Systematic review and meta-analysis of the effects of menopause hormone therapy on cognition

Introduction

Despite evidence from preclinical studies suggesting estrogen's neuroprotective effects, the use of menopausal hormone therapy (MHT) to support cognitive function remains controversial.

Methods

We used random-effect meta-analysis and multi-level meta-regression to derive pooled standardized mean difference (SMD) and 95% confidence intervals (C.I.) from 34 randomized controlled trials, including 14,914 treated and 12,679 placebo participants.

Results

Associations between MHT and cognitive function in some domains and tests of interest varied by formulation and treatment timing. While MHT had no overall effects on cognitive domain scores, treatment for surgical menopause, mostly estrogen-only therapy, improved global cognition (SMD=1.575, 95% CI 0.228, 2.921; P=0.043) compared to placebo. When initiated specifically in midlife or close to menopause onset, estrogen therapy was associated with improved verbal memory (SMD=0.394, 95% CI 0.014, 0.774; P=0.046), while late-life initiation had no effects. Overall, estrogen-progestogen therapy for spontaneous menopause was associated with a decline in Mini Mental State Exam (MMSE) scores as compared to placebo, with most studies administering treatment in a late-life population (SMD=-1.853, 95% CI -2.974, -0.733; P = 0.030). In analysis of timing of initiation, estrogen-progestogen therapy had no significant effects in midlife but was associated with improved verbal memory in late-life (P = 0.049). Duration of treatment >1 year was associated with worsening in visual memory as compared to shorter duration. Analysis of individual cognitive tests yielded more variable results of positive and negative effects associated with MHT.

Discussion

These findings suggest time-dependent effects of MHT on certain aspects of cognition, with variations based on formulation and timing of initiation, underscoring the need for further research with larger samples and more homogeneous study designs.

Outcomes of patients with pre-existing disability managed by mobile stroke units: A sub-analysis of the BEST-MSU study

BACKGROUND

Few data exist on acute stroke treatment in patients with pre-existing disability (PD) since they are usually excluded from clinical trials. A recent trial of mobile stroke units (MSUs) demonstrated faster treatment and improved outcomes, and included PD patients.

AIM

To determine outcomes with tissue plasminogen activator (tPA), and benefit of MSU versus management by emergency medical services (EMS), for PD patients.

METHODS

Primary outcomes were utility-weighted modified Rankin Scale (uw-mRS). Linear and logistic regression models compared outcomes in patients with versus without PD, and PD patients treated by MSU versus standard management by EMS. Time metrics, safety, quality of life, and health-care utilization were compared.

RESULTS

Of the 1047 tPA-eligible ischemic stroke patients, 254 were with PD (baseline mRS 2-5) and 793 were without PD (baseline mRS 0-1). Although PD patients had worse 90-day uw-mRS, higher mortality, more health-care utilization, and worse quality of life than non-disabled patients, 53% returned to at least their baseline mRS, those treated faster had better outcome, and there was no increased bleeding risk. Comparing PD patients treated by MSU versus EMS, 90-day uw-mRS was 0.42 versus 0.36 (p = 0.07) and 57% versus 46% returned to at least their baseline mRS. There was no interaction between disability status and MSU versus EMS group assignment (p = 0.67) for 90-day uw-mRS.

CONCLUSION

PD did not prevent the benefit of faster treatment with tPA in the BEST-MSU study. Our data support inclusion of PD patients in the MSU management paradigm.

Abstract 161: Racial And Ethnic Differences In The Risk Of Ischemic Stroke After Intracerebral Hemorrhage

Background: Intracerebral hemorrhage (ICH) is associated with an increased risk of ischemic stroke. Whether there are racial and ethnic disparities in the risk of ischemic stroke after ICH is poorly understood.

Hypothesis: Non-Hispanic Black and Hispanic ICH patients have a higher risk of ischemic stroke compared to White ICH patients.

Methods: We retrospectively analyzed data from the Healthcare Cost and Utilization Project on all hospitalizations at all nonfederal hospitals in Florida from 2005 to 2018 and New York from 2006 to 2016. We included patients with an ICH, and without a prior or concomitant diagnosis of ischemic stroke. ICH and ischemic stroke were ascertained using validated ICD-9-CM and ICD-10-CM codes. Using Cox proportional hazard models, we studied the relationship between race and risk of ischemic stroke, after adjustment of demographics and comorbidities.

Results: We included 55,582 patients with ICH- 66% Non-Hispanic White, 19% Non-Hispanic Black, and 13% Hispanic. Black and Hispanic patients were younger and had a higher prevalence of cardiovascular comorbidities; however, atrial fibrillation was more prevalent among White patients. During a median follow up period of 3.6 years (IQR 0.7-7.2), an incident ischemic stroke occurred in 3,361 (9%) Non-Hispanic White, 1,308 (12%) Non-Hispanic Black, and 858 (12%) Hispanic patients (p<.001). In adjusted Cox models, the risk of an ischemic stroke was significantly higher among Non-Hispanic Black patients (HR 1.6; 95% CI,1.4-1.7) and Hispanic patients (HR 1.4; 95% CI,1.2-1.5]), compared to non-Hispanic White patients.

Conclusions: Among patients with ICH, Non-Hispanic Black and Hispanic patients had a significantly higher risk of ischemic stroke compared to Non-Hispanic White patients.

Abstract WP6: Strokes Averted by Intravenous Thrombolysis: A Secondary Analysis of the BEST-MSU Trial

Introduction: While the goal of IV tissue plasminogen activator (TPA) is to prevent infarction, few data exist on averted stroke.

Methods: Secondary analysis of a multicenter trial from 2014-2020 comparing outcomes between patients treated for stroke by mobile stroke unit (MSU) vs standard care (SC). The analytical cohort were patients with suspected stroke treated with IV TPA. The primary outcome was a time-defined averted stroke diagnosis, defined as a final diagnosis of stroke with resolution of presenting symptoms/signs by 24 hours. The secondary outcome was a tissue-defined averted stroke diagnosis, defined as a final diagnosis of stroke with resolution of presenting symptoms/signs by 24 hours and no acute infarction/hemorrhage on imaging. We used multivariable logistic regression to evaluate associations between study exposures (demographics, comorbidities, stroke characteristics) and outcomes.

Results: Among 1009 patients with a median last known well-to-TPA time of 87 minutes, 276 patients (27%) had a time-defined averted stroke (31% MSU, 21% SC) and 159 patients (16%) had a tissue-defined averted stroke (18% MSU, 11% SC). Factors independently associated with time-defined averted stroke were younger age (OR, 0.98; 95% CI, 0.96-0.99), female sex (0R, 0.51; 95% CI, 0.36-0.74), hyperlipidemia (OR, 1.81, 95% CI, 1.24-2.64), normal premorbid function (0R, 2.22; 95% CI, 1.37-3.67), lower glucose (OR, 0.996; 95% CI, 0.993-0.999), lower MAP (OR, 0.991; 95% CI, 0.983-0.998), MSU care (OR, 1.77; 95% CI, 1.21-2.62), lower NIH stroke scale (OR, 0.89; 95% CI, 0.86-0.93), and no large vessel occlusion (LVO) (OR, 0.52; 95% CI, 0.32-0.83). For tissue-based averted stroke, younger age, female sex, hyperlipidemia, lower MAP, MSU treatment, lower NIH stroke scale, and no LVO were significantly associated.

