Practice recommendations for neurovascular ultrasound investigations of acute stroke patients in the setting of the COVID-19 pandemic: an expert consensus from the European Society of Neurosonology and Cerebral Hemodynamics.

BACKGROUND AND PURPOSE: Patients with acute ischemic stroke are at high-risk for contracting COVID-19 infection. Additionally, healthcare professionals including neurovascular ultrasound providers are also at risk of being infected by SARS-CoV-2 virus. Yet, preparedness to continue to guarantee hyperacute treatment is vital for patients outcome. In light of this situation, the European Society of Neurosonology and Cerebral Hemodynamic (ESNCH) appointed a task force to provide consensus recommendations for the performance of neurovascular ultrasound investigations in acute ischemic stroke during the COVID-19 pandemic with the aim of protecting both patients and ultrasound providers. METHODS: The "ultrasound in acute stroke working group" of the ESNCH examined literature articles and reviews using the following key words: "corona virus" or "COVID-19" or "SARS-CoV-2 virus", and "acute stroke" or "cerebrovascular disease", and "ultrasound". Thereafter, a thorough discussion was conducted with the "education and guidelines working group" of the ESNCH. RESULTS: We propose rapid up-to-date recommendations for healthcare personnel involved in the pre-hospital and intra-hospital assessment of stroke patients, with a particular attention to neurovascular ultrasound performance. CONCLUSION: The ESNCH provides a guidance summary for the performance of neurovascular ultrasound investigations in acute ischemic stroke in the time of COVID-19.

Mechanisms of post-radiation injury: cerebral microinfarction not a significant factor.

Post-radiation leukoencephalopathy is characterized by cognitive impairment and white matter alternations on imaging. Cerebral small vessel disease (SVD) is one of several suggested etiologies. Cerebral microinfarction (CMI) is a recently described marker of SVD. We sought to examine the rate of CMI as a biomarker of ongoing ischemia among patients who underwent brain radiotherapy (RT). 110 patients treated with RT for primary or metastatic brain tumors were enrolled. A total of 685 brain MRI tests performed 1-108 months post-radiation were examined. The annual incidence of CMI was calculated. Only 2 definite CMI were found (2/685, 0.3 %). The calculated annual incidence of CMI was 0.11. This incidence is similar to the normal population, and lower than the reported incidence in patients with intracerebral hemorrhage or cognitive impairment. CMI incidence in patients treated with brain RT is similar to the general population. This finding suggests that post-radiation leukoencephalopathy and cognitive impairment are not due to active SVD solely but rather secondary to other causes such as inflammation, metabolic or direct cell damage.

Post-stroke cognitive decline: an update and perspectives for clinical research.

The close relationship between stroke and dementia is an important health issue. Ischaemic stroke can facilitate the onset of vascular dementia as well as aggravate pre-existing cognitive decline. The onset of cognitive decline may become manifest immediately following the onset of ischaemic stroke, but often there is a delay in the development of cognitive decline after a stroke. This delay can be seen as a therapeutic time window allowing interventions to be applied to preserve cognition following stroke. Both neurodegenerative and vascular mechanisms are activated and probably result in overlapping processes within the neurovascular unit. This review focuses on the incidence and prevalence of cognitive decline following stroke, predisposing stroke aetiologies, pre-stroke decline, imaging factors and biomarkers. Outcomes are discussed in relation to timing of assessment and neuropsychological tests used for evaluation of cognitive decline in ischaemic stroke patients. Including such tests in routine evaluations of stroke patients after some weeks or months is recommended. Finally, an outlook on ongoing and planned intervention trials is added and some recommendations for future research are proposed.

What are the correlates of cognition and participation to return to work after first ever mild stroke?

