Carotid artery disease and cognitive impairment

The Early Postoperative Course of Cognitive Function and Preoperative Cerebrovascular Reserve

BACKGROUND

 Patients with severe steno-occlusive disease of a main cerebral artery without causative lesions on magnetic resonance imaging (MRI) often develop cognitive impairment. However, the effects of revascularization surgery and the source of the cognitive impairment remain unclear. Therefore, we investigated the early postoperative course of cognitive function and its association with cerebral blood flow (CBF), cerebrovascular reserve (CVR), white matter disease (WMD), lacunar infarction, and cerebrovascular risk factors.

METHODS

 Cognitive function was examined using neurobehavioral cognitive status examination (COGNISTAT) in 52 patients with steno-occlusive disease of a main cerebral artery before and at 6 months after superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis. We examined how cognition changed before and at 1, 3, and 6 months after STA-MCA anastomosis in 27 of 52 patients. CVR and CBF were calculated from 123I-N-isopropyl-p-iodoamphetamine single photon emission computed tomography, in addition to other cerebrovascular risk factors in 34 of 52 patients. Cerebral infarction and WMD (periventricular hyperintensity [PVH] and deep subcortical white matter hyperintensity) were also evaluated preoperatively by MRI.

RESULTS

 COGNISTAT scores improved at 1 month after STA-MCA anastomosis in patients with severe steno-occlusive disease of a main cerebral artery. Multiple stepwise regression analysis revealed that CVR (regression coefficient = -2.237, p = 0.0020) and PVH (regression coefficient = 2.364, p = 0.0029) were the best predictors of postoperative improvement in COGNISTAT scores (R 2 = 0.415; p = 0.0017).

CONCLUSION

 Cognitive function improves in relation to preoperative CVR and PVH early after STA-MCA anastomosis in patients with steno-occlusive disease of a main cerebral artery.

Hemispheric coupling between structural and functional asymmetries in clinically asymptomatic carotid stenosis with cognitive impairment

Advanced carotid stenosis is a known risk factor for ischemic stroke and vascular dementia, and it is associated with multidomain cognitive impairment as well as asymmetric alterations in hemispheric structure and function. Here we introduced a novel measure-the asymmetry index of amplitude of low-frequency fluctuations (ALFF_AI)-derived from resting-state functional magnetic resonance imaging. This measure captures the hemispheric asymmetry of intrinsic brain activity using high-dimensional registration. We aimed to investigate functional brain asymmetric alterations in patients with severe asymptomatic carotid stenosis (SACS). Furthermore, we extended the analyses of ALFF_AI to different frequencies to detect frequency-specific alterations. Finally, we examined the coupling between hemispheric asymmetric structure and function and the relationship between these results and cognitive tests, as well as the white matter hyperintensity burden. SACS patients presented significantly decreased ALFF_AI in several clusters, including the visual, auditory, parahippocampal, Rolandic, and superior parietal regions. At low frequencies (0.01-0.25 Hz), the ALFF_AI exhibited prominent group differences as frequency increased. Further structure-function coupling analysis indicated that SACS patients had lower coupling in the lateral prefrontal, superior medial frontal, middle temporal, superior parietal, and striatum regions but higher coupling in the lateral occipital regions. These findings suggest that, under potential hemodynamic burden, SACS patients demonstrate asymmetric hemispheric configurations of intrinsic activity patterns and a decoupling between structural and functional asymmetries.

Hybrid surgery can improve neurocognitive function in patients with internal carotid artery occlusion

Internal carotid artery occlusion (ICAO) is a relatively uncommon but important cause of transient ischaemic attack and cerebral infarction. Hybrid surgery (HS) improves cerebral perfusion, but its impact on neurocognitive function has been controversial. Patients with symptomatic chronic ICAO treated by hybrid surgery or medical treatment from 2016 to 2019 were included. We recorded and analysed the clinical characteristics, angiographic data, outcomes and cognitive status. Functional assessments, including the National Institutes of Health Stroke Scale (NIHSS), the Barthel Index, and a battery of neuropsychological tests, including the Mini-Mental State Examination (MMSE), Alzheimer Disease Assessment Scale-Cognitive Subtest (ADAS-cog), verbal fluency, and Colour Trail test Parts 1 and 2, were administered. Significant improvements in the ADAS (before, 7.5 ± 6.2 versus after, 5.2 ± 5.7; P = 0.022), MMSE (before, 25.5 ± 2.8 versus after, 28.1 ± 2.3; P = 0.013), and Colour Trail test Part 1 (before, 118.3 ± 26.5 versus after, 96.2 ± 23.1; P = 0.016) were observed six months after HS. Moreover, the abovementioned postprocedure scales were ameliorated in the HS group. This study found that in patients with multiple symptomatic ICAO and objective ipsilateral ischaemia, successful HS leads to improvement in the scores of three cognitive tests.

Influence of Previous General Anesthesia on Cognitive Impairment: An Observational Study Among 151 Patients

Introduction

Preoperative neurocognitive disorder (preO-NCD) is a common condition affecting 14–51. 7% of the elderly population. General anesthesia has already been associated with the one-year post-operative neurocognitive disorder (PostO-NCD), specifically, a deficit in executive function, measured by the Trail Making Test B (TMT-B), but its long-term effects on cognitive function have not been investigated. We aimed to detect preO-NCD prevalence in patients scheduled for cardiac surgery and further investigate the possible role of previous general anesthesia (pGA) in general preoperative cognitive status [measured via the Montreal Cognitive Assessment (MoCA)] and/or in executive functioning (measured via TMT-B).

Methods

In this observational, prospective study, 151 adult patients scheduled for elective cardiac surgery underwent MoCA and TMT-B. Data on age, education, pGA, comorbidities, and laboratory results were collected.

Results

We discovered a general cognitive function impairment of 79.5% and an executive function impairment of 22%. Aging is associated with an increased likelihood (OR 2.99, p = 0.047) and education with a decreased likelihood (OR 0.35, p = 0.0045) of general cognitive impairment, but only education was significantly associated with a decreased likelihood (OR 0.22, p = 0.021) of executive function impairment. While pGA did not significantly affect preO-NCD, a noteworthy interaction between aging and pGA was found, resulting in a synergistic effect, increasing the likelihood of executive function impairment (OR 9.740, p = 0.0174).

Conclusion

We found a high prevalence of preO-NCD in patients scheduled for cardiac surgery. General cognitive function impairment is highly associated with advancing age (not pGA). However, older patients with at least one pGA appeared to be at an increased risk of preO-NCD, especially executive function impairment, suggesting that TMT-B should be associated with MoCA in the preoperative cognitive evaluation in this population.

Carotid revascularization improves cognitive function in patients with asymptomatic carotid artery stenosis

OBJECTIVE

To investigate cognitive changes after carotid revascularization in elderly patients with asymptomatic carotid artery stenosis. We also compared cognitive outcomes of carotid endarterectomy with stenting in asymptomatic patients.

METHODS

From April 2019 to December 2019, patients with ≥70% asymptomatic carotid stenosis who were treated with CEA or CAS were recruited for this study. The Montreal cognitive assessment (MoCA) instrument was used to evaluate cognitive function preoperatively and postoperatively at 3, 6, and 12 months. The incidence of ipsilateral ischemic cerebrovascular events and restenosis were analyzed within 12 months.

RESULTS

In 50 patients treated with CEA or CAS, baseline cognitive function was not different between CEA and CAS groups (P > 0.05). There was no difference in the incidence of ipsilateral ischemic cerebrovascular events and restenosis within the first 12 months between the two groups. There was a significant improvement in the total MoCA score, scores of attention, and delayed recall at 3, 6 and 12 months after revascularization compared with scores at baseline (all p<0.001). At 12 months, scores of cube copying and clock drawing were significantly improved (P=0.014, P=0.020). The clock drawing score was improved at 12 months after CAS compared with CEA (P=0.040).

CONCLUSIONS

Carotid revascularization has a beneficial effect on cognition in asymptomatic patients within 12 months of the procedure. Compared with CEA, CAS show improved test scores of executive functioning by 1 year.

