Babak B Navi

Memorial Sloan-Kettering Cancer Center, New York, New York, United States

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Publications (38)265.19 Total impact

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    ABSTRACT: Objective: To examine the association between incident cancer and the subsequent risk of stroke. Methods: Using the Surveillance Epidemiology and End Results-Medicare linked database, we identified patients with a new primary diagnosis of breast, colorectal, lung, pancreatic, or prostate cancer from 2001 through 2007. These patients were individually matched by age, sex, race, registry, and medical comorbidities to a group of Medicare enrollees without cancer, and each pair was followed through 2009. Validated diagnosis codes were used to identify a primary outcome of stroke. Cumulative incidence rates were calculated using competing risk survival statistics. Results: Among 327,389 pairs of cancer patients and matched controls, the 3-month cumulative incidence of stroke was generally higher in patients with cancer. Cumulative incidence rates were 5.1% (95% confidence interval [CI], 4.9-5.2%) in patients with lung cancer compared to 1.2% (95% CI, 1.2-1.3%) in controls (p<0.001), 3.4% (95% CI, 3.1-3.6%) in patients with pancreatic cancer compared to 1.3% (95% CI, 1.1-1.5%) in controls (p<0.001), 3.3% (95% CI, 3.2-3.4%) in patients with colorectal cancer compared to 1.3% (95% CI, 1.2-1.4%) in controls (p<0.001), 1.5% (95% CI, 1.4-1.6%) in patients with breast cancer compared to 1.1% (95% CI, 1.0-1.2%) in controls (p<0.001), and 1.2% (95% CI, 1.1-1.3%) in patients with prostate cancer compared to 1.1% (95% CI, 1.0-1.2%) in controls (p=0.085). Excess risks attenuated over time and were generally no longer present beyond 1 year. Interpretation: Incident cancer is associated with an increased short-term risk of stroke. This risk appears highest with lung, pancreatic, and colorectal cancers. This article is protected by copyright. All rights reserved. © 2014 American Neurological Association.
    Annals of Neurology 02/2015; 77(2). DOI:10.1002/ana.24325 · 11.91 Impact Factor
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    ABSTRACT: Purpose To project and compare the lifetime health benefits, health care costs, and incremental cost-effectiveness of a decision rule based on assessment of cerebrovascular reserve (CVR) compared with medical therapy and immediate revascularization in asymptomatic patients with carotid artery stenosis for prevention of stroke. Materials and Methods The three strategies compared included immediate revascularization (carotid endarterectomy) and ongoing medical therapy (with antiplatelet, statin, and antihypertensive agents plus lifestyle modification), medical therapy-based treatment with revascularization only for patients who progressed, and use of a CVR-based decision rule for treatment in which patients with CVR impairment undergo immediate revascularization and all others receive medical therapy. A decision analytic model was developed to project lifetime quality-adjusted life years (QALYs) and costs for asymptomatic patients with carotid stenosis with 70%-89% carotid luminal narrowing at presentation. Risks of clinical events, costs, and quality-of-life values were estimated on the basis of those in published sources. The analysis was conducted from a health care system perspective, with health and cost outcomes discounted at 3%. Results Total costs per person and lifetime QALYs were lowest for the medical therapy-based strategy ($14 597, 9.848 QALYs), followed by CVR testing ($16 583, 9.934 QALYs) and immediate revascularization ($20 950, 9.940 QALYs). The incremental cost-effectiveness ratio for the CVR-based strategy compared with the medical therapy-based strategy was $23 000 per QALY and for the immediate revascularization versus the CVR-based strategy was $760 000 per QALY. Results were sensitive to variations in model inputs for revascularization costs and complication risks and baseline stroke risk. Conclusion CVR testing can be a cost-effective tool to identify asymptomatic patients with carotid stenosis who are most likely to benefit from revascularization. © RSNA, 2014 Online supplemental material is available for this article.