Conclusion: In a modern acute stroke trial, one-in-four patients treated with TPA for stroke recovered within 24 hours and one-in-six had no demonstrable brain injury on imaging. Younger age, female sex, hyperlipidemia, lower MAP, MSU care, lower stroke severity, and no LVO may increase the odds of averting stroke.

Abstract WMP2: Acute Stroke Treatment In Patients With Pre-exiting Disability: A Secondary Analysis Of The BEST-MSU Trial

Background: Few data exists on acute stroke treatment in patients with pre-existing disability (PD) since they are usually excluded from clinical trials.

Methods: A pre-specified subgroup analysis of tPA-eligible patients with PD enrolled in a prospective multicenter trial of Mobile Stroke Units (MSUs) vs standard management by emergency medical services (EMS). All patients had baseline mRS scores. Co-primary outcomes were mean utility-weighted modified Rankin Scale score (uw-mRS) and return to baseline mRS at 90 days. Linear and logistic regression models compared outcomes in patients with vs without PD, and patients with PD treated by MSU vs EMS. Time metrics, safety, quality of life, and health-care utilization were also compared.

Results: Of 1047 patients, 254 had baseline mRS >= 2 (159 MSU, 95 EMS; 31% mRS 2, 52% mRS 3, 17% mRS 4). Compared to patients without disability, patients with PD were older, had higher NIHSS, more comorbidities, less often lived at home, were treated slower, and had less thrombectomy. Patients with PD had worse 90-day uw-mRS (0.39 vs 0.80), higher mortality, more health-care utilization and worse quality of life than patients without PD. However, rates of symptomatic intracranial hemorrhage and final diagnoses of stroke mimics were similar between groups, and 52% of patients with PD returned to their baseline mRS. Patients with PD treated within the first hour had better 90-day uw-mRS than those treated later (0.48 vs 0.36, p=0.01). Comparing patients with PD treated by MSU vs EMS, time from last-known-well to tPA bolus was shorter (82 vs 111 min), and 24% vs 0% were treated in the first hour. Among patients with PD, MSU patients had non-significantly better 90-day uw-mRS (0.41 vs 0.35, p=0.09) and higher rate of returning to baseline mRS (56% vs 44%, p=0.09) than EMS patients. There was no interaction between either time to treatment (p=0.24) or MSU vs EMS group assignment (p= 0.42), 90-day uw-mRS, and PD vs no disability status.

Conclusion: Although outcomes after stroke are less favorable in patients with vs without PD, in a large, controlled trial, we found no interaction between baseline disability and the benefit of MSU treatment. Our data support the earliest treatment of acute stroke patients regardless of premorbid functional status.

Comparing hematoma characteristics in primary intracerebral hemorrhage versus intracerebral hemorrhage caused by structural vascular lesions

Intracerebral hemorrhage (ICH) caused by structural vascular lesions is associated with better outcomes than primary ICH, but this relationship is poorly understood. We tested the hypothesis that ICH from a vascular lesion has more benign hematoma characteristics compared to primary ICH. We performed a retrospective study using data from our medical center. The SMASH-U criteria were used to adjudicate the etiology of ICH. The co-primary outcomes were admission parenchymal hematoma volume and hematoma expansion at 24 h. Linear and logistic regression analyses were performed to test associations. A total of 231 patients were included of whom 42 (18%) had a vascular lesion. Compared to primary ICH patients, those with structural vascular lesions were younger (49 vs. 68 years, p < 0.001), less likely to have hypertension (29% vs. 74%, p < 0.001), had lower mean admission systolic blood pressure (140 ± 23 vs. 164 ± 35, p < 0.001), less frequently had IVH (26% vs. 44%, p = 0.03), and had mostly lobar or infratentorial hemorrhages. The median admission hematoma volume was smaller with vascular lesions (5.9 vs. 9.7 mL, p = 0.01). In regression models, ICH from a vascular lesion was associated with smaller admission hematoma volume (beta, -0.67, 95% CI, -1.29 to -0.05, p = 0.03), but no association with hematoma expansion was detected when assessed as a continuous (OR, 0.93; 95% CI, -4.46 to 6.30, p = 0.73) or dichotomous exposure (OR, 1.86; 95% CI, 0.40 to 8.51, p = 0.42). In a single-center cohort, patients with ICH from vascular lesions had smaller hematoma volumes than patients with primary ICH.

Abstract WP183: Pregnancy-related Factors Associated With Stroke In Mothers And Newborns: Data From The International Maternal Newborn Stroke Registry

Background: Maternal and newborn stroke occur during the same period when physiological and anatomic connections between mother and infant may provide a rationale for common pathogenetic mechanisms. The similarities and differences between maternal and newborn stroke remain poorly understood. We created the International Maternal Newborn Stroke Registry - the first database to explore these relationships.

Methods: Eleven international sites participated; 9 enrolled cases for this analysis. Eligible cases were newborns (from 28 weeks gestation to 28 postnatal days) or mothers (peripartum or within 6 weeks postpartum) diagnosed with stroke (ischemic, hemorrhagic, cerebral sinovenous thrombosis). Preterm infants (< 28 weeks gestation) and neonates with germinal matrix/intraventricular hemorrhage were excluded. Descriptive statistics were performed to compare stroke sub-types, demographic and pregnancy-related risk factors.

Results: We enrolled 103 cases, 69 newborn and 34 maternal. Median maternal age was 29 years (IQR 25-36) for the maternal group and 32 years (IQR 30-36) for the neonatal group. Women with maternal strokes were more likely to have pre-eclampsia (15%) and migraine (44%). Compared to maternal strokes, newborn strokes occurred more often in women from urban locations, were ischemic, and were less likely to be associated with alcohol use and pre-eclampsia during pregnancy (Table).

Conclusion: In this novel registry, we describe factors that impact both maternal and newborn stroke. Urban area of residence and maternal age > 30 were associated with newborn strokes, while migraine and pre-eclampsia were strongly associated with maternal strokes. Differing mechanisms and stroke subtypes may explain these differences. In addition, lack of access to healthcare in certain geographical locations may lead to under-identification. Further research is needed to determine if these results are consistent when applied to a larger sample size.

Abstract WMP81: Association Between Systemic Amyloidosis And Intracranial Hemorrhage

Introduction: Isolated amyloid deposition in the brain is associated with intracranial hemorrhage. Whether systemic amyloidosis also increases the risk of intracranial hemorrhage is unclear.

