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  • 1
    In: Stroke, Ovid Technologies (Wolters Kluwer Health), Vol. 43, No. suppl_1 ( 2012-02)
    Abstract: Introduction: Extracranial atherosclerotic stenosis of the vertebral artery occurs characteristically at the vertebral artery origin (VAo) and is an important cause of posterior circulation stroke. The proximal segment of the vertebral artery is technically difficult to insonate. Only a few studies have reported on the prevalence of VAo disease in patients with stroke and little is known about its prevalence in non-hospitalized populations. Our objective was to determine the prevalence of VAo stenosis in subjects referred for outpatient extracranial ultrasonography. Methods: All studies performed in an outpatient neurosonology laboratory, affiliated with an academic medical center were retrospectively reviewed for VAo stenosis. The proximal vertebral segments were insonated following a standard protocol. VAo stenosis was diagnosed if the peak systolic velocity (PSV) 〉 114cm/sec, according to previously validated criteria. We also considered the VAo to be occluded if no flow signal could be found in any of its pre-and intraforaminal segments. Studies were also analyzed for internal carotid artery origin (ICAo) stenosis 〉 50% to allow comparison between prevalence of carotid and VAo stenosis. Results: A total of 2490 subjects were available for analysis. The right and left VAo could not be insonated in18% and 25% of patients. Right-sided VAo stenosis or occlusion was present in 52/1955 (2.7%) and 74/1955 (3.9%) respectively; left-sided VAo stenosis or occlusion was present in 45/1793 (2.5%) and 64/1973 (3.6%) respectively. Overall, in those with at least one VAo insonated, 204/ 2119 (8.2%) patients had VAo stenosis or occlusion. In 29/ 2119 (1.4%), bilateral VAo stenosis or occlusion was found. Mean flow velocities were significantly lower in patients without stenosis (right 54.2±18.9 vs.149.0±57.8cm/s; left 53.5±17.5 vs.143.9±31.4cm/s). The prevalence of having either right or left ICAo stenosis or occlusion was 453/ 2401 (18.9%) and bilateral ICAo stenosis or occlusion was 112/ 2401 (4.7%). In univariate analysis, but not multivariate analysis, hypertension and diabetes were risk factors for VAo stenosis. Conclusion: The prevalence of VAo stenosis and occlusion was 8.2% in a diverse population of patients presenting to an ambulatory ultrasound laboratory. We found the prevalence of ICAo stenosis to be higher than VAo stenosis in the same population. Our findings contribute to the understanding of the prevalence of proximal vertebral artery disease in non-hospitalized patients.
    Type of Medium: Online Resource
    ISSN: 0039-2499 , 1524-4628
    RVK:
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2012
    detail.hit.zdb_id: 1467823-8
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  • 2
    In: Stroke, Ovid Technologies (Wolters Kluwer Health), Vol. 52, No. Suppl_1 ( 2021-03)
    Abstract: Introduction: Social determinants of health (SDH) are major contributors to stroke incidence and disparities, yet their relationship with severity and disability is relatively unexplored. The purpose of this study is to provide preliminary findings on SDH measures at the individual- and ZIP code-level across outcomes of stroke severity and disability. Methods: We used data from 344 stroke patients from the ongoing Transitions of Care Stroke Disparities Study (TCSDS) enrolled 2018-2020 from sites throughout Florida. TCSDS aims to identify disparities in hospital-to-home transition of stroke care. Individual-level SDH were collected by a trained interviewer at discharge; ZIP-level SDH data were obtained from a contracted data company. Outcomes included stroke severity at admission measured by the NIH Stroke Scale (NIHSS; Mild: 0-4; Moderate: 5-14; Severe: ≥15) and obtained from the AHA Get with the Guidelines-Stroke program; and disability at discharge measured by the modified Rankin Scale (mRS; 0-1; 2-5). Non-parametric statistical tests were used to compare individual- and ZIP-level SDH by NIHSS and mRS scores. Results: Most patients were older (median age 62 years, IQR: 19), male (58%), non-Hispanic White (39%) or Hispanic (35%) and suffered mild strokes (median NIHSS, IQR: 2, 4) with mild disability (median mRS: 1, 4). Those living with children (LWC) had more moderate strokes, while those living with a spouse/partner (LWP) had more severe strokes (p=0.004). Less than high school (HS)-, HS-, and college-educated patients had more moderate, mild, and severe strokes, respectively (p=0.02). ZIP-level unemployment rate was positively associated with NIHSS (p=0.031). Higher mRS was seen among Spanish and Haitian Creole speakers (p=0.005); HS- and less than HS-educated patients (p=0.005); and those with lower levels of social support (p=0.019). LWC had higher mRS scores, while the opposite was true for LWP (p=0.001). Conclusions: Despite the intersectional nature of SDH, these findings highlight possible mechanisms by which education, economic conditions and psychosocial factors may influence stroke severity and disability after stroke. More data are necessary to determine whether these SDH influence long term stroke outcomes post-discharge.