BACKGROUND: The percentage of working age people with mild stroke has risen. Evidence indicates that even mild stroke impact cognition, executive functioning, and daily functioning, consequently affecting participation, quality of life (QoL) and return to work (RTW). OBJECTIVES: (1) Compare cognition, participation and QoL between people 3 months post-mild stroke who RTW and those who did not; and (2) To determine the correlates of these variables to RTW of participants 3 months post-stroke. METHODS: We visited at home 163 stroke survivors (117 men, 46 women) 3 months post-mild stroke ranging from 50 to 89 years. Participants who returned to work (n = 114) and those who did not (n = 49). Data collection at home included measures for cognitive status (MoCA), executive functions (EFPT, DEX), depression (GDS), participation (RNL), and QoL (SIS recovery). RESULTS: Significant differences were found between RTW participants and those who did not RTW in measures of cognition, depression, participation and QoL (t = 2.36 to - 5.62, P < 0.022-0.001). No difference was found on age or gender. Stepwise regression showed that significant correlates of RTW were participation (RNL), executive functions (EFPT), and QoL (SIS recovery). CONCLUSIONS: To enable RTW after mild stroke, participation, executive functions and QoL must be considered in planning interventions.

Stroke service: how can we improve and measure outcomes? Consensus summary from a global stroke forum.

The success of acute stroke treatment is first and foremost time-dependent, and the need for improvement in acute stroke management is demonstrated by the fact that only a minority of patients gain access to treatment - in particular, intravenous recombinant tissue plasminogen activator (IV tPA) - within the necessary time window. Standards of acute stroke care vary widely both regionally and nationally; consequently, various healthcare organizations have undertaken initiatives to measure and improve quality of care. To date, most quality measures have been process-based, focusing primarily on metrics of patient care in the acute hospital-based setting (e.g., time to recombinant tPA administration). Therefore, there remains a need for metrics designed to assess how improvements in process translate into patient outcomes. A global forum was convened to share best practice and provide consensus recommendations on core metrics for measuring improvements in access to care and patient outcomes. Recommendations for core metrics of patient outcomes include hospital-based outcomes (e.g., neurological status at 24 h, ambulatory status at discharge) and post-discharge outcomes (e.g., modified Rankin Scale score at 30 and/or 90 days). Recommendations for best practice relating to aspects of people, process, and technology involved in the stroke treatment pathway that may help provide improvements in these core outcome measures are also outlined.

Atherosclerosis and arteriosclerosis parameters in stroke patients associate with paraoxonase polymorphism and esterase activities.

BACKGROUND AND PURPOSE: Polymorphic paraoxonase (PON1) variants can variably prevent low- and high-density lipoprotein oxidation, but their role in provoking atherosclerosis remained unclear. We addressed this issue by profiling PON1 polymorphisms and enzymatic activities, and assessing atherosclerosis and cerebral arteriosclerosis severity in post-stroke patients. METHODS: Carotid artery intima-media-thickness (IMT), cerebral white matter lesions (WML), serum PON1 -108C/T, Q192R and L55M polymorphisms, and PON and acetylcholinesterase (AChE) enzyme activities were determined in 237 patients. RESULTS: Genetic variation at the PON1 locus showed a strong influence on PON1 activity in ischaemic stroke patients, but lacked direct influence on IMT. Stroke patients with PON1 QQ192 or MM55 genotypes demonstrated lower PON and arylesterase activities at both Day 1 and 12 months post-stroke than patients with either RQ/RR192 or LM/LL55 genotypes (P < 0.001). Furthermore, patients with carotid atherosclerosis and/or cerebral arteriosclerosis expressed as IMT, carotid plaques and WML had lower 12 months PON1 activity than patients without (P = 0.02, P = 0.027 and P = 0.001, respectively), and PON and AChE hydrolysis rates were more tightly correlated in patients carrying the PON1 192R compared with the 192QQ allele, in a gene dose-dependent manner (P < 0.001). CONCLUSION: Our findings show inverse PON1 activity-carotid atherosclerosis and -cerebral arteriosclerosis association in stroke patients: the lower the PON1 activity the more progressed is the atherosclerotic process and the weaker is the association with AChE activity. Extending previous PON1 genetic studies in stroke populations, our study emphasizes the PON1 activity as a potential anti-atherogenic element and proposes involvement of cholinesterase activities in its effects.

Cognitive assessment in proximity to acute ischemic stroke/transient ischemic attack: comparison of the montreal cognitive assessment test and mindstreams computerized cognitive assessment battery.

