Carotid Obstruction Research Articles

Apolipoprotein E ε2 allele is associated with lower risk of carotid artery obstruction in a population-based autopsy study

IntroductionApolipoprotein E (APOE) ε4 allele has been associated with higher carotid atherosclerosis risk, while the APOE-ε2 seems to decrease this risk. Data from autopsy studies, where carotid arteries can be evaluated in their full extension, is scarce. Therefore, we investigated the association between APOE alleles and direct morphometric measurements of carotid atherosclerosis in an autopsy study with an admixed sample. MethodsWe measured the intima-media thickness (IMT) and stenosis of the common (CCA) and internal carotid (ICA) arteries. The APOE polymorphisms were determined by real-time polymerase chain reaction. Participants were classified into three groups according to the APOE alleles (ε2, ε3, and ε4). We evaluated the association between APOE groups and carotid atherosclerosis using adjusted regression models and included interaction terms of APOE alleles with age, sex, and race. ResultsWe evaluated 1,850 carotid artery samples from 185 participants (mean age=75±12 years old, 55% female, and 71% White). The APOE-ε2 group (n=17) had a lower carotid obstruction and a lower number of severe stenoses (≥ 70%). Having at least one ε4 allele (n=51) was not associated with carotid atherosclerosis. APOE alleles were also not associated with carotid IMT. Age, sex, and race did not modify these relationships. ConclusionAPOE-ε2 carriers had a lower percentage of carotid obstruction and less severe stenosis. APOE-ε4 was not related to a higher risk of carotid atherosclerosis in this cross-sectional population-based autopsy study.

Evaluation by ultrasound of the velocity time integral in carotid stenosis

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Atherosclerotic disease is one of the main causes of cerebrovascular accident. Doppler ultrasound is one of the most important tools in the diagnosis and quantification of such issues. The classics variables to assess through this method are peak systolic velocity (PSV) at the highest stenosis carotid level, diastolic velocity at such level and the PSV rate between the PSV at the stenosis level of the internal carotid artery (ICA) respect the PSV at the common carotid artery (CCA). Objectives Compare the correlation of the velocity time integral (VTI) and the ratio between VTI of ICA and CCA to identify carotid stenosis by carotid ultrasound. Material and methods We included patients that assist at the institution for a carotid ultrasound to identify a carotid stenosis, between 2017 and 2020. Correlation tests between continuous variables were applied according to the type of distribution. Pearson"s test for continuous variables with normal distribution and Spearman"s for those with abnormal distribution.Fig. 1 Results Three hundred and forty two patients were included, 78% male, mean age 67 ± 8. According to its distribution, the VTI ACI / CCA ratio obtained as the median is 5 cm (1.27-8). By dividing the VTI ratio by quartiles, we observe that the percentage of individuals with a higher degree of carotid obstruction, increase significantly as the quartile increase: 0%, 36.5%, 94.2%, 98.8 %. p: 0.0001. Likewise, a high correlation value between the classical quantitative values and VTI and ratio of VTI at different grade of carotid stenosis was seen by carotid ultrasound (Table 1). Conclusions VTI and VTI ratio are parameters that show good correlation with the classical variables to assess a carotid stenosis by carotid ultrasound. In future investigations, the evaluation of these parameters could lead the estimation of the stenosis area, considering the principles of the continuity equation. Abstract Figure. Fig 1 Abstract Table. 1

Carotid Occlusion Accentuates Aortic Stenosis and Cardiac Remodeling With Preserved Systolic Function in LDL Receptor-Deficient Mice.

