Dataset Information

Normalization of reduced functional connectivity after revascularization of asymptomatic carotid stenosis.

ABSTRACT: Internal carotid artery stenosis is a risk factor for ischemic stroke. Even in the absence of visible structural brain changes, patients with asymptomatic stenosis are prone to cognitive impairment. On a neuronal level, it was suggested that stenosis may lead to disturbed functional brain connectivity. If so, carotid revascularization should have an effect on hypothesized brain network disturbances. We studied functional connectivity in a motor network by resting-state electroencephalography in 12 patients with high grade asymptomatic carotid stenosis before and after interventional or surgical revascularization as compared to 23 controls. In patients with stenosis, functional connectivity of neural oscillations was significantly decreased prior and improved returning to normal connectivity after revascularization. In a subgroup of patients, also studied by contrast perfusion magnetic resonance imaging, reduced connectivity was associated with decreased regional brain perfusion reflected by increased mean transit time in the middle cerebral artery borderzone. Cognitive testing revealed only minor differences between patients and controls. In summary, we identified oscillatory connectivity changes in patients with asymptomatic carotid stenosis correlating with regional hypoperfusion, which both normalized after revascularization. Hence, electrophysiological changes might be a reversible precursor preceding macroscopic structural brain damage and behavioral impairment in patients with asymptomatic carotid stenosis.

SUBMITTER: Quandt F

PROVIDER: S-EPMC7446560 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Normalization of reduced functional connectivity after revascularization of asymptomatic carotid stenosis.

Quandt Fanny F Fischer Felix F Schröder Julian J Heinze Marlene M Kessner Simon S SS Malherbe Caroline C Schulz Robert R Cheng Bastian B Fiehler Jens J Gerloff Christian C Thomalla Götz G

Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism 20190911 9

Internal carotid artery stenosis is a risk factor for ischemic stroke. Even in the absence of visible structural brain changes, patients with asymptomatic stenosis are prone to cognitive impairment. On a neuronal level, it was suggested that stenosis may lead to disturbed functional brain connectivity. If so, carotid revascularization should have an effect on hypothesized brain network disturbances. We studied functional connectivity in a motor network by resting-state electroencephalography in ...[more]

PMID: 31510853

Similar Datasets

Project description:Rationale Trials conducted decades ago demonstrated that carotid endarterectomy by skilled surgeons reduced stroke risk in asymptomatic patients. Developments in carotid stenting and improvements in medical prevention of stroke caused by atherothrombotic disease challenge understanding of the benefits of revascularization. Aim Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial (CREST-2) will test whether carotid endarterectomy or carotid stenting plus contemporary intensive medical therapy is superior to intensive medical therapy alone in the primary prevention of stroke in patients with high-grade asymptomatic carotid stenosis. Methods and design CREST-2 is two multicenter randomized trials of revascularization plus intensive medical therapy versus intensive medical therapy alone. One trial randomizes patients to carotid endarterectomy plus intensive medical therapy versus intensive medical therapy alone; the other, to carotid stenting plus intensive medical therapy versus intensive medical therapy alone. The risk factor targets of centrally directed intensive medical therapy are LDL cholesterol <70 mg/dl and systolic blood pressure <140 mmHg. Study outcomes The primary outcome is the composite of stroke and death within 44 days following randomization and stroke ipsilateral to the target vessel thereafter, up to four years. Change in cognition and differences in major and minor stroke are secondary outcomes. Sample size Enrollment of 1240 patients in each trial provides 85% power to detect a treatment difference if the event rate in the intensive medical therapy alone arm is 4.8% higher or 2.8% lower than an anticipated 3.6% rate in the revascularization arm. Discussion Management of asymptomatic carotid stenosis requires contemporary randomized trials to address whether carotid endarterectomy or carotid stenting plus intensive medical therapy is superior in preventing stroke beyond intensive medical therapy alone. Whether carotid endarterectomy or carotid stenting has favorable effects on cognition will also be tested. Trial registration United States National Institutes of Health Clinicaltrials.gov NCT02089217.

Project description:Asymptomatic carotid artery stenosis (CAS) and occlusion (CAO) disrupt cerebral hemodynamics. There are few studies on the brain network changes and compensation associated with the progression from chronic CAS to CAO. In the current study, our goal is to improve the understanding of the specific abnormalities and compensatory phenomena associated with the functional connection in patients with CAS and CAO. In this prospective study, 27 patients with CAO, 29 patients with CAS, and 15 healthy controls matched for age, sex, education, handedness, and risk factors underwent neuropsychological testing and resting-state functional magnetic resonance (rs-fMRI) imaging simultaneously; graph theoretical analysis of brain networks was performed to determine the relationship between changes in brain network connectivity and the progression from internal CAS to CAO. The global properties of the brain network assortativity (p = 0.002), hierarchy (p = 0.002), network efficiency (p = 0.011), and small-worldness (p = 0.009) were significantly more abnormal in the CAS group than in the control and CAO groups. In patients with CAS and CAO, the nodal efficiency of key nodes in multiple brain regions decreased, while the affected hemisphere lost many key functional connections. In this study, we found that patients with CAS showed grade reconstruction, invalid connections, and other phenomena that impaired the efficiency of information transmission in the brain network. A compensatory functional connection in the contralateral cerebral hemisphere of patients with CAS and CAO may be an important mechanism that maintains clinical asymptomatic performance. This study not only reveals the compensation mechanism of cerebral hemisphere ischemia but also validates previous explanations for brain function connectivity, which can help provide interventions in advance and reduce the impairment of higher brain functions. This trial is registered with Clinical Trial Registration-URL http://www.chictr.org.cn and Unique identifier ChiCTR1900023610.

Dataset Information

Normalization of reduced functional connectivity after revascularization of asymptomatic carotid stenosis.

Publications

Normalization of reduced functional connectivity after revascularization of asymptomatic carotid stenosis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets