Introduction/Objectives:

Asymptomatic carotid artery stenosis (ACAS) contributes stenosis of one or both internal carotid arteries, without cerebral ischemia related to it (transient ischemic attack, cerebral infarction, amaurosis fugax). Several studies showed that ACAS is not really asymptomatic and it is frequently associated with cognitive decline.

This study was aimed to analyze association between vascular risk factors, especially insulin resistance, and cognitive decline in 100 patients with ACAS and 50 age-, sex- and educational level healthy matched control subjects.

Participants, Materials/Methods:

Insulin resistance was tested by homeostasis assessment model (HOMA IR), plasma insulin levels by radioimmunoassay, levels of total-, LDL-, HDL- cholesterol, triglycerides and plasminogen activator inhibitor-1 were measured. Carotid plaques characteristics and intima-media thickness (IMT) were determined by ultrasound system (ALOKA Alpha 10, Japan). We used detailed neuropsychological testing to examine attention and concentration, memory, executive and visual constructional functions, motor performance, language and speech. Study was prospective and all patients were followed-up for 2 years.

Results:

In comparison with controls, ACAS patients had significantly lower results on all neuropsychological tests at the beginning (F [1.71] = 6.37; P < 0.001), and after 2 years of follow-up, with further cognitive decline from the baseline (F [1.71] = 71.12; P < 0.001).Insulin resistance was significantly associated with memory, language and visuospatial disturbances (CC = -0. 3891; P < 0.001) and carotid plaques characteristics with attention, executive and motor functions (CC = -0.4662: P < 0.001).

Conclusions:

ACAS is not asymptomatic, because it is associated with specific profile of cognitive impairment. Specific risk factors predict cognitive decline in certain neuropsychological domains, and this could have important therapeutical implications.