Background: Carotid atherosclerotic disease is associated with aortic stenosis and reduced cardiac function. The causality between carotid and cardiac pathologies is unknown. We aim to explore the effects of carotid stenosis or occlusion on cardiac pathology and function.Methods and Results: We produced carotid obstruction or stenosis in 36 atherogenic mice with 150- or 300-μm tandem surgery or sham surgery. The structure and function of the heart were assessed by histology and animal ultrasound. The 150-μm group had larger plaque burden and thicker valve leaflets in the aortic root than did the control group. Also, the two surgery groups had a thicker left ventricular posterior wall and smaller internal diameter compared with controls. Increased myocardial fibrosis was also found in the 150-μm group compared with controls, although the surgery groups had preserved systolic function compared with that of controls.Conclusions: In a mouse model, carotid occlusion accentuated the formation of aortic stenosis and promoted ventricular remodeling without impairing systolic function. Carotid atherosclerotic plaque may be a pathogenic factor for aortic stenosis and ventricular remodeling.

SOLITARY FIBROUS TUMOR MANIFESTING AS AN EXTENSIVE OROFACIAL SWELLING

An 80-year-old male was referred for evaluation of an extensive swelling on the left side of the face lasting 1 year and with a previous diagnosis of nodular fasciitis. His medical history revealed arterial hypertension, aortic aneurysm, and partial carotid obstruction in clinical control. Clinical examination revealed a swelling in the left side of the face, with mild dystopia, associated with a swelling in the upper anterior and posterior left vestibule. Panoramic radiography showed no alteration in the region. Revision of the histologic slide from the previous biopsy was compatible with solitary fibrous tumor, and a new incisional biopsy was performed, confirming this histologic hypothesis. The patient was submitted to resection of the tumor, and the analysis of the surgical specimen confirmed the diagnosis of solitary fibrous tumor. The patient has been under clinical and radiographic follow-up for 6 months without evidence of local recurrence.

Dual energy CT in the management of antiplatelet therapy in patients with acute ischemic stroke for carotid obstruction.

Acute tandem occlusions often require carotid stenting. Combination of mechanical and pharmacologic therapies in addition to antiplatelet drugs administered to prevent acute stent thrombosis might increase the risk of intracerebral hemorrhage. We present a protocol of antiplatelet regimen based on early post-procedural dual-energy CT (DE-CT). Fifty consecutive stroke patients with tandem occlusions treated with acute carotid stenting after intracranial thrombectomy and TICI 2b/3 were reviewed. All patients received intravenous lysine acetylsalicylate during the procedure. Dual (aspirin+clopidogrel with or without clopidogrel load, groups A and B, respectively) or mono (aspirin) antiplatelet regimen (group C) was administered 12-24 h later according to brain DE-CT findings. Carotid ultrasonography was performed at 24 h and before discharge. We evaluated the rate of subsequent symptomatic intracranial hemorrhage (SICH) and acute stent thrombosis in each group. Between June 2014 and December 2016, 50 patients were included (mean age 66 years, 76% men, baseline NIHSS 16, median time from symptom onset to recanalization 266 min). According to DE-CT, 24 patients were assigned to group A, 19 to group B and 7 to group C (4 of them had SICH at that time). One patient suffered a subsequent SICH (belonging to group B). There was only one stent thrombosis without clinical repercussions in group B. DE-CT may contribute to select antiplatelet regimen after acute carotid stenting in tandem occlusions.

Multicentric Experience in Distal-to-Proximal Revascularization of Tandem Occlusion Stroke Related to Internal Carotid Artery Dissection.

Internal carotid dissection is a frequent cause of ischemic stroke in young adults. It may cause tandem occlusions in which cervical carotid obstruction is associated with intracranial proximal vessel occlusion. To date, no consensus has emerged concerning endovascular treatment strategy. Our aim was to evaluate our endovascular "distal-to-proximal" strategy in the treatment of this stroke subtype in the first large multicentric cohort. Prospectively managed stroke data bases from 2 separate centers were retrospectively studied between 2009 and 2014 for records of tandem occlusions related to internal carotid dissection. Atheromatous tandem occlusions were excluded. The first step in the revascularization procedure was intracranial thrombectomy. Then, cervical carotid stent placement was performed depending on the functionality of the circle of Willis and the persistence of residual cervical ICA occlusion, severe stenosis, or thrombus apposition. Efficiency, complications, and radiologic and clinical outcomes were recorded. Thirty-four patients presenting with tandem occlusion stroke secondary to internal carotid dissection were treated during the study period. The mean age was 52.5 years, the mean initial NIHSS score was 17.29 ± 6.23, and the mean delay between onset and groin puncture was 3.58 ± 1.1 hours. Recanalization TICI 2b/3 was obtained in 21 cases (62%). Fifteen patients underwent cervical carotid stent placement. There was no recurrence of ipsilateral stroke in the nonstented subgroup. Twenty-one patients (67.65%) had a favorable clinical outcome after 3 months. Endovascular treatment of internal carotid dissection-related tandem occlusion stroke using the distal-to-proximal recanalization strategy appears to be feasible, with low complication rates and considerable rates of successful recanalization.