BACKGROUND/AIMS: Even mild stroke survivors may sometimes experience residual cognitive damage. No consensus has emerged about which cognitive test is most appropriate for the diagnosis of poststroke cognitive impairment. We aim to compare a computerized battery of neuropsychological tests for memory, attention and executive functions (MindStreams®) with the Montreal Cognitive Assessment (MoCA) to detect mild-to-moderate cognitive impairments in poststroke patients. METHODS: Subjects enrolled to the TABASCO (Tel Aviv Brain Acute Stroke Cohort) study, a prospective study which includes consecutive first-ever mild-to-moderate stroke patients, were included. All participants underwent neurological and cognitive evaluations. RESULTS: A total of 454 patients with transient ischemic attack (TIA) or stroke are reported. Their mean MoCA and MindStreams scores were lower than normal; however, the TIA group presented significantly better scores using either method. The correlation between the MoCA and the computerized global score was 0.6 (p < 0.001). A significant correlation was found between the subcategory scores (executive function, memory and attention). However, the MoCA identified many more subjects with low scores (<26) compared to the MindStreams (70.6 vs. 15.7%). CONCLUSION: Our results demonstrate that either of the modalities alone is sensitive enough for identifying subtle cognitive impairment and none picks up substantially more cognitive losses than the other in patients with cerebrovascular disease.

Clinical consequences of aspirin and clopidogrel resistance: an overview.

The aim of this review is to introduce the concept of personalized medicine in secondary stroke prevention with antiplatelet medication. In the last years, many studies have been conducted regarding aspirin resistance and genotyping of clopidogrel metabolism. A review of the currently published data on this issue emphasizes the importance of focusing on the individualizing approach in antiplatelet therapy to achieve maximal therapeutic beneficial effect. However, many authors suggest that, before new information from ongoing trials become available, good clinical practice should dictate the use of low dose of aspirin that was shown to be effective in the prevention of stroke and death in patients with ischemic cerebrovascular disease, because higher doses do not have significantly better efficacy than lower doses in secondary stroke prevention, but lower-dose aspirin is associated with less side effects. On the other hand, many factors are associated with clopidogrel resistance, and recent genetic studies showed that the CYP2C19*2 genotype (loss-of-function allele) is related to poor metabolism of clopidogrel, but larger studies are needed to definitively confirm or rule out the clinical significance of this genetic effect. The aim of personalized approach in secondary stroke prevention is to take the most appropriate medicine in the right dose in accordance with the clinical condition of the patient and associated risk factors.

Stroke in the very elderly: characteristics and outcome in patients aged ≥85 years with a first-ever ischemic stroke.

BACKGROUND: Epidemiological and clinical features of very elderly patients with stroke are still uncertain. Our aim was to study the patient characteristics and outcomes in the very elderly (aged ≥85 years) with a first-ever ischemic stroke in the National Acute Stroke Israeli Survey (NASIS) registry. METHODS: The NASIS registry is a nationwide prospective hospital-based study performed triennially (2004, 2007, 2010). Patients with ischemic stroke aged ≥85 years were compared with those 65-84 years old regarding their baseline characteristics, stroke severity, etiology of stroke and stroke outcomes. Logistic regression analyses were used to adjust for potential confounders. Stroke severity was determined according to the National Institute of Health Stroke Scale (NIHSS) score. RESULTS: The proportion of very elderly (≥85 years) patients among the NASIS population increased from 18.3% in 2004 to 19.9% in 2007 and 24.5% in 2010 (p for trend = 0.005). The percentage of women was higher in patients aged ≥85 years (p < 0.0001). Atrial fibrillation, congestive heart disease and prior disability were significantly more common, while diabetes, current smoking and dyslipidemia were less frequent in the very elderly. The very elderly presented with more severe strokes: 36.3% of the ≥85-year-old patients had an NIHSS score ≥11 compared with 22.0% in the younger age group (p < 0.05). CONCLUSIONS: There is an increasing proportion of very elderly subjects, mostly women, among first-ever ischemic stroke patients. Current information on age-specific aspects of stroke in the very elderly is crucial to set up successful prevention pathways and implementing well-organized stroke care for this population.

