Study Protocol: Asymptomatic Intracranial Atherosclerotic Disease in Pakistanis

Conflict of Interest—None declared. Background—Intracranial atherosclerotic disease (ICAD) is the most frequent subtype of ischemic stroke globally. It is important to describe the determinants of early ICAD as a strategy to prevent strokes from clinically evident and progressive ICAD. Our objective is to report the determinants of asymptomatic ICAD by linking the presence or absence of ICAD on magnetic resonance angiogram (MRA) with detailed risk assessment in asymptomatic adults. Methods—This is an observational cross-sectional analytical study. We plan to recruit 200 adult participants from the radiology departments of two tertiary care centers of Karachi, Pakistan. The participants will first be screened for the absence of stroke symptoms via the Questionnaire for Verifying Stroke Free Status (QVSFS). QVSFS negative will be participants will be eligible. After written informed consent, participants will undergo detailed medical, sociodemographic, lifestyle, and anthropometric evaluation by a detailed interview. They will, in addition, undergo MRA to study the presence, degree, and distribution of asymptomatic ICAD. All MRA scans will be reviewed centrally by vascular neurologists blinded to clinical information. These images would be reviewed on DICOM Viewer 3.0 used for calculating the degree of stenosis using Warfarin–Aspirin Symptomatic Intracranial Disease (WASID) study defined criteria employing electronic calipers. A sample size of 200 will achieve 80% power for detecting a minimum difference of 20% in the prevalence of exposure factors (medical and lifestyle) between asymptomatic ICAD