Cognitive outcome differences on the side of carotid artery stenting

Carotid revascularization improves cognition in patients with carotid stenosis

Patients with atherosclerosis in the carotid arteries are at risk of ischemic stroke and cognitive decline due to emboli and chronic hypoperfusion of brain tissue. Revascularization procedures improve cerebral hemodynamics, which has some effect on cognitive function. Some authors suggest that the presence of stenosis in the carotid arteries is an independent factor influencing cognitive decline. The aim of this study was to investigate the relationship between the degree of stenosis of a stented carotid artery and attentional performance in individuals with carotid atherosclerosis. A prospective longitudinal study was conducted at a single center involving patients during cardiology hospitalization (T-1) and 1 year after hospital admission (T-2) for invasive treatment of carotid stenosis. The attention D2 test by R. Brickenkamp was used. The study showed that a critical degree of internal carotid artery stenosis is associated with poorer attentional performance in individuals undergoing carotid artery stenting. However, the ability to concentrate improved one year after the procedure in all groups of patients who underwent carotid artery stenting, regardless of the degree of internal carotid artery stenosis. It was also found that the side of the vasoconstriction (right/left) in patients with atherosclerosis in the carotid arteries has no influence on cognitive functions in relation to attention.

Does Carotid Intervention Improve Cognitive Function?

Carotid artery disease has been linked to baseline cognitive impairment, even in asymptomatic patients. Therefore, there has been a persistent interest in investigating the impact of carotid revascularization on cognitive functions, but the results have been heterogeneous. Our recent prospective evaluation showed improved cognitive scores across multiple cognitive measures following carotid intervention. Herein, we summarize the studies published to date, identify the potential contributors to the inconsistency of post-interventional cognitive outcomes, and explore further opportunities in cognitive evaluations.

MRI Detection of Carotid Intraplaque Hemorrhage and Postintervention Cognition

BACKGROUND AND PURPOSE

Cognitive improvement has been reported after carotid revascularization and attributed to treating stenosis and correcting hypoperfusion. This study investigated the effect of carotid intraplaque hemorrhage on postintervention cognition.

MATERIALS AND METHODS

In this institutional review board-approved single-center study, consecutive patients scheduled for carotid surgery were recruited for preoperative carotid MR imaging (MPRAGE) and pre- and postintervention cognitive testing using the Repeatable Battery for the Assessment of Neuropsychological Status. Pre- and postintervention scores were compared using t tests and multivariable linear regression.

RESULTS

Twenty-three participants were included, with endarterectomy performed in 20 (87%) and angioplasty/stent placement, in 3 (13%). Overall, statistically significant improvements occurred in the pre- versus postintervention mean Total Scale score (92.1 [SD, 15.5] versus 96.1 [SD, 15.8], P = .04), immediate memory index (89.4 [SD, 18.2] versus 97.7 [SD, 14.9], P < .001), and verbal index (96.1 [SD, 14.1] versus 103.0 [SD, 12.0], P = .002). Intraplaque hemorrhage (+) participants (n = 11) had no significant improvement in any category, and the attention index significantly decreased (99.4 [SD, 18.0] versus 93.5 [SD, 19.4], P = .045). Intraplaque hemorrhage (-) participants (n = 12) significantly improved in the Total Scale score (86.4 [SD, 11.8] versus 95.5 [SD, 12.4], P = .004), immediate memory index (82.3 [SD, 14.6] versus 96.2 [SD, 14.1], P = .002), delayed memory index (94.3 [SD, 14.9] versus 102.4 [SD, 8.0], P = .03), and verbal index (94.3 [SD, 13.2] versus 101.5 [SD, 107.4], P = .009). Postintervention minus preintervention scores for intraplaque hemorrhage (+) versus (-) groups showed statistically significant differences in the Total Scale score (-0.4 [SD, 6.8] versus 8.0 [SD, 8.5], P = .02), attention index (-5.9 [SD, 8.5] versus 4.3 [SD, 11.9], P = .03), and immediate memory index (4.2 [SD, 6.7] versus 12.2 [SD, 10.2], P = .04).

CONCLUSIONS

Cognitive improvement was observed after carotid intervention, and this was attributable to intraplaque hemorrhage (-) plaque. MR imaging detection of intraplaque hemorrhage status may be an important determinant of cognitive change after intervention.

