Carotid artery disease, carotid endarterectomy, and behavior

The Impact of Carotid Artery Stenting on Cerebral Perfusion, Functional Connectivity, and Cognition in Severe Asymptomatic Carotid Stenosis Patients

Background and purpose

Asymptomatic carotid artery stenosis can lead to not only stroke but also cognition impairment. Although it has been proven that carotid artery stenting (CAS) can reduce the risk of future strokes, the effect of CAS on cognition is conflicting. In recent years, pulsed arterial spin labeling (pASL) MRI and resting-state functional MRI (R-fMRI) have been employed in cognitive impairment studies. For the present study, cognition is evaluated in severe asymptomatic carotid artery stenosis patients undergoing CAS, and the mechanisms underlying the cognitive change are explored by pASL MRI and R-fMRI.

Materials and methods

We prospectively enrolled 24 asymptomatic, severe (≥70%), unilateral internal carotid artery stenosis patients, who were expecting the intervention of CAS. Cognition assessment (including the Montreal Cognitive Assessment Beijing Version, the Minimum Mental State Examination, the Digit Symbol Test, the Rey Auditory Verbal Learning Test, and the Verbal Memory Test) and an integrated MRI program (pASL MRI, and R-fMRI) were administered 7 days before and 3 months after CAS.

Results

16 subjects completed the follow-up study. After stenting, significant improvement in the scores of the MMSE, the Verbal Memory test, and the delayed recall was found. No significant difference was found in the scores of the Montreal Cognitive Assessment Beijing Version, the Digit Symbol Test, and the immediate recall. After CAS treatment, asymptomatic carotid artery stenosis patients showed increased perfusion in the left frontal gyrus, increased amplitude of low-frequency fluctuation (ALFF) in the right precentral gyrus, and increased connectivity to the posterior cingulate cortex (PCC) in the right supra frontal gyrus. However, no significant correlations were found between these imaging changes and cognition assessments.

Conclusion

Successful CAS can partly improve cognition in asymptomatic carotid artery stenosis patients. The cognition improvement may be partly attributed to the increased perfusion in the left frontal gyrus, increased ALFF in the right precentral gyrus, and increased connectivity to the PCC in the right supra frontal gyrus.

Hypertension and Risk of Post-Operative Cognitive Dysfunction (POCD): A Systematic Review and Meta-Analysis

Background:

Post-operative cognitive dysfunction (POCD) occurs frequently after major surgery. Hypertension is well-established as a risk factor for age-related cognitive impairment, but it is unclear whether or not it also increases the risk of POCD.

Objective:

To evaluate the role of hypertension in POCD risk in a systematic review and meta-analysis.

Method:

PubMed, Ovid SP and the Cochrane Database of Systematic Reviews were searched for longitudinal studies of adults undergoing surgery with reporting of hypertension, blood pressure and/or anti-hypertensive treatment associations with POCD as relative risks or odds ratios. Fixed-effects meta-analyses were performed using Review Manager (version 5.3).

Results:

Twenty-four studies on 4317 patients (mean age 63 years) were included. None of the studies had set out to assess hypertension as a risk factor for POCD. Hypertension was used as a categorical predictor throughout and only 2 studies adjusted for potential confounders. Across all 24 studies, hypertension was not significantly associated with POCD risk (RR 1.01; 95% CI 0.93, 1.09; p=0.82), though among 8 studies with >75% males, we found hypertension associations with a 27% increased risk of POCD (RR 1.27, 95% CI 1.07, 1.49; p=0.005).

Conclusion:

Our findings do not support the hypothesis that hypertension is a risk factor for POCD. However, since none of the studies included in our analysis were hypothesis-driven and most did not adjust for potential confounders, further systematic investigations are needed to evaluate the role of hypertension in the epidemiology of POCD.

Neurocognitive Improvement in Patients Undergoing Carotid Endarterectomy for Atherosclerotic Occlusive Carotid Artery Disease

Objectives: To assess the improvement in neurocognitive functions after carotid endarterectomy (CEA) under local anesthesia (LA) in patients with carotid bifurcation occlusive disease. Place and duration of study: Department of Vascular Surgery, Combined Military Hospital Lahore from January 2013 to January 2015. Patients and Methods: A total of 79 patients with carotid artery occlusive disease, having no history of major stroke, depression, or dementia underwent CEA under LA. Cognitive functions were assessed 3 days before surgery and then 4 weeks and 12 weeks after the surgery using the Addenbrookes cognitive examination (ACE) score and General Practitioner Assessment of Cognition (GPCOG) Score. Results: In ACE score, Attention, Memory, Fluency, Language, and Visuospatial orientation improved by 33.3%, 30.7%, 21.4%, 38.4%, and 31.2%, respectively, by the end of 12 weeks. An overall improvement in neurocognition was 32% (P = 0.03). In GPCOG score, Orientation, Recall, and Memory improved by 33%, 20%, and 100%, respectively, with an overall improvement of 33.3% at the end of 12 weeks (P = 0.02). Conclusion: Both scoring systems show an overall improvement in neurocognition as well as improvements in all the subcategories in each system. Hence, we conclude statistically significant improvement in neurocognitive functions after CEA.

Association between Carotid Artery Stenosis and Cognitive Impairment in Stroke Patients: A Cross-Sectional Study

To investigate potential associations between carotid artery stenosis and cognitive impairment among patients with acute ischemic stroke and to provide important clinical implications. We measured the degree of carotid artery stenosis and recorded the Mini-Mental State Examination score (MMSE) at admission in 3116 acute ischemic stroke patients. The association between carotid stenosis and cognitive impairment assessed by MMSE was tested using multivariate regression analysis. Other clinical variables of interest were also studied. After adjusting for age, gender, education level, marriage, alcohol use, tobacco use, physical activity, hypertension, diabetes, hypercholesterolemia, atrial fibrillation, myocardial infarction and NIHSS (National Institutes of Health Stroke Scale) score, we found that participants with high-grade stenosis of the carotid artery had a higher likelihood of cognitive impairment compared to those without carotid artery stenosis (OR = 1.49, 95%CI: 1.05–2.11, p<0.001). Left common carotid artery stenosis was associated with cognitive impairment in the univariate analysis, although this effect did not persist after adjustment for the NIHSS score. Cognitive impairment was associated with high-grade stenosis of the right carotid artery.

