Cognitive Function Remains Unchanged After Endarterectomy of Unilateral Internal Carotid Artery Stenosis Under Local Anaesthesia

Changes in Cognitive Functions after Carotid Endarterectomy and Carotid Stenting: A Decade-Apart Comparison

BACKGROUND

This study investigates changes in cognitive function in patients with severe carotid stenosis who underwent carotid endarterectomy (CEA) and carotid stenting (CAS) over two decades.

METHODS

We compared cognitive function within 30 days after the procedure in 267 patients (first 100 each for CEA and CAS in two periods: 2008-2012 and 2018-2022) in a single institution. Assessments used Adenbrooke's Cognitive Examination-Revised (ACE-R), the Mini-Mental State Examination (MMSE), Speech Fluency Test (SFT), and Clock Drawing Test (CDT), conducted before and 30 ± 2 days after surgery.

RESULTS

Patients (mean age 67.2 years, 70%+ carotid stenosis) exhibited different cognitive changes over periods. In 2008-2012, significant declines in MMSE (CEA, p = 0.049) and CDT (CAS, p = 0.015) were observed among asymptomatic patients. On the contrary, in 2018-2022, improvements were observed in ACE-R and MMSE for symptomatic and asymptomatic patients undergoing CEA and CAS.

CONCLUSION

Over a decade, advances in interventional techniques and patient management have reduced risks of cognitive decline in patients with asymptomatic carotid stenosis and also have improved cognitive functions in both symptomatic and asymptomatic individuals.

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.

Cognitive function after carotid endarterectomy in asymptomatic patients

Asymptomatic carotid stenosis has been shown to be associated with progressive neurocognitive decline, but the effects of carotid endarterectomy (CEA) on this are not well defined. Due to the wide heterogeneity of studies and lack of standardization in cognitive function tests and study design, there is mounting scientific evidence to support the notion that CEA is effective in reversing or slowing neurocognitive decline; however, definitive conclusions are difficult to make. Further, while the association between ACS and cognitive decline has been well document, a direct etiological role has not been established. More research is required to elucidate the relationship between asymptomatic carotid stenosis and the benefit of carotid endarterectomy and its potential protective effects regarding cognitive decline. This article aims to review current evidence in preoperative and postoperative cognitive function in asymptomatic patients with carotid stenosis undergoing CEA.

A systematic review of cognitive function after carotid endarterectomy in asymptomatic patients

OBJECTIVE

Asymptomatic carotid stenosis has been associated with a progressive decline in neurocognitive function. However, the effect of carotid endarterectomy on this process is poorly understood. We aimed to evaluate pre and post-operative cognitive function changes in asymptomatic patients after carotid endarterectomy METHODS: A systematic review of the existing reports in PubMed/MEDLINE, Embase, and Cochran databases was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis statement recommendations. All original retrospective or prospective studies (including cohort, cross-sectional, case-control, pilot studies, etc.) and clinical trials that compared pre and post-operative neurocognitive function in asymptomatic patients with carotid stenosis after CEA, which were published from January 2000 to April 2021 were identified and considered eligible for inclusion in the study.

RESULTS

Thirteen studies (502 CEAs) comparing cognitive function changes before and after CEA were identified. In seven studies with a total number of 272 patients, a mean age range of 67.3 ± 4.8 to 76.35 years old and after follow-up ranging between 1 and 12 months, overall cognitive function improved after CEA. However, in six studies with a total sample of 230, a mean age range of 68.6 ± 6.9 to 74.4±6.1 years, and follow-up ranged from 24 hours to 3 years, showed no change or decline in overall cognitive function after procedures.

CONCLUSIONS

The lack of standardization of specific cognitive tests and cognitive function assessment timing after CEA does not allow for definite conclusions to be made. However, improving the brain perfusion with combination of CEA and statin therapy may be a protective strategy against cognitive function decline.

Preoperative anxiety as predictor of perioperative clinical events following carotid surgery: a prospective observational study

BACKGROUND

Psychological factors like anxiety and depression are recognised to play a causal role in the development of cardiovascular disease and they may also influence outcome after vascular surgery procedures. The aim of this study was to investigate the association of anxiety and depression with postoperative outcome following elective carotid surgery.