Methods: We evaluated the association between systemic amyloidosis and intracranial hemorrhage using claims data from a 5% national sample of Medicare beneficiaries from 2008-2015. The primary outcome was non-traumatic intracranial hemorrhage, defined as a composite of intracerebral hemorrhage, subarachnoid hemorrhage, and subdural hemorrhage. Secondary outcome were each hemorrhage type assessed separately. The exposure and outcomes were identified using previously validated ICD-9-CM diagnosis codes. We used Cox regression analysis adjusting for demographics and vascular risk factors to evaluate the association between systemic amyloidosis and intracranial hemorrhage. We also examined the risk of hip fracture (negative control). In sensitivity analyses, we excluded patients with cardiac amyloidosis, a subset most likely to be on antithrombotic therapy.

Results: Among 1.8 million Medicare beneficiaries, 924 were diagnosed with systemic amyloidosis. During a median follow-up of 5.3 years (IQR, 2.8- 6.7), the cumulative incidence of intracranial hemorrhage was 19 per 1,000 patients per year among patients with amyloidosis, and 2 per 1,000 patients per year in those without amyloidosis. In adjusted Cox models, systemic amyloidosis was associated with an increased risk of intracranial hemorrhage (HR, 4.3; 95% CI, 2.9-6.3). The association persisted in a sensitivity analysis after excluding beneficiaries with cardiac amyloidosis (HR, 8.0; 95% CI, 5.0-12.7). In secondary analyses, systemic amyloidosis was associated with intracerebral hemorrhage (HR, 5.6; 95% CI, 3.6-8.7), subarachnoid hemorrhage (HR, 14.7; 95% 9.0-24.0), and subdural hemorrhage (HR, 3.6; 95% 2.0-6.2). There was no association between systemic amyloidosis and hip fracture (HR, 0.9; 95% CI, 0.6-1.4).

Conclusions: In a large, heterogeneous national cohort of elderly patients, a diagnosis of systemic amyloidosis was associated with a 4-fold increased risk of intracranial hemorrhage, including intracerebral, subarachnoid, and subdural hemorrhages.

Evaluation of Transient Ischemic Attack and Minor Stroke: A Rapid Outpatient Model for the COVID-19 Pandemic and Beyond

The grim circumstances of the COVID-19 pandemic have highlighted the need to refine and adapt stroke systems of care. Patients' care-seeking behaviors have changed due to perceived risks of in-hospital treatment during the pandemic. In response to these challenges, we optimized a recently implemented, novel outpatient approach for the evaluation and management of minor stroke and transient ischemic attack, entitled RESCUE-TIA. This modified approach incorporated telemedicine visits and remote testing, and proved valuable during the pandemic. In this review article, we provide the evidence-based rationale for our approach, describe its operationalization, and provide data from our initial experience.

Feasibility of a wearable biosensor device to characterize exercise and sleep in neurology residents

BACKGROUND

Research suggests optimizing sleep, exercise and work-life balance may improve resident physician burnout. Wearable biosensors may allow residents to detect and correct poor sleep and exercise habits before burnout develops. Our objectives were to evaluate the feasibility of a wearable biosensor to characterize exercise/sleep in neurology residents and examine its relationship to self-reported, validated survey measures. We also assessed the device's impact on well-being and barriers to use.

METHODS

This prospective cohort study evaluated the WHOOP Strap 2.0 in neurology residents. Participants completed regular online surveys, including self-reported hours of sleep/exercise, and validated sleep/exercise scales at 3-month intervals. Autonomic, exercise, and sleep measures were obtained from WHOOP. Changes were evaluated over time via linear regression. Survey and WHOOP metrics were compared using Pearson correlations.

RESULTS

Sixteen (72.7%) of 22 eligible participants enrolled. Eleven (68.8%) met the minimum usage requirement (6+ months) and were classified as 'consecutive wearers.' Significant increases were found in sleep duration and exercise intensity. Moderate-to-low correlations were found between survey responses and WHOOP measures. Most (73%) participants reported a positive impact on well-being. Barriers to use included 'Forgetting to wear' (20%) and 'not motivational' (23.3%).

CONCLUSION

Wearable biosensors may be a feasible tool to evaluate sleep/exercise in residents.

Prospective, Multicenter, Controlled Trial of Mobile Stroke Units

BACKGROUND

Mobile stroke units (MSUs) are ambulances with staff and a computed tomographic scanner that may enable faster treatment with tissue plasminogen activator (t-PA) than standard management by emergency medical services (EMS). Whether and how much MSUs alter outcomes has not been extensively studied.

METHODS

In an observational, prospective, multicenter, alternating-week trial, we assessed outcomes from MSU or EMS management within 4.5 hours after onset of acute stroke symptoms. The primary outcome was the score on the utility-weighted modified Rankin scale (range, 0 to 1, with higher scores indicating better outcomes according to a patient value system, derived from scores on the modified Rankin scale of 0 to 6, with higher scores indicating more disability). The main analysis involved dichotomized scores on the utility-weighted modified Rankin scale (≥0.91 or <0.91, approximating scores on the modified Rankin scale of ≤1 or >1) at 90 days in patients eligible for t-PA. Analyses were also performed in all enrolled patients.

RESULTS

We enrolled 1515 patients, of whom 1047 were eligible to receive t-PA; 617 received care by MSU and 430 by EMS. The median time from onset of stroke to administration of t-PA was 72 minutes in the MSU group and 108 minutes in the EMS group. Of patients eligible for t-PA, 97.1% in the MSU group received t-PA, as compared with 79.5% in the EMS group. The mean score on the utility-weighted modified Rankin scale at 90 days in patients eligible for t-PA was 0.72 in the MSU group and 0.66 in the EMS group (adjusted odds ratio for a score of ≥0.91, 2.43; 95% confidence interval [CI], 1.75 to 3.36; P<0.001). Among the patients eligible for t-PA, 55.0% in the MSU group and 44.4% in the EMS group had a score of 0 or 1 on the modified Rankin scale at 90 days. Among all enrolled patients, the mean score on the utility-weighted modified Rankin scale at discharge was 0.57 in the MSU group and 0.51 in the EMS group (adjusted odds ratio for a score of ≥0.91, 1.82; 95% CI, 1.39 to 2.37; P<0.001). Secondary clinical outcomes generally favored MSUs. Mortality at 90 days was 8.9% in the MSU group and 11.9% in the EMS group.

CONCLUSIONS

In patients with acute stroke who were eligible for t-PA, utility-weighted disability outcomes at 90 days were better with MSUs than with EMS. (Funded by the Patient-Centered Outcomes Research Institute; BEST-MSU ClinicalTrials.gov number, NCT02190500.).

Association between Pregnancy and Cervical Artery Dissection

OBJECTIVE

We wanted to determine whether pregnancy is associated with cervical artery dissection.

METHODS

We performed a case-control study using claims data from all nonfederal emergency departments and acute care hospitals in New York and Florida between 2005 and 2015. Cases were women 12-42 years of age hospitalized with cervical artery dissection, defined using validated diagnosis codes for carotid/vertebral artery dissection. Controls were women 12-42 years of age with a primary diagnosis of renal colic. Cases and controls were matched 1:1 on age, race, insurance, income, state, and visit year. The exposure variable was pregnancy, defined as labor and delivery within 90 days before or 6 months after the index visit. Logistic regression was used to compare the odds of pregnancy between cases and controls. We performed a secondary cohort-crossover study comparing the risk of cervical artery dissection during pregnancy versus the same time period 1 year later.

