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Dive into the research topics where Karen Marr is active.

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Featured researches published by Karen Marr.


Neurology | 2011

Prevalence, sensitivity, and specificity of chronic cerebrospinal venous insufficiency in MS

Robert Zivadinov; Karen Marr; Gary Cutter; Murali Ramanathan; Rhb Benedict; Cheryl Kennedy; Makki Elfadil; A.E. Yeh; Justine Reuther; Christina Brooks; Kristin Hunt; Michelle Andrews; Ellen Carl; Michael G. Dwyer; David Hojnacki; B. Weinstock-Guttman

Background: Chronic cerebrospinal venous insufficiency (CCSVI) was recently described in patients with multiple sclerosis (MS). A subject is considered CCSVI positive if ≥2 venous hemodynamic (VH) criteria are fulfilled. Objective: To determine prevalence of CCSVI in a large cohort of patients with MS, clinically isolated syndrome (CIS), other neurologic diseases (OND), and healthy controls (HC), using specific proposed echo-color Doppler (ECD) criteria. Methods: Transcranial and extracranial ECD were carried out in 499 enrolled subjects (289 MS, 163 HC, 26 OND, 21 CIS). Prevalence rates for CCSVI were calculated in 3 ways: first, using only the subjects for whom diagnosis was certain (i.e., borderline subjects were excluded); secondly, including the borderline subjects in the “no CCSVI” group; and finally, taking into account subjects who presented any of the VH criteria. Results: CCSVI prevalence with borderline cases included in the “no CCSVI” group was 56.1% in MS, 42.3% in OND, 38.1% in CIS, and 22.7% in HC (p < 0.001). The CCSVI prevalence figures were 62.5% for MS, 45.8% for OND, 42.1% for CIS, and 25.5% for HC when borderline cases were excluded (p < 0.001). The prevalence of one or more positive VH criteria was the highest in MS (81.3%), followed by CIS (76.2%), OND (65.4%), and HC (55.2%) (p < 0.001). CCSVI prevalence was higher in patients with progressive than in nonprogressive MS (p = 0.004). Conclusions: Our findings are consistent with an increased prevalence of CCSVI in MS but with modest sensitivity/specificity. Our findings point against CCSVI having a primary causative role in the development of MS.


BMC Neurology | 2011

Decreased brain venous vasculature visibility on susceptibility-weighted imaging venography in patients with multiple sclerosis is related to chronic cerebrospinal venous insufficiency

Robert Zivadinov; Guy Umberto Poloni; Karen Marr; Claudiu Schirda; Christopher Magnano; Ellen Carl; Niels Bergsland; David Hojnacki; Cheryl Kennedy; Clive B. Beggs; Michael G. Dwyer; Bianca Weinstock-Guttman

BackgroundThe potential pathogenesis between the presence and severity of chronic cerebrospinal venous insufficiency (CCSVI) and its relation to clinical and imaging outcomes in brain parenchyma of multiple sclerosis (MS) patients has not yet been elucidated. The aim of the study was to investigate the relationship between CCSVI, and altered brain parenchyma venous vasculature visibility (VVV) on susceptibility-weighted imaging (SWI) in patients with MS and in sex- and age-matched healthy controls (HC).Methods59 MS patients, 41 relapsing-remitting and 18 secondary-progressive, and 33 HC were imaged on a 3T GE scanner using pre- and post-contrast SWI venography. The presence and severity of CCSVI was determined using extra-cranial and trans-cranial Doppler criteria. Apparent total venous volume (ATVV), venous intracranial fraction (VIF) and average distance-from-vein (DFV) were calculated for various vein mean diameter categories: < .3 mm, .3-.6 mm, .6-.9 mm and > .9 mm.ResultsCCSVI criteria were fulfilled in 79.7% of MS patients and 18.2% of HC (p < .0001). Patients with MS showed decreased overall ATVV, ATVV of veins with a diameter < .3 mm, and increased DFV compared to HC (all p < .0001). Subjects diagnosed with CCSVI had significantly increased DFV (p < .0001), decreased overall ATVV and ATVV of veins with a diameter < .3 mm (p < .003) compared to subjects without CCSVI. The severity of CCSVI was significantly related to decreased VVV in MS (p < .0001) on pre- and post-contrast SWI, but not in HC.ConclusionsMS patients with higher number of venous stenoses, indicative of CCSVI severity, showed significantly decreased venous vasculature in the brain parenchyma. The pathogenesis of these findings has to be further investigated, but they suggest that reduced metabolism and morphological changes of venous vasculature may be taking place in patients with MS.