    Radiology 09/2014; 274(2):140501. DOI:10.1148/radiol.14140501 · 6.21 Impact Factor
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    ABSTRACT: Background and Purpose-Cryptogenic stroke is common in patients with cancer. Autopsy studies suggest that many of these cases may be because of marantic endocarditis, which is closely linked to cancer activity. We, therefore, hypothesized that among patients with cancer and ischemic stroke, those with cryptogenic stroke would have shorter survival. Methods-We retrospectively analyzed all adult patients with active systemic cancer diagnosed with acute ischemic stroke at a tertiary care cancer center from 2005 through 2009. Two neurologists determined stroke mechanisms by consensus. Patients were diagnosed with cryptogenic stroke if no specific mechanism could be determined. The diagnosis of marantic endocarditis was restricted to patients with cardiac vegetations on echocardiography or autopsy and negative blood cultures. Patients were followed until July 31, 2012, for the primary outcome of death. Kaplan-Meier statistics and the log-rank test were used to compare survival between patients with cryptogenic stroke and patients with known stroke mechanisms. Multivariate Cox proportional hazard analysis evaluated the association between cryptogenic stroke and death after adjusting for potential confounders. Results-Among 263 patients with cancer and ischemic stroke, 133 (51%) were cryptogenic. Median survival in patients with cryptogenic stroke was 55 days (interquartile range, 21-240) versus 147 days (interquartile range, 33-735) in patients with known stroke mechanisms (P<0.01). Cryptogenic stroke was independently associated with death (hazard ratio, 1.64; 95% confidence interval, 1.25-2.14) after adjusting for age, systemic metastases, adenocarcinoma histology, and functional status. Conclusions-Cryptogenic stroke is independently associated with reduced survival in patients with active cancer and ischemic stroke.
    Stroke 07/2014; 45(8). DOI:10.1161/STROKEAHA.114.005784 · 6.02 Impact Factor
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    ABSTRACT: Intravenous thrombolysis is the standard treatment for acute ischemic stroke (AIS). However, patients with cancer who have stroke are often precluded from therapy because of coagulopathy or recent surgery. Endovascular therapy may be a more suitable recanalization strategy for some patients with cancer and stroke, but no prior detailed reports documenting its use in this population exist. We present a case series from a tertiary care referral center of 2 patients with active systemic cancer who were successfully treated with endovascular therapy for AIS. Both patients had active lung cancer with excellent premorbid functional status and presented with severe AIS from left middle cerebral artery occlusions. Intravenous thrombolysis was deferred because of absolute contraindications. Mechanical embolectomy was performed instead and revascularization was achieved within 5 hours in both patients, resulting in dramatic neurological recoveries-National Institutes of Health Stroke Scale improved from 14 to 0 and from 23 to 3 from admission to discharge, respectively. In conclusion, endovascular therapy may be beneficial for select patients with cancer and AIS who are ineligible for intravenous thrombolysis. However, further studies are needed to determine the safety and efficacy of endovascular therapy in the population with cancer.
    07/2014; 4(3):133-5. DOI:10.1177/1941874413520509
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    ABSTRACT: Background and Purpose-The risk of stroke and other postpartum cerebrovascular disease (CVD) occurring after hospital discharge for labor and delivery is uncertain. Methods-We performed a retrospective cohort study using administrative databases to identify all pregnant women who were hospitalized for labor and delivery at nonfederal, acute care hospitals in California from 2005 to 2011 and who were discharged without an International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis of CVD. The primary outcome was an acute CVD composite defined as any ischemic stroke, intracranial hemorrhage, cerebral venous sinus thrombosis, pituitary apoplexy, carotid/vertebral artery dissection, hypertensive encephalopathy, or other acute CVD occurring after hospital discharge and before 6 weeks after labor and delivery. Descriptive statistics were used to estimate the incidence of postdischarge CVD. Multivariate logistic regression was used to evaluate the association between selected baseline factors and postdischarge CVD. Results-The rate of any postdischarge acute CVD was 14.8 per 100 000 patients (95% confidence interval [CI], 13.2-16.5). Risk factors for any acute CVD were eclampsia (odds ratio [OR], 10.1; 95% CI, 3.09-32.8), chronic kidney disease (OR, 5.4; 95% CI, 2.5-11.8), black race (OR, 2.5; 95% CI, 1.9-3.3), preeclampsia (OR, 2.1; 95% CI, 1.6-2.8), pregnancy-related hematologic disorders (OR, 1.8; 95% CI, 1.3-2.5), and age (OR, 1.5 per decade; 95% CI, 1.3-1.8). Conclusions-The incidence of postpartum acute CVD after hospital discharge for labor and delivery is similar to rates reported for all postpartum events in previous publications, suggesting that a substantial proportion of postpartum CVD occurs after discharge.
