Relevance of Distal Arterial Collapse in Stenting of Atherosclerotic Near-Occlusion of the Carotid Artery.

BACKGROUND AND PURPOSE: Carotid near-occlusion has been subclassified into near-occlusion with and without collapse. We aimed to compare the technical success and perioperative complication rates of carotid artery stent placement with special attention to these subtypes to see whether there is a clinical relevance of this subclassification. MATERIALS AND METHODS: From January 2014 to January 2018, we retrospectively evaluated all patients with atherosclerotic extracranial carotid stenosis treated by carotid artery stent placement. Patients with near-occlusion were identified based on DSA findings. Patient characteristics, the presence of criteria for near-occlusion and collapse, arterial diameters, technical success rate, and perioperative (≤30 days) complications were analyzed. RESULTS: We identified 59 near-occlusions in 58 (46 men, 11 with collapse) patients. Forty-one patients (70.7%) were symptomatic. Technical success rate was 98.3% (58 of 59 procedures). In 1 case of near-occlusion with collapse, we were not able to pass through the stenosis. Compared with patients without collapse (4.2% of 48 cases), those with collapse (30% of 10 stented patients) had significantly higher rates of postintervention hyperperfusion syndrome (P = .032). In the whole cohort, the permanent morbidity and mortality rate was 3.4% (1.7% permanent morbidity and 1.7% mortality). For asymptomatic and symptomatic near-occlusion groups, the rates were 0% and 4.9%, respectively. The composite risk of stroke, death, and myocardial infarction was similar between the groups with and without collapse (P = .682). Rate of hyperperfusion syndrome (with or without permanent deficit) was similar (P = 1) in preoperatively symptomatic patients versus asymptomatic patients (9.8% vs 5.9%). Internal carotid artery diameter consistently increased after carotid artery stent placement in patients with collapse and was not related to the development of hyperperfusion syndrome. CONCLUSIONS: Care should be taken to minimize hyperperfusion risk in patients with near-occlusion undergoing CAS, especially in the subgroup of patients with collapse and in patients with both symptomatic and asymptomatic carotid stenosis.

Ongoing activity of Toscana virus genotype A and West Nile virus lineage 1 strains in Turkey: a clinical and field survey.

Toscana virus (TOSV), West Nile virus (WNV) and tickborne encephalitis virus (TBEV) are among major viral pathogens causing febrile disease and meningitis/encephalitis. The impact of these viruses was investigated at a referral centre in Ankara Province, Central Anatolia in 2012, where previous reports suggested virus circulation but with scarce information on clinical cases and vector activity. Serum and/or cerebrospinal fluid samples from 94 individuals were evaluated, in addition to field-collected arthropod specimens that included 767 sandflies and 239 mosquitoes. Viral nucleic acids in clinical samples and arthropods were sought via specific and generic nested/real-time PCRs, and antibody responses in clinical samples were investigated via commercial indirect immunofluorescence tests (IIFTs) and virus neutralization. A WNV antigen assay was also employed for mosquitoes. WNV neuroinvasive disease has been identified in a 63-year-old male via RNA detection, and the WNV strain was characterized as lineage 1. TOSV infections were diagnosed in six individuals (6.3%) via RNA or IgM detection. Partial sequences in a 23-year-old female, presented with fever and transient pancytopenia, were characterized as TOSV genotype A. Febrile disease with arthralgia and/or peripheral cranial nerve involvement was noted in cases with TOSV infections. Previous WNV and TOSV exposures have been observed in 5.3% and 2.1% of the subjects, respectively. No confirmed TBEV exposure could be identified. Morphological identification of the field-collected mosquitoes revealed Culex pipiens sensu lato (74.4%), Anopheles maculipennis (20.9%), An. claviger (2.1%) and others. Sandfly species were determined as Phlebotomus papatasi (36.2%), P. halepensis (27.3%), P. major s. l. (19.3%), P. sergenti (8.9%), P. perfiliewi (4.4%), P. simici (2.6%) and others. Viral infections in arthropods could not be demonstrated. TOSV genotype A and WNV lineage 1 activity have been demonstrated as well as serologically proven exposure in patients. Presence of sandfly and mosquito species capable of virus transmission has also been revealed.

Early stroke risk and ABCD2 score performance in tissue- vs time-defined TIA: a multicenter study.