Withania coagulans Protects Striatum from Oxidative Damages Induced by Global Brain Ischemia in Rat

Background: Withania coagulans is a traditional plant that possesses diverse pharmacological characteristics including anti-hyperglycemic, anti-hyperlipidemic, antitumor, anti-inflammatory, and antioxidant effects. Objectives: This study evaluated the effect of preischemic administration of Withania coagulans extract (WCE) on antioxidant status and histopathological alteration of the striatum region in rat model of brain global ischemia reperfusion (I/R). Methods: 48 male Wistar rats were divided into four groups (n = 12): Control, Sham operated (Sham), I/R, and WCE + I/R. The animals received WCE or distilled water by oral gavage for 30 days before I/R except the control group. I/R was induced by two common carotid obstructions for 30 minutes. Three days following I/R, the animals were sacrificed, the brain was removed, and striatum was dissected out. Antioxidant statuses such as superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) activities, and malondialdehyde (MDA) level were measured and histological alteration was investigated in corpus striatum by Nissl and TUNEL staining. Results: The results showed that the CAT, SOD, and GPx activities decreased and MDA level increased in I/R group compare to the control group. Preischemic administration of WCE significantly decreased MDA level and increased antioxidant statuses in the striatum region compared to I/R group (P < 0.001). Histopathological analysis revealed that pretreatment with WCE markedly decreased necrotic and apoptotic neurons (P < 0.001) in striatum and reduced white matter injury induced by I/R. Conclusions: We concluded that WCE by its antioxidant and anti-inflammatory effects could modify ischemia reperfusion damage in rat striatum.

Heat shock protein 70 and antibodies to heat shock protein 60 are associated with cerebrovascular atherosclerosis

ObjectivesHeat shock proteins (Hsps) are produced by all cells, including vascular, to ensure stress protection. Damaged cells release Hsps in their local environment and systemic circulation. The aim of this study was to investigate the involvement and prognostic utility of serum Hsp60 and Hsp70, and the respective antibodies anti-Hsp60 and anti-Hsp70 in subjects with advanced atherosclerosis resulting in high degree of cerebrovascular stenosis. Design and methodsUltrasound Doppler examination of carotid arteries was used to discriminate between control and cerebrovascular atherosclerosis subjects. Twenty eight subjects without carotid obstruction were selected as controls. Fifty patients with obstruction of cerebrovascular blood flow were evaluated for the degree of stenosis of cerebral arteries by digital subtraction angiography. In parallel, serum concentrations of Hsp60, Hsp70, anti-Hsp60 and anti-Hsp70 were measured by ELISA kits. ResultsAnti-Hsp60 was significantly higher (P=0.003) in the atherosclerosis group than in the control group (23.62ng/L vs. 15.28ng/L, respectively, expressed as median). Circulating Hsp70 was lower in the atherosclerosis than in the control group (P=0.048), with respective median values of 0.00μg/L vs. 0.22μg/L. Concentrations of Hsp60 and anti-Hsp70 did not differ significantly between the control and atherosclerosis group. ConclusionsHigher circulating anti-Hsp60 is associated with advanced cerebrovascular atherosclerosis as a consequence of the autoimmunity part of the inflammation and bursting of atherosclerosis. Higher levels of Hsp70 observed in the control group could be protective in the development of atherosclerotic changes.