    Stroke 06/2014; 45(7). DOI:10.1161/STROKEAHA.114.005129 · 6.02 Impact Factor
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    ABSTRACT: To determine the cumulative rate and characteristics of recurrent thromboembolic events after acute ischemic stroke in patients with cancer.METHODS: We retrospectively identified consecutive adult patients with active systemic cancer diagnosed with acute ischemic stroke at a tertiary-care cancer center from 2005 through 2009. Two neurologists independently reviewed all electronic records to ascertain the composite outcome of recurrent ischemic stroke, myocardial infarction, systemic embolism, TIA, or venous thromboembolism. Kaplan-Meier statistics were used to determine cumulative outcome rates. In exploratory analyses, Cox proportional hazard analysis was used to evaluate potential independent associations between a priori selected clinical factors and recurrent thromboembolic events.RESULTS: Among 263 study patients, complete follow-up until death was available in 230 (87%). Most patients had an adenocarcinoma as their underlying cancer (60%) and had systemic metastases (69%). Despite a median survival of 84 days (interquartile range 24-419 days), 90 patients (34%; 95% confidence interval 28%-40%) had 117 recurrent thromboembolic events, consisting of 57 cases of venous thromboembolism, 36 recurrent ischemic strokes, 13 myocardial infarctions, 10 cases of systemic embolism, and one TIA. Kaplan-Meier rates of recurrent thromboembolism were 21%, 31%, and 37% at 1, 3, and 6 months, respectively; cumulative rates of recurrent ischemic stroke were 7%, 13%, and 16%. Adenocarcinoma histology (hazard ratio 1.65, 95% confidence interval 1.02-2.68) was independently associated with recurrent thromboembolism.CONCLUSIONS: Patients with acute ischemic stroke in the setting of active cancer (especially adenocarcinoma) face a substantial short-term risk of recurrent ischemic stroke and other types of thromboembolism.
    Neurology 05/2014; DOI:10.1212/WNL.0000000000000539 · 8.30 Impact Factor
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    ABSTRACT: Amyloid beta-related angiitis (ABRA) of the central nervous system (CNS) is a very rare inflammatory disorder that causes destruction of CNS arteries and subsequent neuronal injury. Most patients with ABRA are old and present with cognitive dysfunction and stroke; however, some patients may present atypically. In this article, we report a 44-year-old man who presented with a first-time seizure but was otherwise neurologically intact and denied any headache. Brain MRI showed right hemispheric and bilateral medial frontal lobe hyperintensities and microhemorrhages that were most suspicious for a mass lesion. An extensive diagnostic evaluation including CSF analysis and catheter angiography was unremarkable. A brain biopsy with specific stains for amyloid surprisingly demonstrated ABRA and led to immunosuppressive treatment. The patient has remained neurologically intact and seizure-free 1 year after presentation. This case demonstrates that ABRA can occur in young patients without headache or neurologic deficits, and should be considered in patients with new-onset seizures and mass lesions. It also reinforces the need to consider a brain biopsy in patients with idiopathic brain lesions and negative non-invasive testing, as it is virtually impossible to confirm the diagnosis of ABRA otherwise.
    04/2014; 4(2):86-9. DOI:10.1177/1941874413502796
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    ABSTRACT: Background The postpartum state is associated with a substantially increased risk of thrombosis. It is uncertain to what extent this heightened risk persists beyond the conventionally defined 6-week postpartum period. Methods Using claims data on all discharges from nonfederal emergency departments and acute care hospitals in California, we identified women who were hospitalized for labor and delivery between January 1, 2005, and June 30, 2010. We used validated diagnosis codes to identify a composite primary outcome of ischemic stroke, acute myocardial infarction, or venous thromboembolism. We then used conditional logistic regression to assess each patient's likelihood of a first thrombotic event during sequential 6-week periods after delivery, as compared with the corresponding 6-week period 1 year later. Results Among the 1,687,930 women with a first recorded delivery, 1015 had a thrombotic event (248 cases of stroke, 47 cases of myocardial infarction, and 720 cases of venous thromboembolism) in the period of 1 year plus up to 24 weeks after delivery. The risk of primary thrombotic events was markedly higher within 6 weeks after delivery than in the same period 1 year later, with 411 events versus 38 events, for an absolute risk difference of 22.1 events (95% confidence interval [CI], 19.6 to 24.6) per 100,000 deliveries and an odds ratio of 10.8 (95% CI, 7.8 to 15.1). There was also a modest but significant increase in risk during the period of 7 to 12 weeks after delivery as compared with the same period 1 year later, with 95 versus 44 events, for an absolute risk difference of 3.0 events (95% CI, 1.6 to 4.5) per 100,000 deliveries and an odds ratio of 2.2 (95% CI, 1.5 to 3.1). Risks of thrombotic events were not significantly increased beyond the first 12 weeks after delivery. Conclusions Among patients in our study, an elevated risk of thrombosis persisted until at least 12 weeks after delivery. However, the absolute increase in risk beyond 6 weeks after delivery was low. (Funded by the National Institute of Neurological Disorders and Stroke.).