Expert Review of Neurotherapeutics | 2011

Chronic cerebrospinal venous insufficiency in multiple sclerosis: diagnostic, pathogenetic, clinical and treatment perspectives

Robert Zivadinov; Murali Ramanathan; Kresimir Dolic; Karen Marr; Yuval Karmon; Adnan H. Siddiqui; Ralph H. B. Benedict; Bianca Weinstock-Guttman

Chronic cerebrospinal venous insufficiency (CCSVI) was recently described in multiple sclerosis patients. CCSVI is characterized by impaired brain venous drainage due to outflow obstruction in the extracranial venous system, mostly related to anomalies in the internal jugular and azygos veins. The current CCSVI diagnosis is based on Doppler sonography of extracranial and transcranial venous hemodynamics criteria. To date, prevalence estimates of CCSVI, provided by different groups using various imaging methods of assessment, vary widely from none to 100%. There is an urgent need to define and validate the spectrum of cranial/extracranial venous anomalies and to establish reliable, diagnostic gold-standard test(s). The potential usefulness of endovascular treatment for CCSVI in multiple sclerosis patients is still unknown.


PLOS ONE | 2011

Risk factors for chronic cerebrospinal venous insufficiency (CCSVI) in a large cohort of volunteers.

Kresimir Dolic; Bianca Weinstock-Guttman; Karen Marr; Vesela Valnarov; Ellen Carl; Jesper Hagemeier; Christina Brooks; Colleen K. Kilanowski; David Hojnacki; Murali Ramanathan; Robert Zivadinov

Background The role of intra- and extra-cranial venous system impairment in the pathogenesis of various vascular, inflammatory and neurodegenerative neurological disorders, as well as in aging, has not been studied in detail. Nor have risk factors been determined for increased susceptibility of venous pathology in the intra-cranial and extra-cranial veins. The aim of this study was to investigate the association between presence of a newly proposed vascular condition called chronic cerebrospinal venous insufficiency (CCSVI) and environmental factors in a large volunteer control group without known central nervous system pathology. Methods and Findings The data were collected in a prospective study from 252 subjects who were screened for medical history as part of the entry criteria and participated in the case-control study of CCSVI prevalence in multiple sclerosis (MS) patients, and then were analyzed post-hoc. All participants underwent physical and Doppler sonography examinations, and were assessed with a structured environmental questionnaire. Fullfilment of ≥2 positive venous hemodynamic (VH) criteria on Doppler sonography was considered indicative of CCSVI diagnosis. Risk and protective factors associated with CCSVI were analyzed using logistic regression analysis. Seventy (27.8%) subjects presented with CCSVI diagnosis and 153 (60.7%) presented with one or more VH criteria. The presence of heart disease (p = .001), especially heart murmurs (p = .007), a history of infectious mononucleosis (p = .002), and irritable bowel syndrome (p = .005) were associated with more frequent CCSVI diagnosis. Current or previous smoking (p = .029) showed a trend for association with more frequent CCSVI diagnosis, while use of dietary supplements (p = .018) showed a trend for association with less frequent CCSVI diagnosis. Conclusions Risk factors for CCSVI differ from established risk factors for peripheral venous diseases. Vascular, infectious and inflammatory factors were associated with higher CCSVI frequency.


American Journal of Neuroradiology | 2012

Intra- and extraluminal structural and functional venous anomalies in multiple sclerosis, as evidenced by 2 noninvasive imaging techniques.