Ignoring floor and ceiling effects may underestimate the effect of carotid artery stenting on cognitive performance

Introduction

Data on neuropsychological outcome after carotid artery stenting (CAS) remain inconsistent, furthermore cognitive outcome seems to be unpredictable in the individual case. Previous studies reporting improvement or decline might be due to ceiling and floor effects of the applied cognitive tests. We applied cognitive testing before and after CAS, avoiding the pitfall of ceiling and floor effects.

Methods

In our prospective database, we identified 72 patients free of clinical stroke with ≥70% carotid artery stenosis, who were treated with CAS. They were administered a neurocognitive test battery before and 3 months after CAS to compare cognitive performance before and after CAS. To avoid ceiling and floor effects of test performances, we additionally analysed subgroups of patients without baseline floor and ceiling cognitive performance.

Results

Pre-interventional to post-interventional cognitive performance improved significantly in the subtests measuring verbal episodic memory; deterioration was observed in spatial memory. The subgroups of patients without baseline floor and ceiling cognitive performance improved in measures of global cognition, verbal episodic memory (patients with left-sided CAS) and divided attention (patients with right-sided CAS); we observed no significant effects in the other domains.

Conclusions

Ignoring floor and ceiling effects may underestimate the impact of CAS on cognitive performance.

Psychometric and EEG changes after carotid endarterectomy

The influence of carotid stenosis and its surgical treatment on brain function is still poorly defined. We therefore performed a study to assess psychometric and quantified EEG findings after carotid endarterectomy (CEA). Sixty-nine non-demented patients (aged 72 ± 7 years) with severe carotid stenosis (≥ 70%) eligible for CEA were studied. Forty patients (group A) had unilateral stenosis, and 29 patients (group B) had bilateral stenosis. Before and 5 months after CEA all the patients were evaluated by the Trail Making Test A, the Symbol Digit Test, and spectral EEG analysis. At baseline, compared to group A, group B patients performed slowly the Trail Making Test A (Z: 1.45 ± 1.4 vs. 0.76 ± 1.3; p <  0.05), but not the Symbol Digit Test (Z: 0.83 ± 1.38 vs. 0.64 ± 1.26; p = 0.59). Altogether, the patients with at least one abnormal psychometric test were 29% (group A: 26%; group B: 33%, p = 0.56). The EEG did not differ significantly between patients of group A compared to group B. After CEA, psychometric tests improved (mean Z score from 0.73 ± 1.12 to 0.45 ± 1.15, p <  0.05). The improvement was similar in group A and B. The EEG mean dominant frequency improved only in group B patients and it was related to the improvement in psychometric tests (r = 0.43, p = 0.05). Low psychometric performance was detectable in about 1/ 3 of non-demented patients with severe carotid stenosis. CEA improved mental performance and, in patients with severe bilateral stenosis, accelerated the EEG frequency.

Neuropsychological sequelae of carotid angioplasty with stent placement: correlation with ischemic lesions in diffusion weighted imaging

Background and Purpose

Few studies investigated the neuropsychological outcome after carotid angioplasty with stent placement (CAS), yielding partially inconsistent results. The present investigation evaluated the effect of CAS in patients with high-grade stenosis and assessed the predictive value of ischemic lesion number for postinterventional cognitive deterioration.

Methods

22 patients were tested neuropsychologically before and six weeks after CAS. Cerebral ischemic changes were assessed with diffusion weighted imaging (DWI) prior to and after angioplasty.

Results

Pre- to postinterventional cognitive performance improved significantly in terms of verbal memory (t = −2.30; p<0.05), whereas significant deterioration was noted regarding verbal memory span (t = 2.31; p<0.05). 8 (36%) persons conformed to the criteria of cognitive improvement. 6 patients (27%) were postinterventionally classified as having deficits. Analysis yielded no statistically significant correlations between lesion quantity and cognitive change.

Conclusion

Both improvement and deterioration of cognitive functioning was observed in our collective of patients, leaving the neuropsychological outcome after percutaneous transluminal angioplasty unpredictable in individual cases. The presence of acute ischemic lesions on DWI was found to be not tightly associated with cognitive dysfunction after CAS.

Cognitive function after carotid endarterectomy: greater risk of decline in symptomatic patients with left internal carotid artery disease

BACKGROUND

The risk of cognitive decline in patients undergoing carotid endarterectomy (CE) for left internal carotid artery (ICA) (LICA) disease before or after the occurrence of ischemic symptoms has not been fully elucidated. We evaluated whether patients undergoing CE for symptomatic LICA stenosis have greater risk of cognitive decline than patients with asymptomatic LICA disease or right ICA disease.

METHODS

In a series of patients aged 65 years and older, consecutively undergoing CE and free from cognitive impairment, cognitive function was evaluated through the age- and education-adjusted Mini Mental State Examination and the Clock Drawing Task at baseline and at the end of the study period (average follow-up: 44.4 +/- 14.3 months).

RESULTS

The analysis included 103 patients (mean age 72.6 +/- 7.0 years; 73 men), of whom 50 had LICA disease (29 symptomatic). At the end of the study period, Mini Mental State Examination score was reduced in patients with symptomatic LICA disease (P < .001) but not in other patients, whereas the Clock Drawing Task score was reduced in both patients with LICA and right ICA. Patients with symptomatic LICA disease had greater risk of cognitive decline than other individuals, either measured by the Mini Mental State Examination score (F = 5.18, P = .002) or by the Clock Drawing Task score (F = 9.42, P = .001).

CONCLUSIONS

Patients undergoing CE for symptomatic LICA disease appear to be at increased risk of cognitive decline than other individuals. Further studies are needed to confirm these findings and to evaluate whether LICA endarterectomy before occurrence of cerebrovascular ischemic symptoms may provide additive benefit in the prevention of cognitive decline.

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.