    New England Journal of Medicine 02/2014; 370(14). DOI:10.1056/NEJMoa1311485 · 54.42 Impact Factor
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    ABSTRACT: The Network Modification (NeMo) Tool uses a library of brain connectivity maps from normal subjects to quantify the amount of structural connectivity loss caused by focal brain lesions. We hypothesized that the Network Modification Tool could predict remote brain tissue loss caused by poststroke loss of connectivity. Baseline and follow-up MRIs (10.7±7.5 months apart) from 26 patients with acute ischemic stroke (age, 74.6±14.1 years, initial National Institutes of Health Stroke Scale, 3.1±3.1) were collected. Lesion masks derived from diffusion-weighted images were superimposed on the Network Modification Tool's connectivity maps, and regional structural connectivity losses were estimated via the Change in Connectivity (ChaCo) score (ie, the percentage of tracks connecting to a given region that pass through the lesion mask). ChaCo scores were correlated with subsequent atrophy. Stroke lesions' size and location varied, but they were more frequent in the left hemisphere. ChaCo scores, generally higher in regions near stroke lesions, reflected this lateralization and heterogeneity. ChaCo scores were highest in the postcentral and precentral gyri, insula, middle cingulate, thalami, putamen, caudate nuclei, and pallidum. Moderate, significant partial correlations were found between baseline ChaCo scores and measures of subsequent tissue loss (r=0.43, P=4.6×10(-9); r=0.61, P=1.4×10(-18)), correcting for the time between scans. ChaCo scores varied, but the most affected regions included those with sensorimotor, perception, learning, and memory functions. Correlations between baseline ChaCo and subsequent tissue loss suggest that the Network Modification Tool could be used to identify regions most susceptible to remote degeneration from acute infarcts.
    Stroke 02/2014; 45(3). DOI:10.1161/STROKEAHA.113.003645 · 6.02 Impact Factor
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    ABSTRACT: Whether transient global amnesia (TGA) represents an arterial insult that heralds ischemic stroke remains unclear. Therefore, we examined stroke risk after TGA in a population-based cohort. After performing chart review at our institution to validate the International Classification of Diseases, 9th Edition, Clinical Modification diagnosis code for TGA, we used administrative claims data to identify all patients discharged from nonfederal California emergency departments or acute care hospitals between 2005 and 2010 with a primary discharge diagnosis of TGA. Patients with a primary discharge diagnosis of migraine, seizure, or transient ischemic attack were included as controls. Kaplan-Meier statistics were used to calculate rates of ischemic stroke, and Cox proportional hazards analyses were used to compare stroke risk among the 4 exposure groups while controlling for traditional stroke risk factors. International Classification of Diseases, 9th Edition, Clinical Modification code 437.7 had a sensitivity of 86% and a specificity of 95% for TGA. The cumulative 1-year rate of stroke was 0.54% (95% confidence interval [CI], 0.36-0.81) after TGA, 0.22% (95% CI, 0.20-0.25) after migraine, 0.90% (95% CI, 0.83-0.97) after seizure, and 4.72% (95% CI, 4.60-4.85) after transient ischemic attack. After adjustment for demographic characteristics and stroke risk factors, TGA was not associated with stroke risk when compared with migraine (hazard ratio, 0.82; 95% CI, 0.61-1.10). The likelihood of stroke after TGA was lower than after seizure (hazard ratio, 0.57; 95% CI, 0.44-0.76) or transient ischemic attack (hazard ratio, 0.27; 95% CI, 0.20-0.35). Compared with patients diagnosed with migraine or seizure, patients diagnosed with TGA do not seem to face a heightened risk of stroke.
