Asymptomatic spontaneous cerebral emboli and cognitive decline in a cohort of older people: a prospective study

Asymptomatic Carotid Artery Stenosis, Cognitive Function, and the Impact of Carotid Revascularization: A Narrative Review

BACKGROUND

The association between asymptomatic carotid artery stenosis and impaired cognition, and the cognitive changes after revascularization remain active areas of interest in the field of carotid disease. This narrative review focuses on the association between carotid artery atherosclerosis and impaired cognitive function, proposed mechanisms, and the effects of carotid revascularization on cognition.

METHODS

A critical review of the literature to identify studies evaluating carotid artery stenosis, cognition, and carotid revascularization was performed using PubMed to query the MEDLINE database through March 2023.

RESULTS

Many studies demonstrate a link between carotid disease and cognitive impairment but direct evidence is lacking. Revascularization may offer cognitive benefits but the effect is likely subtle and affected by the choice of revascularization procedure.

CONCLUSIONS

Integrating cognitive outcomes into ongoing randomized controlled trials such as the nested CREST-H arm of the CREST-2 trial hold promise for offering new insight into the role of carotid artery stenosis and carotid revascularization on cognition.

Impact of carotid stenosis on cerebral hemodynamic failure and cognitive impairment progression: a narrative review

Carotid atherosclerosis has a relevant impact on cerebral blood flow regulation. There is accruing evidence that hemodynamic impairment related to the presence of a significant carotid lumen narrowing may predispose to the development of cerebral dysfunctions, including a reduction in cognitive abilities. In the last years an increasing number of findings showed that carotid stenosis did contribute to cognitive impairment not only in relation to the occurrence of cerebral ischemic lesions, but also as an independent risk factor. The principal mechanisms involved are chronic hypoperfusion, microembolization and cerebrovascular reactivity impairment. Moreover, more recent studies showed alterations of regional functional connectivity. In this narrative review, we analyzed the relationships between carotid stenosis, cerebral hemodynamic derangement and cognitive impairment onset and progression, and underlined that cognitive impairment is the final result of the complex interaction between different elements, including also collateral circulation, cerebral hemodynamic status, brain connectivity and pro-inflammatory state. Further, therapeutic approaches, with a specific focus on vascular risk factors correction and on the effectiveness of surgical or endovascular interventions were discussed. We particularly focused our attention on the concept of “asymptomatic carotid stenosis”, and how could a cognitive impairment improve after an intervention, and how this could change the indications to surgical approach. Larger studies and randomized controlled trials are urgently required to better define time, characteristics and effectiveness of both medical and surgical/endovascular approaches.

Psychological Determinants of Attitude to Surgery in Internal Carotid Artery Stenosis Patients

The basic way to prevent cerebral stroke in symptomatic 70–99% stenosis of internal carotid artery (ICA) is an open or endovascular surgical procedure. Psychological research done so far among ICA stenosis patients focused on cognitive functioning changes. The objective was to assess attitude to surgery in relation to self-efficacy, life quality perception, and health locus of control in ICA stenosis patients. Materials and Methods: The study involved 53 asymptomatic ICA stenosis patients, aged from 53 to 81. Four scales were applied: Generalized Self-Efficacy Scale (GSES); Satisfaction With Life Scale (SWLS); Multidimensional Health Locus of Control Scale (MHLC); and a simple scale to examine the attitude to surgery, where “−10” stands for the maximally negative attitude, “0”—neutral, and “+10”—maximally positive. The obtained results were put to statistical analysis. Results: It was found that women and men assessed their attitude to the surgery as positive (M = 7.92; SD = 3.094), though the men estimated it slightly higher (M = 8.03; SD = 3.02) than the women (M = 7.67; SD = 3.37). The mean value of self-efficacy was high (M = 32.53; SD = 6.231), and slightly higher for the men (M = 32.79; SD = 5.576) compared to the women (M = 31.87; SD = 7.836). The patients generally tended to manifest the external personal health locus of control (M = 28.62; SD = 3.17). The runner-up was internal health locus of control (M = 26.02; SD = 3.775), and the next one—external impersonal aspect (chance/luck) (M = 23.57; SD = 4.457). The mean assessment of the patients’ own life quality proved to be above average (M = 23.60) but varied (SD = 5.95). The women perceived the quality of their lives as better (M = 24.33; SD = 6.422) than the men (M = 23.32; SD = 5.818). Very strong positive correlations were found between self-efficacy and life quality assessment (p < 0.001) and between the internal and external personal aspects of health locus of control (p < 0.007) in the women, and positive correlations were found between the attitude to surgery and internal health locus of control (p < 0.021) in the men. Conclusions: When breaking the news of a need to have a surgical intervention due to ICA stenosis, the physician should strongly refer to the value of human life and health. The message should arise from external (in the case of women) or internal (in the case of men) motivation to undergo surgery, and enhance the patient’s conviction that the disease should be considered a challenge which must be taken to reverse their unfavorable situation and improve life quality.