METHODS

Single centre prospective observational study of patients treated for asymptomatic carotid artery stenosis at an academic vascular surgery centre. Preoperative anxiety and depression were evaluated using self-reporting questionnaires: Spielberger State-Trait Anxiety Inventory (STAI-S/-T) and Hospital Anxiety and Depression Scale (HADS-A/-D). Postoperative morbidity and mortality were assessed with the primary composite endpoint of stroke, myocardial infarction (MI) and death. Standard reporting guidelines for carotid disease were applied.

RESULTS

From June 2012 to November 2015, 393 carotid endarterectomies (CEA) were performed at our institution. Out of those, 98 asymptomatic patients were available for analysis (78% male; median age, 71.1 years). Median scores of self-reporting questionnaires did not differ from published data of the general population (STAI-T, trait component, median, 36; IQR, 31-42.75; STAI-S, state component, median, 38; IQR, 32-43; HADS-A median, 6; IQR, 3-8; HADS-D median, 4; IQR, 2-7). Cardiovascular risk factors were similar in anxious and non-anxious patients. The composite endpoint of stroke, MI and death occurred significantly more often in patients presenting with a preoperative HADS-A score higher than 6 (10.5%, 95% CI, 3-25; p =.020).

CONCLUSIONS

The present study indicates that preoperative anxiety is associated with the occurrence of intra- and postoperative neurological events in patients undergoing CEA. Patients who had a preoperative HADS-A score of 6 or less had a very low probability of experiencing these complications.

Physical and psychological functioning of patients with chronic limb ischemia during a 1-year period after endovascular revascularization

OBJECTIVE

Symptoms of peripheral artery disease (PAD) and patients' physical and psychological status are related in a vicious circle. The aim of this study was to determine the relationships between improvement in parameters of PAD after endovascular procedures and changes in patients' physical and psychological status.

METHODS

We studied 140 consecutive PAD patients: 50 patients with chronic limb-threatening ischemia (CLTI), 50 patients with intermittent claudication (IC) undergoing an endovascular procedure, and 40 IC patients who were not qualified for leg revascularization. All participating patients were assessed at the beginning of the study and at 3 and 12 months of follow-up; scores taken included: ankle-brachial index, 6-minute walking test distance, Barthel index, activities of daily living (ADL) index, instrumental activities of daily living (IADL) index, Mini-Mental State Examination (MMSE), and Hospital Anxiety and Depression Scale (HADS).

RESULTS

After 12 months of follow-up, an improvement in PAD-related symptoms following leg revascularization had been maintained in 56% of the patients with CLTI and in 68% of those with IC. Twelve months after endovascular leg revascularization, the scores in respect of ADL, IADL, and MMSE had increased, and scores for HADS had decreased in both CLTI and IC patients. A higher baseline score in the IADL index was associated with a reduction in the 1-year cardiovascular event risk (OR; 95% CI: 0.70; 0.54-0.91; P < .01).

CONCLUSIONS

In PAD patients, endovascular procedures not only improved PAD-related symptoms, but also ameliorated patients' physical state, improved cognitive function, and reduced depression.

Carotid revascularization and cognitive impairment: the neglected role of cerebral small vessel disease

Carotid atherosclerosis is a pathological process that leads to narrowing of the vessel lumen and a consequent risk of stroke. Revascularization procedures such as carotid endarterectomy (CEA) and carotid stenting aim to reduce occurrence of stroke in selected patients. Due to the proven benefit and low intraoperative risk, CEA is currently the preferred choice in candidates for carotid revascularization. However, the risk of cognitive impairment subsequent to CEA has not been fully elucidated and is unclear whether certain conditions, such as frailty, may increase this risk. There is consistent evidence that shows that frail patients have higher risk of cognitive impairment after surgical procedure. Moreover, brain pre-existing conditions may play a role in cognitive impairment after CEA. Cerebral small vessel disease (SVD) is a pathology that involves microcirculation and is detectable with computed tomography or magnetic resonance. SVD shares common vascular risk factors with carotid atherosclerosis, is a major contributor to vascular cognitive impairment and vascular dementia, and has been proposed as a marker of brain frailty. In this review, we discuss the current evidence about the link between carotid revascularization and cognitive impairment and advance the hypothesis that SVD may play a relevant role in development of cognitive impairment after carotid revascularization.

