Positive syphilis serology contributes to intracranial stenosis in ischemic stroke patients

The risk of ischemic stroke is increased among people living with syphilis infection; however, whether syphilis is an independently risk for stenosis is unclear. We investigated the clinical, laboratory, and vascular stenosis features of ischemic stroke patients living with positive syphilis serology to evaluate the role of syphilis in cerebral artery stenosis.

The demographic, clinical characteristics, and the distribution of cerebral artery stenosis were compared between 668 syphilis-positive and 785 syphilis-negative ischemic stroke patients. Multivariate logistic regression analysis was performed to determine the degree and distribution of stenosis associated with positive syphilis serology and estimate the factors related to artery stenosis in the syphilis-positive ischemic stroke patients.

Syphilis-positive ischemic stroke patients were distinct from the nonsyphilis population, with a younger age, fewer women, and a different risk factor profile. Positive syphilis serology was independently associated with moderate stenosis (OR, 2.31; 95% CI 2.02-2.69; p = .003) and severe stenosis (OR, 6.15; 95% CI, 2.85-8.94; p < .001), mainly intracranial stenosis (OR, 1.49; 95% CI, 1.15-1.92; p = .002) rather than extracranial stenosis. Among stroke patients with positive syphilis serology, the higher RPR titer (OR, 1.18, 95% CI, 1.07-1.89 for RPR titer 1:16; OR, 5.16, 95% CI 2.99-8.89 for RPR titer > 1:32) and previous unknown or untreated syphilis (OR, 3.63; 95% CI, 2.72-4.03; p < .001) were the factors related to stenosis.

Syphilis infection, especially when less well controlled, may play an important role in intracranial stenosis of ischemic stroke patients.