Effect of carotid artery stenting on cognitive function in patients with carotid artery stenosis: preliminary results

BACKGROUND AND PURPOSE

Stenosis of the carotid artery may be a cause of reduced cognitive performance that can be ameliorated with placement of a stent. The goal of this study was to measure cognitive performance and speed of psychomotor performance prospectively before and after carotid stent placement.

MATERIALS AND METHODS

Patients referred for stent placement for a unilateral carotid artery stenosis were enrolled in the study. Neuropsychologic testing was performed with a Mini-Mental State Examination, an extended mental status examination, a subjective cognitive status measure, and a psychomotor performance test for speed. The severity of the stenosis was measured on angiograms performed before stent placement. Three months after stent placement, CT angiograms were performed and the neuropsychologic testing was repeated. Differences in neuropsychologic test scores before and after stent placement were calculated and tested for significance with a Student t test.

RESULTS

Seventeen patients with a single unilateral carotid stenosis of more than 50% completed the study. Stenosis of the carotid artery averaged 80% before treatment and 18% after treatment. After stenting, the scores from the extended mental status examination improved significantly. The scores from the subjective cognitive status measure also improved. No significant change was noted in the scores from the Mini-Mental State Examination or in the speed of psychomotor performance.

CONCLUSION

Carotid stent placement in patients with a unilateral stenosis of the carotid artery resulted in significant improvement in cognitive test scores in this highly selected patient group. Further studies are needed to confirm these preliminary observations.

Cognitive dysfunction in 16 patients with carotid stenosis: detailed neuropsychological findings

Background

Impairment of cognitive function is often present in patients with carotid artery stenosis but the details of this dysfunction have rarely been reported. Our purpose was to elucidate the cognitive dysfunction in patients with unilateral severe carotid stenosis using comprehensive neuropsychological testing, and also to identify the specific underlying clinical and radiological factors.

Methods

We analyzed the results of neuropsychological testing, the clinical history, and MR findings in 16 consecutive patients with angiographically proven severe (70-99%) stenosis of the extra cranial internal carotid artery (ICA). Cognitive functions were examined using the Seoul Neuropsychological Screening Battery and the Neglect Battery. We excluded patients with cortical infarction and those with contra lateral ICA occlusion or severe stenosis.

Results

Our comprehensive neuropsychological testing revealed obvious cognitive deficits in all patients with unilateral severe ICA stenosis, the most common being frontal executive impairment. The mean cognitive score on the memory test was also significantly lower in patients with symptomatic ICA stenosis than in asymptomatic patients (29.33±10.98, mean±SD, p < 0.05). The total score on the global cognitive test was significantly lower in patients with an ischemic lesion on MRI than in no lesion patients (113.23±34.78, p < 0.05). The presence of symptoms related to the ICA stenosis was related to cognitive dysfunction even when there were no ischemic lesions on MRI. SPECT revealed ipsilateral cortical hypoperfusion in 9 of 12 patients (75%).

Conclusions

Cognitive deficits are common in patients with unilateral severe ICA stenosis. Our findings suggest that an additional mechanism beyond the structural lesion such as chronic hypoperfusion may affect cognitive function in patients with high-grade ICA stenosis.

Postoperative cognitive dysfunction: incidence and prevention

Postoperative cognitive dysfunction (POCD) is a decline in cognitive function for weeks or months after surgery. Due to its subtle nature, neuropsychological testing is necessary for its detection. The interpretation of literature on POCD is difficult because of numerous methodological limitations, particularly the different definitions of POCD and the lack of data from control groups. POCD is common after cardiac surgery, and recent studies have now verified that POCD also exists after major non-cardiac surgery, although at a lower incidence. The risk of POCD increases with age, and the type of surgery is also important because there is a very low incidence associated with minor surgery. Regional anaesthesia does not seem to reduce the incidence of POCD, and cognitive function does not seem to improve after carotid surgery as has previously been suggested.

Neuropsychological Changes in Patients with Carotid Stenosis after Carotid Endarterectomy

We investigated changes in neuropsychological function in patients with carotid stenosis following carotid endarterectomy (CEA) in relation to cerebral hemodynamics. The subjects were 24 patients who underwent CEA and 17 healthy controls matched by age, educational level, gender and handedness. Cerebral angiography, single-photon emission computed tomography (SPECT) and neuropsychological tests were performed approximately 1 week before and 3 weeks after CEA in all patients. In the patient group, the categories achieved in the new modified Wisconsin Card Sorting Test (WCST) improved significantly after CEA (4.0 +/- 2.0; before CEA: 2.3 +/- 2.1, p < 0.01). The perseverative errors of Nelson in the WCST improved significantly (before CEA: 9.1 +/- 6.9, after CEA: 3.3 +/- 3.4, p < 0.01). The difficulty maintaining set in the WCST improved significantly (before CEA: 2.3 +/- 1.9, after CEA: 1.3 +/- 1.7, p < 0.05). In the control group, none of the test scores showed significant improvement between the first and second tests. Moreover, frontal lobe function improved significantly in those patients with baseline carotid artery diameter of more than 70% of normal, or whose preoperative cerebral perfusion reserve was reduced by less than 15% of a response to acetazolamide. Our results suggest that CEA improves frontal lobe function in patients with severe carotid stenosis or reduced cerebral perfusion reserve.

Cognitive functions in patients with cerebrovascular disease: potential impact of revascularization

The purpose of this review is to assess the impact of luminal restoring of carotid artery stenosis on cognitive functions. Therefore, papers dealing with the neuropsychological influence of carotid artery stenosis and studies comparing the neuropsychological course after respective recanalization have been included.

Does carotid endarterectomy improve cognitive functioning?

BACKGROUND

Carotid endarterectomy (CEA) might improve cognitive functioning, but studies thus far have produced mixed results. The aim of the present study was to examine the effect of CEA on cognitive functions in a methodologically more strict design, first by testing the presumption of preoperative cognitive impairment and second through a better control for the possible influence of the nonspecific effects of practice and surgery.

METHODS

Preoperative performance on a neuropsychologic test battery of 56 patients with severe occlusive disease of the carotid artery but without history of major stroke was compared with the performance of 46 healthy control subjects and 23 patients before endarterectomy of the superficial femoral artery (remote endarterectomy). The degree of cognitive change in the 2 patient groups was compared at 3 and 12 months postoperatively. We assessed mood to control for possible momentary affective influences on cognition.