OBJECTIVES: Stroke risk immediately after TIA defined by time-based criteria is high, and prognostic scores (ABCD2 and ABCD3-I) have been developed to assist management. The American Stroke Association has proposed changing the criteria for the distinction between TIA and stroke from time-based to tissue-based. Research using these definitions is lacking. In a multicenter observational cohort study, we have investigated prognosis and performance of the ABCD2 score in TIA, subcategorized as tissue-positive or tissue-negative on diffusion-weighted imaging (DWI) or CT imaging according to the newly proposed criteria. METHODS: Twelve centers provided data on ABCD2 scores, DWI or CT brain imaging, and follow-up in cohorts of patients with TIA diagnosed by time-based criteria. Stroke rates at 7 and 90 days were studied in relation to tissue-positive or tissue-negative subcategorization, according to the presence or absence of brain infarction. The predictive power of the ABCD2 score was determined using area under receiver operator characteristic curve (AUC) analyses. RESULTS: A total of 4,574 patients were included. Among DWI patients (n = 3,206), recurrent stroke rates at 7 days were 7.1%(95% confidence interval 5.5-9.1) after tissue-positive and 0.4% (0.2-0.7) after tissue-negative events (p diff < 0.0001). Corresponding rates in CT-imaged patients were 12.8% (9.3-17.4) and 3.0% (2.0-4.2), respectively (p diff < 0.0001). The ABCD2 score had predictive value in tissue-positive and tissue-negative events (AUC = 0.68 [95% confidence interval 0.63-0.73] and 0.73 [0.67-0.80], respectively; p sig < 0.0001 for both results, p diff = 0.17). Tissue-positive events with low ABCD2 scores and tissue-negative events with high ABCD2 scores had similar stroke risks, especially after a 90-day follow-up. CONCLUSIONS: Our findings support the concept of a tissue-based definition of TIA and stroke, at least on prognostic grounds.

Severity of leukoaraiosis determines clinical phenotype after brain infarction.

OBJECTIVE: To determine whether the extent of leukoaraiosis, a composite marker of baseline brain integrity, differed between patients with TIA with diffusion-weighted imaging (DWI) evidence of infarction (transient symptoms with infarction [TSI]) and patients with ischemic stroke. METHODS: Leukoaraiosis volume on MRI was quantified in a consecutive series of 153 TSI and 354 ischemic stroke patients with comparable infarct volumes on DWI. We explored the relationship between leukoaraiosis volume and clinical phenotype (TIA or ischemic stroke) using a logistic regression model. RESULTS: Patients with TSI tended to be younger (median age 66 vs 69 years, p = 0.062) and had smaller median normalized leukoaraiosis volume (1.2 mL, interquartile range [IQR] 0.2-4.7 mL vs 3.5 mL, IQR 1.2-8.6 mL, p < 0.001). In multivariable analysis controlling for age, stroke risk factors, etiologic stroke mechanism, infarct volume, and infarct location, increasing leukoaraiosis volume remained associated with ischemic stroke (odds ratio 1.05 per mL, 95%confidence interval 1.02-1.09, p = 0.004), along with infarct volume and infarct location. CONCLUSION: The probability of ischemic stroke rather than TSI increases with increasing leukoaraiosis volume, independent of infarct size and location. Our findings support the concept that the integrity of white matter tracts connecting different parts of the brain could contribute to whether or not patients develop TSI or ischemic stroke in an event of brain infarction.

The Causative Classification of Stroke system: an international reliability and optimization study.

BACKGROUND: Valid and reliable ischemic stroke subtype determination is crucial for well-powered multicenter studies. The Causative Classification of Stroke System (CCS, available at http://ccs.mgh.harvard.edu) is a computerized, evidence-based algorithm that provides both causative and phenotypic stroke subtypes in a rule-based manner. We determined whether CCS demonstrates high interrater reliability in order to be useful for international multicenter studies. METHODS: Twenty members of the International Stroke Genetics Consortium from 13 centers in 8 countries, who were not involved in the design and development of the CCS, independently assessed the same 50 consecutive patients with acute ischemic stroke through reviews of abstracted case summaries. Agreement among ratings was measured by kappa statistic. RESULTS: The κ value for causative classification was 0.80 (95% confidence interval [CI] 0.78-0.81) for the 5-subtype, 0.79 (95% CI 0.77-0.80) for the 8-subtype, and 0.70 (95% CI 0.69-0.71) for the 16-subtype CCS. Correction of a software-related factor that generated ambiguity improved agreement: κ = 0.81 (95% CI 0.79-0.82) for the 5-subtype, 0.79 (95% CI 0.77-0.80) for the 8-subtype, and 0.79 (95% CI 0.78-0.80) for the 16-subtype CCS. The κ value for phenotypic classification was 0.79 (95% CI 0.77-0.82) for supra-aortic large artery atherosclerosis, 0.95 (95% CI 0.93-0.98) for cardioembolism, 0.88 (95% CI 0.85-0.91) for small artery occlusion, and 0.79 (0.76-0.82) for other uncommon causes. CONCLUSIONS: CCS allows classification of stroke subtypes by multiple investigators with high reliability, supporting its potential for improving stroke classification in multicenter studies and ensuring accurate means of communication among different researchers, institutions, and eras.

A score to predict early risk of recurrence after ischemic stroke.