RESULTS

Pregnancy was twice as common among 826 women with cervical artery dissection compared with the 826 matched controls with renal colic (odds ratio, 2.5; 95% confidence interval [CI], 1.3-4.7). In our secondary analysis, pregnancy was associated with a higher risk of cervical artery dissection (incidence rate ratio [IRR], 2.2; 95% CI, 1.3-3.5), with the heightened risk limited to the postpartum period (IRR, 5.5; 95% CI, 2.6-11.7).

INTERPRETATION

Pregnancy, specifically the postpartum period, was associated with hospitalization for cervical artery dissection. Although these findings might in part reflect ascertainment bias, our results suggest that arterial dissection is one mechanism by which pregnancy can lead to stroke. ANN NEUROL 2020;88:596-602.

Risk of Ischemic Stroke in Patients With Coronavirus Disease 2019 (COVID-19) vs Patients With Influenza

IMPORTANCE

It is uncertain whether coronavirus disease 2019 (COVID-19) is associated with a higher risk of ischemic stroke than would be expected from a viral respiratory infection.

OBJECTIVE

To compare the rate of ischemic stroke between patients with COVID-19 and patients with influenza, a respiratory viral illness previously associated with stroke.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study was conducted at 2 academic hospitals in New York City, New York, and included adult patients with emergency department visits or hospitalizations with COVID-19 from March 4, 2020, through May 2, 2020. The comparison cohort included adults with emergency department visits or hospitalizations with influenza A/B from January 1, 2016, through May 31, 2018 (spanning moderate and severe influenza seasons).

EXPOSURES

COVID-19 infection confirmed by evidence of severe acute respiratory syndrome coronavirus 2 in the nasopharynx by polymerase chain reaction and laboratory-confirmed influenza A/B.

MAIN OUTCOMES AND MEASURES

A panel of neurologists adjudicated the primary outcome of acute ischemic stroke and its clinical characteristics, mechanisms, and outcomes. We used logistic regression to compare the proportion of patients with COVID-19 with ischemic stroke vs the proportion among patients with influenza.

RESULTS

Among 1916 patients with emergency department visits or hospitalizations with COVID-19, 31 (1.6%; 95% CI, 1.1%-2.3%) had an acute ischemic stroke. The median age of patients with stroke was 69 years (interquartile range, 66-78 years); 18 (58%) were men. Stroke was the reason for hospital presentation in 8 cases (26%). In comparison, 3 of 1486 patients with influenza (0.2%; 95% CI, 0.0%-0.6%) had an acute ischemic stroke. After adjustment for age, sex, and race, the likelihood of stroke was higher with COVID-19 infection than with influenza infection (odds ratio, 7.6; 95% CI, 2.3-25.2). The association persisted across sensitivity analyses adjusting for vascular risk factors, viral symptomatology, and intensive care unit admission.

CONCLUSIONS AND RELEVANCE

In this retrospective cohort study from 2 New York City academic hospitals, approximately 1.6% of adults with COVID-19 who visited the emergency department or were hospitalized experienced ischemic stroke, a higher rate of stroke compared with a cohort of patients with influenza. Additional studies are needed to confirm these findings and to investigate possible thrombotic mechanisms associated with COVID-19.

Risk of Ischemic Stroke in Patients with Covid-19 versus Patients with Influenza

Importance:

Case series without control groups suggest that Covid-19 may cause ischemic stroke, but whether Covid-19 is associated with a higher risk of ischemic stroke than would be expected from a viral respiratory infection is uncertain.

Objective:

To compare the rate of ischemic stroke between patients with Covid-19 and patients with influenza, a respiratory viral illness previously linked to stroke.

Design:

A retrospective cohort study.

Setting:

Two academic hospitals in New York City.

Participants:

We included adult patients with emergency department visits or hospitalizations with Covid-19 from March 4, 2020 through May 2, 2020. Our comparison cohort included adult patients with emergency department visits or hospitalizations with influenza A or B from January 1, 2016 through May 31, 2018 (calendar years spanning moderate and severe influenza seasons).

Exposures:

Covid-19 infection confirmed by evidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the nasopharynx by polymerase chain reaction, and laboratory-confirmed influenza A or B.

Main Outcomes and Measures:

A panel of neurologists adjudicated the primary outcome of acute ischemic stroke and its clinical characteristics, etiological mechanisms, and outcomes. We used logistic regression to compare the proportion of Covid-19 patients with ischemic stroke versus the proportion among patients with influenza.

Results:

Among 2,132 patients with emergency department visits or hospitalizations with Covid-19, 31 patients (1.5%; 95% confidence interval [CI], 1.0%-2.1%) had an acute ischemic stroke. The median age of patients with stroke was 69 years (interquartile range, 66-78) and 58% were men. Stroke was the reason for hospital presentation in 8 (26%) cases. For our comparison cohort, we identified 1,516 patients with influenza, of whom 0.2% (95% CI, 0.0-0.6%) had an acute ischemic stroke. After adjustment for age, sex, and race, the likelihood of stroke was significantly higher with Covid-19 than with influenza infection (odds ratio, 7.5; 95% CI, 2.3-24.9).

Conclusions and Relevance:

Approximately 1.5% of patients with emergency department visits or hospitalizations with Covid-19 experienced ischemic stroke, a rate 7.5-fold higher than in patients with influenza. Future studies should investigate the thrombotic mechanisms in Covid-19 in order to determine optimal strategies to prevent disabling complications like ischemic stroke.

Differences in Admission Blood Pressure Among Causes of Intracerebral Hemorrhage

Background and Purpose- It is unknown whether admission systolic blood pressure (SBP) differs among causes of intracerebral hemorrhage (ICH). We sought to elucidate an association between admission BP and ICH cause. Methods- We compared admission SBP across ICH causes among patients in the Cornell Acute Stroke Academic Registry, which includes all adults with ICH at our center from 2011 through 2017. Trained analysts prospectively collected demographics, comorbidities, and admission SBP, defined as the first recorded value in the emergency department or on transfer from another hospital. ICH cause was adjudicated by a panel of neurologists using the SMASH-U criteria. We used ANOVA to compare mean admission SBP among ICH causes. We used multiple linear regression to adjust for age, sex, race, Glasgow Coma Scale score, and hematoma size. In secondary analyses, we compared hourly SBP measurements during the first 72 hours after admission, using mixed-effects linear models adjusted for the covariates above plus antihypertensive agents. Results- Among 484 patients with ICH, admission SBP varied significantly across ICH causes, ranging from 138 (±24) mm Hg in those with structural vascular lesions to 167 (±35) mm Hg in those with hypertensive ICH (P<0.001). The mean admission SBP in hypertensive ICH was 17 (95% CI, 11-24) mm Hg higher than in ICH of all other causes combined. These differences remained significant after adjustment for age, sex, race, Glasgow Coma Scale score, and hematoma size (P<0.001), and this persisted throughout the first 72 hours of hospitalization (P<0.001). Conclusions- In a single-center ICH registry, SBP varied significantly among ICH causes, both on admission and during hospitalization. Our results suggest that BP in the acute post-ICH setting is at least partly associated with ICH cause rather than simply representing a physiological reaction to the ICH itself.