The relationship between carotid artery colour Doppler finding and cerebral oximetry.

Background:In some cases, permanent reduction in cerebral functioning affects a high percentage of patients undergoing cardiovascular surgery. We studied the relationship between the results of preoperative bilateral carotid artery colour Doppler sonography and regional cerebral oxygen saturation (rSO2) during coronary artery bypass graft surgery (CABG).Materials and Methods:This study was a cross-sectional analytical study conducted with 96 candidates for off-pump CABG. This study determined the percentage of the correlation of rSO2 with demographic information, diabetes, hyperlipidemia, hypertension, myocardial infraction (MI), and smoking, and also provided information on the presence and type of plaque, intima-media thickness (IMT), and percentage of stenosis of carotid artery detected through colour Doppler sonography. Data were analyzed by the t-test, the Chi-square test, and simple linear regression.Results:In this study, the mean value of rSO2 increased after intubation compared to the mean before intubation, the difference being statistically significant (P = 0.005). A comparison of the mean rSO2 of the right side of the brain and the percentage of right carotid obstruction (stenosis of less than 50% vs. stenosis with a range of 50-69%) revealed that the mean rSO2 at the time of the partial-clamp between carotid stenosis less than 50% and carotid stenosis with a range of 50-69% was statistically significant (P = 0.043).Conclusions:There is no statistically significant correlation between rSO2 and percentage of carotid artery stenosis less than 70%. It is advised that rSO2 and carotid stenosis of greater than 70% be studied in future.

Penetrating trans-orbital injury from a brush handle lodged in the infra-temporal fossa.

Penetrating trans-orbital injury from a brush handle lodged in the infra-temporal fossa.

E-021 Acute Interventional Treatment of Atherosclerotic Carotid Occlusion and Intracranial Thromboembolism

The patient presenting with acute carotid occlusion and intracranial embolism poses additional challenges compared with the patient with intracranial embolism and no cervical carotid obstruction. There are technical challenges of...

Carotid stenosis after adjuvant cervical radiotherapy in patients with head and neck cancers: a prospective controlled study

To determine the prevalence of radiation-induced carotid stenosis, in patients who were treated for head and neck malignancies, using colour-flow duplex scanning. Prospective controlled study at a single medical centre. We enrolled two groups of patients. The first (radiotherapy group) consisted of patients who received surgical treatment and adjuvant radiotherapy of the neck. The control group consisted of patients with head and neck malignancies who received only surgical treatment. All patients were evaluated with carotid artery ecoDoppler imaging 1 week before and 36 months after the surgical procedure. Intima-media thickness was measured bilaterally at the internal carotid artery and at the bifurcation. Carotid obstruction was classified as low (0-30%), moderate (31-49%) or severe (≥50%). The preoperative stenosis grade did not differ between groups. In 15/25 patients (60%) in the radiotherapy group, mild stenosis evolved to moderate stenosis, while only 6/37 (16%) of the controls did (P = 0.004). Additionally, 9/39 (23%) patients in the radiotherapy group progressed to severe stenosis compared with only 3/54 (6%) controls (P = 0.029). The overall evolution showed that stenosis worsened in 24/32 (62%) patients in the radiotherapy group and 9/54 (17%) patients in the control groups (P < 0.0001). These results highlight the need to study the long-term incidence of cerebrovascular events in these two different populations (radiation treated and surgically treated) to identify increased cerebrovascular morbidity.

Carotid angioplasty is an alternative therapeutic option to carotid endarterectomy for a defined group of patients