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.

Combination of Isoflurane and Propofol as General Anesthesia During Orthopedic Surgery of Perioperative Cerebral Hypoperfusion Rats to Avoid Cognitive Impairment

Background: Perioperative cerebral hypoperfusion (CH) is common, although the underlying mechanism of cognitive impairment that results due to perioperative cerebral hypoperfusion remains to be determined. Isoflurane anesthesia induces neuronal injury via endoplasmic reticulum (ER) stress, whereas a sub-anesthetic dose of propofol improves postoperative cognitive function. However, the effects of the combination of isoflurane plus propofol, which is a common aesthetic combination administered to patients, on ER stress and cognition remain unknown. Methods: We sought to determine the effects of isoflurane plus propofol on ER stress and cognitive function in rats insulted by cerebral hypoperfusion. Ligation of the bilateral common carotid arteries (CCA) was adopted to develop the cerebral hypoperfusion rat model. A second surgery, open reduction and internal fixation (ORIF), requiring general anesthesia, was performed 30 days later so that the effects of anesthetics on the cognitive function of CH rats could be assessed. Rats received isoflurane alone (1.9%), propofol alone (40 mg·kg^-1·h^-1) or a combination of isoflurane and propofol (1% and 20 mg·kg^-1·h^-1 or 1.4% and 10 mg·kg^-1·h^-1). Behavioral studies (contextual fear conditioning [FC] test), histological analyses (Nissl staining) and biochemical analyses (western blotting of the harvested rat brain tissues) were employed. Results: Hippocampus-dependent memory of rats in group IP₁ (1% isoflurane plus 20 mg·kg^-1·h^-1 propofol) was not impaired, and expression level of γ-aminobutyric acid A type receptor α1 subunit, a key cognition-related protein, remained normal. ER stress alleviator, binding immunoglobulin protein, increased extremely while ER stress transcription factor, C/EBP homologous protein, showed no statistical difference compared with the control group. Numbers of surviving neurons confirmed the substantial neuronal damage caused by propofol or isoflurane alone. Conclusions: These data suggest that ER stress contributes to the underlying mechanism of cognitive impairment and that the combination of isoflurane and propofol did not aggravate cognitive impairment and ER stress in aging rats with CH that were further subjected to ORIF surgery.

Carotid Plaque Strain Indices Were Correlated With Cognitive Performance in a Cohort With Advanced Atherosclerosis, and Traditional Doppler Measures Showed no Association

OBJECTIVES

Traditional Doppler measures have been used to predict cognitive performance in patients with carotid atherosclerosis. Novel measures, such as carotid plaque strain indices (CPSIs), have shown associations with cognitive performance. We hypothesized that lower mean middle cerebral artery (MCA) velocities, higher bulb-internal carotid artery (ICA) velocities, the MCA pulsatility index (PI), and CPSIs would be associated with poorer cognitive performance in individuals with advanced atherosclerosis.

METHODS

Neurocognitive testing, carotid ultrasound imaging, transcranial Doppler imaging, and carotid strain imaging were performed on 40 patients scheduled for carotid endarterectomy. Kendall tau correlations were used to examine relationships between cognitive tests and the surgical-side maximum peak systolic velocity (PSV; from the bulb, proximal, mid, or distal ICA), mean MCA velocity and PI, and maximum CPSIs (axial, lateral, and shear strain indices used to characterize plaque deformations with arterial pulsation). Cognitive measures included age-adjusted indices of verbal fluency, verbal and visual learning/memory, psychomotor speed, auditory attention/working memory, visuospatial construction, and mental flexibility.

RESULTS

Participants had a median age of 71.0 (interquartile range, 9.75) years; 26 were male (65%), and 14 were female (35%). Traditional Doppler parameters, PSV, mean MCA velocity, and MCA PI did not predict cognitive performance (all P > .05). Maximum CPSIs were significantly associated with cognitive performance (P < .05).

