Early Recurrence in Patients with Symptomatic, Non-Cardioembolic, Internal Carotid Artery Occlusion.

Background: There are limited data on the clinical course of patients with non-cardioembolic, mostly atherosclerotic, internal carotid artery occlusion (ICAO). The purpose of this study was to elucidate the frequency and underlying pathogenesis of early recurrent ischemic stroke in symptomatic non-cardioembolic ICAO.

Methods: Consecutive patients with symptomatic non-cardioembolic ICAO were retrospectively reviewed. Those who had a tandem occlusion of the proximal middle cerebral artery (MCA) or underwent endovascular thrombectomy were excluded. Early recurrent stroke was defined as deterioration of the NIHSS score by ≥1 point with new lesions on magnetic resonance (MR) diffusion-weighted imaging (DWI) in the ipsilateral territory of the ICAO within 30 days of the index stroke onset. Patients were classified into two groups on carotid ultrasonography: cervical occlusion and intracranial occlusion. The presumed pathogenesis of recurrent stroke was categorized as embolic or hemodynamic according to the topographical features of subsequent lesions on DWI.

Results: Of 36 consecutive medically treated patients with symptomatic non-cardioembolic ICAO without tandem MCA occlusion, 23 patients had cervical occlusion, and 13 had intracranial occlusion. Early recurrent stroke occurred in 16 patients (44.4%), which happened much more with intracranial occlusion than with cervical occlusion (69.2% vs 30.4%, p<0.02). Focusing on the presumed pathogenesis, hemodynamic was more common than embolic (68.8% vs 31.2%), especially with intracranial occlusion (77.8%).

Conclusions: Early recurrent stroke occurs at a high frequency in symptomatic non-cardioembolic ICAO, and intracranial occlusion may be a risk factor for early recurrent stroke. The pathogenesis of recurrence is more often hemodynamic than embolic.