    Type of Medium: Online Resource
    ISSN: 0039-2499 , 1524-4628
    RVK:
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2021
    detail.hit.zdb_id: 1467823-8
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  • 3
    In: Journal of Clinical Ultrasound, Wiley, Vol. 50, No. 4 ( 2022-05), p. 480-486
    Abstract: Stroke, the most devastating consequence of sickle cell anemia (SCA), is associated with endothelial damage and intracranial artery stenosis. We aimed to assess transcranial Doppler (TCD) ultrasound accuracy in detecting intracranial stenosis when compared to magnetic resonance angiography (MRA). Methods Children with SCA and at least one TCD and MRA within 1 month were identified from a retrospectively collected database. Sensitivity and specificity were obtained to assess the overall accuracy of TCD mean flow velocity (mFV) ≥200 cm/s in detecting vessel stenosis of ≥50%. Multivariate analysis identified independent factors associated with MRA stenosis. Results Among 157 patients in the database, 64 had a TCD and MRA within 1 month (age 11.8 ± 5.3 years, 56% female, 20% with cerebral infarcts on MRI, 8 or 13% had mFV ≥200 cm/s and 20% or 21%, had intracranial stenosis ≥50% on MRA). TCD mFV ≥200 cm/s had a high specificity (95%) but low sensitivity (29%) to detecting intracranial stenosis. As a continuous variable, TCD mFV of 137.5 cm/s had maximal specificity (77%) and sensitivity (72%). After adjustment for age, hemoglobin level, transfusion status, hydroxyurea treatment, and vessel, for every increase in cm/sec on TCD, there was a 2% increase in the odds of ≥50% stenosis on MRA ( p   〈  0.001). Conclusion Our study reports TCD mFV is a positive predictor of MRA stenosis in SCA, independent of patient characteristics, including hemoglobin. A mFV ≥200 cm/s is highly specific but less sensitive in detecting stenosis ≥50%. Lower mFV cut points may be needed for the early detection of intracranial stenosis.
    Type of Medium: Online Resource
    ISSN: 0091-2751 , 1097-0096
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2022
    detail.hit.zdb_id: 1492376-2
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  • 4
    Online Resource
    Online Resource
    Elsevier BV ; 2012
    In:  Journal of Stroke and Cerebrovascular Diseases Vol. 21, No. 6 ( 2012-8), p. 487-492
    In: Journal of Stroke and Cerebrovascular Diseases, Elsevier BV, Vol. 21, No. 6 ( 2012-8), p. 487-492
    Type of Medium: Online Resource
    ISSN: 1052-3057
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2012
    detail.hit.zdb_id: 2052957-0
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  • 5
    Online Resource
    Online Resource
    Ovid Technologies (Wolters Kluwer Health) ; 2007
    In:  Stroke Vol. 38, No. 3 ( 2007-03), p. 1079-1081
    In: Stroke, Ovid Technologies (Wolters Kluwer Health), Vol. 38, No. 3 ( 2007-03), p. 1079-1081
    Abstract: Background and Purpose— Intra-operative cerebral microembolism may be a factor in the etiology of cognitive decline after orthopedic surgery. We here examine the impact of intra-operative microembolism on cognitive dysfunction after hip and knee replacement surgery. Methods— We enrolled 24 patients, at least 65 years old, requiring elective knee or hip replacement surgery. A transcranial Doppler shunt study was done to determine study eligibility so that the final study population consisted of 12 consecutive patients with and 12 consecutive patients without a venous-arterial shunt. A standard neuropsychological test battery was administered before surgery, at hospital discharge and 3 months after surgery. All patients were monitored intra-operatively for microemboli. Quality of life data were assessed at 1 year. Results— The mean age of patients was 74 years. All patients had intra-operative microemboli. The mean number of emboli was 9.9±18. Cognitive decline was present in 18/22 (75%) at discharge and in 10/22 (45%) at 3 months, despite improved quality of life measures. There was no correlation between cognitive decline and intra-operative microembolism. Conclusion— Cognitive decline was seen frequently after hip and knee surgery. Intra-operative microembolism occurred universally but did not significantly influence postoperative cognition. Quality of life and functional outcome demonstrated improvement in all cases in spite of cognitive dysfunction.