CONCLUSIONS

Traditional velocity measurements of the maximum bulb-ICA PSV, mean MCA velocity, and PI were not associated with cognitive performance in patients with advanced atherosclerotic disease; however, maximum CPSIs were associated with cognitive performance. These findings suggest that cognition may be associated with unstable plaque rather than blood flow.

Animal Models of Chronic Cerebral Hypoperfusion: From Mouse to Primate

Vascular cognitive impairment (VCI) or vascular dementia occurs as a result of brain ischemia and represents the second most common type of dementia after Alzheimer’s disease. To explore the underlying mechanisms of VCI, several animal models of chronic cerebral hypoperfusion have been developed in rats, mice, and primates. We established a mouse model of chronic cerebral hypoperfusion by narrowing the bilateral common carotid arteries with microcoils, eventually resulting in hippocampal atrophy. In addition, a mouse model of white matter infarct-related damage with cognitive and motor dysfunction has also been established by asymmetric common carotid artery surgery. Although most experiments studying chronic cerebral hypoperfusion have been performed in rodents because of the ease of handling and greater ethical acceptability, non-human primates appear to represent the best model for the study of VCI, due to their similarities in much larger white matter volume and amyloid β depositions like humans. Therefore, we also recently developed a baboon model of VCI through three-vessel occlusion (both the internal carotid arteries and the left vertebral artery). In this review, several animal models of chronic cerebral hypoperfusion, from mouse to primate, are extensively discussed to aid in better understanding of pathophysiology of VCI.

Cognitive improvement after carotid artery stenting in patients with symptomatic internal carotid artery near-occlusion

BACKGROUND AND PURPOSE

To investigate the influence of carotid artery stenting (CAS) with embolic protection device (EPD) on the cognitive function of patients with near-occlusion of the cervical internal carotid artery (ICA).

METHODS

From February 2014 to December 2017, a total of 79 symptomatic patients were recruited in this study. Of these patients, 31 patients refused to receive CAS therapy. They were divided into the CAS group (48 patients) and the medical treatment group (31 patients). Montreal cognitive assessment (MoCA) instrument was used for the evaluation of cognitive function. The analyzed endpoints included cumulative 12 month incidence of ipsilateral ischemic cerebrovascular events and MoCA scores at 1 month and 12 months after treatment.

RESULTS

Cumulative 12 months incidence of ipsilateral ischemic cerebrovascular events was lower in patients who underwent CAS than in patients on medical treatment (P < 0.05). In CAS group, the total MoCA score, scores of attention and delayed recall at months 1 and 12 increased when compared with those at baseline (P < 0.05). In medical treatment group, the total MoCA score and attention score at month 12 decreased when compared with those at baseline (P < 0.05). In CAS group, the total MoCA score, scores of line connection test, drawing clock, attention and delayed recall were improved at 1 and 12 months when compared with medical treatment at the same time points (P < 0.05).

CONCLUSIONS

CAS with EPD not only decreases the risk of ipsilateral TIA and stroke but also may improve the cognitive function of symptomatic patients with ICA near-occlusion.

Asymptomatic carotid stenosis and concomitant silent brain infarctions

Objectives

This review aims to clarify (1) the definition of silent brain infarct (SBI), (2) the diagnostic criteria of SBI using magnetic resonance imaging (MRI), (3) the prevalence of patients with asymptomatic carotid stenosis and SBI based on MRI assessment, (4) the association of SBI and asymptomatic carotid stenosis and the risk of stroke compared to patients without SBI, (5) the association between development of dementia/cognitive impairment in people with asymptomatic carotid stenosis and SBI, and (6) the evidence for treating patients with carotid stenosis and SBI.

Methods

A systematic search of PubMed and Scopus including all studies published from 2000 to 2018 and written in English.

Results

No consensus of the definition and diagnostic criteria for SBI was found. The prevalence of SBI in asymptomatic carotid patients is 17–33.3%. SBI is a significant risk factor for future stroke, OR 4.6 (95% CI: 3.0–7.2; p < 0.0001). One substudy showed that immediate CEA is beneficial compared to delayed CEA in these patients, showing a 45% reduction in annual stroke rate from 1.5%/year to 0.7%/year.