Resistive index of internal carotid artery and brain networks in patients with chronic cerebral ischemia

Quantitative assessment of cerebral hemodynamics is important for patients with chronic cerebral ischemia (CCI), as it helps to reveal the pathogenesis of the disease and set the course for effective prevention and treatment. The study was aimed to assess the correlation of the left carotid artery (ICA) resistive index (RI) with cognitive functions and brain network organization based on fMRI data in patients with CCI (51 males and 105 females). The listed above indicators were studied in patients with the left ICA RI values below and above the average (0.54 ± 0.013). The lower, normal physiological ICA resistance levels corresponded to the more successful realization of verbal cognitive functions. In the first group, RI was within normal range (RI = 0.42 ± 0.007), and in the second group RI exceeded normal levels (RI = 0.61 ± 0.01). Variation of the right ICA RI did not correlate with the characteristics of verbal cognitive functions. FMRI data analysis was used to assess the differences in connectivity between various brain regions in the groups with low and high RI. The normal physiological and elevated RI values of the left ICA correlated with differences in the organization of brain networks: normal physiological RI values corresponded to a better organization of hemispheric connections in the basal ganglia and brainstem, and high RI values corresponded to a better organization of connections between the frontal regions and the cerebellum as well as occipital areas of the cerebral cortex. The left ICA RI can be considered as a biomarker of cognitive decline and brain networks reorganization in patients with CCI.

Cognitive Functions in Patients after Carotid Artery Revascularization-A Narrative Review

Carotid revascularization may lead to improved cognitive function beyond stroke prevention. This article summarizes the conclusions from available studies on the effects of carotid reperfusion procedures on cognitive function. The papers cited used different neuropsychological tests for cognitive assessment, resulting in different methodologies and the results obtained were not always convergent. However, most studies reported an improvement in neurocognitive abilities after both vascular interventions, but a more precise assessment of the specific benefits is still awaited. Clinical determinants to predict the effects of these treatments on cognitive function are still being sought, but results are not yet satisfactory. In view of these studies, carotid stenosis seems to be an independent risk factor for cognitive deterioration, and the main mechanisms responsible are embolism and cerebral hypoperfusion. The aim of this study is to order the knowledge about the effects of carotid artery stenting (CAS) and endarterectomy (CEA) on neurocognitive functions and to verify the usefulness of using these treatments.

Carotid Artery Stenting and Its Impact on Cognitive Function: A Prospective Observational Study

PURPOSE

Carotid artery stenting (CAS) has evolved as a first-line therapeutic option for carotid revascularization in indicated patients for stroke prevention, but there is still a lack of data on its effect on cognitive function (CF), especially among Indian patients. To determine the effect of CAS on CF and to study the immediate and delayed complications of CAS in Indian patients.

MATERIALS AND METHODS

This was a prospective, observational, single-center study. CF was assessed using Addenbrooke's cognitive examination version III (ACE) before and 3 months after stenting. The demographic and clinical parameters were also assessed. A follow-up evaluation after 3 months was done to compare CF and to observe the occurrence of any complications.

RESULTS

Out of 31 patients, 3 were lost to follow up. There were no immediate or delayed procedure-related complications. There was a statistically significant improvement in overall ACE score and memory before and after stenting. On subgroup analysis of those with and without strokes, there was a significant improvement in visuospatial function and mean ACE score. Those with left CAS had significant improvement in memory, visuospatial, language, and ACE scores than right CAS.

CONCLUSION

CAS was associated with significant improvement in CF in patients.

Diffusion-weighted imaging detects early brain injury after hypothermic circulatory arrest in pigs

OBJECTIVES

Cerebral injury is a complication of surgery with deep hypothermic circulatory arrest (DHCA). This study aimed to evaluate diffusion-weighted imaging (DWI) for the early detection of brain injury after DHCA in an animal model.

METHODS

Twelve healthy, adult, male miniature pigs were randomly divided into the DHCA (to receive DHCA; n = 6) and the control (sham surgery under anaesthesia; n = 6) groups. All animals received DWI, T1-weighted imaging (T1WI) and T2WI the day before surgery, 7 h postoperatively and 24 h postoperatively. Histopathological evaluation of the brain tissues was performed in the DHCA group using the Fluoro-Jade C staining to detect neuronal degeneration, the Nissl staining to show neuronal morphology and the TUNEL assay for apoptosis. The Cohen's kappa coefficient was used to compare the results of DWI with those of the histopathological evaluation.