Kresimir Dolic; Karen Marr; Vesela Valnarov; Michael G. Dwyer; Ellen Carl; Y. Karmon; Cheryl Kennedy; Christina Brooks; Colleen K. Kilanowski; Kristin Hunt; Adnan H. Siddiqui; David Hojnacki; B. Weinstock-Guttman; Robert Zivadinov

Here is another article that should add to the controversy over the relationship between MS and venous anomalies. The authors assessed the utility of sonography and MRV (2 different techniques) for detecting intra- and extraluminal venous abnormalities in 150 patients with MS and 63 matched controls. Results were as follows: patients with MS had significantly more intraluminal and structural abnormalities than controls and patients with progressive MS had more extraluminal and flow abnormalities than those with nonprogressive disease. BACKGROUND AND PURPOSE: Chronic cerebrospinal venous insufficiency (CCSVI) is a vascular condition characterized by anomalies of the main extracranial cerebrospinal venous routes that interfere with normal venous outflow. Research into CCSVI will determine its sensitivity and specificity for a diagnosis of MS, its prevalence in MS patients, and its clinical, MRI, and genetic correlates. Our aim was to investigate the prevalence and number of intra- and extraluminal structural and functional extracranial venous abnormalities by using DS and MRV, in patients with MS and HCs. MATERIALS AND METHODS: One hundred fifty patients with MS, 104 (69.3%) with RR and 46 (30.7%) with a progressive MS course, and 63 age- and sex-matched HCs were scanned with 3T MR imaging by using TOF and TRICKS sequences (only patients with MS). All subjects underwent DS examination for intra- and extraluminal structural and functional abnormalities of the IJVs. Absent/pinpoint IJV flow morphology on MRV was considered an abnormal finding. Prominence of collateral extracranial veins was assessed with MRV. RESULTS: Patients with MS had a significantly higher number of functional (P < .0001), total (P = .001), and intraluminal (P = .005) structural IJV DS abnormalities than HCs. There was a trend for more patients with MS with extraluminal IJV DS abnormalities (P = .023). No significant differences were found on the MRV IJV flow morphology scale between patients with MS and HCs. Patients with progressive MS showed more extraluminal IJV DS abnormalities (P = .01) and more MRV flow abnormalities on TOF (P = .006) and TRICKS (P = .01) than patients with nonprogressive MS. There was a trend for a higher number of collateral veins in patients with MS than in HCs (P = .016). CONCLUSIONS: DS is more sensitive than MRV in detecting intraluminal structural and functional venous abnormalities in patients with MS compared with HCs, whereas MRV is more sensitive in showing collaterals.


Journal of Vascular and Interventional Radiology | 2013

Changes of cine cerebrospinal fluid dynamics in patients with multiple sclerosis treated with percutaneous transluminal angioplasty: a case-control study.

Robert Zivadinov; Christopher Magnano; Roberto Galeotti; Claudiu Schirda; Erica Menegatti; Bianca Weinstock-Guttman; Karen Marr; Ilaria Bartolomei; Jesper Hagemeier; Anna Maria Malagoni; David Hojnacki; Cheryl Kennedy; Ellen Carl; Clive B. Beggs; Fabrizio Salvi; Paolo Zamboni