    Stroke 12/2013; 45(2). DOI:10.1161/STROKEAHA.113.003916 · 6.02 Impact Factor
  • Jahan Fahimi, Babak B Navi, Hooman Kamel
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    ABSTRACT: We evaluate the incidence of potentially incorrect emergency department (ED) diagnoses of Bell's palsy and identify factors associated with identification of a serious alternative diagnosis on follow-up. We performed a retrospective cohort study from California's Office of Statewide Health Planning and Development for 2005 to 2011. Subjects were adult patients discharged from the ED with a diagnosis of Bell's palsy. Information related to demographics, imaging use, and comorbidities was collected. Our outcome was one of the following diagnoses made within 90 days of the index ED visit: stroke, intracranial hemorrhage, subarachnoid hemorrhage, brain tumor, central nervous system infection, Guillain-Barré syndrome, Lyme disease, otitis media/mastoiditis, or herpes zoster. We report hazard ratios (HRs) and 95% confidence intervals (CIs) for factors associated with misdiagnosis. A total of 43,979 patients were discharged with a diagnosis of Bell's palsy. Median age was 45 years. On 90-day follow-up, 356 patients (0.8%) received an outcome diagnosis, and 39.9% were made within 7 days. Factors associated with the outcome included increasing age (HR 1.11, 95% CI 1.01 to 1.21, every 10 years), black race (HR 1.68; 95% CI 1.13 to 2.48), diabetes (HR 1.46; 95% CI 1.10 to 1.95), and computed tomography or magnetic resonance imaging use (HR 1.43; 95% CI 1.10 to 1.85). Private insurance was negatively associated with an alternative diagnosis (HR 0.65; 95% CI 0.46 to 0.93). Stroke, herpes zoster, Guillain-Barré, and otitis media accounted for 85.4% of all alternative diagnoses. Emergency providers have a very low rate of misdiagnosing Bell's palsy. The association between imaging use and misdiagnosis is likely confounded by patient acuity. Increasing age and diabetes are modest risk factors for misdiagnosis.
    Annals of emergency medicine 07/2013; DOI:10.1016/j.annemergmed.2013.06.022 · 4.33 Impact Factor
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    ABSTRACT: The interval from presentation with systemic inflammatory response syndrome (SIRS) to the start of antibiotic administration affects mortality in patients with sepsis. However, patients with subarachnoid hemorrhage (SAH) often develop SIRS directly from their brain injury, making it a less useful indicator of infection. We therefore hypothesized that SIRS would not be a suitable trigger for antibiotics in this population. We examined the time from the development of SIRS until antibiotic initiation and its relationship to long-term neurological outcomes in patients with nontraumatic SAH. Patients' baseline characteristics, time of antibiotic administration, and hospital course were collected from retrospective chart review. The primary outcome, 6-month functional status, was prospectively determined using blinded, structured interviews incorporating the modified Rankin Scale (mRS). Sixty-six of 70 patients with SAH during the study period had 6-month follow-up and were included in this analysis. SIRS developed in 57 patients (86 %, 95 % CI 78-95 %). In ordinal logistic regression models controlling for age and illness severity, the time from SIRS onset until antibiotic initiation was not associated with 6-month mRS scores (OR per hour, 0.994; 95 % CI 0.987-1.001). In this cohort of patients with SAH, time from SIRS onset until antibiotic administration was not related to functional outcomes. Our results indicate that SIRS is nonspecific in patients with SAH, and support the safety of withholding antibiotics in those who lack additional evidence of infection or hemodynamic deterioration.