Geographic Analysis of Mobile Stroke Unit Treatment in a Dense Urban Area: The New York City METRONOME Registry

Background Mobile stroke units (MSUs) reduce time to intravenous thrombolysis in acute ischemic stroke. Whether this advantage exists in densely populated urban areas with many proximate hospitals is unclear. Methods and Results We evaluated patients from the METRONOME (Metropolitan New York Mobile Stroke) registry with suspected acute ischemic stroke who were transported by a bi-institutional MSU operating in Manhattan, New York, from October 2016 to September 2017. The comparison group included patients transported to our hospitals via conventional ambulance for acute ischemic stroke during the same hours of MSU operation (Monday to Friday, 9 am to 5 pm). Our exposure was MSU care, and our primary outcome was dispatch-to-thrombolysis time. We estimated mean differences in the primary outcome between both groups, adjusting for clinical, demographic, and geographic factors, including numbers of nearby designated stroke centers and population density. We identified 66 patients treated or transported by MSU and 19 patients transported by conventional ambulance. Patients receiving MSU care had significantly shorter dispatch-to-thrombolysis time than patients receiving conventional care (mean: 61.2 versus 91.6 minutes; P=0.001). Compared with patients receiving conventional care, patients receiving MSU care were significantly more likely to be picked up closer to a higher mean number of designated stroke centers in a 2.0-mile radius (4.8 versus 2.7, P=0.002). In multivariable analysis, MSU care was associated with a mean decrease in dispatch-to-thrombolysis time of 29.7 minutes (95% CI, 6.9-52.5) compared with conventional care. Conclusions In a densely populated urban area with a high number of intermediary stroke centers, MSU care was associated with substantially quicker time to thrombolysis compared with conventional ambulance care.

Abstract WP104: Clinical Characteristics of Stroke Mimics Treated on an Urban Mobile Stroke Unit

Introduction: It is unknown how the clinical characteristics of stroke mimics treated on Mobile Stroke Units (MSUs) compare to confirmed acute strokes treated on these units.

Methods: We retrospectively analyzed all patients transported by the NewYork-Presbyterian MSU in New York City from October 2016-May 2018. A vascular neurologist assigned a final diagnosis after comprehensive medical record review. Clinical data were abstracted, including comorbidities, presenting symptoms, stroke severity, acute treatments, and short-term outcomes. We compared characteristics of patients with a stroke mimic diagnosis versus those with acute ischemic or hemorrhagic stroke using targeted minimum loss-based estimation to adjust for demographics, comorbidities, NIH Stroke Scale (NIHSS) score, and intravenous tPA administration.

Results: Among 92 suspected stroke patients transported by MSU, 56 (61%) had confirmed acute stroke (77% ischemic, 23% hemorrhagic) and 36 (39%) had a stroke mimic. Mimics consisted of seizure (n=8), metabolic encephalopathy (n=6), somatoform disorders (n=4), and others (n=18). The mean NIHSS score was 8 (SD 7) among mimics versus 11 (SD 8) among confirmed strokes (p=0.14). The top presenting symptoms among mimics were unilateral weakness (n=8), aphasia (n=6), confusion (n=6), and decreased consciousness (n=6). Nine mimics (25%) received tPA and none had hemorrhagic conversion; while 30 (53%) confirmed strokes received tPA and 2 (7%) had hemorrhagic conversion. There was no difference in MSU arrival-to-tPA time between groups (46 vs. 44 minutes, p=0.70). In multivariable analyses, compared to patients with confirmed stroke, mimics had significantly lower NIHSS scores, higher initial blood pressures, and shorter lengths-of-stay. Rates of death and discharge disposition were similar between groups.

Conclusions: Among patients transported by a MSU for suspected stroke, two-fifths were stroke mimics. Seizure, metabolic encephalopathy, and somatoform disorders were the most common mimic diagnoses. Patients with stroke mimics had lower NIHSS scores and less often were treated with tPA.

Abstract WP92: Radiologist Inter-rater Reliability of Prehospital Alberta Stroke Program Early CT Scores on a Mobile Stroke Unit

Introduction: The computed tomography (CT) capabilities of mobile stroke units (MSUs) may facilitate prehospital triaging of patients with suspected large-vessel occlusion directly to thrombectomy-capable centers. However, little is known about the reliability of radiological interpretation of early ischemic changes on prehospital CTs.

Methods: We identified all patients transported by the NewYork-Presbyterian MSU to Weill Cornell Medical Center with the diagnosis of acute ischemic stroke, transient ischemic attack, or stroke mimic between October 3, 2016 and December 31, 2017. All patients underwent noncontrast head CT on board the MSU using a CereTom® scanner. As controls, we matched these patients 1:1 by diagnosis to patients who were transported by standard ambulance and underwent noncontrast brain CT in our emergency department (ED) over the same period. Two neuroradiologists, blinded to patients’ characteristics and final diagnosis, independently calculated Alberta Stroke Program Early CT Scores (ASPECTS) on all scans. Weighted percent agreement and Cohen’s κ were used to assess inter-rater reliability, and paired t-tests were used to compare these metrics between MSU and ED scans.

Results: Among 46 MSU patients and 46 ED patients, 52% had a diagnosis of acute ischemic stroke, 46% a diagnosis of stroke mimic, and 2% a diagnosis of transient ischemic attack. For ASPECTS score as a continuous outcome, the weighted inter-rater agreement was 98% for MSU scans versus 96% for ED scans (mean difference, 2%; 95% CI, -1% to 5%) and the weighted κ was 0.49 for MSU scans versus 0.54 for ED scans (mean difference, -0.05; 95% CI, -0.61 to 0.51). For ASPECTS score categorized as 0-4, 5-7, or 8-10, the weighted inter-rater agreement was 99% for MSU scans versus 97% for ED scans (mean difference, 2%; 95% CI, -2% to 7%) and the weighted κ was 0.66 for MSU scans versus 0.55 for ED scans (mean difference, 0.10; 95% CI, -0.87 to 1.08).

Conclusions: In a sample of 96 patients, which limited our power to detect small differences, we found no substantial difference in the inter-rater reliability of ASPECTS scores obtained from MSU CTs versus ED CTs.

Superficial Siderosis of Central Nervous System as Primary Clinical Manifestation Secondary to Intradural Thoracic Disk Herniation

BACKGROUND

Superficial siderosis of the central nervous system is a rare neurologic disorder characterized by the superficial deposition of hemosiderin in the subpial layer resulting in iron-related progressive neurodegeneration.

CASE DESCRIPTION

In this report, we present a case of superficial siderosis of the central nervous system secondary to an intradural thoracic disk herniation causing a cerebrospinal fluid (CSF) leak.