Stroke is the third cause of death and the leading cause of disability worldwide. In the United States approximately 795000 cases of stroke are produced annually with a mortality rate of 17%. (1) Atherosclerotic disease of the extracranial internal carotid artery (ICA) is responsible for 20% to 25% of all ischemic strokes, and both medical therapy (MT) and carotid endarterectomy (CE) have been previously used to prevent them. Medical therapy is currently considered the first choice in the treatment of asymptomatic patients with ≤ 80% carotid obstruction. Regarding CE, both American and European guidelines recommend its use in symptomatic patients with stenosis between 70 % and 99% (Class I, level of evidence A). Carotid percutaneous transluminal angioplasty (PTA) is the third therapeutic option which started to be used 15 years ago and several randomised studies have attempted to better define its role with respect to MT and CE. CAVATAS (2) was the first multicentric, randomised study, which included 504 patients with symptomatic carotid artery disease for PTA and CE. There were no significant differences between both treatments in the endpoint of death or stroke at 30 days (10%) and at 3 years (14%). The surgical team had a greater rate of cranial nerve paralysis (CE: 8.7%, PTA: 0%; p < 0.0001). No cerebral protection (CP) system was employed and stenting was used only in 26% of the cases. SAPPHIRE (3) included 334 symptomatic and asymptomatic (70%) patients with high risk surgical criteria. According to protocol, CP was used in all PTA patients. The primary endpoint of death, stroke or acute myocardial infarction (AMI) at 30 days plus ipsilateral stroke or death due to neurological causes between 31 days and 1 year occurred in 12.2% of the PTA group patients and 20.1% of the CE group patients (p = 0.004 for noninferiority and p = 0.05 for superiority). The rates of stroke and death at 30 days were similar in both groups and in the CE group there was a greater proportion of infarction (6.6% vs. 1.9%; p = 0.04) and cranial nerve paralysis (5.3% vs. 0%; p = 0.003). SPACE (4) and EVA-3S (5) published in 2006, were multicentric, randomised and noninferiority studies. The SPACE study enrolled 1200 symptomatic patients and CP was used in 27% of the PTA group patients. The primary endpoint of ipsilateral stroke or death from any cause at 30 days, occurred in 41 patients of the PTA group (6.84%) and in 37 patients in the CE group (6.34%) (absolute difference 0.51%; p = 0.09 for noninferiority). No significant differences were found for death, global stroke, non-fatal ipsilateral ischemic stroke, disabling stroke and nonfatal ipsilateral intracerebral bleeding. Even though the SPACE study could not prove noninferiority of PTA compared with CE, the difference between both treatments was of only four events in almost 600 patients treated per group.

Ocular Ischemia following Vitreoretinal Surgery in Unsuspected Carotid Insufficiency

Purpose: To report two cases that developed neovascuarization of iris, secondary to anterior segment ischemia following vitreoretinal surgery with encirclage. Methods: Retrospective chart review. Patients: Two patients of age 64 and 67 years, who had successful vitreoretinal surgery with encirclage for rhegmatogenous retinal detachment, presented few months later with NVI and features of anterior segment ischemia. Carotid evaluation revealed 50 to 60% carotid obstruction in both patients. Encircling band was sectioned in both the patients. Results: Partial regression of NVI with reversal of symptoms occurred in one patient while ocular ischemia could not be reversed in the other. Conclusion: Carotid insufficiency should be suspected in elderly patients when anterior segment ischemia develops following placement of encircling buckle.

Systemic lupus erythematosus associated with vasculitic syndrome (Takayasu’s arteritis)

A 43-year-old woman reported pain in the right hypochondrium, which had started 3 years before and had been worsening for the past few days. Claudication in the superior and inferior limbs, diffuse myalgia, dyspnea, precordialgia followed by dizziness and visual turbidity were added to the clinical picture. In the physical examination bilateral carotid bruit was observed, abdominal aorta murmur and the decrease of the right radial and left pedis pulses and arterial hypertension with difference in the diastolic pressure between limbs >10 mmHg was also observed. On cardiac catheterisation with aortography, right coronary with proximal parietal irregularities, slight pressure increase in right chambers and pulmonary artery, preserved left ventricle contractility, competent valves, carotid and subclavian partial obstruction, severe narrowing of the abdominal aorta below the diaphragm (80%) and right renal artery significant stenosis were observed. Takayasu's arteritis (TA) diagnosis was established according to the ACR criteria based on the clinical symptomatology, on physical and image test findings. Two years later she presented malar rash, photosensitivity, nephropathy, leukopenia, lymphopenia and hemolytic anemia confirming the systemic lupus erythematosus (SLE) diagnosis. TA coexisting with SLE has rarely been reported.