Changes in Cognition, Depression and Quality of Life after Carotid Stenosis Treatment

BACKGROUND

Although several studies have evaluated the change of cognitive performance after severe carotid artery stenosis, the results still remain elusive. The objective of this study was to assess changes in cognitive function, depressive symptoms and Health Related Quality of Life (HRQoL) after carotid stenosis revascularisation and Best Medical Treatment (BMT).

METHODS

Study involved 213 patients with ≥70% carotid stenosis who underwent assessment of cognitive function using Montreal Cognitive Assessment scale (MoCA), depressive symptoms - using Patient Health Questionnaire-9 (PHQ-9) and HRQoL - using Medical Outcome Survey Short Form version 2 (SF-36v2). The assessment was performed before and at 6 and 12 months followup periods in patients who had Carotid Endarterectomy (CEA), Carotid Artery Stenting (CAS) or received BMT only.

RESULTS

Improvement in the total MoCA scores was observed after 6 and 12 months (p<0.001, Kendall's W=0.28) in the CEA group. In the CAS group - after 12 months (p=0.01, Kendall's W=0.261) whereas in the BMT group - no significant changes (p=0.295, Kendall's W=0.081) were observed. Reduction of depressive symptoms was not found in any of the study groups. Comparing mean SF-36v2 scores in the CEA group, there was no significant difference in any of 10 subscales. Likewise in the CAS group - no significant difference in 9 of 10 subscales (p=0.028, η2=0.343) was observed. Three subscales worsened in the BMT group during the 1-year follow-up period.

CONCLUSION

Patients with severe carotid stenosis who underwent revascularisation enhanced their cognitive performance without exerting significant change of depressive symptoms. Preoperative HRQoL may be maintained for at least one year in the CEA group.

Dexmedetomidine improves cognition after carotid endarterectomy by inhibiting cerebral inflammation and enhancing brain-derived neurotrophic factor expression

Objectives

Carotid endarterectomy (CEA) is efficient in preventing stroke for patients with significant carotid stenosis, but results in mild cognitive dysfunction. Dexmedetomidine is neuroprotective in stroke models. We hypothesized that dexmedetomidine may improve cognition after CEA.

Methods

Forty-nine patients scheduled for elective CEA were randomly assigned to intravenous dexmedetomidine treatment group (n = 25) and control group C (normal saline, n = 24). Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MOCA), as well as lactate, TNF-α, IL-6, and BDNF levels in blood, were assessed before, during, and after surgery.

Results

MMSE and MOCA scores showed subtle decline in both groups at 24 hours postoperatively; this decline remained at 48 hours postoperatively in group C. Both scores were higher in group D than in group C at 48 and 72 hours postoperatively. TNF-α and IL-6 were lower from 5 minutes post-clamping through 24 hours postoperatively in group D; lactate was lower at 5 minutes post-clamping in group D. BDNF was higher from 5 minutes post-clamping through 1 hour postoperatively in both groups, and remained high in group D at 24 hours postoperatively.

Conclusions

Dexmedetomidine improved recovery of cognition after CEA, potentially due to reduced inflammation and enhanced BDNF expression.

Convergence Analysis of Micro-Lesions (CAML): An approach to mapping of diffuse lesions from carotid revascularization

Carotid revascularization (endarterectomy, stenting) prevents stroke; however, procedure-related embolization is common and results in small brain lesions easily identified by diffusion weighted magnetic resonance imaging (DWI). A crucial barrier to understanding the clinical significance of these lesions has been the lack of a statistical approach to identify vulnerable brain areas. The problem is that the lesions are small, numerous, and non-overlapping. Here we address this problem with a new method, the Convergence Analysis of Micro-Lesions (CAML) technique, an extension of the Anatomic Likelihood Analysis (ALE). The method combines manual lesion tracing, constraints based on known lesion patterns, and convergence analysis to represent regions vulnerable to lesions as probabilistic brain atlases. Two studies were conducted over the course of 12 years in an active, vascular surgery clinic. An analysis in an initial group of 126 patients at 1.5 T MRI was cross-validated in a second group of 80 patients at 3T MRI. In CAML, lesions were manually defined and center points identified. Brains were aligned according to side of surgery since this factor powerfully determines lesion distribution. A convergence based analysis, was performed on each of these groups. Results indicated the most consistent region of vulnerability was in motor and premotor cortex regions. Smaller regions common to both groups included the dorsolateral prefrontal cortex and medial parietal regions. Vulnerability of motor cortex is consistent with previous work showing changes in hand dexterity associated with these procedures. The consistency of CAML also demonstrates the feasibility of this new approach to characterize small, diffuse, non-overlapping lesions in patients with multifocal pathologies.