Off-hours admission for acute stroke is not associated with worse outcome--a nationwide Israeli stroke project.

BACKGROUND AND PURPOSE: Several studies reported worse outcome for stroke patients arriving on weekends. We compared working hours to off-work hours throughout the week as there is lack of experienced staff and special services during off-hours. METHODS: A nationwide stroke survey project on acute stroke was carried out in all acute care hospitals in Israel during 2004, 2007 and 2010 (2-month each). 'On-hours' were defined as regular Israel working hours and the rest, including holidays, were defined as 'off-hours'. The modified Rankin scale (mRS) at discharge was used for the main analysis on outcome. RESULTS: A total of 4827 acute strokes patients were analyzed (2139 arrived on-hours and 2688 during off-hours). 'Off-hours' patients were 1 year younger (mean 70 vs. 71 years in 'on-hours') had lower rates of prior cardiac interventions, but had higher admission blood pressure levels and had more intracerebral hemorrhages (ICH) (11% vs. 8% in 'on-hours' patients, P < 0.001). Death during hospitalization was recorded in 9% of 'off-hours' vs. 6% of 'on-hours' patient (P = 0.004). Controlling for age, blood pressure, stroke type, pre-stroke mRS, admission NIHSS, and thrombolysis, the relative odds of poor outcome (i.e. mRS ≥ 2) amongst 'off-hours' admissions compared to on-hours was 1.09 (95% CI: 0.92-1.30). Odds ratio amongst ischaemic stroke patients was 1.08 (95% CI: 0.88-1.33). CONCLUSIONS: Off-hours stroke admissions were associated with higher short-term mortality rate, probably due to a higher rate of ICH. After controlling for the latter and other potential confounders, 'off-hours' admissions were not different from 'on-hours' with respect to poor outcome.

Mannheim carotid intima-media thickness and plaque consensus (2004-2006-2011). An update on behalf of the advisory board of the 3rd, 4th and 5th watching the risk symposia, at the 13th, 15th and 20th European Stroke Conferences, Mannheim, Germany, 2004, Brussels, Belgium, 2006, and Hamburg, Germany, 2011.

Intima-media thickness (IMT) provides a surrogate end point of cardiovascular outcomes in clinical trials evaluating the efficacy of cardiovascular risk factor modification. Carotid artery plaque further adds to the cardiovascular risk assessment. It is defined as a focal structure that encroaches into the arterial lumen of at least 0.5 mm or 50% of the surrounding IMT value or demonstrates a thickness >1.5 mm as measured from the media-adventitia interface to the intima-lumen interface. The scientific basis for use of IMT in clinical trials and practice includes ultrasound physics, technical and disease-related principles as well as best practice on the performance, interpretation and documentation of study results. Comparison of IMT results obtained from epidemiological and interventional studies around the world relies on harmonization on approaches to carotid image acquisition and analysis. This updated consensus document delineates further criteria to distinguish early atherosclerotic plaque formation from thickening of IMT. Standardized methods will foster homogenous data collection and analysis, improve the power of randomized clinical trials incorporating IMT and plaque measurements and facilitate the merging of large databases for meta-analyses. IMT results are applied to individual patients as an integrated assessment of cardiovascular risk factors. However, this document recommends against serial monitoring in individual patients.

Vasomotor reactivity as a predictor for syncope in patients with orthostatism.

OBJECTIVES: Syncope in patients with orthostatic hypotension (OH) may be the result of impaired cerebral autoregulation. Cerebral autoregulation status can be determined by assessing cerebral vasomotor reactivity (VMR). We assessed and compared VMR in patients with OH with and without syncope. MATERIAL AND METHODS: Twenty-nine patients with OH underwent transcranial Doppler (TCD) and the Diamox test (1 g acetazolamide IV) for assessing VMR during elaboration of their OH syndrome. The percent difference between cerebral blood flow velocities (BFV) in the middle cerebral (MCA) and vertebral (VA) arteries before and after acetazolamide was defined as VMR%. We considered increases of BFV of ≥ 40% as being indicative of good VMR and classified our study patients as having good or impaired VMRs accordingly. RESULTS: Mean VMR% values of the MCA and VA in patients with OH with syncope (n = 12) were significantly lower as compared with patients with OH without syncope (n = 17): 25.2 ± 20.5% and 42.5 ± 18.6%; 20.9 ± 15.5% and 40.8 ± 28.5%, respectively (P < 0.05). CONCLUSIONS: Among patients with OH, we found an association between the presence of syncope and impaired VMR. Assessment of VMR among patients with OH may predict those who are at higher risk to faint and fall and to support more aggressive intervention.