RESULTS

Before CEA, patients showed reduced functioning compared with that seen in healthy control subjects in terms of attention, verbal and visual memory, planning of motor behavior, psychomotor skills, and executive function. Performance of patients before remote endarterectomy was reduced as well. Improvements in several cognitive functions were observed after both types of surgical interventions and were attributed to psychologic relief from uncomplicated surgery and to practice.

CONCLUSIONS

No specific restorative effect of CEA on cognitive functioning was observed. The preoperative impairment in several cognitive domains might be caused by factors that patients with various types of vascular disease might have in common, such as small-vessel disease or other undetected abnormalities within the brain.

Carotid endarterectomy improves cognitive function in patients with exhausted cerebrovascular reserve

OBJECTIVE

To investigate changes in cognitive function following carotid endarterectomy (CEA).

DESIGN

Prospective study with controls.

METHODS

CEA patients (n=159) were compared to a urology surgery control group (n=20). In CEA patients cerebrovascular reserve (CVR) was measured preoperatively. During surgery emboli and blood flow velocity in the middle cerebral artery were measured by transcranial Doppler (TCD) and cerebral oxygen saturation (CsO2) by near infrared spectroscopy. Cognitive function was measured preoperatively and at 5 days and 8 weeks postoperatively using a standardised computer battery of tests.

RESULTS

Only 8% of patients had normal CVR bilaterally. The median number of emboli during CEA was 12 (range 0-181). On carotid clamping, TCD velocity fell a median of 41% and cerebral oxygen saturation by 5%. Attention deteriorated compared to controls 5 days following CEA (p=0.003) and this deterioration was related to the rise in TCD velocity on declamping (r=-0.3, p=0.002). Median attention reaction times improved significantly by 8 weeks (p=0.001) especially in patients' with severely impaired CVR before surgery (p=0.02).

CONCLUSIONS

Attention improved at 2 months following CEA in patients with impaired CVR. CEA may offer more than reduced stroke risk to patients with impaired CVR.

Effects of carotid endarterectomy on cerebral blood flow and neuropsychological test performance in patients with high-grade carotid stenosis

We examined the changes in cognitive function following carotid endarterectomy (CEA) in relation to the cerebral blood flow (CBF) in patients with high-grade carotid stenosis. The subjects consisted of 23 patients who underwent CEA and 17 controls matched by age and education. Single photon emission computed tomography (SPECT) and neuropsychological tests were performed 2 weeks before and 4 weeks after CEA in all patients. The preoperative CBF tests revealed a decreased vasodilatory reserve in the ipsilateral cerebral hemisphere in nine patients, which was increased after CEA. In these patients, the grade of carotid stenosis was significantly higher than in those with a normal perfusion reserve (90.2+/-8.1% vs. 78.6+/-11.3%, respectively, p<0.05). In the patient group, the postoperative scores (27.2+/-2.9) of the mini-mental state examination (MMSE) improved significantly over the preoperative ones (26.1+/-3.2, p<0.05). Moreover, the scores in the block-design test after CEA (86.8+/-19.8) were significantly higher than those before the operation (81.8+/-22.3, p<0.01). The error score in immediate retention improved from 9.0+/-3.1 to 7.7+/-4.0 following CEA (p<0.05). In the control group, none of the test scores showed significant improvement between the first and second tests. In the patients with an impaired vasodilatory reserve, the mean score of the block-design test significantly improved from 65.6+/-22.1 to 74.0+/-19.2 after CEA compared with those in patients without impairment (p<0.05). High-grade carotid stenosis was thus concluded to cause cognitive impairment due to cerebral hemodynamic failure, which is presumably reversed by CEA.

Peripheral arterial disease and cognitive function

OBJECTIVE

Peripheral arterial disease (PAD) is associated with comorbid atherosclerosis of the coronary and carotid arteries and is a significant risk factor for stroke. However, cognitive function in PAD patients before clinically evident stroke remains poorly characterized. Here we hypothesized that, on neuropsychological testing, PAD patients would perform more poorly than healthy control subjects, and persons with mild cardiovascular disease (essential hypertension), but better than stroke patients, thus reflecting a continuum of cognitive impairment associated with increased severity of vascular disease.

METHOD

The cognitive performance of 38 PAD patients (mean ankle-brachial index=0.67, Fontaine Class II) was contrasted with that of 23 healthy normotensive controls, 20 essential hypertensives, and 26 anterior ischemic stroke patients on twelve neuropsychological tests.

RESULTS

PAD patients performed significantly more poorly than hypertensives and normotensives, but better than stroke patients, on seven tests of nonverbal memory, concentration, executive function, perceptuo-motor speed, and manual dexterity. Hypertensives displayed poorer performance than normotensives on tests of nonverbal memory and manual dexterity. These findings were independent of age, education, and depression scores. Higher diastolic blood pressure and plasma glucose levels predicted poorer performance of select cognitive tests by PAD patients. Eight to 67% of PAD patients displayed impaired performance (< 5(th) percentile of normotensive controls) on the seven aforementioned cognitive tests.

CONCLUSIONS

PAD patients exhibit diminished performance across a variety of domains of cognitive function. Findings also suggest a continuum of cognitive impairment associated with increasingly severe manifestations of cardiovascular disease, thus emphasizing the need for enhanced preventative measures to avert functional declines.

Depression in older people with mild stroke, carotid stenosis and peripheral vascular disease: a comparison with healthy controls

BACKGROUND

Although depression has a recognised association with stroke, the role of "silent" cerebrovascular pathology associated with carotid stenosis and peripheral vascular disease remains unexplored.

METHODS

Four groups of 25 community residents aged 65 and over were recruited, comprising first anterior circulation stroke, carotid stenosis accompanied by transient ischaemic attack, peripheral vascular disease and a non-vascular control group. All participants were interviewed using the Hamilton Rating Scale for Depression [HRSD] (including a modified version) and Geriatric Depression Scale. DSM IV criteria for major depression and measures of handicap, social support and physical illness were also administered. Head computerised tomography (CT) scans were performed on stroke patients to examine the relationship between lesion location and depression.