    Type of Medium: Online Resource
    ISSN: 0039-2499 , 1524-4628
    RVK:
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2007
    detail.hit.zdb_id: 1467823-8
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  • 6
    In: Stroke, Ovid Technologies (Wolters Kluwer Health), Vol. 52, No. Suppl_1 ( 2021-03)
    Abstract: Background: Stroke is among the most devastating consequences of sickle cell disease (SCD). Most SCD strokes occur due to intracranial stenosis, that can be detected by increased flow velocities on Transcranial Doppler (TCD). However, increased velocities may also reflect anemia rather than arteriopathy and vessel stenosis. We aimed to assess the accuracy of TCD in detection of intracranial stenosis in SCD. Methods: Pediatric SCD patients with at least one TCD and MRA within one month apart were identified from a retrospectively collected database maintained at our institution from January 2000 to December 2016. Patient demographics, hemoglobin level, transfusion and hydroxyurea status were collected, along with mean flow velocities (mFV) and degree of stenosis from bilateral middle and anterior cerebral, and internal carotid arteries. A mFV of 〉 200 cm/s and vessel stenosis 〉 50% were considered abnormal. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were obtained to assess overall accuracy of TCD velocities in relation to vessel stenosis. Multivariate analysis was performed to identify independent factors associated with MRA stenosis. Results: A total of 164 patients were included in the database (median age 12 [IQR 8.9] years, 56% had ischemic strokes) and 64 of them had at least one TCD and MRA one month apart. Of these, 20% had ischemic strokes, 17% had MRA stenosis 〉 50% and 10% had TCD velocity 〉 200 cm/s. TCD mFV 〉 200 cm/s had a high specificity (95%) and NPV (87%) but low sensitivity (29%) and PPV (55%) when compared to MRA stenosis 〉 50%. As a continuous variable, TCD mFV 137.5 cm/s had the best balance between maximal specificity (77%) and sensitivity (72%). After adjustment for age, hemoglobin level, transfusion status, hydroxyurea, and vessel, for every increase in cm/sec on TCD, there was a 2% increase in the odds of 〉 50% stenosis on MRA (OR=1.02, 95% CI 1.01-1.03, p 〈 0.001). Conclusion: Our study reports that TCD mFV is a positive predictor of MRA stenosis in SCD, independent of patient characteristics, including hemoglobin. A mFV 〉 200 cm/s is highly specific but less sensitive to detect stenosis 〉 50%. Lower mFV cut points may need to be considered for early detection of intracranial stenosis and risk of stroke.