PURPOSE To investigate characteristics of cine phase contrast-calculated cerebrospinal fluid (CSF) flow and velocity measures in patients with relapsing-remitting (RR) multiple sclerosis (MS) receiving standard medical treatment who had been diagnosed with chronic cerebrospinal venous insufficiency (CCSVI) and underwent percutaneous transluminal angioplasty (PTA). MATERIALS AND METHODS This case-controlled, magnetic resonance (MR) imaging-blinded study included 15 patients with RR MS who presented with significant stenoses (≥50% lumen reduction on catheter venography) in the azygous or internal jugular veins. Eight patients underwent PTA in addition to medical therapy immediately following baseline assessments (case group) and seven had delayed PTA after 6 months of medical therapy alone (control group). CSF flow and velocity measures were quantified over 32 phases of the cardiac cycle by a semiautomated method. Outcomes were compared between groups at baseline and at 6 and 12 months of the study by mixed-effect model analysis. RESULTS At baseline, no significant differences in CSF flow or velocity measures were detected between groups. At month 6, significant improvement in flow (P<.001) and velocity (P = .013) outcomes were detected in the immediate versus the delayed group, and persisted to month 12 (P = .001 and P = .021, respectively). Within-group flow comparisons from baseline to follow-up showed a significant increase in the immediate group (P = .033) but a decrease in the delayed group (P = .024). Altered CSF flow and velocity measures were associated with worsening of clinical and MR outcomes in the delayed group. CONCLUSIONS PTA in patients with MS with CCSVI increased CSF flow and decreased CSF velocity, which are indicative of improved venous parenchyma drainage.


Journal of Magnetic Resonance Imaging | 2014

Aqueductal cerebrospinal fluid pulsatility in healthy individuals is affected by impaired cerebral venous outflow

Clive B. Beggs; Christopher Magnano; Simon J. Shepherd; Karen Marr; Vesela Valnarov; David Hojnacki; Niels Bergsland; Pavel Belov; Steven Grisafi; Michael G Dwyer; Ellen Carl; Bianca Weinstock-Guttman; Robert Zivadinov

To investigate cerebrospinal fluid (CSF) dynamics in the aqueduct of Sylvius (AoS) in chronic cerebrospinal venous insufficiency (CCSVI)‐positive and ‐negative healthy individuals using cine phase contrast imaging.


Neurology | 2014

Prospective randomized trial of venous angioplasty in MS (PREMiSe)

Adnan H. Siddiqui; Robert Zivadinov; Ralph H. B. Benedict; Yuval Karmon; Jihnhee Yu; Mary L. Hartney; Karen Marr; Vesela Valnarov; Cheryl Kennedy; Murali Ramanathan; Deepa P. Ramasamy; Kresimir Dolic; David Hojnacki; Ellen Carl; Elad I. Levy; Hopkins Ln; Bianca Weinstock-Guttman

Objective: We report the results of the investigation of safety and efficacy of venous angioplasty in patients with multiple sclerosis (MS) with findings of extracranial venous anomalies, considered hallmarks of chronic cerebrospinal venous insufficiency (CCSVI), in a 2-phase study (ClinicalTrials.gov NCT01450072). Methods: Phase 1 was an open-label safety study (10 patients); phase 2 was sham-controlled, randomized, and double-blind (10 sham procedure, 9 treated). All study patients fulfilled venous hemodynamic screening criteria indicative of CCSVI. Assessment was at 1, 3, and 6 months postprocedure with MRI, clinical, and hemodynamic outcomes. Primary endpoints were safety at 24 hours and 1 month, venous outflow restoration >75% at 1 month, and effect of angioplasty on new lesion activity and relapse rate over 6 months. Secondary endpoints included changes in disability, brain volume, cognitive tests, and quality of life. Results: No perioperative complications were noted; however, one patient with history of syncope was diagnosed with episodic bradycardia requiring placement of a pacemaker before discharge. Doppler evidence-based venous hemodynamic insufficiency severity score (VHISS) was reduced >75% compared to baseline in phase 1 (at 1 month) but not phase 2. In phase 2, higher MRI activity (cumulative number of new contrast-enhancing lesions [19 vs 3, p = 0.062] and new T2 lesions [17 vs 3, p = 0.066]) and relapse activity (4 vs 1, p = 0.389) were identified as nonsignificant trends in the treated vs sham arm over 6 months. Using analysis of covariance, significant cumulative new T2 lesions were related to larger VHISS decrease (p = 0.028) and angioplasty (p = 0.01) over the follow-up. No differences in other endpoints were detected. Conclusion: Venous angioplasty is not an effective treatment for MS over the short term and may exacerbate underlying disease activity. Classification of evidence: This is a Class I study demonstrating that clinical and imaging outcomes are no better or worse in patients with MS identified with venous outflow restriction who receive venous angioplasty compared to sham controls who do not receive angioplasty. This study also includes a Class IV phase 1 study of safety in 10 patients receiving the angioplasty procedure.


