Laterality of Posterior Cerebral Artery and White Matter Hyperintensities in Patients with Severe Internal Carotid Artery Stenosis

Background: Collateral status of the circle of Willis was associated with white matter hyperintensities (WMHs) in patients with internal carotid artery (ICA) stenosis, but few have investigated the effect of leptomeningeal anastomoses. Objective: The aim of this study was to observe the association between WMHs and the laterality of the posterior cerebral artery (PCA) that presents leptomeningeal anastomoses in patients with severe ICA stenosis. Materials and Methods: WMHs and ipsilateral PCA laterality were evaluated in patients with unilateral ICA stenosis >= 70% (including occlusion) and contralateral ICA stenosis <50% or no stenosis. Ipsilateral PCA laterality was compared between two groups of no/mild and severe score of global, deep and periventricular WMHs, respectively. Results: We included 115 patients with unilateral ICA stenosis =70%. There were 60 patients with no/mild and 55 with severe global WMHs. The patients with severe global WMHs were older (OR = 1.849, 95% CI: 1.058-3.229, P = 0.031) and had higher incidence of negative PCA laterality (OR = 3.301, 95% CI: 1.140-9.558, P = 0.028). The patients with severe deep WMHs were also older (OR = 2.031, 95% CI: 1.130-3.651, P = 0.018) and had higher incidence of negative PCA laterality (OR = 4.250, 95% CI: 1.501-12.032, P = 0.006). There was no significant difference between the patients with no/mild and severe periventricular WMHs in the incidence of negative PCA laterality. Conclusions: The incidence of negative PCA laterality was higher in patients with severe global and deep WMHs, but not higher in patients with severe periventricular WMHs. The leptomeningeal anastomoses may affect the deep WMHs in patients with severe ICA stenosis.