Intracranial atherosclerotic stenosis (ICAS) is a major risk factor for cognitive impairment. This study aimed to investigate the relationship between hemodynamic abnormalities, as assessed by transcranial Doppler (TCD) ultrasonography, and cognitive function in patients with unilateral middle cerebral artery (MCA) severe stenosis or occlusion. In this cross-sectional observational study, a total of 66 patients with unilateral MCA severe stenosis or occlusion due to ICAS were enrolled, including 42 symptomatic (sICAS group) and 24 asymptomatic (AsICAS group) patients, along with 23 age-matched healthy controls (HCs). All participants underwent comprehensive neuropsychological assessments and TCD measurements. TCD parameters, including peak systolic velocity (PSV), end-diastolic velocity (EDV), and mean flow velocity (MFV) in the anterior cerebral artery (ACA), MCA, and posterior cerebral artery (PCA) were used to assess hemodynamic status. The differences in cognitive function and hemodynamics between patients and HCs were subsequently analyzed, and the correlation between hemodynamic changes and cognitive function was further analyzed. Neuropsychological testing revealed significant cognitive impairment in MCA stenosis or occlusion patients, with a gradual decline in performance across the HC, AsICAS group, and sICAS groups. Ultrasound findings revealed increased PSV, EDV, and MFV in the ipsilateral ACA and PCA in both patient groups compared with those in the HCs, whereas MCA velocities were reduced. On the contralateral side, AsICAS patients presented elevated velocities across the ACA, MCA, and PCA relative to both sICAS patients and HCs, whereas sICAS patients presented higher ACA and MCA velocities than HCs did. Additionally, in the AsICAS group, contralateral MCA velocities were significantly correlated with executive function (PSV: r = -0.526 95% CI: -0.763 to -0.157, P = 0.008; EDV: r = -0.441 95% CI: -0.712 to -0.054, P = 0.031; MFV: r = -0.471 95% CI: -0.730 to -0.090, P = 0.020). Patients with severe MCA stenosis or occlusion exhibit significant cognitive impairment. Compared with symptomatic patients, asymptomatic patients demonstrate relatively better cognitive performance, which may be associated with differences in cerebral hemodynamic status.
Ruan et al. (Wed,) studied this question.