    Neurocritical Care 07/2013; 21(1). DOI:10.1007/s12028-013-9846-x · 3.04 Impact Factor
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    ABSTRACT: BACKGROUND AND PURPOSE: It is unknown whether supraventricular arrhythmias other than atrial fibrillation or flutter are associated with stroke. METHODS: To examine the association between paroxysmal supraventricular tachycardia (PSVT) and stroke, we performed a retrospective cohort study using administrative claims data from all emergency department encounters and hospitalizations at California's nonfederal acute care hospitals in 2009. Our cohort comprised all adult patients with ≥1 emergency department visit or hospitalization from which they were discharged alive and without a diagnosis of stroke. Our primary exposure was a diagnosis of PSVT recorded at an encounter before stroke or documented as present-on-admission at the time of stroke. To reduce confounding, we excluded patients with diagnoses of atrial fibrillation. We defined PSVT, stroke, and atrial fibrillation using International Classification of Diseases, Ninth Revision, Clinical Modification codes previously validated by detailed chart review. RESULTS: Of 4806830 eligible patients, 14121 (0.29%) were diagnosed with PSVT and 14402 (0.30%) experienced a stroke. The cumulative rate of stroke after PSVT diagnosis (0.94%; 95% confidence interval, 0.76%-1.16%) significantly exceeded the rate among patients without a diagnosis of PSVT (0.21%; 95% confidence interval, 0.21%-0.22%). In Cox proportional hazards analysis controlling for demographic characteristics and potential confounders, PSVT was independently associated with a higher risk of subsequent stroke (hazard ratio, 2.10; 95% confidence interval, 1.69-2.62). CONCLUSIONS: In a large and demographically diverse sample of patients, we found an independent association between PSVT and ischemic stroke. PSVT seems to be a novel risk factor that may account for some proportion of strokes that are currently classified as cryptogenic.
    Stroke 04/2013; 44(6). DOI:10.1161/STROKEAHA.113.001118 · 6.02 Impact Factor
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    ABSTRACT: Dizziness is a frequent reason for neuroimaging and neurological consultation, but little is known about the utility of either practice. We sought to characterize the patterns and yield of neuroimaging and neurological consultation for dizziness in the emergency department (ED). We retrospectively identified consecutive adults presenting to an academic ED from 2007 to 2009, with a primary complaint of dizziness, vertigo, or imbalance. Neurologists reviewed medical records to determine clinical characteristics, whether a neuroimaging study (head computed tomography [CT] or brain magnetic resonance imaging [MRI]) or neurology consultation was obtained in the ED, and to identify relevant findings on neuroimaging studies. Two neurologists assigned a final diagnosis for the cause of dizziness. Logistic regression was used to evaluate bivariate and multivariate predictors of neuroimaging and consultation. Of 907 dizzy patients (mean age 59 years; 58% women), 321 (35%) had a neuroimaging study (28% CT, 11% MRI, and 4% both) and 180 (20%) had neurological consultation. Serious neurological disease was ultimately diagnosed in 13% of patients with neuroimaging and 21% of patients with neurological consultation, compared to 5% of the overall cohort. Headache and focal neurological deficits were associated with both neuroimaging and neurological consultation, while age ≥60 years and prior stroke predicted neuroimaging but not consultation, and positional symptoms predicted consultation but not neuroimaging. In a tertiary care ED, neuroimaging and neurological consultation were frequently utilized to evaluate dizzy patients, and their diagnostic yield was substantial.
    01/2013; 3(1):7-14. DOI:10.1177/1941874412458677
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    ABSTRACT: BACKGROUND AND PURPOSE: Observational studies indicate that outpatient cardiac monitoring detects previously undiagnosed atrial fibrillation (AF) in 5% to 20% of patients with recent stroke. However, it remains unknown whether the yield of monitoring exceeds that of routine clinical follow-up. METHODS: In a pilot trial, we randomly assigned 40 patients with cryptogenic ischemic stroke or high-risk transient ischemic attack to wear a Cardionet mobile cardiac outpatient telemetry monitor for 21 days or to receive routine follow-up alone. After thorough investigation, we excluded patients with documented AF or other apparent stroke pathogenesis. We contacted patients and their physicians at 3 months and at 1 year to ascertain any diagnoses of AF or recurrent stroke or transient ischemic attack. RESULTS: The baseline characteristics of our cohort broadly matched those of previous observational studies of monitoring after stroke. In the monitoring group, patients wore monitors for 64% of the assigned days, and 25% of patients were not compliant at all with monitoring. No patient in either study arm received a diagnosis of AF. Cardiac monitoring revealed AF in zero patients (0%; 95% confidence interval, 0%-17%), brief episodes of atrial tachycardia in 2 patients (10%; 95% confidence interval, 1%-32%), and nonsustained ventricular tachycardia in 2 patients (10%; 95% confidence interval, 1%-32%). CONCLUSIONS: In the first reported randomized trial of cardiac monitoring after cryptogenic stroke, the rate of AF detection was lower than expected, incidental arrhythmias were frequent, and compliance with monitoring was suboptimal. Our findings highlight the challenges of prospectively identifying stroke patients at risk for harboring paroxysmal AF and ensuring adequate compliance with cardiac monitoring.Clinical Trial Registration Information- Unique identifier: NCT00932425.