CONCLUSIONS

The patient was successfully treated with T6-T8 transpedicular partial corpectomy, as well as diskectomy with decompression followed by watertight closure of the CSF leak. Intraoperative watertight closure of the CSF leak was achieved.

Clinical Information Systems Integration in New York City's First Mobile Stroke Unit

BACKGROUND

Mobile stroke units (MSUs) reduce time to thrombolytic therapy in acute ischemic stroke. These units are widely used, but the clinical information systems underlying MSU operations are understudied.

OBJECTIVE

The first MSU on the East Coast of the United States was established at New York Presbyterian Hospital (NYP) in October 2016. We describe our program's 7-month pilot, focusing on the integration of our hospital's clinical information systems into our MSU to support patient care and research efforts.

METHODS

NYP's MSU was staffed by two paramedics, one radiology technologist, and a vascular neurologist. The unit was equipped with four laptop computers and networking infrastructure enabling all staff to access the hospital intranet and clinical applications during operating hours. A telephone-based registration procedure registered patients from the field into our admit/discharge/transfer system, which interfaced with the institutional electronic health record (EHR). We developed and implemented a computerized physician order entry set in our EHR with prefilled values to permit quick ordering of medications, imaging, and laboratory testing. We also developed and implemented a structured clinician note to facilitate care documentation and clinical data extraction.

RESULTS

Our MSU began operating on October 3, 2016. As of April 27, 2017, the MSU transported 49 patients, of whom 16 received tissue plasminogen activator (t-PA). Zero technical problems impacting patient care were reported around registration, order entry, or intranet access. Two onboard network failures occurred, resulting in computed tomography scanner malfunctions, although no patients became ineligible for time-sensitive treatment as a result. Thirteen (26.5%) clinical notes contained at least one incomplete time field.

CONCLUSION

The main technical challenges encountered during the integration of our hospital's clinical information systems into our MSU were onboard network failures and incomplete clinical documentation. Future studies are necessary to determine whether such integrative efforts improve MSU care quality, and which enhancements to information systems will optimize clinical care and research efforts.

Modeling the Impact of Interhospital Transfer Network Design on Stroke Outcomes in a Large City

BACKGROUND AND PURPOSE

We sought to model the effects of interhospital transfer network design on endovascular therapy eligibility and clinical outcomes of stroke because of large-vessel occlusion for the residents of a large city.

METHODS

We modeled 3 transfer network designs for New York City. In model A, patients were transferred from spoke hospitals to the closest hub hospitals with endovascular capabilities irrespective of hospital affiliation. In model B, which was considered the base case, patients were transferred to the closest affiliated hub hospitals. In model C, patients were transferred to the closest affiliated hospitals, and transfer times were adjusted to reflect full implementation of streamlined transfer protocols. Using Monte Carlo methods, we simulated the distributions of endovascular therapy eligibility and good functional outcomes (modified Rankin Scale score, 0-2) in these models.

RESULTS

In our models, 200 patients (interquartile range [IQR], 168-227) with a stroke amenable to endovascular therapy present to New York City spoke hospitals each year. Transferring patients to the closest hub hospital irrespective of affiliation (model A) resulted in 4 (IQR, 1-9) additional patients being eligible for endovascular therapy and an additional 1 (IQR, 0-2) patient achieving functional independence. Transferring patients only to affiliated hospitals while simulating full implementation of streamlined transfer protocols (model C) resulted in 17 (IQR, 3-41) additional patients being eligible for endovascular therapy and 3 (IQR, 1-8) additional patients achieving functional independence.

CONCLUSIONS

Optimizing acute stroke transfer networks resulted in clinically small changes in population-level stroke outcomes in a dense, urban area.

Association Between Troponin Levels and Embolic Stroke of Undetermined Source

Background

Our aim was to determine whether patients with embolic strokes of undetermined source (ESUS) have higher rates of elevated troponin than patients with noncardioembolic strokes.

Methods and Results

CAESAR (The Cornell Acute Stroke Academic Registry) prospectively enrolled all adults with acute stroke from 2011 to 2014. Two neurologists used standard definitions to retrospectively ascertain the etiology of stroke, with a third resolving disagreements. In this analysis we included patients with ESUS and, as controls, patients with small‐ and large‐artery strokes; only patients with a troponin measured within 24 hours of stroke onset were included. A troponin elevation was defined as a value exceeding our laboratory's upper limit (0.04 ng/mL) without a clinically recognized acute ST‐segment elevation myocardial infarction. Multiple logistic regression was used to evaluate the association between troponin elevation and ESUS after adjustment for demographics, stroke severity, insular infarction, and vascular risk factors. In a sensitivity analysis we excluded patients diagnosed with atrial fibrillation after discharge. Among 512 patients, 243 (47.5%) had ESUS, and 269 (52.5%) had small‐ or large‐artery stroke. In multivariable analysis an elevated troponin was independently associated with ESUS (odds ratio 3.3; 95% confidence interval 1.2, 8.8). This result was unchanged after excluding patients diagnosed with atrial fibrillation after discharge (odds ratio 3.4; 95% confidence interval 1.3, 9.1), and the association remained significant when troponin was considered a continuous variable (odds ratio for log[troponin], 1.4; 95% confidence interval 1.1, 1.7).

Conclusions

Elevations in cardiac troponin are more common in patients with ESUS than in those with noncardioembolic strokes.

Abstract WMP52: Incidence of Ischemic and Hemorrhagic Stroke Amongst Asians in the United States

Background: Studies from Asia suggest that the overall proportion of hemorrhagic stroke is much higher compared to other parts of the world. We sought to evaluate the incidence of ischemic and hemorrhagic strokes in Asians living in the U.S. versus U.S. patients of other races and ethnicities.

Methods: We identified all adult patients with acute ischemic or hemorrhagic stroke in the Nationwide Inpatient Sample from 2002-2011, using well-validated International Classification of Diseases, 9 th Revision, Clinical Modification ( ICD-9-CM ) diagnosis codes. Our predictor variable was self-reported Asian race. Our primary outcome was the relative proportion of hemorrhagic compared to ischemic strokes. Survey weights were used to account for the sampling methodology. Trend analysis was then performed using the Chi square test for linear association.

Results: We included 4,449,516 patients in the U.S. with stroke, of whom 3,794,438 (85.3%) had ischemic stroke and 655,078 (14.7%) had hemorrhagic stroke. Of these patients, 98,964 (2.2%) were Asian. Amongst the entire sample of stroke patients, Asians had a higher proportion of hemorrhagic strokes compared to the general population (24.0% vs. 14.5%, p<0.001). Asian patients were also more likely to have diabetes mellitus (28.8% vs. 23.7%, p<0.001) and hypertension (82.4% vs. 75.1%, p<0.001) compared to other races and ethnicities. Conversely, atrial fibrillation was less common in Asians (14.8% vs. 19%, p<0.001). There were no significant trends in the relative proportions of stroke types among different races and ethnicities over the past decade.