RESULTS

One hundred patients were interviewed. Stroke patients were more likely to live in a nursing home and had less social support than other groups. Mean scores on the modified Hamilton and Geriatric Depression Scales were higher in stroke and carotid stenosis groups than controls. Patients with stroke did not show a higher prevalence of DSM IV major depressive disorder than those with carotid stenosis. There was no relationship between the presence of lesions affecting the frontal/subcortical system and prevalence/severity of depression.

LIMITATIONS

Small numbers, mortality of stroke patients in hospital, possible selection bias in the control group and use of a previously unvalidated depression rating scale all limit the study.

CONCLUSIONS

A possible role for carotid stenosis in the pathogenesis of depressive disorder is suggested. Larger studies incorporating brain imaging may be required to examine the mechanism of this association more closely. The use of a shorter version of the HRSD in older people with cerebrovascular disease may warrant further exploration.

Neuropsychometric changes in patients after carotid endarterectomy

BACKGROUND AND PURPOSE

One hundred twelve patients undergoing elective carotid endarterectomy for symptomatic and asymptomatic carotid artery stenosis were enrolled in a prospective study to evaluate the incidence of change in postoperative cerebral function.

METHODS

Patients were evaluated preoperatively and postoperatively before hospital discharge and at follow-up 1 and 5 months later with a battery of neuropsychometric tests. The results were analyzed by both event-rate and group-rate analyses. For event-rate analysis, change was defined as either a decline or improvement in postoperative neuropsychometric performance by 25% or more compared with a preoperative baseline.

RESULTS

Approximately 80% of patients showed decline in one or more test scores, and 60% had one or more improved test scores at the first follow-up examination. The percentage of declined test scores decreased and the percentage of improved test scores increased with subsequent follow-up examinations. Group-rate analysis was similar for group performance on individual tests. However, a decline in performance was seen most commonly on verbal memory tests, and improved performance was seen most commonly on executive and motor tests.

CONCLUSIONS

Neuropsychometric evaluation of patients undergoing carotid endarterectomy for significant carotid artery stenosis demonstrates both declines and improvements in neuropsychometric performance. The test changes that showed decreased performance may be associated with ischemia from global hypoperfusion or embolic phenomena, and the improvement seen may be related to increased cerebral blood flow from removal of stenosis.

Vascular dementia: dead or alive?

The term 'Vascular Dementia' remains popular as a diagnostic entity, since it encompasses a variety of vascular pathologies. This is in stark contrast to many clinical classificatory systems that weight their definitions strongly towards stroke alone. A diagnosis of vascular dementia is complicated by compounding factors that reduce both the validity and specificity of diagnostic systems. This review highlights some of the problems faced in epidemiological, clinical, neuropathological and radiological studies attempting to define a clear-cut syndrome of dementia associated with cerebrovascular disease. The role of non-stroke ischaemia is also discussed. It is concluded that the term vascular dementia may have outlived its usefulness as a valid concept; alternative approaches are suggested.

Cognitive testing in patients undergoing carotid endarterectomy

OBJECTIVES

To determine by literature review the effect of carotid endarterectomy (CEA) as a modulator of cognitive function in patients with carotid arterial disease. Derive recommendations for standardising cognitive testing of patients with carotid arterial disease.

DESIGN AND METHODS

The English language literature was interrogated using a CD-ROM driven medline search using carotid endarterectomy and cognitive function as keywords between 1986-1995. These subsets were scanned and papers of direct relevance or commonality were selected. Cited papers prior to 1986 from these references were then sought directly.

RESULTS

There are few controlled studies reporting on the effect of CEA. There is no consensus in the literature for the effect of CEA on cognition or which tests should be used. Studies reporting a benefit for CEA lack a control group and fail to eliminate the effect of practice. Reports suggesting cognitive impairment following CEA performed follow-up tests early.

CONCLUSIONS

There are many methodological problems with the study of cognitive function before and after carotid endarterectomy and wide disagreement in the interpretation of results. Further studies should contain control groups, use tests resistant to practice and be performed when the effects of surgery and anaesthesia are passed.

Evaluation of cerebral function after carotid endarterectomy

Neuroimaging methods have failed to disclose correlation between degree of cerebral atrophy and blood flow in carotid artery stenosis patients. Moreover, intellectual improvement after carotid endarterectomy does not correlate fully with neuroimaging data in such patients. We performed brain electrical activity mapping and psychological testing before and 4 weeks after operation in 28 patients with symptomatic, high-grade, carotid stenosis. Postoperatively, electroencephalographic (EEG) mean frequency and absolute theta power improved significantly (p < 0.01). Mean frequency increased >1 Hz in most areas while power decreased dramatically, mainly because of resolution of high-voltage foci in 8 patients. Differences were conspicuous in both frontal lobes irrespective of the operated side, which suggests changes in perfusion affecting the whole brain. This is a positive effect of endarterectomy. Mini-Mental test and Set Test for verbal fluency had a positive correlation with the qEEG changes. Quantitative EEG as a measure of cerebral function has disclosed discriminative improvement in the early postoperative period. Our results support the thesis of improvement subsequent to endarterectomy.

Cognitive deficits in peripheral vascular disease. A comparison of mild stroke patients and normal control subjects

BACKGROUND AND PURPOSE

Evidence indicates that peripheral vascular disease (PVD) and cerebrovascular disease (CVD) coexist and therefore reflect a generalized pattern of atherosclerotic disease in an individual. Given the known deleterious effects of CVD on cognitive function, it was hypothesized that patients with PVD may have impaired cerebral function due to concomitant but clinically unrecognized CVD. The purpose of this study was to determine whether neuropsychological tests would reveal this potential dysfunction.

METHODS

Neuropsychological test scores (n = 25) were compared across three groups: (1) 29 PVD patients (13 amputees, 16 nonamputees), (2) 29 age- and education-matched patients with atherothrombotic brain infarcts (ie, CVD), and (3) 30 age- and education-matched control subjects.