Ethnic variations in acute ischemic stroke: findings from the National Acute Stroke Israeli Survey (NASIS).

BACKGROUND: We intended to determine ethnic differences in the characteristics, management and outcome of acute ischemic stroke between the Israeli Arab and Jewish populations. METHODS: A national survey was conducted in 2004 at all 28 hospitals in Israel. Information on demographics, transportation, risk factors, clinical presentation, stroke severity, type and subtype, management and clinical outcome was obtained. Mortality during the 36 months after hospitalization was assessed by matching with national mortality data. RESULTS: Of the 1,540 patients, 169 (11%) were Arabs and 1,371 (89%) were Jews. The mean age of Arab patients was 9 years younger than in Jewish patients (63 ± 11 vs. 72 ± 12 years). Also, Arabs were more likely to be obese (OR = 1.72; 95% CI: 1.19-2.50) and have diabetes (OR = 1.41; 95% CI: 1.01-1.96), while Jews were more likely to have dyslipidemia (OR = 1.56; 95% CI: 1.11-2.17). A greater percentage of the Arab patients arrived at the hospital independently (OR = 3.85; 95% CI: 2.56-5.56) and were less likely to arrive within 3 h of symptom onset (OR = 2.33; 95% CI: 1.39-3.85). Arabs suffered increased rates of lacunar stroke (OR = 1.67; 95% CI: 1.14-2.43) and were discharged home more often (OR = 2.40; 95% CI: 1.35-4.25). No differences in severity of stroke, management, complications, disability or mortality were found between the 2 groups. CONCLUSIONS: The unique characteristics of the Arab and Jewish populations should be considered when planning stroke-care services and culturally oriented public education programs.

Persistent hyperglycemia at 24-48 h in acute hyperglycemic stroke patients is not associated with a worse functional outcome.

BACKGROUND: Recently, it was shown that the relation between admission glucose and functional outcome after ischemic stroke is described by a J-shaped curve, with a glucose range of 3.7-7.3 mmol/l associated with a favorable outcome. We tested the hypothesis that persistence of hyperglycemia above this threshold at 24-48 h after stroke onset impairs 3-month functional outcome. METHODS: We analyzed all patients with glucose >7.3 mmol/l on admission from the Acute STroke Registry and Analysis of Lausanne (ASTRAL). Patients were divided into two groups according to their subacute glucose level at 24-48 h after last well-being time (group 1: ≤7.3 mmol/l, group 2: >7.3 mmol/l). A favorable functional outcome was defined as a modified Rankin Score (mRS) ≤2 at 3 months. A multiple logistic regression analysis of multiple demographic, clinical, laboratory and neuroimaging covariates was performed to assess predictors of an unfavorable outcome. RESULTS: A total of 1,984 patients with ischemic stroke were admitted between January 1, 2003 and October 20, 2009, within 24 h after last well-being time. In the 421 patients (21.2%) with admission glucose >7.3 mmol/l, the proportion of patients with a favorable outcome was not statistically significantly different between the two groups (59.2 vs. 48.7%, respectively). In multiple logistic regression analysis, unfavorable outcome was significantly associated with age (odds ratio, OR: 1.06, 95% confidence interval, 95% CI: 1.03-1.08 for every 10-year increase), National Institute of Health Stroke Score, NIHSS score, on admission (OR: 1.16, 95% CI: 1.11-1.21), prehospital mRS (OR: 12.63, 95% CI: 2.61-61.10 for patients with score >0), antidiabetic drug usage (OR: 0.36, 95% CI: 0.15-0.86) and glucose on admission (OR: 1.16, 95% CI: 1.02-1.31 for every 1 mmol/l increase). No association was found between persistent hyperglycemia at 24-28 h and outcome in either diabetics or nondiabetics. CONCLUSIONS: In ischemic stroke patients with acute hyperglycemia, persistent hyperglycemia (>7.3 mmol/l) at 24-48 h after stroke onset is not associated with a worse functional outcome at 3 months whether the patient was previously diabetic or not.