BMC Medicine | 2013

The role of noninvasive and invasive diagnostic imaging techniques for detection of extra-cranial venous system anomalies and developmental variants

Kresimir Dolic; Adnan H. Siddiqui; Yuval Karmon; Karen Marr; Robert Zivadinov

The extra-cranial venous system is complex and not well studied in comparison to the peripheral venous system. A newly proposed vascular condition, named chronic cerebrospinal venous insufficiency (CCSVI), described initially in patients with multiple sclerosis (MS) has triggered intense interest in better understanding of the role of extra-cranial venous anomalies and developmental variants. So far, there is no established diagnostic imaging modality, non-invasive or invasive, that can serve as the “gold standard” for detection of these venous anomalies. However, consensus guidelines and standardized imaging protocols are emerging. Most likely, a multimodal imaging approach will ultimately be the most comprehensive means for screening, diagnostic and monitoring purposes. Further research is needed to determine the spectrum of extra-cranial venous pathology and to compare the imaging findings with pathological examinations. The ability to define and reliably detect noninvasively these anomalies is an essential step toward establishing their incidence and prevalence. The role for these anomalies in causing significant hemodynamic consequences for the intra-cranial venous drainage in MS patients and other neurologic disorders, and in aging, remains unproven.


BMC Neurology | 2012

Clinical correlates of chronic cerebrospinal venous insufficiency in multiple sclerosis

B. Weinstock-Guttman; Murali Ramanathan; Karen Marr; David Hojnacki; Ralph H. B. Benedict; Charity J. Morgan; Eluen Ann Yeh; Ellen Carl; Cheryl Kennedy; Justine Reuther; Christina Brooks; Kristin Hunt; Makki Elfadil; Michelle Andrews; Robert Zivadinov

BackgroundChronic cerebrospinal venous insufficiency (CCSVI) is a vascular condition characterized by anomalies of the primary veins outside the skull that has been reported to be associated with MS. In the blinded Combined Transcranial (TCD) and Extracranial Venous Doppler Evaluation (CTEVD) study, we found that prevalence of CCSVI was significantly higher in multiple sclerosis (MS) vs. healthy controls (HC) (56.1% vs. 22.7%, p < 0.001).The objective was to evaluate the clinical correlates of venous anomalies indicative of CCSVI in patients with MS.MethodsThe original study enrolled 499 subjects; 163 HC, 289 MS, 21 CIS and 26 subjects with other neurological disorders who underwent a clinical examination and a combined Doppler and TCD scan of the head and neck. This analysis was restricted to adult subjects with MS (RR-MS: n = 181, SP-MS: n = 80 and PP-MS: n = 12). Disability status was evaluated by using the Kurtzke Expanded Disability Status Scale (EDSS) and MS severity scale (MSSS).ResultsDisability was not associated with the presence (≥2 venous hemodynamic criteria) or the severity of CCSVI, as measured with venous hemodynamic insufficiency severity score (VHISS). However, the severity of CCSVI was associated with the increased brainstem functional EDSS sub-score (p = 0.002). In logistic regression analysis, progressive MS (SP-MS or PP-MS) vs. non-progressive status (including RR-MS) was associated with CCSVI diagnosis (p = 0.004, OR = 2.34, CI = 1.3–4.2).ConclusionsThe presence and severity of CCVSI in multiple sclerosis correlate with disease status but has no or very limited association with clinical disability.

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Robert Zivadinov

State University of New York System

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Bianca Weinstock-Guttman

State University of New York System

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Ellen Carl

State University of New York System

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David Hojnacki

State University of New York System

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Kresimir Dolic

State University of New York System

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Jesper Hagemeier

State University of New York System

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Murali Ramanathan

State University of New York System

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Vesela Valnarov

State University of New York System

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Christina Brooks

State University of New York System

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