Background

The severity of cerebral hemodynamic impairment in patients with carotid artery stenosis or occlusion (CASO) is not always correlated with the severity of stenosis or occlusion. There are no established noninvasive indicators of cerebral hemodynamic impairment in CASO.

Objective

The study aimed to identify impaired neurocognitive domains as promising noninvasive severity markers.

Methods

In a retrospective study of 142 patients with asymptomatic CASO, we assessed associations of Montreal Cognitive Assessment (MoCA) and Alzheimer's Disease Assessment Scale-Cognitive Subscale 14 (ADAS-Cog) with 15O-gas positron emission tomography.

Results

In patients with right CASO (n = 45), worse delayed recall on MoCA was significantly associated with decreased CBF (adjusted β for cerebral blood flow [CBF] 1.70, 95% confidence interval [CI] 0.21-3.28, p = 0.027), with the cutoff value of 1/2 for CBF of <35.0 mL/100 g/min (sensitivity 100%). In patients with left CASO (n = 60), language comprehension on ADAS-Cog was significantly associated with increased OEF (adjusted β for oxygen extraction fraction 5.48, 95% CI 2.29-8.67, p = 0.001), with the cutoff value of 0/1 for OEF of >52.9% (specificity 96.4%). In patients with bilateral CASO (n = 37), worse executive function on MoCA score was significantly associated with decreased CBF (adjusted beta for CBF 2.70, 95% CI 0.29-5.13, p = 0.030), with the cutoff value of 2/3 for CBF of <35.0 mL/100 g/min (sensitivity 83.3%).

Conclusions

Neuropsychological examinations could be useful for noninvasively estimating the severity of cerebral hemodynamic impairment in patients with CASO.