To investigate the associations of hemodynamic features of symptomatic intracranial atherosclerotic disease (sICAD) with imaging markers and overall burden of cerebral small vessel disease (CSVD).

Factors associated with CSVD in sICAD were not well established.

Patients with symptomatic ICAD (50-99% stenosis) in the anterior circulation were analyzed in this cross-sectional study. Translesional pressure ratio (PR) and wall shear stress ratio (WSSR) across a sICAD lesion were obtained using CT angiography-based computational fluid dynamics modeling. PR ≤median was defined as low (“abnormal”) PR, and WSSR ≥4^th quartile as high (“abnormal”) WSSR. The severity of three CSVD imaging markers in MRI, cortical microinfarcts (CMIs), white matter hyperintensities (WMHs) and lacunes, were summed up to reflect the overall CSVD burden and dichotomized as none-to-mild and moderate-to-severe, respectively in ipsilateral and contralateral hemispheres to sICAD. We compared the imaging markers and overall burden of CSVD in bilateral hemispheres, and associated the hemodynamic metrics of sICAD lesions with ipsilateral CSVD.

Among 83 patients, moderate-to-severe CSVD burden was more commonly seen in the ipsilateral than contralateral hemisphere (13.3% vs 2.4%, p =0.022). A lower translesional PR (medians 0.78 versus 0.93; p=0.003) and a higher WSSR (medians 36.8 versus 11.1; p=0.008) were associated with moderate-to-severe CSVD burden ipsilaterally. Abnormal PR and abnormal WSSR were independently associated with moderate-to-severe CSVD ipsilaterally [adjusted OR (aOR)=6.06 and 4.13 respectively; both p<0.05]. Patients with abnormal PR&WSSR were more likely to have moderate-to-severe CSVD (54.5% versus 15.3%; aOR=9.46; p=0.013), CMIs (p=0.033) and moderate-to-severe WMHs (p=0.032) ipsilaterally, compared with those with normal PR & WSSR.