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Convergence Analysis of Micro-Lesions technique finds patterns in diffuse lesions.

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Lesions from carotid revascularization affect consistent brain targets.

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Motor cortex is the most vulnerable brain region to these lesions.

Influence of Severe Carotid Stenosis on Cognition, Depressive Symptoms and Quality of Life

BACKGROUND

Carotid artery disease is not just a causal risk factor of ischemic stroke, but may predispose patients to depressive symptoms and low health related quality of life (HRQoL).

OBJECTIVES

The objectives of the present study were to assess the association between severe carotid artery stenosis (CAS) and cognitive impairment, frequency of depressive symptoms and status of HRQoL.

METHODS

Cross - sectional study involved 55 patients with severe CAS and 54 patients with lower extremity peripheral artery disease (PAD). Cognitive impairment was assessed using Montreal Cognitive Assessment Scale (MoCA), depressive symptoms - PHQ-9 scale. HRQoL was measured using Medical Outcome Survey Short Form version 2 (SF-36v2).

RESULTS

Median MoCA score 24 [23;26] was significantly lower in patients with severe CAS than in patients with PAD - 26 [25-28],(p=0.005; effect size r=0.3). There was no statistically significant difference of median PHQ-9 scores the in CAS group (median PHQ-9 score 4.0 [5]) and in the PAD group (median PHQ-9 score 5.5 [7]), (p=0.08, effect size r=0.18). Mean SF-36v2 scores were similar in CAS and PAD groups except for bodily pain (p=0.001, Cohen's d value = 0.77) and vitality (p=0.02, Cohen's d value = 0.49).

CONCLUSION

In summary, our findings indicate that severe CAS could play a role in cognitive decline. Further studies should be conducted using larger patient cohorts without ischemic brain lesions and with balanced vascular risk profiles to investigate impact of CAS on cognition. There was no association between severe CAS and depressive symptoms in the present study. As patients with severe CAS did not exhibit physical symptoms, HRQoL was better for those patients than for patients with lower extremity PAD.

A Prospective Evaluation of Systemic Biomarkers and Cognitive Function Associated with Carotid Revascularization

OBJECTIVE

To determine factors affecting cognition and identify predictors of long-term cognitive impairment following carotid revascularization procedures.

BACKGROUND

Cognitive impairment is common in older patients with carotid occlusive diseases.

METHODS

Patients undergoing carotid intervention for severe occlusive diseases were prospectively recruited. Patients received neurocognitive testing before, 1, and 6 months after carotid interventions. Plasma samples were also collected within 24 hours after carotid intervention and inflammatory cytokines were analyzed. Univariate and multivariate logistic regressions were performed to identify risk factors associated with significant cognitive deterioration (>10% decline).

RESULTS

A total of 98 patients (48% symptomatic) were recruited, including 55 patients receiving carotid stenting and 43 receiving endarterectomy. Mean age was 69 (range 54-91 years). Patients had overall improvement in cognitive measures 1 month after revascularization. When compared with carotid stenting, endarterectomy patients demonstrated postoperative improvement in cognition at 1 and 6 months compared with baseline. Carotid stenting (odds ratio 6.49, P = 0.020) and age greater than 80 years (odds ratio 12.6, P = 0.023) were associated with a significant long-term cognitive impairment. Multiple inflammatory cytokines also showed significant changes after revascularization. On multivariate analysis, after controlling for procedure and age, IL-12p40 (P = 0.041) was associated with a higher risk of significant cognitive impairment at 1 month; SDF1-α (P = 0.004) and tumor necrosis factor alpha (P = 0.006) were independent predictors of cognitive impairment, whereas interleukin-6 (P = 0.019) demonstrated cognitive protective effects at 6 months after revascularization.

