Differences in Cognitive Impairment and Functional Plasticity Between Asymptomatic Cerebral Arterial Stenosis and...

Asymptomatic carotid stenosis (ACS) and asymptomatic intracranial atherosclerotic stenosis (aICAS) present ongoing treatment challenges. These conditions can lead to cognitive impairment through cerebral hypoperfusion and silent cerebral embolism. However, it is unclear whether they result in the same degree of cognitive dysfunction. Furthermore, the neurological mechanisms behind these dysfunctions are still not well understood. This study used cognitive neuro-electrophysiological techniques to examine differences in cognitive impairment caused by ACS and aICAS.

A total of 22 patients with ACS and 15 patients with aICAS were enrolled, all with at least 70% unilateral severe stenosis. The control group (CG) consisted of 23 patients who were matched with the ACS and aICAS groups for age, gender and vascular risk factors. All participants conducted the flanker task, and their behavioral and neuroelectric data were also collected. Cognitive impairment of the hypoperfused hemisphere was compared with the normally perfused hemisphere.

At the level of behavioral performance, the ACS group presented longer reaction times (RTs) for both flanker types. At the level of event-related potentials, patients in both the ACS and aICAS groups showed decreased N2 amplitudes in the parietal region of the hypoperfused hemisphere. They also showed reduced P300 amplitudes in the anterior frontal regions of both the hypoperfused and normally perfused hemispheres. Patients in the ACS group exhibited longer P300 latencies in the bilateral anterior frontal regions. In addition, both groups showed an increase in P300 amplitude in the central parietal region of the hypoperfused hemisphere. Notably, the aICAS group showed stronger compensatory capacity.

ACS and aICAS patients exhibit different cognitive dysfunctions, with ACS patients presenting with more severe dysfunction of executive control. aICAS patients present with stronger compensatory capacity.