White thrombus as a possible feature of atypical stroke etiology: Coxiella burnetii as the primary cause of acute ischemic stroke

Abstract

Acute ischemic stroke (AIS) is the most common neurologic complication of infective endocarditis. We describe a singular case report of a 62- year-old male with AIS related to the occlusion of the left middle cerebral artery. Thrombus-aspiration allowed retrieving a 6 millimeters white thrombus. The real-time polymerase chain reaction performed on the thrombus detected Coxiella Burnetii allowed the diagnosis of infective endocarditis (IE) and the identification of the specific pathogen. Coxiella Burnetii is an endemic, small, intracellular, gram-negative coccobacillus and it is a rare cause of IE. The management of AIS caused by IE remains controversial, although in the cases of major occlusion mechanical thrombectomy is associated with better clinical outcomes. IE patients could not present symptoms and signs related to the infection, therefore we underline the importance of the microbiological analysis of the retrieved thrombi especially when atypical etiology is suspected.

Keywords: Stroke; clot; endocarditis; thrombectomy.

Figure 1.

Baseline MRI: diffusion-weighted imaging sequence (a) showing the acute ischemic lesion in the left MCA territory, slightly visible in the FLAIR sequence (b); the Gradient-Echo sequence (c) did not reveal the presence of a left ICA terminus-MCA clot. Pre-treatment Digital Subtraction Angiography (DSA) showing a left proximal MCA occlusion (d, white arrow). Post mechanical thrombectomy DSA (e) documented the complete recanalization of the left MCA. The retrieved 6-millimeters white thrombus (f) was dissected showing its encapsulated aspect (g). The 24-hour follow-up MRI (h) showed the constituted ischemic core in the FLAIR sequence (h) without further extension of the ischemic area.