CONCLUSIONS

Carotid interventions affect cognitive function. Systemic biomarkers can be used to identify patients at risk of significant cognitive decline postprocedures that benefit from targeted cognitive training.

Beneficial effects of intravenous dexmedetomidine on cognitive function and cerebral injury following a carotid endarterectomy

The present study aimed to investigate the effects of dexmedetomidine (DEX) on cognition following a carotid endarterectomy (CEA). In addition, the neuroprotective effects of DEX against ischemia-reperfusion injury during CEA were analyzed. Patients due to undergo elective CEA under general anesthesia were randomly assigned to either the DEX-treated group (group D; n=25) or the control group (group C; n=25). Patients in group D were treated with 0.3 µg/kg DEX pre-CEA, followed by 0.3 µg/kg/h DEX intraoperatively up to 30 min prior to the completion of surgery, and the patients in group C received an equal volume of normal saline. Cognitive function was assessed prior to CEA (T0), and at 24, 48, and 72 h, 7 days and 1 month post-surgery (T1-5, respectively), using the Mini-Mental State Examination (MMSE). Blood samples were drawn from the ipsilateral jugular bulb of all patients at 20 min prior to anesthesia (t0), and at 10 min following tracheal intubation, 15 min following clamping and unclamping of the carotid artery, and at 6 and 24 h postoperatively (t1-5, respectively). The protein expression levels of markers of cerebral ischemia and injury, namely S100 calcium-binding protein B (S100B) and neuron-specific enolase (NSE), and the concentration of the oxidative stress marker malondialdehyde (MDA), were analyzed. Patients in group D exhibited elevated MMSE scores at T2 and T3 post-CEA, as compared with group C. Furthermore, the protein expression level of S100B and the concentration of MDA in the jugular bulb of group D patients were markedly decreased compared with those in group C at t3-5 and t3, respectively. The results of the present study suggested that DEX was able to enhance the recovery of cognition following CEA, and this was associated with decreased cerebral damage and antioxidative effects.

Cognitive Deficits in Symptomatic and Asymptomatic Carotid Endarterectomy Surgical Candidates

The role played by vessel disease in stroke-related cognition dysfunction is unclear. We assessed the impact of significant atherosclerotic disease on cognition-even in patients asymptomatic for stroke. We hypothesized that patients would perform poorly relative to controls, but that symptomatic/asymptomatic status (history of stroke/transient ischemic attack) would have no effect. Fifty-two carotid endarterectomy candidates with >60% carotid stenosis and 17 controls underwent a 60-min neuropsychological test protocol. Symptomatic and asymptomatic patients showed deficits in executive function, delayed verbal recall, and general knowledge. Patients symptomatic for stroke also performed worse on tests of language and motor/visuomotor ability. Symptomatic and asymptomatic patients differed in working memory and language task performance. Although all patients showed deficits in executive function and memory, only symptomatic patients showed additional deficits in language and motor function. Cognitive abnormalities in patients viewed as "asymptomatic" for stroke underscore the need for early identification and treatment.

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.

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 changes after eversion carotid endarterectomy under local anesthesia

BACKGROUND

The effects of carotid endarterectomy (CEA) on cognitive function have yet to be fully elucidated. The aim of our study was to administer a battery of cognitive tests to identify any cognitive changes occurring in a consecutive series of patients who underwent CEA using the eversion technique under local anesthesia.

METHODS

This prospective study was designed to analyze a consecutive series of patients undergoing eversion CEA under local anesthesia for significant carotid stenosis at our vascular surgery unit over a period of 6 months. Patients underwent tests to rule-out those who already had cognitive impairments or states of depression/anxiety capable of interfering with cognitive testing outcomes. Patients then completed a battery of 10 neurocognitive tests preoperatively and again 30 days and 4 months after surgery to assess the functions of both cerebral hemispheres as thoroughly as possible.