Oscillatory cerebral hemodynamics—the macro- vs. microvascular level

The phase shift between oscillations of blood pressure (BP) and Doppler middle cerebral artery flow velocity (MCAFV) reflects continuous cerebral autoregulatory action. It is not known whether a similar phase shift exists for cortical hemodynamics (‘microvascular level’) assessed by near infrared spectroscopy (NIRS) and what the effects are of pathological conditions. This study investigates the phase relations between oscillations of BP, MCAFV and NIRS parameters in 38 healthy older adults and 28 patients with unilateral severe obstructive carotid disease. BP was recorded noninvasively by finger plethysmography. Stable 0.1 Hz oscillations of all hemodynamic parameters were induced by regular breathing at a rate of 6/min. Basic results were that: (1) BP-induced cortical microvascular oscillations (NIRS) follow those of macrovascular oscillations (MCAFV) with a phase of 80–90° (corresponding to 2–2.5 s at 0.1 Hz), most likely reflecting a transit time phenomenon; (2) oxy- and deoxyhemoglobin thereby oscillate in counterphase; (3) hemodynamic compromise in carotid obstruction leads to (a) delayed NIRS oscillations in comparison to BP which are highly correlated to a shorter phase lead of MCAFV against BP and (b) a decoupling of the oxy-/deoxyhemoglobin counterphase to 240°. Cortical hemodynamic responses to BP oscillations follow specific phase relationships due to cerebral autoregulatory action and circulatory transit times. With hemodynamic impairment, as in unilateral carotid obstruction, these phases are significantly changed reflecting disturbed autoregulation.

Carotid intima–medial thickness as a marker of disease activity in Takayasu's arteritis

Background Assessment of disease activity in patients with Takayasu's arteritis (TA) is difficult due to absence of definitive tests. Presence of carotid intima–medial thickening has been suggested as a possible marker of inflammation and disease activity. Methods We evaluated common carotid artery carotid intima–medial thickness (CCA–IMT) in 56 common carotid arteries (CCAs) in 28 healthy controls and 74 CCAs in 37 patients of TA. We correlated these findings with the presence of activity as assessed by the National Institutes of Health (NIH) criteria. Results CCA–IMT was increased (> 0.8 mm) in 59% of the patients with TA. In patients with disease activity, the CCA–IMT was more than in those without activity (1.5 ± 0.16 vs. 0.9 ± 0.2 mm, P < 0.005). This is presumably because of ongoing inflammation causing abnormal thickening. Even among patients without active disease, CCA–IMT was more than in controls (0.9 ± 0.2 vs. 0.6 ± 0.1 mm, P < 0.05) possibly due to a milder degree of inflammation or healing with fibrosis. All patients with angiographic carotid obstruction had increased CCA–IMT irrespective of whether they were active or not. However, in patients with angiographically normal carotid arteries, CCA–IMT was increased only among the patients who were active (1.4 ± 0.2 vs. 0.7 ± 0.04, P < 0.05). Abnormal CCA–IMT as marker of disease activity had a sensitivity of 82% and specificity of 60%. On excluding patients with increased CCA–IMT who had angiographic carotid stenosis (because the increase in CCA–IMT cannot be attributed entirely to activity alone in these patients), the specificity increased to 70%. Conclusion Increased CCA–IMT is a reliable marker of active disease, especially in the absence of angiographically visible carotid disease.

Circulating tissue kallikrein levels correlate with severity of carotid atherosclerosis.