RESULTS

All animals survived surgery. In the control group, no new focal brain lesions were detected by postoperative DWI, T1WI or T2WI. In the DHCA group, new focal brain lesions were detected as early as 7 h postoperatively by DWI but not T1WI or T2WI. All three imaging sequences revealed abnormalities 24 h after surgery. In sections from areas showing abnormalities on DWI, the Fluoro-Jade C staining detected neuronal degeneration, the Nissl staining showed morphological abnormalities and the TUNEL assay demonstrated apoptotic cells. The Cohen's kappa statistics showed agreement between DWI findings and the results of all 3 histopathological examinations (TUNEL: kappa = 0.553; Nissl: kappa = 0.652; Fluoro-Jade C: kappa = 0.778; all P < 0.001).

CONCLUSIONS

DWI is superior to T1WI or T2WI for the early detection of neurological lesions after DHCA in pigs.

Cognition in relation to independency in older, comorbid stroke patients in a stroke unit

OBJECTIVE

The objective of this study was to ascertain if cognition helps to predict functional outcome in older comorbid stroke patients with severe loss of independence.

DESIGN

This is a cross-sectional study.

SUBJECTS

The subjects of this study are patients who have suffered a stroke and who rehabilitated in the nursing homes' rehabilitation units and patients (n = 160) (mean age: 77; SD: 9.5) with a mean Barthel Index of 11.02.

METHOD

Demographic, illness-related, functional and cognitive data were selected at baseline.

MAIN ASSESSMENT MEASURES

Functional abilities were tested using the Barthel Index. Cognitive functions were assessed using a wide variety of neuropsychological tests.

RESULTS

Patients faced cognitive impairments especially in executive functioning and memory. Stepwise linear regression analysis shows that executive functioning (p = 0.050) and memory (p = 0.000; confidence interval -1.255, -0.403) are significantly associated with functional outcome.

CONCLUSION

From a clinical point of view, we suggest combining physical and cognitive training from the very early phase of recovery.

Atherosclerotic carotid stenosis and cognitive function

Atherosclerosis carotid stenosis is associated with stroke and cognitive impairment. Progressive cognitive decline may be an even greater problem than stroke, but it has not been widely recognized and therefore must be adequately addressed. Although both Carotid Endarterectomy (CEA) and Carotid Artery Stenting (CAS) have been proven can prevent future stroke in patients with atherosclerotic carotid stenosis, the influence of CEA and CAS on cognitive function is not clear. In the first part of this review, we evaluated the literature concerning carotid stenosis and the risk of cognitive impairment. Studies have suggested that both symptomatic and asymptomatic carotid stenosis are associated with cognitive impairment. In the second part, we reviewed the impact of CEA and CAS on cognitive function, some studies have shown benefits, but others have not.

The Alzheimer's Prevention Clinic at Weill Cornell Medical College / New York - Presbyterian Hospital: Risk Stratification and Personalized Early Intervention

In July 2013, Weill Cornell Medical College founded the first Alzheimer's Prevention Clinic (APC) in the United States, providing direct clinical care to family members of patients with Alzheimer's disease (AD) as part of the Weill Cornell Memory Disorders Program. At the APC, patients seeking to lower their AD risk undergo a comprehensive assessment, receive a personalized plan based on rapidly evolving scientific evidence, and are followed over time using validated as well as emerging clinical and research technologies. The APC approach applies the principles of pharmacogenomics, nutrigenomics and clinical precision medicine, to tailor individualized therapies for patients. Longitudinal measures currently assessed in the clinic include anthropometrics, cognition, blood biomarkers (i.e., lipid, inflammatory, metabolic, nutritional) and genetics, as well as validated, self-reported measures that enable patients to track several aspects of health-related quality of life. Patients are educated on the fundamental concepts of AD prevention via an interactive online course hosted on Alzheimer's Universe (www.AlzU.org), which also contains several activities including validated computer-based cognitive testing. The primary goal of the APC is to employ preventative measures that lower modifiable AD risk, possibly leading to a delay in onset of future symptoms. Our secondary goal is to establish a cohort of at-risk individuals who will be primed to participate in future AD prevention trials as disease-modifying agents emerge for testing at earlier stages of the AD process. The clinical services are intended to lower concern for future disease by giving patients a greater sense of control over their brain health.

Effect of carotid artery stenting on cognitive function in patients with carotid artery stenosis: a prospective, 3-month-follow-up study

Background and Purpose

Carotid artery stenting (CAS) is emerging as an alternative to carotid endarterectomy for the treatment of carotid artery stenosis (CS), but the effect of CAS on the cognitive function of patients with severe CS has not been fully investigated. The aim of this study was to use comprehensive neuropsychological tests to determine the effect of CAS on cognitive function from baseline to 3 months postprocedure in patients with severe CS.