RESULTS

Of the 48 patients initially considered for our study, 39 completed the follow-up. They were 71.4 ± 8.2 (mean ± SD) years of age; 30 were men and 9 were women. Six were symptomatic for carotid stenosis and 33 were asymptomatic. All patients were examined by a neurologist and underwent pre- and postoperative nuclear MRI or CT scan of the brain to identify any cerebral ischemia potentially correlated with the surgical procedure. In all cases, the cognitive test findings tended to improve postoperatively; this improvement was statistically significant in 7 tests. Post-hoc analysis confirmed an improvement between the pre- and postoperative test results. Among the different variables considered, only age <75 years seems to have influenced cognitive improvement.

CONCLUSIONS

The effects on cognitive function of carotid stenosis, particularly CEA, is still a much debated issue. The data reported in the literature vary considerably, preventing any final conclusions from being drawn. The mechanisms capable of inducing changes in cognitive status after CEA have yet to be precisely clarified. In our study, a suitable battery of tests were used to analyze the trend of cognitive function correlating with eversion CEA under local anesthesia. Our results demonstrate substantially improved cognitive function after CEA, which was statistically significant in 7 of 10 tests. We surmise that the CEA procedure, per se, can help to protect patients against cognitive deterioration, especially in those <75 years of age.

The effect of carotid occlusion in cognition before endarterectomy

The role of carotid stenosis on cognition remains to be determined. To study whether people with stenosis of the carotid artery have increased cognitive impairments, we studied 53 patients with moderate or severe carotid stenosis (with no symptoms of stroke or dementia) and 53 controls. We describe which cognitive functions were impaired in the patients and whether there were differences based on the side, the severity of the stenosis or the presence of neurological symptoms. Using the Repeatable Battery for the Assessment of Neuropsychological Status, we found that the patients with carotid stenosis had lower cognitive performances in attention, verbal memory, visuospatial capacity and verbal fluency. Patients with lesser degrees of stenosis than healthy control patients had better scores in learning and memory. The results from this study suggest that patients with severe carotid stenosis have a lower cognitive status than healthy control patients, which is associated with the degree of total carotid stenosis.

Pre-operative education and counselling are associated with reduced anxiety symptoms following carotid endarterectomy: a randomized and open-label study

BACKGROUND

Post-operative anxiety is common and may have significant impact on the post-operative recovery of the patients. Theatre nurse visits before surgery has been shown to reduce patient's anxiety levels following general surgery.

AIM

To investigate the effect of pre-operative visits and counselling by intensive care unit (ICU) nurses on patient's anxiety levels following carotid endarterectomy.

METHODS

This is an open-label and randomized clinical trial. Patients undergoing carotid endarterectomy were divided into study (n=60) and control group (n=60). For the study group, in addition to routine pre-operational counselling by the surgeons, ICU nurses visited the patients and provided a structured counselling the day before surgery. For the control group, only routine pre-operative counselling was provided. Anxiety levels were assessed by Zung self-rating anxiety scale (SAS) the day before surgery and on the day after being discharged from ICU to the ward.

RESULTS

The two groups were comparable in age, sex, surgical methods, and duration of ICU stays. Following the surgery, the mean SAS score in the control group increased from 50.5±5.4 to 58.5±7.3 (p=0.03), whereas the mean SAS score in the study group reduced from 51.5±4.3 to 45.1±6.5 (p=0.02). The proportion of patients with anxiety symptoms in the control group was higher than in the study group following the surgery (58.3% vs. 33.3%, p=0.001).

CONCLUSIONS

Pre-operative visits and counselling by ICU nurses could reduce patient's anxiety levels following carotid endarterectomy.

The impact of general versus local anesthesia on early subclinical cognitive function following carotid endarterectomy evaluated using P3 event-related potentials

BACKGROUND

Postoperative cognitive dysfunction (POCD) is detected in 25% of patients undergoing carotid endarterectomy (CEA). The mechanism of POCD is poorly understood, but it is believed that general anesthesia (GA) itself may contribute significantly to POCD. The aim of our prospective study was to compare, with the aid of event-related potentials, the impact of general anesthesia (GA) and local anesthesia (LA) on POCD in patients undergoing CEA.

