Selective Vulnerability of Cortical Border Zone to Microembolic Infarct

Abstract

Background and Purpose-Endovascular procedures, including atrial fibrillation transcatheter ablation, may cause microembolization of brain arteries. Microemboli often cause small sized and clinically silent cerebral ischemias (SCI). These lesions are clearly visible on early postoperative magnetic resonance diffusion-weighted images. We analyzed SCI distribution in a population of patients submitted to atrial fibrillation transcatheter ablation. Methods-Seventy-eight of 927 consecutive patients submitted to atrial fibrillation transcatheter ablation were found positive for acute SCI on a postoperative magnetic resonance. SCI were identified and marked, and their coordinates were transformed from native space into the International Consortium for Brain Mapping/Montreal Neurological Institute space. We then computed the voxel-wise probability distribution map of the SCI using the activation likelihood estimation approach. Results-SCI were more commonly found in the cortex. In supratentorial regions, SCI selectively involved cortical border zone between anterior, middle, and posterior cerebral arteries; in infratentorial regions, distal territory of posteroinferior cerebellar artery. Possible explanations include selective embolization, linked to the vascular anatomy of pial arteries supplying those territories, reduced clearance of emboli in a relatively hypoperfused zone, or a combination of both. This particular distribution of lesions has been reported in both animal models and in patients with microemboli of different sources. Conclusions-A selective vulnerability of cortical border zone to microemboli occurring during atrial fibrillation transcatheter ablation was observed. We hypothesize that such selectivity may apply to microemboli of different sources.

Cerebral border zone infarction: an etiological study

“…2 ). Sorgun et al ( 2015b ) and Bergui et al ( 2015 ) are in harmony with this result and reported a high vulnerability of cortical BZI among AF patient’s secondary to micro emboli. On the other side, Bladin and Chambers ( 1993 ) found high incidences of cardiac diseases in internal BZI patients, but this difference may be due to combined ischemic heart diseases and dysrhythmias in their included patients.…”

Carotid atherosclerosis, silent ischemic brain damage and brain atrophy: A systematic review and meta-analysis

“…Research in this field, however, yielded mixed results. [53][54][55] Indeed, the association may be accounted for by the risk factors shared by carotid atherosclerosis, WMH and SBI, including age, hypertension, dyslipidemia, smoking and diabetes. [9,12] Carotid atherosclerosis may be considered a marker of higher ischemic vulnerability of the brain.…”

Pearls & Oy-sters: Iatrogenic relative hypotension leading to diffuse internal borderzone infarctions and coma

“…7 Additional evidence that CBZ infarcts are more likely to be caused by an embolic etiology comes from a recent study of patients undergoing transcatheter atrial fibrillation ablation. 8 In this study, 78 of 927 (8.4%) consecutive patients who underwent ablation were found to have acute silent cerebral infarcts on postoperative MRI. These silent periprocedural infarcts were much more frequently located in the CBZ than the IBZ, consistent with the notion that emboli are more likely to cause injury in these locations.…”