Conclusions: The incidence of hemorrhagic strokes appears to be higher among Asian compared to patients of other races and ethnicities in the U.S. Further study is warranted to delineate the role of genetic versus environmental factors in explaining the greater propensity to hemorrhagic as opposed to ischemic stroke in Asians.

Internal Carotid Artery Dissection After Indirect Blunt Cervical Trauma in an Ice Hockey Goaltender

Internal carotid artery dissections are rare injuries that can result from both direct cervical trauma and indirect trauma causing sudden cervical hyperextension. Depending on the magnitude of the dissection, clinical presentation ranges from neurologic symptoms, such as Horner syndrome, to relatively mild but persistent headache symptoms, as in the case reported in this article. High clinical suspicion with subsequent neuroimaging is recommended in similar clinical scenarios. Our patient, an ice hockey goaltender, was conservatively treated with rest and serial neuroimaging studies to ensure resolution of the dissection. Eight weeks later, he returned to athletic competition with resolved symptoms and radiologically improved arterial stenosis.

Brain contusion with aphasia following an ice hockey injury

Head injuries are relatively common in ice hockey, with the majority represented by concussions, a form of mild traumatic brain injury. More severe head injuries are rare since the implementation of mandatory helmet use in the 1960s. We present a case of a 27 year-old male who sustained a traumatic intraparenchymal hemorrhage with an associated subdural hematoma resulting after being struck by a puck shot at high velocity. The patient presented with expressive aphasia, with no other apparent neurologic deficits. Acutely, he was successfully treated with observation and serial neuroimaging studies ensuring an absence of hematoma expansion. After a stable clinical picture following 24 hours of observation, the patient was discharged and managed with outpatient speech therapy with full resolution of symptoms and return to play 3 months later. We will outline the patient presentation and pertinent points in the management of acute head injuries in athletes.

Intracerebral Hemorrhage Outcomes in Patients with Systemic Cancer

BACKGROUND

Single-center studies suggest that patients with cancer have similar outcomes after intracerebral hemorrhage (ICH) compared to patients without cancer. However, these studies were limited by small sample sizes and high rates of intratumoral hemorrhage. Our hypothesis was that systemic cancer patients without brain involvement fare worse after ICH than patients without cancer.

METHODS

We identified all patients diagnosed with spontaneous ICH from 2002 to 2011 in the Nationwide Inpatient Sample. Our predictor variable was systemic cancer. Our primary outcome was discharge disposition, dichotomized into favorable discharge (home/self-care or rehabilitation) or unfavorable discharge (nursing facility, hospice, or death). We used logistic regression to compare outcomes and performed secondary analyses by cancer subtype (i.e., nonmetastatic solid tumors, nonmetastatic hematologic tumors, and metastatic solid or hematologic tumors).

RESULTS

Among 597,046 identified ICH patients, 22,394 (3.8%) had systemic cancer. Stroke risk factors such as hypertension and diabetes were more common in patients without cancer, whereas anticoagulant use and higher Charlson comorbidity scores were more common among cancer patients. In multivariate logistic regression analysis adjusted for demographics, comorbidities, and hospital-level characteristics, patients with cancer had higher odds of death (OR 1.62, 95% CI 1.56-1.69) and lower odds of favorable discharge (OR .59, 95% CI .56-.63) than patients without cancer. Among cancer groups, patients with nonmetastatic hematologic tumors and those with metastatic disease fared the worst.

CONCLUSIONS

Patients with systemic cancer have higher mortality and less favorable discharge outcomes after ICH than patients without cancer. Cancer subtype may influence outcomes after ICH.

Acute cerebrovascular disease occurring after hospital discharge for labor and delivery

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.

Appropriate use of CT perfusion following aneurysmal subarachnoid hemorrhage: a Bayesian analysis approach

BACKGROUND AND PURPOSE

In recent years CTP has been used as a complementary diagnostic tool in the evaluation of delayed cerebral ischemia and vasospasm. Our aim was to determine the test characteristics of CTP for detecting delayed cerebral ischemia and vasospasm in SAH, and then to apply Bayesian analysis to identify subgroups for its appropriate use.

MATERIALS AND METHODS

Our retrospective cohort comprised consecutive patients with SAH and CTP performed between days 6 and 8 following aneurysm rupture. Delayed cerebral ischemia was determined according to primary outcome measures of infarction and/or permanent neurologic deficits. Vasospasm was determined by using DSA. The test characteristics of CTP and its 95% CIs were calculated. Graphs of conditional probabilities were constructed by using Bayesian techniques. Local treatment thresholds (posttest probability of delayed cerebral ischemia needed to initiate induced hypertension, hypervolemia, and hemodilution or intra-arterial therapy) were determined via a survey of 6 independent neurologists.

RESULTS

Ninety-seven patients with SAH were included in the study; 39% (38/97) developed delayed cerebral ischemia. Qualitative CTP deficits were seen in 49% (48/97), occurring in 84% (32/38) with delayed cerebral ischemia and 27% (16/59) without. The sensitivity, specificity, and positive and negative predictive values (95% CI) for CTP were 0.84 (0.73-0.96), 0.73 (0.62-0.84), 0.67 (0.51-0.79), and 0.88 (0.74-0.94), respectively. A subgroup of 57 patients underwent DSA; 63% (36/57) developed vasospasm. Qualitative CTP deficits were seen in 70% (40/57), occurring in 97% (35/36) with vasospasm and 23% (5/21) without. The sensitivity, specificity, and positive and negative predictive values (95% CI) for CTP were 0.97 (0.92-1.0), 0.76 (0.58-0.94), 0.88 (0.72-0.95), and 0.94 (0.69-0.99), respectively. Treatment thresholds were determined as 30% for induced hypertension, hypervolemia, and hemodilution and 70% for intra-arterial therapy.

CONCLUSIONS

Positive CTP findings identify patients who should be carefully considered for induced hypertension, hypervolemia, and hemodilution and/or intra-arterial therapy while negative CTP findings are useful in guiding a no-treatment decision.

Paroxysmal supraventricular tachycardia and the risk of ischemic stroke

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 4 806 830 eligible patients, 14 121 (0.29%) were diagnosed with PSVT and 14 402 (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.

Osmotherapy for intracranial hypertension: mannitol versus hypertonic saline

PURPOSE OF REVIEW

Hyperosmolar therapy is one of the core medical treatments for brain edema and intracranial hypertension, but controversy exists regarding the use of the most common agents, mannitol, and hypertonic saline. This article describes the relative merits and adverse effects of these agents using the best available clinical evidence.

RECENT FINDINGS

Mannitol is effective and has been used for decades in the treatment of traumatic brain injury, but it may precipitate acute renal failure if serum osmolarity exceeds 320 mOsm/L. Hypertonic saline appears to be safe, and serum sodium has been elevated to as high as 180 mEq/L in clinical settings without significant neurologic, cardiac, or renal injury. In small comparative trials both agents are effective and no clinically significant difference has been noted, but a properly powered trial has not yet been performed.