    Stroke 11/2012; 44(2). DOI:10.1161/STROKEAHA.112.679100 · 6.02 Impact Factor
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    ABSTRACT: BACKGROUND: Little is known about nationwide patterns of hospitalization after transient ischemic attack (TIA). METHODS: In a nationally representative sample of Emergency Department (ED) visits included in the National Hospital Ambulatory Medical Care Survey (NHAMCS) from 1997 through 2008, we estimated rates of hospitalization among patients with a primary ED diagnosis of TIA (International Classification of Diseases, 9th Revision (ICD-9), code 435). We used multiple logistic regression analysis to examine the association between hospitalization and demographic characteristics, geographic region, year of the visit, time of the visit, and markers of stroke risk. RESULTS: On the basis of 782 cases of TIA sampled by the NHAMCS, 57% (95% confidence interval [CI], 52%-61%) of patients with TIA nationwide were hospitalized. A higher proportion of patients was hospitalized in 2003 to 2008 (62%; 95% CI, 56%-68%) than in 1997 to 2002 (52%; 95% CI, 46%-58%; P = .02). Compared with the US Northeast, patients were less likely to be hospitalized in the Midwest (odds ratio [OR], 0.5; 95% CI, .3-.9), the South (OR, 0.3; 95% CI, .2-.5), or the West (OR, 0.2; 95% CI, .1-.4). Compared with white patients, hospitalization was more likely among patients who were black (OR, 2.4; 95% CI, 1.3-4.5), Hispanic (OR, 3.8; 95% CI, 1.4-10.2), or of other races (OR, 3.5; 95% CI, 1.3-9.6). Patients with Medicaid were admitted less often than those with private insurance (OR, 0.3; 95% CI, .2-.8). CONCLUSIONS: Nationwide patterns of hospitalization after TIA show significant regional and demographic variation. These results may provide a useful roadmap for efforts to improve systems of care for TIA across the country.
    Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association 11/2012; 22(7). DOI:10.1016/j.jstrokecerebrovasdis.2012.09.016 · 1.99 Impact Factor
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    ABSTRACT: OBJECTIVE: To describe the rate and predictors of central nervous system (CNS) disease in emergency department (ED) patients with dizziness in the modern era of neuroimaging. PATIENTS AND METHODS: We retrospectively reviewed the medical records of all adults presenting between January 1, 2007, and December 31, 2009, to an academic ED for a primary triage complaint of dizziness, vertigo, or imbalance. The final diagnosis for the cause of dizziness was independently assigned by 2 neurologists, with a third neurologist resolving any disagreements. The primary outcome was a composite of ischemic stroke, intracranial hemorrhage, transient ischemic attack, seizure, brain tumor, demyelinating disease, and CNS infection. Univariate and multivariate logistic regression were used to assess the association between clinical variables and serious CNS causes of dizziness. RESULTS: Of 907 patients experiencing dizziness (mean age, 59 years; 58% women [n=529]), 49 (5%) had a serious neurologic diagnosis, including 37 cerebrovascular events. Dizziness was often caused by benign conditions, such as peripheral vertigo (294 patients [32%]) or orthostatic hypotension (121 patients [31%]). Age 60 years or older (odds ratio [OR], 5.7; 95% confidence interval [CI], 2.5-11.2), a chief complaint of imbalance (OR, 5.9; 95% CI, 2.3-15.2), and any focal examination abnormality (OR, 5.9; 95% CI, 3.1-11.2) were independently associated with serious neurologic diagnoses, whereas isolated dizziness symptoms were inversely associated (OR, 0.2; 95% CI, 0.0-0.7). CONCLUSION: Dizziness in the ED is generally benign, although a substantial fraction of patients harbor serious neurologic disease. Clinical suspicion should be heightened for patients with advanced age, imbalance, or focal deficits.