Methods

Thirty-one patients due to undergo CAS due to high-grade CS (≥70%) and 11 control subjects who were diagnosed with CS, but who did not undergo CAS, and who visited the clinic or emergency room between February 2009 and February 2012 were recruited consecutively at baseline (i.e., pre-CAS). Follow-up neuropsychological evaluations after 3 months were completed by 23 of the 31 patients who underwent CAS, and by 10 of the 11 control subjects. The primary cognitive outcome was assessed using a neuropsychological test containing subcategories designed to test general cognitive function, attention, visuospatial function, language and related functions, memory, and frontal lobe/executive function.

Results

Of the 23 patients undergoing CAS who completed the 3-month follow-up tests, 12 had asymptomatic CS. During the 3-month follow-up period, the patients who underwent CAS and those with asymptomatic CS achieved similar results to the control group on all cognitive tests. However, symptomatic CS patients (n=11) who underwent CAS exhibited improvements in visuospatial function (p=0.046) and total Seoul Neuropsychological Screening Battery-Dementia Version scores (p=0.010) in comparison with both the asymptomatic CS patients and the control group.

Conclusions

The findings of this study suggest that CAS has a positive effect on cognitive function in patients with symptomatic CS over a 3-month follow-up period. A long-term, multicenter, prospective case-control study would be helpful to predict quality of life and prognoses for patients undergoing CAS.

The impact of carotid artery stenting on cognitive function in patients with extracranial carotid artery stenosis

BACKGROUND

The effect of carotid artery stenting (CAS) on cognitive function in patients with extracranial carotid artery stenosis is equivocal. The aim of this study was to examine the impact of CAS on various domains of cognitive function.

METHODS

We performed a meta-analysis of the studies evaluating various domains of cognitive function before and after CAS, namely, (1) global cognition using Mini-Mental State Examination (MMSE) and Rey Auditory Verbal Learning Test (RAVLT), (2) executive function using Trail Making Test (TMT) A or Color Trails Test (CTT) A and TMT B or CTT B, (3) language ability using Boston Naming Test (BNT), (4) memory, (5) attention/psychomotor speed, and (6) functional ability, using various cognitive tests. Pooled weighted mean differences (WMDs) and standardized mean differences (SMDs) with 95% confidence intervals (95% CIs) were appropriately calculated using fixed or random effects models after assessing between-study heterogeneity. Meta-regression analysis was performed with number of patients per study; mean age (years); follow-up (months); proportion of men; proportion of patients with hypertension, diabetes mellitus, hyperlipidemia, smoking, and coronary artery disease; proportion of symptomatic patients; and degree of ipsilateral and degree of contralateral carotid stenosis as covariates.

RESULTS

Sixteen studies were eligible, including a total of 626 CAS patients. A statistically significant improvement of global cognition was detected with MMSE (WMD = 0.67, 95% CI = 0.29-1.05, P < 0.001; follow-up = 5.6 months), but not with RAVLT (SMD = 0.45, 95% CI = -0.03 to 0.93, P = 0.07; follow-up = 2.4 months). Significant improvement of memory (SMD = 0.33, 95% CI = 0.11-0.55, P < 0.01; follow-up = 4.1 months) and attention/psychomotor speed (SMD = 0.21, 95% CI = 0.04-0.39, P = 0.02; follow-up = 4 months) was also detected. No statistically significant effect on executive function (TMT A/CTT A and TMT B/CTT B; SMD = 0.08, 95% CI = -0.10 to 0.26, P = 0.39; follow-up = 3.9 months and SMD = -0.02, 95% CI = -0.20 to 0.16, P = 0.82, respectively; follow-up = 3.9 months), language ability (BNT; SMD = 0.24, 95% CI = -0.05 to 0.54, P = 0.10; follow-up = 4 months), and functional ability (SMD = -0.05, 95% CI = -0.25 to 0.15, P = 0.63; follow-up = 3.8 months) was observed. No significant effects of the examined covariates were demonstrated in the meta-regression analyses.

CONCLUSIONS

CAS may be associated with improvement in global cognition, memory, and attention/psychomotor speed. There was no positive effect on executive function, language, and functional ability, but CAS was not associated with a decline in any area of cognitive function. Future studies in larger groups of patients are probably needed to fully investigate the long-term effect of CAS on cognition in patients with carotid artery stenosis.

