approximately 30% of myxoma patients present with systemic or cerebral emboli. 2 Cerebral infarction in myxoma patients is secondary to embolization of tumor particles or thrombotic material covered with tumor cells. 3 In fact, several case reports on mechanical thrombectomy for treatment of acute ischemic stroke in myxoma patients have demonstrated myxomatous tissue in the retrieved emboli. 4 , 5
Stroke Secondary to Cardiac Myxoma
Infarction due a cardiac myxoma commonly manifests as multiple infarcts in more than one vascular territory due to its cardioembolic nature. 3 Case series on the prognosis of myxomatous emboli have found that nearly 50% of patients have severe neurological deficits and 20% of patients die related to complications of cerebral infarction. The multivessel territory of the infarcts are thought to contribute to a poorer prognosis in these patients. 6 Reported complications following ischemic stroke secondary to cardiac myxoma include herniation and hemorrhagic transformation. 7
While there are several cases describing the use of intravenous thrombolysis in the treatment of ischemic strokes secondary to myxoma, the results have been mixed. 5 , 8 , 9 , 10 , 11 This is thought to be secondary to the fact that emboli are primarily composed of tumor cells rather than thrombus. Case reports of endovascular recanalization in the setting of large vessel occlusion have yielded promising results. Overall, most authors favor the use of thrombolysis or endovascular recanalization when no contraindications exist. 4 , 5
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