Carotid plaque morphology improves stroke risk prediction: usefulness of a new ultrasonographic score.

Carotid thickening and plaque detected by B-mode imaging ultrasound are useful to improve the ischemic risk evaluation in asymptomatic subjects over and beyond the traditional cardiovascular risk factors. Some plaque's echographic parameters help describing the vascular risk. We hypothesized that the stenosis degree, plaque surface irregularity, echolucency and texture, compounded in a Total Plaque Risk Score (TPRS), are predictors of the ischemic events in the San Daniele study, a general population-based study of 1,348 subjects followed for 12 years in average. In the 171 subjects with at least one plaque at baseline, high TPRS was the most powerful independent predictor of cerebrovascular events, which occurred in 115 subjects. Addition of plaque characteristics significantly increased the area under the ROC curve (0.90 vs. 0.88, p = 0.04) versus the Framingham risk score alone. The TPRS is a potential new tool to improve the stroke risk prediction.

Clinical, radiological and pathological correlates of leukoaraiosis.

INTRODUCTION: Leukoaraiosis is characterized by an abnormal appearance of the brain white matter on imaging. Its pathogenesis is still a matter of investigation. The purpose of this study was to investigate the radiological, clinical and pathological correlates of leukoaraiosis. METHODS: The study population consisted of 93 deceased patients. The pre-mortem T2W magnetic resonance images were evaluated for the presence and grading of leukoaraiosis. The clinical and pathological characteristics based on the clinical charts and autopsy reports were evaluated. Tissue specimens of the blocks of 19 brains that demonstrated severe leukoaraiosis and those of five control brains were excised and stained. RESULTS: The variables found to be significantly associated with leukoaraiosis were age and a clinical history of Parkinson's disease. Other risk factors and pathological markers of atherosclerosis were not significantly correlated with leukoaraiosis. No significant difference was found between the scoring of the myelin integrity, glial fibrillary acidic protein, cluster of differentiation 68 and smooth muscle actin. There was a significant difference with respect to thickening of vessels walls. CONCLUSIONS: Our pathological results indicate that structural vascular abnormalities characterized by vessel wall thickening are associated with leukoaraiosis, supporting the assertion that vascular changes and ischemia generate leukoaraiosis. The relations between parkinsonism and leukoaraiosis may be explicable through vascular effects on the circuitry of the basal ganglia.

Cerebral microinfarcts disruption of remote cortical thickness.

INTRODUCTION: Cerebral microinfarcts (CMI) are common lesions, carrying an important contribution to small-vessel-related cognitive impairment. CMIs were previously found to cause local microstructural damage and disruption of white matter integrity. This study examines CMIs influence on cortical thickness in remote brain areas. METHODS: Six small silent diffuse weighted imaging (DWI) lesions corresponding to subacute CMI were identified among five patients who underwent baseline and follow-up MRI scans from the Tel-Aviv Acute Brain Stroke Cohort (TABASCO). Regions of interest (ROIs) corresponding to the site of the DWI lesions and of the non-lesioned contralateral hemisphere (control ROI) were co-registered. DTI tractography was additionally performed to reconstruct the white matter tracts containing the ROIs. The normalized cortical thickness was calculated for the DWI lesional tract as well as for the contralateral non-lesional tract, and the lesion-to-control cortical thickness ratio (CTR) was calculated. RESULTS: Post-lesional scans, performed 25.1 ± 1.2 months after CMI detection, demonstrated reduced mean CTR within the ROI from 1.8 to 1.1 (p = 0.032). There was no difference between the CTR of the right hemisphere relative to those on the left hemisphere, or between the CTR change of the cortical and non-cortical CMI. DISCUSSION: This study demonstrated the prolonged influence of CMI on cortical thickness in remote ROI. The total number of CMIs is difficult to determine, however it has been shown that detecting even a single CMI suggests the existence of hundreds to thousands lesions. Therefore, the cumulative impact of these widely distributed lesions on cerebral cortex may have a significant contribution to the development of vascular cognitive impairment.