BACKGROUND: There is currently no instrument to stratify patients presenting with ischemic stroke according to early risk of recurrent stroke. We sought to develop a comprehensive prognostic score to predict 90-day risk of recurrent stroke. METHODS: We analyzed data on 1,458 consecutive ischemic stroke patients using a Cox regression model with time to recurrent stroke as the response and clinical and imaging features typically available to physician at admission as covariates. The 90-day risk of recurrent stroke was calculated by summing up the number of independent predictors weighted by their corresponding beta-coefficients. The resultant score was called recurrence risk estimator at 90 days or RRE-90 score (available at: http://www.nmr.mgh.harvard.edu/RRE-90/). RESULTS: Sixty recurrent strokes (54 had baseline imaging) occurred during the follow-up period. The risk adjusted for time to follow-up was 6.0%. Predictors of recurrence included admission etiologic stroke subtype, prior history of TIA/stroke, and topography, age, and distribution of brain infarcts. The RRE-90 score demonstrated adequate calibration and good discrimination (area under the ROC curve [AUC] = 0.70-0.80), which was maintained when applied to a separate cohort of 433 patients (AUC = 0.70-0.76). The model's performance was also maintained for predicting early (14-day) risk of recurrence (AUC = 0.80). CONCLUSIONS: The RRE-90 is a Web-based, easy-to-use prognostic score that integrates clinical and imaging information available in the acute setting to quantify early risk of recurrent stroke. The RRE-90 demonstrates good predictive performance, suggesting that, if validated externally, it has promise for use in creating individualized patient management algorithms and improving clinical practice in acute stroke care.

Severity of leukoaraiosis correlates with clinical outcome after ischemic stroke.

BACKGROUND: Leukoaraiosis (LA) is closely associated with aging, a major determinant of clinical outcome after ischemic stroke. In this study we sought to identify whether LA, independent of advancing age, affects outcome after acute ischemic stroke. METHODS: LA volume was quantified in 240 patients with ischemic stroke and MRI within 24 hours of symptom onset. We explored the relationship between LA volume at admission and clinical outcome at 6 months, as assessed by the modified Rankin Scale (mRS). An ordinal logistic regression model was developed to analyze the independent effect of LA volume on clinical outcome. RESULTS: Bivariate analyses showed a significant correlation between LA volume and mRS at 6 months (r = 0.19, p = 0.003). Mean mRS was 1.7 +/- 1.8 among those in the lowest (< or =1.2 mL) and 2.5 +/- 1.9 in the highest (>9.9 mL) quartiles of LA volume (p = 0.01). The unfavorable prognostic effect of LA volume on clinical outcome was retained in the multivariable model (p = 0.002), which included age, gender, stroke risk factors (hypertension, diabetes mellitus, atrial fibrillation), previous history of brain infarction, admission plasma glucose level, admission NIH Stroke Scale score, IV rtPA treatment, and acute infarct volume on MRI as covariates. CONCLUSIONS: The volume of leukoaraiosis is a predictor of clinical outcome after ischemic stroke and this relationship persists after adjustment for important prognostic factors including age, initial stroke severity, and infarct volume.

Neuroanatomic correlates of stroke-related myocardial injury.

BACKGROUND: Myocardial injury can occur after ischemic stroke in the absence of primary cardiac causes. The neuroanatomic basis of stroke-related myocardial injury is not well understood. OBJECTIVE: To identify regions of brain infarction associated with myocardial injury using a method free of the bias of an a priori hypothesis as to any specific location. METHODS: Of 738 consecutive patients with acute ischemic stroke, the authors identified 50 patients in whom serum cardiac troponin T (cTnT) elevation occurred in the absence of any apparent cause within 3 days of symptom onset. Fifty randomly selected, age- and sex-matched patients with ischemic stroke without cTnT elevation served as controls. Diffusion-weighted images with outlines of infarction were co-registered to a template, averaged, and then subtracted to find voxels that differed between the two groups. Voxel-wise p values were determined using a nonparametric permutation test to identify specific regions of infarction that were associated with cTnT elevation. RESULTS: The study groups were well balanced with respect to stroke risk factors, history of coronary artery disease, infarction volume, and frequency of right and left middle cerebral artery territory involvement. Brain regions that were a priori associated with cTnT elevation included the right posterior, superior, and medial insula and the right inferior parietal lobule. Among patients with right middle cerebral artery infarction, the insular cluster was involved in 88% of patients with and 33% without cTnT elevation (odds ratio: 15.00; 95% CI: 2.65 to 84.79). CONCLUSIONS: Infarctions in specific brain regions including the right insula are associated with elevated serum cardiac troponin T level indicative of myocardial injury.

Granulomatous hypophysitis and bilateral optic neuropathy.

A 53-year-old woman with symptoms of hypopituitarism and ophthalmoplegia was diagnosed as having idiopathic granulomatous hypophysitis and later developed bilateral optic neuritis. She responded well to steroid treatment. Granulomatous hypophysitis is a rare entity, and this is the first reported case associated with optic neuritis.