RESUMEN
OBJECTIVE: The distal hyperintense vessel sign (DHV) on fluid-attenuated inversion recovery magnetic resonance image (MRI) is an imaging biomarker of slow leptomeningeal collateral flow in the presence of large artery stenosis or occlusion reflecting impaired cerebral hemodynamics. In this study, we aim to investigate the significance of the DHV sign in patients with symptomatic ≥ 70% intracranial atherosclerotic stenosis. METHODS: We retrospectively reviewed patients with ischemic stroke or transient ischemic attack admitted to a single center from January 2010 to December 2017. Patients were included if they had symptomatic ≥ 70% atherosclerotic stenosis of the intracranial internal carotid artery or middle cerebral artery. The presence of the DHV sign was evaluated by blinded neuroradiologist and vascular neurologists. Recurrent ischemic stroke in the vascular territory of symptomatic intracranial artery was defined as new neurological deficits with associated neuroimaging findings during the follow up period. RESULTS: A total of 109 patients were included in the study, of which 55 had DHV sign. Average duration of follow up was 297 ± 326 days. Four patients were lost during follow up. Patients with the DHV sign had a higher rate of recurrent ischemic stroke (38%), compared to patients without the DHV sign (17%; p=0.018). In multivariate regression analysis, the presence of DHV sign was an independent predictor of recurrent ischemic stroke. A DHV score of ≥ 2 had a 63% sensitivity and 69% specificity for recurrent ischemic stroke. INTERPRETATION: In patients with severe symptomatic intracranial atherosclerotic stenosis, those with a DHV sign on MRI are at higher risk of recurrent ischemic stroke.
Asunto(s)
Aterosclerosis , Arteriosclerosis Intracraneal , Ataque Isquémico Transitorio , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Aterosclerosis/complicaciones , Infarto Cerebral/complicaciones , Constricción Patológica/complicaciones , Humanos , Arteriosclerosis Intracraneal/complicaciones , Arteriosclerosis Intracraneal/diagnóstico por imagen , Ataque Isquémico Transitorio/complicaciones , Ataque Isquémico Transitorio/etiología , Accidente Cerebrovascular Isquémico/diagnóstico por imagen , Accidente Cerebrovascular Isquémico/etiología , Estudios Retrospectivos , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/etiologíaRESUMEN
BACKGROUND: The correlation between noninvasive (oscillometric) blood pressure (NBP) and intra-arterial blood pressure (IAP) in critically ill patients receiving vasoactive medications in a Neurocritical Care Unit has not been systematically studied. The purpose of this study is to examine the relationship between simultaneously measured NBP and IAP recordings in these patients. METHODS: Prospective observational study of patients (N = 70) admitted to a neurocritical care unit receiving continuous vasopressor or antihypertensive infusions. Paired NBP/IAP observations along with covariate and demographic data were abstracted via chart audit. Analysis was performed using SAS v9.4. RESULTS: A total of 2177 paired NBP/IAP observations from 70 subjects (49% male, 63% white, mean age 59 years) receiving vasopressors (n = 21) or antihypertensive agents (n = 49) were collected. Paired t test analysis showed significant differences between NBP versus IAP readings: ([systolic blood pressure (SBP): mean = 136 vs. 140 mmHg; p < 0.0001], [diastolic blood pressure (DBP): mean = 70 vs. 68 mmHg, p < 0.0001], [mean arterial blood pressure (MAP): mean = 86 vs. 90 mmHg, p < 0.0001]). Bland-Altman plots for MAP, SBP, and DBP demonstrate good inter-method agreement between paired measures (excluding outliers) and demonstrate NBP-IAP SBP differences at extremes of blood pressures. Pearson correlation coefficients show strong positive correlations for paired MAP (r = 0.82), SBP (r = 0.84), and DBP (r = 0.73) recordings. An absolute NBP-IAP SBP difference of > 20 mmHg was seen in ~ 20% of observations of nicardipine, ~ 25% of observations of norepinephrine, and ~ 35% of observations of phenylephrine. For MAP, the corresponding numbers were ~ 10, 15, and 25% for nicardipine, norepinephrine, and phenylephrine, respectively. CONCLUSION: Despite overall strong positive correlations between paired NBP and IAP readings of MAP and SBP, clinically relevant differences in blood pressure are frequent. When treating with vasoactive infusions targeted to a specific BP goal, it is important to keep in mind that NBP and IAP values are not interchangeable.