    Type of Medium: Online Resource
    ISSN: 0039-2499 , 1524-4628
    RVK:
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2021
    detail.hit.zdb_id: 1467823-8
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  • 7
    In: Journal of Clinical Ultrasound, Wiley, Vol. 40, No. 9 ( 2012-11), p. 554-558
    Abstract: Both CO 2 inhalation followed by hyperventilation and breath‐holding have been utilized to measure cerebral vasomotor reactivity (VMR) but their correlation has been poorly studied and understood. Methods. A retrospective study was conducted in 143 subjects (62.6 ± 15.8 years old, 64% men) with transcranial Doppler ultrasonography measurement of mean flow velocity (MFV) at baseline, after 30 seconds of breath‐holding, and after CO 2 inhalation followed by hyperventilation, in the left and right middle cerebral artery. Breath‐holding index (BHI) was calculated as the percentage of MFV increase from baseline per second of apnea. CO 2 inhalation/hyperventilation index (CO 2 /HV) was calculated as the percentage of MFV difference between CO 2 inhalation and hyperventilation. Results. There were 75 carotid arteries with 〉 70% stenosis or occlusion, and 18 middle cerebral arteries with 〉 50% stenosis or occlusion. The mean BHI was 0.93 ± 0.7 and 0.89 ± 0.6, whereas the mean CO 2 /HV was 61 ± 26% and 60 ± 26%, respectively, on the right and left sides. The correlation between BHI and CO 2 /HV was moderate on the right ( r = 0.33; p 〈 0.01) and left sides ( r = 0.38; p 〈 0.01). Multivariate linear regression analysis indicated that age ( p = 0.01) and history of stroke ( p = 0.007) were associated independently with an impaired VMR on the right as measured by CO 2 /HV. No predictors for impaired VMR by CO 2 /HV on the left and by BHI on either side were found. Conclusions. CO 2 /HV and BHI are only moderately correlated. Further studies are necessary to determine which method more accurately predicts clinical morbidity. © 2012 Wiley Periodicals, Inc. J Clin Ultrasound 2012; Published online in Wiley Online Library
    Type of Medium: Online Resource
    ISSN: 0091-2751 , 1097-0096
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2012
    detail.hit.zdb_id: 1492376-2
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  • 8
    Online Resource
    Online Resource
    Wiley ; 2007
    In:  Journal of Neuroimaging Vol. 17, No. 4 ( 2007-10), p. 332-335
    In: Journal of Neuroimaging, Wiley, Vol. 17, No. 4 ( 2007-10), p. 332-335
    Abstract: Diffusion‐weighted (DW) imaging abnormalities often develop in patients after invasive procedures associated with cerebral microembolism. Cerebral microembolism has recently been shown during orthopedic surgery. We here examine the effects of intraoperative microembolism on acute magnetic resonance(MR) imaging in patients undergoing hip and knee replacement. METHODS We enrolled 24 patients, at least 65 years old, requiring elective knee or hip replacement surgery. MR with DW and axial fluid‐attenuated inversion recovery (FLAIR) imaging was performed pre‐ and postoperatively. All patients were monitored intraoperatively for microemboli. RESULTS The mean age of patients was 74 years. All patients had intraoperative microemboli. The mean number of emboli detected was 9.9 ± 18 per surgery. MR imaging was obtained a mean of 3.5 days postoperatively. No DW imaging abnormalities were found after surgery. One patient had new findings on postoperative FLAIR imaging. CONCLUSION Intraoperative microembolism occurred universally, but did not lead to acute DW imaging abnormalities following knee and hip replacement. Acute imaging abnormalities on FLAIR imaging are rare but may occasionally occur after joint surgery.
    Type of Medium: Online Resource
    ISSN: 1051-2284 , 1552-6569
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2007
    detail.hit.zdb_id: 2035400-9
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  • 9
    In: Blood, American Society of Hematology, Vol. 138, No. Supplement 1 ( 2021-11-05), p. 4054-4054
    Abstract: Background: There are significant limitations in Haiti for the diagnosis and management of sickle cell disease (SCD), including the non-availability of universal newborn screening (NBS) and transcranial Doppler (TCD) ultrasound screening, and the lack of diagnostic laboratory resources, oral penicillin and hydroxyurea (HU). Methods: Beginning in September 2019, CSHSCD (R01HL149121), a 5-year NIH-sponsored observational comparative study of children with SCD from Haitian ethnicity in Miami and in Haiti compared to children of African American ethnicity with SCD, was designed to increase access to care in Haiti. The study aims are 1) to compare the incidence of SCD among newborns from Haitian and African American ethnicity in Miami, 2) to establish NBS programs for hemoglobinopathies in Haiti, and 3) to compare cohorts of children in SCD at the study sites. The participating sites are the University of Miami (UM, Miami, Florida), Hôpital Saint Damien (HSD, Tabarre, Haiti), Hôpital de l'Université d'Etat d'Haïti (HUEH, Port-au-Prince, Haiti), Hôpital Universitaire Justinien (HUJ, Cap Haitien, Haiti), and Hôpital Sacré Coeur (HSC, Milot, Haiti). HUJ and HSC use two NBS screening methods (isoelectric focusing and Sickle SCAN rapid test) and HSD and HUEH use isoelectric focusing only. CSHSCD supplies penicillin and HU and trains TCD examiners to implement stroke risk screening. Data