Conclusion

This review emphasizes the need to standardize the definition and diagnostic criteria of SBI on MRI. Current evidence suggests an increased risk and a small potential benefit of offering carotid endarterectomy to patient with silent brain infarct. Prospective studies are warranted to elucidate these issues further.

Neuropsychological Outcome One Year after Carotid Revascularization: A before-and-after Study

Purpose

The aim of our study was to determine the clinical profile of patients considered cognitive 'responders' to surgery in order to establish clinical variables associated with a favorable cognitive performance.

Materials and Methods

A total of 70 patients were included in the study. A well-validated, comprehensive standardized neurocognitive battery of tests of about 2 hours was administered. Patients were examined twice, 1-week before surgery and 1-year postoperatively. The criterion to be included in the 'responder' group was the following: to obtain a positive difference between post-revascularization and pre-revascularization neuropsychological assessment ≥1 standard deviation in ≥2 tests.

Results

Twenty-seven patients (38.6%) were cognitive responders to treatment. In bivariate analysis between responders and non-responders, presence of atrophy (P=0.003), small vessels (P=0.577), symptoms (P=0.046), and age (P=0.030) were the factors statistically significant. When comparing cognitive performance before and after carotid revascularization, significant differences were observed in semantic fluency with a lower performance after 12 months (P=0.004, d=0.29), and in the Language index (Repeatable Battery for the Assessment of Neuropsychological Status) (P=0.005, d=0.34).

Conclusion

Patients without neurological symptoms, of a younger age and without atrophy and white matter small vessel lesions are better cognitive responders 1-year after carotid revascularization.

Predictive Value of Dynamic Cerebral Autoregulation Assessment in Surgical Management of Patients with High-Grade Carotid Artery Stenosis

Dynamic cerebral autoregulation (DCA) capacity along with the degree of internal carotid artery (ICA) stenosis and characteristics of the plaque can also play an important role in selection of appropriate treatment strategy. This study aims to classify the patients with severe ICA stenosis according to preoperative state of DCA and to assess its dynamics after surgery. Thirty-five patients with severe ICA stenosis having different clinical type of disease underwent reconstructive surgery. DCA was assessed with transfer function analysis (TFA) by calculating phase shift (PS) between Mayer waves of blood flow velocity (BFV) and blood pressure (BP) before and after operation. In 18 cases, regardless of clinical type, preoperative PS on ipsilateral side was within the normal range and did not change considerably after surgery. In other 17 cases preoperative PS was reliably lower both in patients with symptomatic and asymptomatic stenosis. Surgical reconstruction led to restoration of impaired DCA evidenced by significant increase of PS in postoperative period. Our data suggest that regardless clinical type of disease various state of DCA may be present in patients with severe ICA stenosis. This finding can contribute to establishing the optimal treatment strategy, and first of all for asymptomatic patients. Patients with compromised DCA should be considered as ones with higher risk of stroke and first candidates for reconstructive surgery.

[Severe carotid stenosis: cerebral autoregulation in the ipsilateral region]

AIM

To study cerebral autoregulation (CA) in region of the stenotic carotid artery.

MATERIAL AND METHODS

The study involved 35 patients with critical stenosis of the carotid arteries, including 24 patients were asymptomatic and 11 patients with symptomatic course. Blood flow velocity in middle cerebral arteries was monitored using Multi Dop X (DWL, Germany) with simultaneous noninvasive systemic blood pressure registration (CNAP, Austria). CA was assessed by calculating the phase shift (PS) between spontaneous oscillations of blood flow velocity and blood pressure within the range of systemic Mayer waves (80-120 mHz).

RESULTS

In 18 patients, the CA indicators were in the normal range (PS 1.2±0.3 rad). Seventeen patients, including asymptomatic as well as symptomatic types, had impaired CA (PS 0.2±0.2 rad and 0.3±0.2 rad, respectively). Reconstructive surgery, irrespective of clinical manifestations, led to the significant increase in PS (p<0.001) in the early postoperative period (0.9±0.5 and 0.9±0.3 rad, respectively).