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Antihipertensivos/administración & dosificación , Determinación de la Presión Sanguínea/normas , Presión Sanguínea/efectos de los fármacos , Cuidados Críticos/métodos , Enfermedades del Sistema Nervioso/terapia , Vasoconstrictores/administración & dosificación , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios ProspectivosRESUMEN
The square antiprism/twisted square antiprism ratio in LnDOTA-tetraamide chelates is a critical parameter in governing water-exchange kinetics and ultimately the utility of a chelate as a PARACEST MRI contrast agent. In LnDOTA-tetraamide chelates with tertiary amides, this ratio and the rate of interconversion between these two structural isomers are found to be dramatically dependent upon the solvent and possibly other local environmental factors.
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Quelantes/química , Medios de Contraste/química , Compuestos Heterocíclicos/química , Elementos de la Serie de los Lantanoides/química , Compuestos Organometálicos/química , Agua/química , Amidas/química , Ciclamas , Cinética , Imagen por Resonancia Magnética , Estructura Molecular , Solventes/química , EstereoisomerismoRESUMEN
BACKGROUND AND PURPOSE: Cerebral microbleeds (CMB) are reported to be frequent in moyamoya disease (MMD) and moyamoya syndrome (MMS) in the Asian population. It is associated with an increased risk of intracerebral hemorrhage. The significance of CMB in MMD/MMS in non-Asian populations has not been well established. Our study aimed to investigate the prevalence of CMB in MMD/MMS in a moymoya cohort with a majority of non-Asians and to identify risk factors for developing a CMB and its predictive value for subsequent vascular events. METHODS: The moyamoya database was compiled by screening for MMD/MMS among patients admitted to the Zale-Lipshy University Hospital at the University of Texas Southwestern Medical Center. We identified and analyzed data of 67 patients with MMD or MMS. Patients were characterized as CMB+ or CMB- based on MRI findings. In CMB+ patients, the total number and location of CMB were identified. Univariate and multivariate logistic regression were used to identify risk factors for developing CMB and whether CMB are associated with the development of subsequent vascular events. RESULTS: Out of a total of 67 patients, 11 (16%) had CMB. Males had significantly higher odds of having CMB as compared to females (OR 1.76; 95% CI 1.40-24.3, p = 0.021). The incidence of CMB was also associated with age at diagnosis (mean age of CMB+ patients vs. CMB- patients: 44 vs. 34 years, respectively, p = 0.024), smoking (p = 0.006), and hemorrhagic stroke at presentation (p = 0.034). Logistic regression with multivariate analysis found that gender and age at diagnosis remained statistically significant. New ischemic events occurred in 2 (20%) out of 10 CMB+ patients and 13 (23%) out of 55 CMB- patients, respectively (p = 0.79). While 2 (3%) CMB- patients had a new cerebral hemorrhage during follow-up, none of the CMB+ patients did. CONCLUSIONS: CMB are less prevalent in MMD/MMS in the USA than in Asia. An older age at diagnosis and male gender were associated with CMB. The presence of CMB was not associated with an increased risk of a subsequent ischemic or hemorrhagic stroke.
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Isquemia Encefálica/epidemiología , Hemorragias Intracraneales/epidemiología , Enfermedad de Moyamoya/epidemiología , Accidente Cerebrovascular/epidemiología , Adulto , Factores de Edad , Isquemia Encefálica/diagnóstico , Femenino , Humanos , Incidencia , Hemorragias Intracraneales/diagnóstico , Masculino , Enfermedad de Moyamoya/diagnóstico , Prevalencia , Pronóstico , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Factores Sexuales , Accidente Cerebrovascular/diagnóstico , Texas/epidemiologíaRESUMEN
BACKGROUND: The Brain Trauma Foundation has developed treatment guidelines for the care of patients with acute traumatic brain injury. The Adam Williams Initiative is a program established to provide education and resources to encourage hospitals across the United States to incorporate the guidelines into practice. OBJECTIVE: To explore the relationship in hospitals between participation in the Adam Williams Initiative and adherence to the Brain Trauma Foundation guidelines for patients with acute traumatic brain injury. METHOD: Hospitals that participated in the Adam Williams Initiative entered data into an online tracking system of patients with traumatic brain injury for at least 2 years after the initial site training. Data included baseline hospital records and daily records on hospital care of patients with traumatic brain injury, including blood pressure, intracranial pressure, cerebral perfusion pressure, oxygenation, and other data relevant to the 15 key metrics in the Brain Trauma Foundation guidelines. RESULTS: The 16 hospitals funded by the Adam Williams Initiative had good overall adherence to the 15 key metrics of the recommendations detailed in the Brain Trauma Foundation guidelines. Variability in results was primarily due to data collection methods and analysis. CONCLUSIONS: The Adam Williams Initiative helps promote adherence to the Brain Trauma Foundation guidelines for hospital care of patients with traumatic brain injury by providing a platform for developing and standardizing best practices. Participation in the initiative is associated with high adherence to clinical guidelines, a situation that may subsequently improve care and outcomes for patients with traumatic brain injury.