Comparisons of cognitive function and serum S-100B level between diabetic and non-diabetic patients after the implantation of carotid artery stent (CAS)

To investigate cognitive function improvement in diabetic and non-diabetic patients after the implantation of Carotid Artery Stent (CAS), 128 patients suffering severe carotid stenosis were successfully enrolled in this study. Tests including, the Mini Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-Cog), Clock Drawing Test (CDT), Hasegawa's Dementia Scale-Revised (HDS-R) and the serum levels of S-100B, were all measured at baseline for 3 months after the implantation of CAS. The baseline characteristics were similar between the patients with and without diabetes. 3 months after the implantation, significant improvements in MMSE (24.8 ± 2.2 vs. 25.2 ± 2.1, p=0.003), MoCA (25.6 ± 2.0 vs. 26.1 ± 1.9, p=0.000), ADAS-Cog (6.5 ± 1.3 vs. 6.1 ± 1.3, p=0.000), and CDT (3.3 ± 0.7 vs. 3.5 ± 0.7, p=0.034) were observed in the non-diabetic group. In contrast, there was no significant improvement in any of the cognitive test for the diabetic group. Another interesting discovery was the CAS procedure significantly decreased the S-100B level in the non-diabetic group (0.11 ± 0.04 ng/mL vs. 0.10 ± 0.04 ng/mL, p=0.000), but similar phenomena were not discovered in the diabetic group. In this light, the change of the S-100B level was negatively correlated with the results in the MMSE (p<0.01) and the MoCA (p<0.01) tests, and positively correlated with the result in ADAS-Cog (p<0.05) test. Our findings suggest that the CAS-induced beneficial effects on cognitive function might have a correlation relationship with the serum level of S-100B.

Neurocognitive functioning after carotid revascularization: a systematic review

BACKGROUND

The objective of this study was to review the recent literature regarding the neurocognitive consequences of carotid endarterectomy (CEA) and carotid stenting (CAS).

METHODS AND RESULTS

A PubMed and Web of Science search was conducted using the key words 'carotid' in combination with 'cognitive', 'cognition', 'neurocognition', 'neurocognitive', 'neuropsychology', and 'neuropsychological'. Bibliographies of relevant articles were cross-referenced. We included 37 studies published since 2007 of which 18 examined CEA, 12 CAS, and 7 compared CEA to CAS. There is a wide variability in the reported neurocognitive outcome following CEA and CAS. Nonetheless, none of the included studies unveiled significant differences between CEA and CAS on postoperative neurocognitive functioning. Postoperative changes observed for CEA and CAS separately seem limited to a small percentage (around 10-15%) of patients and can either present as an improvement or impairment.

KEY MESSAGES

The available data seem to suggest that no obvious cognitive differences between CAS and CEA can be observed after intervention. Both improvement and deterioration in cognitive functioning can be observed following CAS or CEA. Methodological differences such as patient heterogeneity, implementation and type of control groups, type of psychometric tests used, statistical analyses, or timing of the assessments play an important role in explaining the sometimes divergent results of the included studies. Large-scale and methodologically solid studies comparing CEA and CAS on neurocognitive outcome remain warranted. Future studies should implement adequate control groups to correct for practice effects in the target groups.

Carotid stenting versus endarterectomy cognitive outcomes

BACKGROUND

The objectives are to analyze the impact of carotid revascularization on cognitive performance after a 3-month period in patients, who have undergone carotid artery stenting (CAS) or carotid endarterectomy (CEA), and to compare the cognitive outcomes between these 2 groups of patients. This a nonrandomized and prospective single-center experience.

METHODS

This study was performed in the University of Campinas Hospital from January 2010 to January 2012 and included 30 patients with carotid stenosis who received carotid interventions. Nineteen patients received CEA and 11 patients received CAS. Neuropsychologic evaluation included general cognitive, language, visuospatial, attentional, executive function, and memory tests.

RESULTS

After the follow-up period, there was improvement in episodic memory, encoding subitem (P = 0.02), and delayed recall (P = 0.02) for the CEA group. The CAS group improved in episodic memory, encoding subitem (P = 0.009), working memory (P = 0.04), and executive functions (P = 0.02). Comparing the techniques, the CAS group showed higher scores only in executive functions (P = 0.02).

CONCLUSIONS

Both groups had a similar performance in cognitive tests, comparing preoperative and postoperative results. However, patients who underwent CAS tended to achieve higher scores in executive function and operational memory/attention tests.