Anterior Thalamic Infarction as Initial Manifestation of a Right Atrial Lipoma

Abstract

Cardiac tumors are an infrequent source of embolism to the brain in young adults. Myxomas are the most common among them and they are mainly located in the left atrium.1 Cardiac lipomas are a very rare benign neoplasm of the heart usually located in the right atrium.2,3 Its etiological relationship with stroke is not well established. We describe the case of a thalamic stroke probably caused by paradoxical embolism from a right atrial lipoma through a patent foramen ovale. CASE REPORTA 46-year-old male with mild hypertension, presented with speech and behavioral alterations first noticed on awakening without a previous Valsalva manoeuvre. On admission his blood pressure was 150/90 mm Hg, with a pulse of 70 beats/min and O 2 saturation of 97%. He was apyretic and cardiac and cervical auscultation was unremarkable. On neurologic examination, a non-fluent dysphasia with word finding difficulties, right facial paresis and a left Horner's syndrome was observed. He also presented mild right hemiparesis and myoclonic-dystonic movements in lower limbs (NIHSS 7). Cervical and Transcranial Doppler (TCD) were normal. Cranial computerized tomography was normal. A cranial magnetic resonance (MR) demonstrated on diffusion sequences the presence of an acute non-hemorrhagic infarction involving the anterior area of the left thalamus ( Figure 1A). Perfusion MR sequences and cerebral magnetic angioresonance were normal. The patient was admitted to the stroke unit. Conservative treatment was initiated. No arrhythmia was registered during hospitalization. Duplex sonography excluded atherosclerotic lesions in the carotid arteries. The next day, a right to left massive shunt was found on TCD bubble study ( Figure 1B). This test was performed using agitated saline as a contrast agent. Thrombophilic screening, neoplastic markers and autoimmune assays were negative. Transthoracic and transesophageal echocardiograms (TEE) were performed showing a mobile mass of homogeneous density attached to the free wall of the right atrium ( Figure 1C). No other cardioembolic lesions such as aortic plaques or dysfunctional left ventricle were found. The mass could be optimally assessed by cardiac MR as a well defined, slightly lobulated and homogeneous lesion, strongly hyperintense on T1 sequences, with low signal intensity on Fat-suppressed sequences (T2 STIR) and without contrast enhancement after gadolinium administration ( Figure 1D), highly suggestive of a lipoma. A patent foramen ovale (PFO) without associated aneurysmal septum could also be seen on TEE. The mass and the foramen ovale were surgically removed THE CANADIAN JOURNAL OF NEUROLOGICAL SCIENCES 379