are collected in REDCap. Results: During the first 2 years and despite the COVID-19 pandemic, we established NBS sites with a cohesive network of physicians and nurses trained in the care of children with SCD in Haiti. This capacity building will support sustainability of the program. We successfully identified at least 15 new cases of SCD via newborn screening, trained six TCD examiners, and enrolled 130 children with SCD in follow up, providing them with penicillin prophylaxis and hydroxyurea for severe cases according to local protocols . Implementation activities which have helped are close communications between the investigators, monthly Zoom meetings to coordinate efforts with enrollment updates every month, the availability of rapid tests (Sickle SCAN and Gazelle miniature cellulose acetate electrophoresis) for the diagnosis of SCD, especially when there is no laboratory equipment on site. Implementation challenges we have faced are mostly two. The first is the timely completion of DUNS and SAM registration for the two public hospitals, with one site achieving this after 9 months and the other site taking 18 months to complete. The reasons for the delay are the inability for the UM site to direct these efforts, following strict rules, and the Haitian hospital officers' lack of familiarity with website requirements. We were able to achieve these registrations with the assistance of one Haitian study staff who is very acquainted with internet navigation and became familiarized with requirements. Outsourcing materials to Haiti is another major challenge, with either gaps in the delivery of supplies because of multiple steps involved in ordering and shipping or with delays in releasing equipment once it is at the Port-au-Prince customs, resulting in gaps in NBS in one of the sites for 8 weeks. We have minimized these issues by opening a one-year ticket to order materials from the different companies involved. Also, Haiti's lack of infrastructure, available materials and medications, and political instability limit health care delivery. Conclusion: Since its inception, we have achieved major milestones, including capacity building and implementation of NBS, TCD training, and enrollment of children with SCD into the prospective cohorts despite the current COVID-19 pandemic. Material outsourcing challenges have been the major implementation problem we have faced due to systemic factors. We anticipate that these factors will be corrected or minimized as we have learned how to handle them. These problems were expected as part of conducting an international study in a low-resource setting. Acknowledgment: We acknowledge NHLBI for supporting this work. Disclosures Alvarez: Forma Therapeutics: Membership on an entity's Board of Directors or advisory committees; GBT: Membership on an entity's Board of Directors or advisory committees. Romano: Genentech: Research Funding; Vycor: Current holder of individual stocks in a privately-held company; NovaVision: Consultancy.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
    RVK:
    RVK:
    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2021
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
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  • 10
    In: Journal of Neuroimaging, Wiley, Vol. 31, No. 5 ( 2021-09), p. 931-939
    Abstract: It is unknown whether intracranial atherosclerotic disease (ICAD), in addition to causing stenosis, also associates with abnormal arterial enlargement, a condition known as intracranial dolichoectasia (IDE). Across symptomatic ICAD patients, we aim to determine IDE prevalence and IDE impact on cerebral hemodynamics and recurrent cerebral ischemia. Methods We analyzed 98 participants (mean age 63.8 11.9 years, 56.1% men) of the prospective observational study MYRIAD. Participants were enrolled within 21 days of an ischemic stroke or transient ischemic attack caused by moderate‐to‐severe ICAD. Semi‐automatic vessel segmentation was used to determine diameters, length, and tortuosity‐index of proximal intracranial arteries. Either ectasia (increased diameter) or dolichosis (increased length or TI) defined IDE. We assessed IDE association with new infarcts during 12‐month follow‐up, and IDE correlation with cerebral hemodynamics determined by quantitative MR‐angiography (QMRA), MR‐perfusion weighted‐imaging, and transcranial Doppler breath‐holding index. Results IDE was present in 35.7% of patients and 10.2% of symptomatic arteries. Basilar stenosis was associated with higher IDE prevalence (27.8% vs. 8.8%, p = 0.04), whereas other symptomatic arteries showed no association with IDE. Symptomatic arteries with IDE had lower hypoperfusion prevalence on MR‐PWI (11.1% vs. 28.4%, p = 0.03). Increased diameter ( r = 0.33, p 〈 0.01) and tortuosity‐index ( r = 0.29, p = 0.01) showed positive correlation with QMRA flow rate. IDE was not associated with new infarcts during follow‐up. Conclusions IDE was common among symptomatic ICAD patients. IDE was not associated with stroke recurrence. Instead, increased diameter and tortuosity correlated with improved blood flow across the stenotic artery, suggesting that IDE may originate as an adaptive mechanism in ICAD.
    Type of Medium: Online Resource
    ISSN: 1051-2284 , 1552-6569
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2021
    detail.hit.zdb_id: 2035400-9
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