Vascular growth factors are upregulated in stroke patients, but it remains unknown if they correlate with carotid atherosclerosis. A case-control study was conducted to determine: (1) possible association between biomarkers of angiogenesis or inflammation and carotid stenosis; and (2) the impact of revascularization on the same biomarkers. Circulating vascular endothelial growth factor (VEGF), basic fibroblast GF (bFGF), tissue kallikrein (tK), and high-sensitivity C-reactive protein (hs-CRP) were measured in 89 patients with carotid obstruction and 45 age-matched controls. Patients were stratified as <50% carotid stenosis (CAS; n=16); 50% to 69% CAS (n=12); 70% to 99% CAS (n=43); and carotid occlusion (CAO; n=18). No association was found between VEGF, bFGF, or hs-CRP and obstruction grading. TK augmented from 360+/-30 in <50% CAS (P=NS versus controls) to 509+/-72 in moderate CAS (P<0.05), 1159+/-178 in high-grade CAS (P<0.02), and 1616+/-403 pg/mL in CAO (P<0.01). A threshold of 508 pg/mL provided the maximized predictive value of high-grade obstruction. After revascularization, tK decreased from 1410+/-352 to 782+/-86 pg/mL (P<0.01), whereas no change was detected in nonoperated cases. Hs-CRP was unaffected by revascularization. Angiogenic factors are heterogeneously expressed in patients with carotid atherosclerosis. The tK measurement may be useful for the diagnosis and monitoring of atherosclerotic disease.

Cognitive disorders in patients with occlusive disease of the carotid artery: a systematic review of the literature.

We present a systematic review of the literature on the prevalence, nature, severity, course, and causes of cognitive deficits in patients with occlusive disease of the carotid artery prior to surgery (if surgery was under discussion). Searches were carried out on Medline and Psychlit from 1980 to 1999 using neurovascular and psychological index terms, and papers and books were checked for further references. Studies describing neuropsychological assessment of groups of patients with carotid obstruction were included. Eighteen studies were found. We extracted from the papers data on study design, demographic characteristics of patients, clinical diagnosis, carotid obstruction, cerebral imaging, time interval between ischemic episode and neuropsychological assessment, neuropsychological assessment procedures, integration and interpretation of test performances, and conclusions of authors. Fourteen studies concluded that there are cognitive deficits both in patients with symptomatic and in those with asymptomatic carotid obstruction; four studies denied cognitive impairment. There were no differences in patient characteristics, study design, or neuropsychological assessment procedures between the 14 studies that found deficits and the 4 that did not. There are indications for a mild, diffuse detrimental effect of carotid occlusive disease on cognitive functioning. However, methodological problems prevent a definitive conclusion. Further research is needed to confirm these findings and to ascertain the neurovascular risk factors for and the natural course of cognitive impairment in patients with carotid occlusive disease.

Influencia de la presión arterial en el estudio de la reactividad cerebrovascular en oclusiones carotídeas

Cerebrovascular reactivity (CVR) is the capacity of the cerebral microcirculation to increase cerebral blood flow on vasodilator stimulation. This is reduced in patients with carotid obstruction. The changes in arterial pressure produced whilst carrying out different tests for estimation of the CVR may affect its measurement by transcranial Doppler. To evaluate the concordance between the different methods for estimation of the CVR by transcranial Doppler in patients with carotid obstruction and to evaluate the importance of monitoring the arterial pressure during CVR tests. We evaluated 17 patients with internal carotid artery obstruction confirmed on arteriography. The CVR was determined by three different methods: apnea test. Breath-Holding Index (BHI) and intravenous acetazolamide test. During the tests of RCV the arterial pressure was monitored. We found that there was a reduction in the average basal rate of flow and of the pulsatile index on the obstructed side, with a statistically significant association in relation to the contralateral side (p < 0.001). There was good concordance between the different tests of CVR, with reduced CVR seen on the obstructed side as compared to the contralateral side (p < 0.001) for the different tests. However, this correlation was not seen in stenosis < 70%. During the apnea test changes in blood pressure occurred, with a tendency to increase in the systolic pressure. However, there were no significant changes in blood pressure during the acetazolamide test. There is good concordance in the CVR between the apnea, BHI and acetazolamide tests in carotid obstruction. Changes in arterial pressure occurred during the apnea and BHI tests. However, the acetazolamide test caused no change in arterial pressure.