Neuroprotection in acute ischemic stroke--current status.

With the growing understanding of the mechanism of cell death in ischemia, new approaches for treatment such as neuroprotection have emerged. The basic aim of this strategy is to interfere with the events of the ischemic cascade, blocking the pathological processes and preventing the death of nerve cells in the ischemic penumebra. This concept involves inhibition of the pathological molecular events which eventually leads to the influx of calcium, activation of free radicals and neuronal death. Despite encouraging data from experimental animal models, all clinical trials of neuroprotective therapies have to date been unsuccessful. This article reviews some of the reasons for the failure of neuroprotection in the clinical trials so far. Despite all the negative reports, we believe it would be wrong to give up at this point, since there is still reasonable hope of finding an effective neuroprotection for stroke.

Long-term follow-up of patients with asymptomatic occlusion of the internal carotid artery with good and impaired cerebral vasomotor reactivity.

BACKGROUND: Cerebral hemodynamic status might be prognostic for either the symptomatic or asymptomatic course of carotid occlusive disease. It is determined by evaluating cerebral vasomotor reactivity (VMR). We assessed VMR in asymptomatic patients with total occlusion of the internal carotid artery (ICA) and followed them to evaluate the role of impaired VMR in predicting ischaemic stroke (IS). METHODS: Thirty-five patients (21 men, mean age ± SD 68 ± 7.5 years) with unilateral asymptomatic ICA occlusion were studied by transcranial Doppler and the Diamox test (intravenous 1.0 g acetazolamide) and followed for 48 months or until reaching the end-points of IS, transient ischaemic attack, or vascular death. VMR% was evaluated by recording the percent differences in peak systolic blood flow velocities in each middle cerebral artery at baseline and after Diamox administration. RESULTS: Based on VMR% calculations, 14 (40%) patients had good VMRs and 21 (60%) had impaired VMRs. The global annual risk of ipsilateral ischaemic events was 5.7%. The annual ipsilateral ischaemic event risk was 1.8% in patients with good VMRs, whilst it was 7.1% in patients with impaired VMRs. An impaired VMR was significantly correlated with ipsilateral IS (Kaplan-Meier log rank statistic, P = 0.04). CONCLUSIONS: Our results support the value of VMR assessment for identifying asymptomatic patients with carotid occlusion who belong to a high-risk subgroup for IS. New trials using extracranial-to-intracranial bypass surgery in patients with asymptomatic ICA occlusion and impaired VMRs are warranted.

Cerebral vasomotor reactivity and dementia after ischemic stroke.

OBJECTIVES: Cerebral hemodynamic features of patients with post-stroke dementia (PSD) are still obscure. We compared cerebral vasomotor reactivity (VMR) assessed in the acute phase of ischemic stroke (IS) in patients with and without PSD. VMR was also assessed and compared in demented and non-demented patients in the late phase of IS. MATERIALS AND METHODS: VMR was assessed by transcranial Doppler and the Diamox test (1 g acetazolamide i.v.). PSD was confirmed by the National Institute of Neurological Disorders and Stroke and the Association Internationale pour la Recherche et I'Enseignement en Neurosciences (NINDS-AIREN) and the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria. VMR% values were compared to verify correlation with dementia. RESULTS: Thirty patients with acute IS (AIS) were studied and followed for 3-6 months. An additional group of 37 patients was studied in the late post-stroke period (PIS). VMR% values in the AIS groups with and without PSD were similar (25.3 ± 20.3% and 36.5 ± 22.4%, respectively, NS). The mean VMR% in the PIS groups with and without PSD were similar (32.3 ± 19.5% and 41.2 ± 24.8%, respectively, NS). CONCLUSIONS: VMR cannot predict the development of dementia after AIS and cannot identify patients with dementia in the late phase of stroke.