    Mayo Clinic Proceedings 10/2012; 87(11). DOI:10.1016/j.mayocp.2012.05.023 · 5.79 Impact Factor
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    ABSTRACT: BACKGROUND: Although there are extensive data on long-term disability after subarachnoid hemorrhage (SAH), there are few data on the trajectory of functional recovery after hospital discharge. METHODS: From October 2009 to April 2010, we prospectively followed consecutive patients with non-traumatic SAH discharged from a university hospital. Modified Rankin Scale (mRS) scores were calculated at discharge from chart review and at 6 months by standardized telephone interview. Good functional status was defined as a mRS score of 0-2, and poor status as an mRS score of 3-6. Descriptive statistics were used to assess the trajectory of functional recovery and determine the proportion of patients whose functional status improved from poor to good. RESULTS: Among 52 patients with non-traumatic SAH (79 % aneurysmal) who were discharged alive, most (71 %) were discharged home. Median (IQR) mRS score was 3 (2-4) at discharge and 2 (1-2) at 6 months. Some functional recovery (any improvement in mRS score) was seen in most patients (83 %; 95 % CI, 72-93 %). Of the 28 patients with poor functional status at discharge, 16 (57 %) improved to good functional status at 6 months. All patients with Hunt-Hess grade 4 or 5 hemorrhages (n = 14) had poor functional status at discharge, but half (95 % CI, 20-80 %) recovered to a good functional status at 6 months. CONCLUSIONS: Although our sample size is small, our findings suggest that a substantial proportion of patients with SAH who are disabled at discharge go on to regain functional independence within 6 months.
    Neurocritical Care 08/2012; 17(3). DOI:10.1007/s12028-012-9772-3 · 3.04 Impact Factor
  • Babak B. Navi, Hooman Kamel, Anthony S. Kim
    Stroke 07/2012; 43(8):e79-e79. DOI:10.1161/STROKEAHA.112.660423 · 6.02 Impact Factor
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    ABSTRACT: BACKGROUND: To determine the incidence of electrographic seizures during continuous electroencephalography (cEEG) in the medical and surgical ICU. METHODS: We retrospectively reviewed the records of all adults who underwent cEEG in our medical and surgical ICU over a 4.5 year period. Patients with acute brain injury were excluded. Our primary outcome was cEEG documentation of an electrographic seizure, defined as a rhythmic discharge or spike and wave pattern demonstrating definite evolution and lasting at least 10 s. To assess inter-rater variability in cEEG interpretation, two electrophysiologists independently reviewed all available cEEGs of subjects with electrographic seizures documented on their clinical cEEG report and those of an equal number of randomly selected subjects from the remaining cohort. RESULTS: Kappa analysis showed a value of 0.88, indicating excellent inter-rater agreement. Electrographic seizures were identified in 12 of 105 patients (11 %, 95 % CI 5-18 %). This rate did not change after excluding patients with a history of seizure, remote brain injury, or seizure-like events before cEEG. In an ordinal logistic regression model controlling for age, sex, and SOFA score, electrographic seizures were associated with lower odds of good outcomes on the Glasgow Outcome Scale at discharge (OR 0.3, 95 % CI 0.1-0.8). CONCLUSION: In a tertiary care medical and surgical ICU, electrographic seizures were seen on 11 % of cEEGs ordered for the evaluation of encephalopathy, and were associated with worse functional outcomes at discharge. Our findings confirm the results of a prior study suggesting a substantial burden of electrographic seizures in critically ill encephalopathic patients.
    Neurocritical Care 07/2012; DOI:10.1007/s12028-012-9736-7 · 3.04 Impact Factor

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269 Citations
265.19 Total Impact Points

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  • 2009–2014
    • Memorial Sloan-Kettering Cancer Center
      • Department of Neurology
      New York, New York, United States
  • 2008–2014
    • Weill Cornell Medical College
      • • Division of Neurobiology
      • • Department of Neurology and Neuroscience
      New York, New York, United States
  • 2011
    • University of California, San Francisco
      San Francisco, California, United States
  • 2010
    • Cornell University
      Итак, New York, United States