CONCLUSION

A significant variability in the cerebrovascular reserve capacity in symptomatic and asymptomatic types of carotid artery stenosis was found. CA can be used in determining the indications for surgical treatment and evaluation of its effectiveness in patients with stenosis of carotid arteries.

Transcranial Doppler and Microemboli Detection: Relationships to Symptomatic Status and Histopathology Findings

The purpose of this study was to determine the relationship between symptomatic status, transcranial Doppler (TCD) microemboli presence and plaque histopathology findings. TCD was performed on 60 patients (37 symptomatic, 23 asymptomatic) before undergoing clinically indicated carotid endarterectomy. The frequency of microemboli signals was not significantly different between symptomatic and asymptomatic subject groups (p = 0.88) and there were no differences observed in the macroscopic or histopathology scoring of these plaques (p-values all > 0.05). The presence of microemboli was associated with an ulceration score (regardless of symptomatic or asymptomatic status, p = 0.034), with a one-level increase in ulceration rating associated with an odds ratio of 5.86 (95% [CI] 1.55, 43.4). These findings suggest that both symptomatic and asymptomatic patients may have plaque with similar features of instability and ability to create emboli. Thus, identifying new ways to measure plaque instability may provide important information for optimizing treatment to prevent future stroke.

Improvement of neurovascular function and cognitive impairment after STA-MCA anastomosis

OBJECTIVE

In patients with severe steno-occlusive disease of a main cerebral artery, decreased cerebrovascular reserve (CVR) and cognitive impairment without causative focal lesions on magnetic resonance imaging have been reported. We examined ipsilateral and contralateral CVR and cognition before and after superficial temporal artery-middle cerebral artery (MCA) anastomosis operation in patients with internal carotid artery (ICA) or MCA occlusion.

METHODS

In 30 patients with ICA or MCA occlusion, cognitive impairment, and decreased CVR, we examined cognition, CVR, leukoaraiosis grades, and blood data. Data from 15 patients who underwent anastomosis were compared to that in 15 patients who did not undergo anastomosis, and to bilateral data already reported on 65 patients with severe steno-occlusive disease.

RESULTS

Cerebral blood flow, CVR, and cognition improved after anastomosis compared to before, and compared to patients without anastomosis; improved values were maintained for 5years. CVR recovered after anastomosis, matching the linear relationship between ipsilateral and contralateral CVR seen in the 65 patients.

CONCLUSION

The postoperative improvement in cognition and synchronized recovery on the regression line between CVR of the ipsilateral occlusion and contralateral sides may suggest that the CVR is widespread and nonselectively related to cognitive function.

Carotid stenosis and cognitive impairment amongst older Chinese adults living in a rural area: a population-based study

BACKGROUND AND PURPOSE

The possible association between carotid stenosis and cognitive impairment in the Chinese population has been rarely investigated. The association between the severity of carotid stenosis and cognitive impairment amongst older Chinese people living in a rural area was assessed.

METHODS

This cross-sectional study included 1375 participants (age ≥60 years) from the Confucius Hometown Aging Project in Shandong. In 2010-2011, data were collected through interviews and clinical examinations. Carotid stenosis was assessed using ultrasonography. Cognitive impairment was defined according to the education-specific cutoff scores of the Mini-Mental State Examination. Data were analyzed using multinomial logistic models.

RESULTS

The overall prevalence was 7.0% for moderate carotid stenosis, 2.0% for severe stenosis and 6.0% for cognitive impairment. The multi-adjusted odds ratio of cognitive impairment was 1.43 (95% confidence interval 0.63-3.22) for moderate carotid stenosis and 3.75 (1.24-11.40) for severe carotid stenosis (P(trend) = 0.023). Similar results were obtained in people without a history of cerebrovascular disease.

CONCLUSIONS

Severe carotid stenosis, even asymptomatic, is associated with cognitive impairment independent of atherosclerotic risk factors and disorders amongst older Chinese people.

