This study concluded that no matter mild or moderate- severe internal carotid artery stenosis, no matter left or right stenosis, will lead to cognitive dysfunction.It is also confirmed that the etiology of VCI involves many reasons.For patients with severe cerebrovascular stenosis, vascular lesions are likely to cause ischemic brain injury, such as low perfusion, subcortical small infarction, lacunar infarction, micro infarction, white matter injury may also be related to the occurrence of cognitive impairment. Many studies[8–11] have shown that angioplasty, stenting, endarterectomy, sta-mca bypass and other procedure can improve patients' cognitive function to varying degrees, suggesting that cognitive function may be related to brain attention. In other study, CT perfusion(CTP) imaging was performed on patients with carotid artery stenosis at different degrees, and the differences in cerebral perfusion results were analyzed in each group. The results showed that the perfusion parameters regional cerebral blood flow (regional cerebral blood flow(rCBF) regional cerebral blood volume (rCBV), mean transit time (MTT), time to peak (TTP) and delay time (DT) ) in the mild and moderate stenosis group had no statistical significance, only severe stenosis group showed decreased perfusion. However, in this study, patients with mild and moderate internal carotid artery stenosis still showed decreased cognitive function, the authors speculate that lacunar infarction, demyelination, arteriolosclerosis, Cerebral Amyloid Angiopathy(CAA), and immune response may be related to cognitive decline, except for the causes of reduced cerebral perfusion. Studies have shown that local innate or adaptive immune responses or the removal of damaged proteins are also important for tissue damage and cognitive impairment. Other literatures have mentioned that pathological changes such as neuronal atrophy, oligodendrocyte and astrocyte changes in white matter are related to cognitive decline, and the related pathological changes need to be further confirmed by animal experiments.
With the changes in human diet, environment and lifestyle, 5.9–6.9% of people over 60 years old in China suffer from intracranial arterial stenosis. In this group of patients, asymptomatic stenosis were more likely to be ignored as a risk factor for stroke. The incidence of MCI is high, and the rate of progression to AD is also high. As we all know, the quality of life of AD patients is low, and the high incidence of AD in the population over 60 years old is also a major burden for society and families, therefore, how to effectively prevent MCI has important social significance. Among the many causes of MCI, VCI is an important subgroup.A number of studies[8–11] had shown that treatment of intracranial vascular stenosis significantly improved patients' cognitive function. The results of this study showed that no matter what degree and what kind of lateral stenosis were significantly correlated with cognitive function. Therefore, for patients suffering from high blood pressure,diabetes,hyperlipidemia,cerebral infarction,cerebral hemorrhage, loose white matter, and chronic diseases such as cerebral ischemia, should be checked as soon as possible and cerebrovascular, diagnosed with asymptomatic stenosis (especially mild to moderate stenosis overlooked inspection) or symptomatic stenosis, and cognitive function checks (such as MMSE, MoCA, WSCT) found MCI or VCI as soon as possible, in time for the secondary prevention drug therapy or surgery can make people better prognosis. As above, early detection, early diagnosis of cerebral vascular stenosis and cognitive dysfunction, treatment for vascular stenosis (including control risk factors, internal medicine improved drug therapy and surgical intervention[19–20]), the reasonable treatment of cognitive impairment (including neurotrophic drugs, brain metabolism activating agent, antioxidant, acetyl choline enzyme inhibitors, exercise training and vascular risk factors, cognitive control of multimode interference[21, 22]), are likely to reduce the incidence of MCI, reduce the possibility of MCI progression to AD, so as to improve the quality of survival, reduce the burden of society and family.
This study sample size was small, considering the scale examination time adherence, cultural level and other factors, represented by using memory assessment scale and improvement of WCST test patients' cognitive function, unable to detailed understanding of naming, attention, language, abstract thinking, and other cognitive functions, it was not the results of the study in the difference between cerebrovascular stenosis with higher nervous function in the field of every detailed correlation, hoping for a larger sample size, a more reasonable inventory check related research confirms that the correlation of internal carotid artery stenosis with MCI.