Ultrasound Diagnostic Method in Vascular Dementia: Current Concepts

BACKGROUND

Increasing interest in identifying cerebral hemodynamics alterations as a cause of possible onset or worsening of cognitive impairment in elderly patients with vascular risk factors.

INTRODUCTION

Intracranial ultrasound is a non-invasive, repeatable inexpensive method for recording variation of the cerebral vascular tree in physiological and pathological conditions and the diagnosis of vascular dementia (VaD).

METHODS

PubMed, Embase, Cochrane library and reference lists have been searched for articles published until March 30, 2020.

RESULTS

Clinical studies reported different Transcranial Doppler (TCD) parameters and subsequently transcranial duplex with color code (TCCD) in patients affected by vascular dementia. The number of studies using TCCD remains limited and most of the available data are still based on TCD. However, the use of transcranial Doppler could better stratify elderly patients with initial signs of cognitive impairment.

CONCLUSION

Intracranial ultrasound employment to detect cerebral hemodynamic changes in VaD patients has been briefly discussed in this review.

Editor's Choice - Asymptomatic Carotid Stenosis and Cognitive Impairment: A Systematic Review

OBJECTIVE

The aim was to evaluate the relationship between asymptomatic carotid stenosis (ACS) of any severity and cognitive impairment and to determine whether there is evidence supporting an aetiological role for ACS in the pathophysiology of cognitive impairment.

DATA SOURCES

PubMed/Medline, Embase, Scopus, and the Cochrane library.

REVIEW METHODS

This was a systematic review (35 cross sectional or longitudinal studies) RESULTS: Study heterogeneity confounded data interpretation, largely because of no standardisation regarding cognitive testing. In the 30 cross sectional and six longitudinal studies (one included both), 33/35 (94%) reported an association between any degree of ACS and one or more tests of impaired cognitive function (20 reported one to three tests with poorer cognition; 11 reported four to six tests with poorer cognition, while three studies reported seven or more tests with poorer cognition). There was no evidence that ACS caused cognitive impairment via silent cortical infarction, or via involvement in the pathophysiology of lacunar infarction or white matter hyperintensities. However, nine of 10 studies evaluating cerebral vascular reserve (CVR) reported that ACS patients with impaired CVR were significantly more likely to have cognitive impairment and that impaired CVR was associated with worsening cognition over time. Patients with severe ACS but normal CVR had cognitive scores similar to controls.

CONCLUSION

Notwithstanding significant heterogeneity within the constituent studies, which compromised overall interpretation, 94% of studies reported an association between ACS and one or more tests of cognitive impairment. However, "significant association" does not automatically imply an aetiological relationship. At present, there is no clear evidence that ACS causes cognitive impairment via silent cortical infarction (but very few studies have addressed this question) and no evidence of ACS involvement in the pathophysiology of white matter hyperintensities or lacunar infarction. There is, however, better evidence that patients with severe ACS and impaired CVR are more likely to have cognitive impairment and to suffer further cognitive decline with time.

Effects of Carotid Artery Stent and Carotid Endarterectomy on Cognitive Function in Patients with Carotid Stenosis

BACKGROUND

Carotid artery stenosis is closely related to cognitive dysfunction, in which decreased cerebral perfusion is one of the important factors. Both carotid artery stent implantation and carotid endarterectomy can relieve stenosis and increase cerebral perfusion. In this study, we aimed to compare the effects of carotid artery stent implantation and endarterectomy on cognitive function.

METHODS

A total of 98 patients with carotid artery stenosis hospitalized in our hospital from July 2015 to January 2017 were included. Among them, 50 cases underwent carotid artery stent implantation treatment as stent implantation group (CAS group), and 48 cases underwent carotid artery endarterectomy treatment as carotid endarterectomy group (CEA group). Using the Mini-Mental State Examination Scale (MMSE Scale) and the Montreal Cognitive Assessment Scale (MoCA Scale), the cognitive function scores of the two groups of patients before and after 3 and 6 months of operation were measured, and the patients were also measured before and after surgery, after the serum NSE, hs-CRP content.