METHODS

Sixty patients were included in this study and were divided into two groups: CEA was performed in 30 patients placed under GA (total intravenous anesthesia), herein the GA group, while 30 patients underwent CEA under LA (cervical plexus block), herein LA group. Cognitive outcome was assessed with the use of auditory event-related potentials (ERPs), P3 response. The measurements were taken before surgery (pre-op) and on the first (1.post-op) and the sixth postoperative days (6.post-op).

RESULTS

Preoperative cognitive functions did not differ significantly between the two groups. A significant decrease in P3 amplitude was found on the first postoperative day (1.post-op) in the GA group (p = 0.0005), but normalization of P3 amplitude was detected at the second postoperative measurement (6.post-op). The patients operated on under local anesthesia (LA group) showed stable P3 amplitudes in all three measurements. No significant changes in P3 latencies were observed in either group. There were no significant differences between the two groups regarding demographic characteristics, preoperative and postoperative clinical condition, percentage significance of carotid artery stenosis, duration of carotid cross-clamping or in the frequency of shunt use (zero frequency for both groups).

CONCLUSIONS

Our study showed that general anesthesia, used for patients undergoing CEA, negatively influenced cognitive function during the immediate period after surgery (the first postoperative day). However, by the sixth postoperative day, this cognitive impairment was no longer being detected. POCD occurring shortly after carotid endarterectomy is the result of general anesthesia, which is probably an independent evoking factor in itself. The cognitive deficit recorded only during the immediate postoperative period, is not a negative effect of GA but merely a side-effect and thus GA should not be considered inferior to LA for use during CEA.

Subclinical neurocognitive dysfunction after carotid endarterectomy-the impact of shunting

BACKGROUND

Subclinical neurocognitive deficit after carotid endarterectomy (CEA) has been reported in 25% of patients. The influence of the type of anesthesia and shunting on early postoperative neurocognitive function remains unclear. Therefore, we analyzed the cognitive function after CEA using a battery of psychometric tests before surgery and on the first postoperative day.

METHODS

Twenty nine patients under regional and 28 under general anesthesia were included in the study. Regional anesthesia was administered inducing a superficial cervical block, and the general anesthesia was induced using a standardized manner. Then cognitive function was tested using a battery of psychometric tests before and 24 hours after surgery. S 100 beta was determined at the same time points.

RESULTS

A statistical difference was found between the results of the testing before and after CEA: decline in digit symbol test (9%), perceptual speed (6%), and spatial working memory (44%) and improvement in verbal fluency (6%) and attention (5%). The only intraoperative factor that correlated with the cognitive dysfunction was shunt insertion; patients with a shunt had a lower perceptual speed (P=0.005) and worse spatial working memory (P=0.004). No correlation was found between the type of anesthesia or S 100 beta level and any psychometric test, but these results might be influenced by the small sample size in our study.

CONCLUSIONS

Shunt insertion was the only parameter correlated with cognitive decline on the first day after CEA. Regional anesthesia might offer indirect benefit because of a reduced need of shunting in wakeful patients. Larger studies are required to clarify the role of shunting and type of anesthesia in early neurocognitive deficit after CEA and its impact on the quality of life.

Changes in cognitive function during the 1-year period following endarterectomy and stenting of patients with high-grade carotid artery stenosis

BACKGROUND

In patients with severe carotid artery stenosis, cognitive decline and changes in cognitive function before to after treatment have been noted, though the true effects of treatment in such patients remain unclear. A convenient and repeatable neuropsychological test battery is needed for such patients.

METHODS

In 26 patients with severe carotid artery stenosis treated by carotid endarterectomy (CEA) and stenting (CAS), cognitive function was examined before and 1 week, 3 months, 6 months, and 1 year after treatment. RBANS and MMSE were selected as a test battery, and changes in test scores and long-term results of revascularization were evaluated.

RESULTS

RBANS was useful and suitable for neuropsychological testing in such patients, and yielded the following results: (1) Patients before treatment had, on average, RBANS scores rated low average, with mild but relatively diffuse cognitive impairment; (2) RBANS scores were increased significantly at 3 months after CEA and CAS, and cognitive improvement was maintained over 1 year; and (3) scores were decreased temporarily at 1 week after CEA, but not after CAS.

