Cognitive Function and Brain Connectivity in CAS Patients:a Rs-fMRI Study

Carotid artery stenting (CAS) can significantly decrease the incidence of ischemic stroke in patients with severe carotid artery stenosis has been confirmed in large randomized controlled studies (1, 2).Previous studies showed carotid artery stenosis is closely related to cognitive dysfunction, including asymptomatic carotid artery stenosis(≥70%).Cognitive impairment is one of the most serious problem facing the elderly. The impact on cognitive function in patients with CAS has been discussed by many researchers, however the effect still remained conflicting.

In past few years, several imaging techniques, such as resting-state functional MRI (R-fMRI), had been increasingly used to study cognitive impairment in humans. In this study, we evaluated the cognition performance in severe carotid artery stenosis patients undergoing CAS and explored the mechanisms underlying the cognition changes by the Rs-fMRI.

Inclusion criteria:

• age between 55 years and 80 years
• unilateral internal carotid artery stenotic degree ≥ 70%
• right-hand-dominant
• free of dementia, and depression
• modified Rankin Scale: 0 or 1
• education ≥6 years
• obtained written informed consent.

Exclusion criteria:

• contralateral internal carotid artery stenosis ≥ 50%
• posterior circulation diseases
• MMSE < 26, which is a cut-off value for mild cognitive impairment
• severe systemic diseases and neuropsychiatric diseases (such as congestive heart failure)
• any contraindications for MRI scan (e.g., metal implants)
• Non atherosclerotic stenosis, such as dissection, vasculitis.