RESULTS

PVD patients performed significantly worse (P < .002) than control subjects on eight neuropsychological measures of executive function, attention, and visuopatial function. The pattern and, in certain instances, the magnitude of impairment was highly similar between PVD and CVD subjects. Regression analysis revealed that PVD severity and ischemic heart disease were significant negative predictors of test performance. Depression and atherosclerotic risk factors did not explain neuropsychological deficits after the effects of PVD and ischemic heart disease were considered.

CONCLUSIONS

PVD patients exhibit neuropsychological deficits that suggest the presence of mild vascular-related brain dysfunction. Patients with multiple manifestations of generalized atherosclerosis (ie, severe PVD, ischemic heart disease) appear to be particularly at risk. Clinicians should be alert to these potential deficits and to the possibility of further vascular-related cognitive decline.

Uncomplicated carotid endarterectomy is not associated with neuropsychological impairment

Whether neuropsychological changes follow carotid artery surgery is unclear, in part because of complications by multiple perioperative variables. Therefore, we carried out a detailed analysis of patients who underwent carotid artery surgery in which we attempted to control for the most important variables by excluding patients with a preoperative stroke and by adopting a standard operative technique without use of intraoperative carotid shunts. Thirty inpatients with symptomatic carotid artery disease admitted for carotid endarterectomy were assessed with a comprehensive battery of neuropsychological tests administered immediately before and after (48-72 h) surgery. No carotid bypass shunt was inserted during the operation. The battery included dementia and depression screening tests, standardised neuropsychological measures including Verbal Fluency and the National Adult Reading Test, and a battery of contemporary computerised tasks designed to measure different aspects of memory and attention from the Cambridge Neuropsychological Test Automated Battery (CANTAB). No significant difference was found in the cognitive scores postoperatively as compared with the patients' preoperative scores or compared with scores of a control group matched by age and intelligence.

The event-related P300 potential approach to cognitive functions of nondemented patients with cerebral and peripheral arteriosclerosis

OBJECTIVES

To detect subtle cognitive dysfunction in non-demented patients with either cerebral (cAD) or peripheral (pAD) arteriosclerotic disease, and to evaluate in these patients the effects on cognitive functions of carotid endarterectomy and bypass surgery, respectively.

DESIGN

Case-control study.

SETTING

Tertiary care referral center.

PARTICIPANTS

Eighty consecutive patients with moderate to high-grade stenosis of the internal carotid artery (ICA) (mean age +/- SD, 62 +/- 8 years), 53 patients with stenoses of the peripheral arteries (60 +/- 10 years), and 80 healthy volunteers (58 +/- 15 years) enrolled in a study on healthy aging. Cerebral and peripheral arteriosclerotic disease was verified by digital subtraction angiography, and all patients were screened for confounding effects of concomitant diseases.

MAIN OUTCOME MEASURES

Cognitive functions by event-related visual P300 potentials.

RESULTS

Patients with cAD showed prolonged P300 latencies and reduced P300 amplitudes, whereas pAD patients had reduced P300 amplitudes only. On an individual scale, 25% of cAD patients, but only 6% of pAD patients, revealed P300 abnormalities. In the cAD, but not in the pAD patients, the P300 latencies were especially prolonged in the older patients, but other factors such as sex, cerebral symptoms, degree of ICA stenosis, and premorbid intelligence did not play any role in either group. Within 1 to 2 weeks of surgery, the P300 latencies shortened in both cAD and pAD patients with high initial values.

CONCLUSIONS

As demonstrated by P300 potentials, even nondemented arteriosclerotic patients reveal signs of subtle cognitive dysfunction affecting especially the older cAD patient. In the short-term, carotid endarterectomy presumably improves cognitive functions unspecifically in nondemented patients with a higher initial degree of P300 abnormality.

Hypertension and neuropsychological function: a lifespan perspective

This article explores the relationship of hypertension to neuropsychological performance from a lifespan perspective. First, I examine cross-sectional and longitudinal studies of neuropsychological performance in cohorts of young to middle-aged hypertensive patients (ages 20-60); older hypertensive patients (ages 60-80+); and the young, normotensive offspring of hypertensive parents (ages 18-25). The pattern of performance deficits associated with hypertension is generally found to differ from that related to hypertension risk. Next, I discuss potential mechanisms underlying hypertension-performance relationships in the aforementioned cohorts. I suggest that lowered levels of performance in the offspring of hypertensives reflect genetic risk for hypertension. Compromised neuropsychological function in young and middle-aged hypertensives may occur secondary to alterations in neurophysiological function that result from elevated blood pressure. Such neurophysiological changes may predispose to neuroanatomical changes in older hypertensive patients.

Symptomatic and asymptomatic high-grade unilateral internal carotid artery stenosis: scalp topography of event-related potentials (P300) and psychometric testing

Unilateral internal carotid artery (ICA) stenosis may be accompanied by widespread atherosclerosis of extra- and intracranial vessels leading to subtle cognitive disorders. We applied multichannel recording of P300 in 28 patients (68.3 +/- 8.1 years; 15 asymptomatic, 13 with a history of transient ischemic attack (TIA)) and compared them with an age- and sex-matched control group. All underwent a visual "odd-ball paradigm" as well as a psychometric test, the Cognitive Performance Test (CPT), testing mainly visual attention and memory. The potentials were derived from 16 electrodes according to the 10/20 system against linked mastoids. The latencies and amplitudes of N250 and P300 were measured and their amplitudes additionally mapped. Furthermore, the early sensory exogenous potentials, P1 and N1, within the P300 potentials as well as conventional pattern reversal visual evoked potentials (PVEPs) were evaluated. (1) Both the early exogenous potentials and the conventional PVEPs showed no significant differences among all groups. (2) There were no significant differences between asymptomatic patients and those with a TIA history in all parameters of the P300 complex so that one total patient group was constructed and compared to the controls. (3) Patients' P300 amplitudes showed significant reductions over hemispheres ipsilateral (P < or = 0.014) and contralateral (P < or = 0.044) to the stenosis. (4) The N250 amplitudes were reduced only in the central leads (P < or = 0.05). (5) The latencies of N250 potentials were significantly prolonged at many electrodes, not only ipsi-(P < or = 0.0007) but also contralateral (P < or = 0.022) to the stenosis. (6) The patients' P300 latencies showed significant lengthening only at occipital sites (P < or = 0.05) compared to controls. (7) In all measured parameters, within the patient group, the differences between hemispheres ipsilateral versus contralateral to the ICA stenoses did not reach statistical significance. (8) The CPT values detected slight cognitive disorders for both patient groups and they correlated significantly with the latencies in many leads. (9) The highest test sensitivity to classify patients versus controls (z score > 2) was reached in P300 maps of TIA patients (77%). An altered P300 indicates electrophysiologically, and CPT behaviorally, subclinical cognitive deficits even in asymptomatic patients with unilateral tight ICA stenoses. Interestingly, no differences between asymptomatic and TIA patients with a high-grade unilateral ICA stenosis could be found.