CONCLUSIONS

Patients with severe carotid artery stenosis exhibited mild decline in cognitive function, which was improved after CEA and CAS. RBANS is a suitable test battery for this type of patient.

The Role of Carotid Artery Stenting and Carotid Endarterectomy in Cognitive Performance

Background and Purpose— Change in cognition is being increasingly recognized as an important outcome measure; however, the role of carotid revascularization on this issue remains to be determined. It is still under debate whether carotid artery stenting and carotid endarterectomy have the same influence on neuropsychological functions.

Summary of Review— This article systematically reviews recent literature in an attempt to clarify this issue. A total of 32 papers reporting on neurocognition after carotid endarterectomy (n=25), carotid artery stenting (n=4), or carotid artery stenting versus carotid endarterectomy (n=3) were identified. The studies were different for many methodological factors, eg, sample size, type of patients and control group, statistical measure, type of test, timing of assessment, and so on. There was a lack of consensus in defining the improvement or impairment after either carotid artery stenting or carotid endarterectomy. Furthermore, there were nonuneqivocal results regarding the same domain of assessment (memory, visuomotor, attention). Based on available evidence, it is probable that carotid endarterectomy as well as carotid artery stenting do not change neuropsychological function “per se.”

Conclusions— Assessment of cognition after carotid revascularization is probably influenced by many confounding factors such as learning effect, type of test, type of patients, and control group, which are often minimized in their importance. The role of carotid revascularization is to prevent stroke in patients with severe carotid stenosis as highlighted by previous large randomized trials. Although an effect of carotid revascularization on cognition could be missed as a consequence of underpowered studies included in this review, at this time, no prediction can be done regarding its repercussions on higher intellectual functions. Larger studies appropriately designed and powered to assess cognition after carotid revascularization might change this view.

COGNITIVE OUTCOMES AFTER CAROTID REVASCULARIZATION

OBJECTIVE

Carotid artery stenting (CAS) and carotid endarterectomy (CEA) are currently being compared in ongoing randomized, controlled trials using postprocedural 30-day stroke rate, myocardial infarction, and mortality as primary endpoints. Recent data suggest that cognitive function may decline after CEA. Understanding the mechanisms that affect cognitive outcomes after carotid revascularization will be important in the design of future comparative studies of CAS and CEA incorporating cognitive outcome as an endpoint.

SUMMARY OF REVIEW

The effects of carotid revascularization procedures on cognitive outcome are unclear. Several factors contribute to the difficulty in interpreting cognitive data, including patient heterogeneity, variability of surgical techniques, and the differences in neuropsychological testing methodology. Mechanisms underlying cognitive effects during CEA have emerged, including the potential detrimental effect of procedural emboli and the beneficial effect of improved cerebral hemodynamics. The emergence of CAS as an alternative to CEA for treating carotid stenosis again raises questions about cognitive outcomes. Despite the use of distal protection devices, CAS is associated with a higher burden of microemboli. CAS does not, however, require the extent of temporary vessel occlusion associated with CEA. Quantifying microemboli and changes in cerebral hemodynamics along with standardization of neuropsychological testing may lead to meaningful comparisons of cognitive data for patients undergoing carotid revascularization procedures.

CONCLUSION

As use of CAS increases, it is important for randomized, controlled trials comparing CAS with CEA to include cognitive outcomes assessments. Furthermore, understanding the key mechanisms resulting in cognitive impairment during carotid revascularization procedures might limit injury.

Chronic ischemia and neurocognition

Cognitive impairment from a major stroke as a consequence of carotid disease is an acknowledged clinical outcome; however, cognitive impairment without major stroke is open to discussion. The three recognized mechanisms for cognitive dysfunction from internal carotid artery are microembolization, white-matter disease, and hypoperfusion. The last has been most difficult to characterize physiologically. In this article, the authors review evidence supporting the existence of chronic ischemia in the brain and its direct impact on cognitive functions. By incorporating the pathophysiology of chronic ischemia into the algorithm of the management of carotid artery disease, we may be able to extend the goals of carotid artery revascularization beyond merely preventing stroke to include preventing or reversing cognitive decline.