Prevalence and Etiologies of Intracranial Stenosis in Patients With Antiphospholipid Syndrome

Investigators shall perform cranial MRI examinations. The scanning protocol will employ an MRI scan protocol with T1-weighted, T2-weighted, FLAIR, susceptibility weighted imaging, diffusion weighted imaging, and time-of-flight magnetic resonance angiography (MRA) sequences. In addition, high-resolution magnetic resonance vessel wall imaging (HRMRI) allows assessment of the vessel wall using specific the SPACE sequence and the MATCH sequence. Assessors of the HRMRI images shall be blinded to the group allocation and clinical information.

Investigators shall perform carotid duplex ultrasonography (CD) assessment, focusing on the peak systolic (PSV) and end diastolic velocity (EDV) of bilateral extracranial internal carotid arteries (ICA) Brightness mode imaging shall gauge the intimal thickness and plaque characteristics (if any) of bilateral ICAs.

Nine milliliters of EDTA blood will be drawn during the research clinic visit for evaluation of the degree of neurovascular inflammation. Serum plasminogen activator inhibitor-1 (PAI-1) and high-sensitive C-reactive protein (hsCRP) are markers of vascular inflammation, atherosclerosis, and thrombotic risk. Serum neurofilament light chain (NfL) is a biomarker for neuroaxonal injury that correlates with small vessel disease.