RESULTS

The serum NSE, hs-CRP content, MMSE score, and MoCA score of the two groups before treatment were not statistically significant (P > 0.05). The MMSE score and MoCA score of the two groups of patients before treatment were lower than the normal value, suggesting carotid artery stenosis combined with different degrees of cognitive dysfunction. Carotid artery stenosis is different, and patients' cognitive function is also different. The MMSE score and MoCA score of the two groups at 3 and 6 months after operation were higher than before treatment, and there was a statistically significant difference between 6 and 3 months after operation (P < 0.05), but at each time There was no statistically significant difference between the two groups (P > 0.05). The NSE content of the two groups of patients after operation decreased compared with that before treatment, and the decrease in 6 months after operation was more obvious than that in March (P < 0.05). However, the difference between the two groups at each time point was not statistically significant (P > 0.05). The content of hs-CRP in the two groups of patients was higher than that before the operation, and the CAS group was significantly higher than the CEA group; the difference was statistically significant (P < 0.05).

CONCLUSION

Carotid artery stent and carotid endarterectomy are effective in improving the cognitive function of patients with carotid stenosis, but there is no significant difference between the two.

Why is the management of asymptomatic carotid disease so controversial?

BACKGROUND

Despite level I evidence supporting a role for carotid endarterectomy (CEA) in the management of patients with asymptomatic carotid disease, there is surprisingly little international consensus regarding the optimal way to manage these patients.

METHODS

Review of current strategies for managing asymptomatic carotid disease

MAIN FINDINGS

Those favouring a pro-interventional approach argue that: (i) until new randomised trials demonstrate that best medical therapy (BMT) is better than CEA or carotid artery stenting (CAS) in preventing stroke, guidelines of practice should remain unchanged; (ii) strokes secondary to carotid thromboembolism harboured a potentially treatable asymptomatic lesion prior to the event. Because 80% of strokes are not preceded by a TIA/minor stroke, CEA/CAS is the only way of preventing these strokes; (iii) screening for carotid disease could identify patients with significant asymptomatic stenoses who could undergo prophylactic CEA/CAS in order to prevent avoidable stroke; (iv) international guidelines already advise that only 'highly-selected' patients should undergo CEA/CAS; (v) the 30-day risks of death/stroke after CEA/CAS are diminishing and this will increase long-term stroke prevention and (vi) the alleged decline in annualized stroke rates in medically treated patients is based upon flawed data.

CONCLUSIONS

The inescapable conclusion is that only a relatively small proportion of asymptomatic patients benefit from prophylactic CEA/CAS. The key question, therefore, remains; is society prepared to invest sufficient resources in identifying these 'high risk for stroke' patients so that they can benefit from aggressive BMT and CEA or CAS, leaving the majority of lower risk patients to be treated medically?

Cerebrovascular function in aging and dementia: a systematic review of transcranial Doppler studies

Background/Aim

The contribution of cerebrovascular dysfunction to the manifestation of dementia and cognitive decline in late life is gaining increased attention. We aimed to systematically review evidence for associations between dementia or aging and cerebrovascular function as measured using transcranial Doppler (TCD) examination.

Methods

A total of 1,172 articles were retrieved from PsychInfo and PubMed searches, and 34 relevant articles were identified using a variety of TCD methods.

Results

The pulsatility index (vessel resistance), spontaneous emboli and cerebrovascular reactivity to hyper-/hypocapnia appeared good discriminators of dementia. Aging was associated with a slowing in blood flow velocity.

Conclusion

TCD ultrasonography is inexpensive, portable and well tolerated by aged and demented subjects. The technique stands to make a valuable contribution to the knowledge regarding the underlying functional biology of age-related cognitive change and dementia.

Comparison of stent free cell area and cerebral lesions after unprotected carotid artery stent placement

OBJECTIVE

This study evaluates the correlation between closed, semi-closed and open-cell stent design and the association between stent type and clinical outcome as well as magnetic resonance imaging (MRI) findings.

DESIGN

A total of 194 patients who underwent unprotected carotid artery stenting (CAS) as well as diffusion-weighted magnetic resonance imaging (DW-MRI) before and after intervention were retrospectively reviewed.

MATERIALS AND METHODS

Three stent designs were studied: closed cell, semi-closed cell and open cell. Spearman's Rho test was performed between the stent free cell area and the number and area of ischaemic lesions found after intervention. Adverse events were evaluated.

RESULTS

There was no significant difference in clinical outcome between the three stent groups (Zilver, Cook Europe, Denmark; Smart, Codman, MA; and Wallstent, Stryker, MN, USA). A significant correlation was found between the stent free cell area and the number and area of new ischaemic lesions on DW-MRI (P = 0.023). There were significantly fewer new lesions with an open-cell design (Zilver; 12.76 mm(2) free cell area) than with a closed-cell design (Wallstent; 1.08 mm(2) free cell area).

CONCLUSIONS

Open-cell stent was related to a lower number and area of silent cerebral ischaemic lesions after unprotected CAS. However, clinical outcome, measured by incidence of adverse events and clinical neurologic assessment, was not significantly different between patients with different stent designs.