Neuropsychological function in peripheral vascular disease amputee patients

Approximately 75% of major lower-extremity amputations are the result of peripheral vascular disease (PVD). Factors that predispose a patient to PVD (smoking, hyperlipidemia, diabetes mellitus) are also risk factors for the development of cerebrovascular disease, which could adversely affect rehabilitation. The purpose of this study was to test the hypothesis that cognitive deficits are present in amputee patients with PVD. Fourteen patients with lower-extremity amputations secondary to PVD (4 women, 10 men; mean age = 67.4 years) were recruited from a tertiary-care center for physical rehabilitation. Fourteen community-dwelling healthy volunteers (9 women, 5 men; mean age = 69.9 years) served as age-matched and education-matched controls. To assess a broad range of cognitive function, we administered standard neuropsychological tests of memory and learning, language, praxis, visuospatial skills, and abstract reasoning. PVD patients performed significantly more poorly on certain measures of psychomotor speed (Wechsler Adult Intelligence Scale-Revised Digit Symbol subtest) and problem solving/abstract reasoning (Modified Card Sorting Test) relative to controls (using the Bonferroni correction for multiple comparisons, p < .002). There were trends toward poorer patient performance on certain measures of oral fluency, concentration, reasoning, and visuoperceptual organization and constructional skills (p < .01). We propose that these cognitive deficits may be the result of unrecognized concomitant cerebrovascular disease in PVD patients and are part of a generalized pattern of vascular disease. Future research should control affective factors such as stress or depression surrounding amputation and attempt to identify the etiologic or demographic factors that are associated with neuropsychological deficits in patients with PVD.

[Effects of carotid endarterectomy on various neuropsychologic parameters. A neuropsychologic longitudinal study]

Carotid endarterectomy was performed in 25 patients with symptomatic cerebrovascular disease. All patients underwent detailed neuropsychological investigations immediately before surgery, immediately after surgery, and again after a follow-up period of 14 months. Immediately after surgery the flicker fusion frequency was temporarily reduced, indicating an impairment of global cognitive functioning. Postoperatively, verbal attention was found to be improved, particularly in younger patients, in patients with TIA, and in patients with left-sided operation. Finally, visual retention (Benton) was improved at the end of the observation period, especially in older patients and in patients with left-sided operation. Considering the complexity of pathologic brain perfusion, the effects of carotid endarterectomy can only be explained if a multidimensional approach is adopted.

Quality of life and cognitive performance after carotid endarterectomy during long-term follow-up

The quality of life and the cognitive performance of patients with extracranial carotid stenosis were investigated 8-11 years after treatment in 18 non-operatively treated patients and 44 patients treated with carotid endarterectomy. The cognitive performance was compared with data on a normal control group. Cognitive performance was assessed with neuropsychological tests and the quality of life by personal interview based on a questionnaire. Most of the carotid stenosis patients recovered well both subjectively and cognitively regardless of the type of treatment. Only the subgroup operated twice was subjectively worse compared to the other groups. Even 10 years later the cognitive performance of carotid stenosis patients was remarkably close to normal.

Effect of repeated administration of a neuropsychological battery in the elderly

Our study explored the magnitude of practice effect in repeated administration of NP measures that tap different cognitive domains in normal elderly subjects (N = 122) between ages 57 and 85, who were evaluated over three annual testing probes. Results revealed that WAIS-R PIQ, serial recall of words, WMS visual memory, and memory for logical passages (immediate and delayed) are likely to improve on the retest due to practice effect in individuals below age 75, whereas test-retest changes in older people show a different pattern. Implications of age-specific changes on retest for differential diagnosis of dementia in clinical practice were considered.

Effects of medical and surgical treatment on cerebral perfusion and cognition in patients with chronic cerebral ischemia

The effects of medical treatment with and without cerebral revascularization procedures on cognition and cerebral blood flow were compared among 36 patients with extracranial occlusive cerebrovascular disease and cognitive impairments. Three comparable groups were studied. The first group (N = 18) received only medical treatment by control of risk factors for stroke (including hypertension, diabetes, and hyperlipidemia) and antiplatelet aggregant medication. The second group (N = 10) had the same medical treatment plus superficial temporal-to-middle cerebral artery bypass, and the third group had the same medical treatment plus carotid endarterectomy. Regional cerebral blood flow and cognition were monitored in all three treatment groups over a 3-year interval. All groups showed stabilization without expected rates of decline for both cerebral blood flow and cognition, but no statistically significant differences emerged among the treatment groups.

Neuropsychological improvement versus practice effect following unilateral carotid endarterectomy in patients without stroke

Patients who were admitted to hospital for a recent transient ischemic attack were entered into one of three groups based on medical and surgical characteristics; those with an abnormal neurological examination or a focal abnormality on CT Scan were omitted from the study. The two surgical groups (12 patients each) underwent either a left or right endarterectomy for a symptomatic atheroma of the ipsilateral carotid artery. The control group consisted of 12 patients who either demonstrated minor or nonexistent carotid abnormalities or a TIA distribution that was contralateral to what would otherwise have been a surgically treatable lesion. Patients were tested before surgery and again 6-8 weeks later with the WAIS, WMS, and other neuropsychological measures. Significant improvement on some measures at follow-up was strictly equivalent across all groups and was attributed to practice effects.