Cognitive impairment is associated with medication nonadherence in asymptomatic carotid stenosis

OBJECTIVE

Adherence to medical management of vascular risk is vital for stroke prevention in patients with asymptomatic carotid stenosis. Because carotid disease is a risk factor for cognitive impairment, we sought to determine whether undiagnosed cognitive impairment affects medication adherence in this setting.

METHODS

Sixty patients with asymptomatic ≥50% internal carotid artery stenosis without known dementia or stroke were screened for evidence of cognitive impairment using the Montreal Cognitive Assessment. Medication adherence was monitored using electronic pharmacy prescription refills. Medications studied included antiplatelet agents, statins, antihypertensives, and diabetes medications. Nonadherence was defined as a refill lag of ≥3 months during the 12 months before cognitive screening.

RESULTS

Sixty percent of patients (36/60) had evidence of cognitive impairment (Montreal Cognitive Assessment <26). Medication adherence was noted in 31% (11/36) of cognitively impaired patients and 88% (21/24) of patients without cognitive impairment (P < .0001). Antiplatelet therapy adherence was significantly lower among cognitively impaired patients compared with those without cognitive impairment (P = .009). A trend toward decreased adherence to statins (P = .09) and antihypertensives (P = .06) was observed.

CONCLUSIONS

Medication adherence in patients with asymptomatic carotid stenosis is significantly reduced among those with undiagnosed cognitive impairment. Cognitive screening of asymptomatic patients with carotid stenosis identifies those who may benefit from increased supervision to improve medication adherence.

Association between carotid stenosis or lacunar infarction and incident dementia in patients with vascular risk factors

BACKGROUND AND PURPOSE

The association between vascular risk factors and dementia is of interest. Several studies have shown that cerebral small vessel disease (SVD) is associated with dementia. However, the association between cerebral large vessel disease (LVD) and dementia has not been thoroughly examined.

METHODS

The Osaka Follow-up Study for Carotid Atherosclerosis, Part 2, was a prospective cohort study of cardiovascular events and dementia in which patients (n = 1106) with vascular risk factors underwent carotid ultrasound. Of these patients, 600 who had normal cognitive function were included and underwent brain magnetic resonance imaging. The presence of lacunar infarction and carotid stenosis served as markers for SVD and LVD, respectively.

RESULTS

Amongst 600 patients (mean 68 years, 57% men), 261 (44%) showed lacunar infarction and 94 (16%) showed carotid stenosis. During the follow-up period (median 8.0 years), 57 patients had incident dementia. Patients with carotid stenosis and lacunar infarction were significantly more likely to be diagnosed with dementia (log-rank test, P = 0.037 and P < 0.001, respectively). The association between lacunar infarction and dementia remained significant after adjusting for risk factors including stroke history, apolipoprotein E genotype and years of education (hazard ratio 2.64, 95% confidence interval 1.22-6.09). However, the presence of carotid stenosis was not associated with incident dementia after adjusting for age and sex (P = 0.477).

CONCLUSIONS

This study demonstrated that carotid stenosis had little association with dementia, but lacunar infarction had a significant association. The impact of SVD on dementia could be much greater than that of LVD.

Influence of carotid artery stenting on cognition of elderly patients with severe stenosis of the internal carotid artery

Background

The aim of this study was to investigate the influence of carotid artery stenting (CAS) on the cognition and quality of life of elderly patients with severe stenosis of the internal carotid artery.

Material/Methods

65 elderly patients with symptomatic severe stenosis of internal carotid artery were recruited into 2 groups: the pharmacotherapy group (n=29) and the CAS group (n=36). Before surgery and 1, 3, 6, and 12 months after surgery, Montreal cognitive assessment (MoCA) was used for the evaluation of cognition and WHOQOL-BREF was used for the assessment of quality of life.

Results

At 12 months after surgery, total MoCA score and WHOQOL-BREF score in the pharmacotherapy group was significantly reduced when compared with those before surgery (P<0.05). In the CAS group, the total MoCA score, scores of attention and delayed recall, and WHOQOL-BREF score increased significantly at different time points after surgery when compared with those before surgery (P<0.05). Moreover, in CAS group, the MoCA score and WHOQOL-BREF markedly increased gradually over time (P<0.05). Compared with the pharmacotherapy group, cognition and quality of life in the CAS group were improved dramatically during the follow-up period (P<0.05).