Neurobehavioral investigation as a tool for revealing preclinical disorders

This paper calls attention to the methodologies designed to investigate the higher cortical functions in order to elicit signis of encephalopathy in apparently normal conditions. This can be done by testing the blobal hemispheric funcionts or the interhemispheric functional balance. This shows up the clinical sequels that may precede or be the outcome both of transient pathological disorders, such as transient global anemia, migraine, TIAs and subarachnoid hemorrhage without apparent clinical consequences and of nontransient pathological conditions, such as epilepsy, occupational diseases, arterial hypertension and cerebral revascularization.

Neuropsychological deficits and real-world dysfunction in cerebral revascularization candidates

An assessment strategy using multiple levels of observation permitted description of problems in everyday living experienced by cerebral revascularization candidates. We contrasted the neuropsychological deficits and real-world dysfunction displayed by candidates for cerebral revascularization with that manifested by patients with severe spinal complaints. Correlations between selected neuropsychological scores and life quality measures were modest. Prediction of real-world performance in individuals likely will require multivariate combinations of measures. Relationships between life quality measures and neuropsychological scores may differ for patients with known or suspected neurological disease and patients with disorders which do not threaten cognitive functioning.

Three-year neuropsychological follow-up of patients with reversible ischemic attacks

A short neuropsychological test battery designed to measure language, memory and visuospatial abilities was administered to 217 patients with reversible ischemic attacks. Patients were tested twice: the first time more than one month, but less than one year, from the last ischemic episode, and the second time three years later. A comparison between the first and the second testing session did not disclose any significant worsening. The degree of atherosclerosis and the occurrence of further ischemic episodes during the follow-up period were found to be unrelated to change in performance at the test battery. These results seems to challenge the hypothesis that multi-infarct dementia may follow apparently reversible, or even clinically silent, ischemic episodes.

Carotid surgery, cognitive function, and cerebral blood flow in patients with transient ischemic attacks

Psychological testing, cerebral blood flow (CBF) measurement, and computed tomographic scan were performed before and 3 months after operation in 31 patients subjected to endarterectomy of the internal carotid artery (ICA) because of transient ischemic attacks and in 11 control patients operated on for atherosclerosis of the lower extremities. In preoperative psychological testing both carotid surgery patients and controls performed somewhat below the normal level for their age group. Postoperatively, cognitive functions improved in the carotid surgery group but not in the control group. The improvement was related to the laterality of the operation, being more marked in verbal tests in patients with left ICA operation and in visuospatial tests in patients with right ICA operation. Postoperatively regional CBF improved in 2 patients only. Hence the intellectual improvement could not be related to changes in CBF. Intellectual deterioration in patients with internal carotid atherosclerosis may be delayed or terminated by surgical abolition of the source of multiple cerebral embolizations.

Cerebral angiography and neuropsychological measurement: the twain may meet

In a sample of 31 cerebral revascularization candidates, severity and dissemination of atherosclerosis on the cerebral angiogram were correlated with two of three global indicators of neurobehavioral impairment. Additionally, the angiographic rating was correlated with age and with an index of medical risk factors, but not with duration of the longest symptomatic episode. It seems likely that several variables, particularly collateral circulation, help to determine whether a given pattern of stenoses results in neuropsychological dysfunction and what type of behavioral deficit occurs. In many cases, the configuration of neuropsychological test scores may not directly mirror the pattern of cerebrovascular stenoses.

Carotid endarterectomy: does it improve cognitive or motor functioning?

In a group of 20 patients who were to undergo endarterectomy for atherosclerotic occlusive disease of the internal carotid artery, the stenosis did not appear to have resulted in cognitive or motor deficits. Consistent with this finding, surgery could not be shown to have a beneficial effect on cognitive or motor functioning. Control data were supplied by 20 patients who underwent peripheral vascular surgery and 20 healthy subjects. The test-retest interval was 10 weeks.

A neuropsychological study of 12 patients with transient ischemic attacks before and after EC/IC bypass surgery

A neuropsychological study of 12 patients with transient ischemic attacks from the carotid artery territory was carried out about 2 months following their latest attack, about a week before STA/MCA bypass operation, and again 3 months postoperatively. The results suggest that the TIA patients as a group were slightly intellectually impaired preoperatively. After the operation, a minor neuropsychological improvement had taken place although they still were not fully intellectually rehabilitated.

Neuropsychological evaluation in transient ischaemic attack and minor stroke

Two groups of patients with transient ischaemic attack and minor stroke without detectable haemodynamic stenotic lesions were evaluated by neuropsychological tests and compared with a control group. The mean values of the scores adjusted for age and educational background demonstrated that the patients with transient ischaemic attack did not have a worse performance than normal subjects in any of the tests, the patients with minor stroke had a worse performance than normals, particularly in Rey's figure-copying test (P less than 0.025), and the latter test was not affected by educational background or age of the subjects. The results are discussed with reference to other case series, and the importance of age and cerebral damage in causing intellectual impairment evaluated by neurophysiological tests is stressed.

Neuropsychological changes associated with stenoses or occlusions of the carotid arteries. A comparative psychometric study

A total of 33 patients with a relevant stenosis or occlusion of extracranial arteries were tested for a number of neuropsychological functions. Most of them [22] suffered from transient ischemic attacks, 6 from strokes, 5 were asymptomatic. Compared to an age-matched population of normals, patients showed an impairment in their mnemic functions, and attention under stress as well as in their psychomotor function. The degree of neuropsychological impairment was independent of the unilaterality or bilaterality of carotid stenoses. The results illustrate the neuropsychological deficit even in asymptomatic patients and those with complete recovery from transient neurological deficits.

Neuropsychological functions after carotid endarterectomy

Psychological testing was performed on 23 patients (mean age 60.7 years) with unilateral or bilateral stenoses of the carotid arteries prior to and 10 months after carotid endarterectomy. Intellectual functions were slightly improved, mnemic functions impaired, psychomotor functions and dimension of personality remained unchanged. Carotid endarterectomy, although improving neuropsychological functions in a few cases, on average does not cause a significant improvement. This underscores the preventive character of the surgical intervention.