Conclusions

Severe stenosis of the internal carotid artery is a cause of cognition impairment, and CAS may improve cognition and quality of life.

Influence of stent-assisted angioplasty on cognitive function and affective disorder in elderly patients with symptomatic vertebrobasilar artery stenosis

BACKGROUND

We aimed to investigate cognitive function and affective disorder in elderly patients with symptomatic vertebrobasilar artery stenosis (SVAS) after stent-assisted angioplasty (SAA) and to explore the potential mechanism.

MATERIAL AND METHODS

The study subjects were 26 elderly SVAS patients who were non-responsive to pharmacotherapy and received SAA (study group) and 30 patients receiving intracoronary stent implantation (control group). Montreal cognitive assessment (MoCA), Hamilton depression rating scale (HAMD), and Hamilton anxiety rating scale (HAMA) were used.

RESULTS

The total MoCA score, scores of line connection, copying cube, drawing clock, and delayed recall increased significantly in the study group after surgery (P<0.05, P<0.01). In addition, the MoCA score increased over time and the total MoCA score at 12 months was markedly higher than that at 1 month (P<0.05). The scores of HAMD and HAMA decreased dramatically after surgery compared with before surgery in these patients (P<0.01). A comparison at the corresponding period was performed between study group and control group, and it was found that the differences in total MoCA scores and scores of line connection, copying cube, drawing clock, and delayed recall before surgery and at 1 month after surgery were significant (P<0.05, P<0.01).

CONCLUSIONS

SAA may improve the visuospatial/executive abilities and delayed recall, as well as the depression and anxiety in patients with SVAS. Larger and controlled trails are needed to investigate the effect of SAA on cognition and affection in these patients.

Neurosonological Examination: A Non-Invasive Approach for the Detection of Cerebrovascular Impairment in AD

There has been a growing interest in vascular impairment associated with Alzheimer’s disease (AD). This interest was stimulated by the findings of higher incidence of vascular risk factors in AD. Signs of vascular impairment were investigated notably in the field of imaging methods. Our aim was to explore ultrasonographic studies of extra- and intracranial vessels in patients with AD and mild cognitive impairment (MCI) and define implications for diagnosis, treatment, and prevention of the disease. The most frequently studied parameters with extracranial ultrasound are intima-media thickness in common carotid artery, carotid atherosclerosis, and total cerebral blood flow. The transcranial ultrasound concentrates mostly on flow velocities, pulsatility indices, cerebrovascular reserve capacity, and cerebral microembolization. Studies suggest that there is morphological and functional impairment of cerebral circulation in AD compared to healthy subjects. Ultrasound as a non-invasive method could be potentially useful in identifying individuals in a higher risk of progression of cognitive decline.

Cognitive impairment and memory dysfunction after a stroke diagnosis: a post-stroke memory assessment

Cognitive impairment and memory dysfunction following stroke diagnosis are common symptoms that significantly affect the survivors' quality of life. Stroke patients have a high potential to develop dementia within the first year of stroke onset. Currently, efforts are being exerted to assess stroke effects on the brain, particularly in the early stages. Numerous neuropsychological assessments are being used to evaluate and differentiate cognitive impairment and dementia following stroke. This article focuses on the role of available neuropsychological assessments in detection of dementia and memory loss after stroke. This review starts with stroke types and risk factors associated with dementia development, followed by a brief description of stroke diagnosis criteria and the effects of stroke on the brain that lead to cognitive impairment and end with memory loss. This review aims to combine available neuropsychological assessments to develop a post-stroke memory assessment (PSMA) scheme based on the most recognized and available studies. The proposed PSMA is expected to assess different types of memory functionalities that are related to different parts of the brain according to stroke location. An optimal therapeutic program that would help stroke patients enjoy additional years with higher quality of life is presented.