SUMMARY

Both mannitol and hypertonic saline are effective and have an acceptable risk profile for use in the treatment of elevated intracranial pressure secondary to brain edema.

Spreading depolarization: a possible new culprit in the delayed cerebral ischemia of subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (SAH) is a devastating disease with a high mortality and morbidity rate. Gradual improvements have been made in the reduction of mortality rates associated with the disease during the last 30 years. However, delayed cerebral ischemia (DCI), the major delayed complication of SAH, remains a significant contributor to mortality and morbidity despite substantial research and clinical efforts. During the last several years, the predominant role of cerebral vasospasm, the long-accepted etiologic factor behind DCI, has been questioned. It is now becoming increasingly clear that the pathophysiology underlying DCI is multifactorial. Cortical spreading depression is emerging as a likely factor in this complex web of pathologic changes after SAH. Understanding its role after SAH and its relationship with the other pathologic processes such as vasospasm, microcirculatory dysfunction, and microemboli will be vital to the development of new therapeutic approaches to reduce DCI and improve the clinical outcome of the disease.

Ethyl Pyruvate Provides Durable Protection Against Inflammation-Induced Intestinal Epithelial Barrier Dysfunction

Ethyl pyruvate (EP) has been shown to be an effective anti-inflammatory agent. Herein, we sought to test the following hypotheses: 1) the pharmacological effects of EP persist after cells have been exposed to the compound in vitro, even if the cultures are washed to minimize the amount of EP that is retained in the media; 2) the pharmacological effects of EP persist in vivo, even after waiting a prolonged period (i.e., 6 h) after the last dose of the compound; and 3) the in vivo pharmacological effects of EP are distinct from those of the closely related compound, sodium pyruvate. Incubation of Caco-2 human enterocyte-like monolayers with cytomix, a mixture of interleukin-1beta, interferon-gamma, and tumor necrosis factor, increased permeability to the fluorescent macromolecule, FITC-labeled Dextran (mol wt 4,000 Da). Co-incubation of the cells with 5 mM EP ameliorated cytomix-induced hyperpermeability and induction of iNOS mRNA expression. EP was associated with similar pharmacological effects when cells were pre-incubated with the compound for 24 h prior and then washed extensively prior to adding the cytokine cocktail. Injecting C57Bl/6 mice with lipopolysaccharide (LPS) resulted in gut barrier dysfunction and hepatocellular injury. Although equivalent doses of both EP and sodium pyruvate ameliorated these phenomena, EP was more efficacious than pyruvate. Pretreatment with EP ameliorated the deleterious effects of LPS, even when the duration between the last dose of EP and the endotoxic challenge was 6 h. We conclude that EP provides durable protection against some of the deleterious effects of LPS or pro-inflammatory cytokines.

Effect of hypervolemic therapy on cerebral blood flow after subarachnoid hemorrhage : a randomized controlled trial

BACKGROUND AND PURPOSE

Cerebral blood flow (CBF) is reduced after subarachnoid hemorrhage (SAH), and symptomatic vasospasm is a major cause of morbidity and mortality. Volume expansion has been reported to increase CBF after SAH, but CBF values in hypervolemic (HV) and normovolemic (NV) subjects have never been directly compared.

METHODS

On the day after aneurysm clipping, we randomly assigned 82 patients to receive HV or NV fluid management until SAH day 14. In addition to 80 mL/h of isotonic crystalloid, 250 mL of 5% albumin solution was given every 2 hours to maintain normal (NV group, n=41) or elevated (HV group, n=41) cardiac filling pressures. CBF ((133)xenon clearance) was measured before randomization and approximately every 3 days thereafter (mean, 4.5 studies per patient).

RESULTS

HV patients received significantly more fluid and had higher pulmonary artery diastolic and central venous pressures than NV patients, but there was no effect on net fluid balance or on blood volume measured on the third postoperative day. There was no difference in mean global CBF during the treatment period between HV and NV patients (P=0.55, random-effects model). Symptomatic vasospasm occurred in 20% of patients in each group and was associated with reduced minimum regional CBF values (P=0.04). However, there was also no difference in minimum regional CBF between the 2 treatment groups.

CONCLUSIONS

HV therapy resulted in increased cardiac filling pressures and fluid intake but did not increase CBF or blood volume compared with NV therapy. Although careful fluid management to avoid hypovolemia may reduce the risk of delayed cerebral ischemia after SAH, prophylactic HV therapy is unlikely to confer an additional benefit.

Myocardial injury and left ventricular performance after subarachnoid hemorrhage

BACKGROUND AND PURPOSE

Electrocardiographic abnormalities and elevations of the creatine kinase myocardial isoenzyme (CK-MB) occur frequently after subarachnoid hemorrhage. In some patients, a reversible and presumably neurogenic form of left ventricular dysfunction is demonstrated by echocardiography. It is not known whether cardiac injury of this type adversely affects cardiovascular hemodynamic performance.

METHODS

We retrospectively studied 72 patients admitted to our neuro-ICU for aneurysmal subarachnoid hemorrhage over a 2.5-year period. We selected patients who met the following criteria: (1) CK-MB levels measured within 3 days of onset, (2) pulmonary artery catheter placed, (3) echocardiogram performed, and (4) no history of preexisting cardiac disease. Hemodynamic profiles were recorded on the day after surgery (n=67) or on the day of echocardiography (n=5) if surgery was not performed (mean, 3. 3+/-1.7 days after onset). The severity of cardiac injury was classified as none (peak CK-MB <1%, n=36), mild (peak CK-MB 1% to 2%, n=21), moderate (peak CK-MB >2%, n=6), or severe (abnormal left ventricular wall motion, n=9).

RESULTS

Abnormal left ventricular wall motion occurred exclusively in patients with peak CK-MB levels >2% (P<0.0001), poor neurological grade (P=0.002), and female sex (P=0.02). Left ventricular stroke volume index and stroke work index were elevated above the normal range in patients with peak CK-MB levels <1% and fell progressively as the severity of cardiac injury increased, with mean values for patients with abnormal wall motion below normal (both P<0.0001 by ANOVA). Cardiac index followed a similar trend, but the effect was less pronounced (P<0.0001). Using forward stepwise multiple logistic regression, we found that thick subarachnoid clot on the admission CT scan (odds ratio, 1.9; 95% confidence interval [95% CI], 1.0 to 3.4; P=0.04) and depressed cardiac index (odds ratio, 2.1; 95% CI, 1.0 to 4.1; P=0.04) were independent predictors of symptomatic vasospasm.

CONCLUSIONS

Myocardial enzyme release and echocardiographic wall motion abnormalities are associated with impaired left ventricular performance after subarachnoid hemorrhage. In severely affected patients, reduction of cardiac output from normally elevated levels may increase the risk of cerebral ischemia related to vasospasm.

Perilesional blood flow and edema formation in acute intracerebral hemorrhage: a SPECT study

BACKGROUND AND PURPOSE

Secondary brain injury and edema formation contribute significantly to morbidity and mortality after intracerebral hemorrhage (ICH). The pathogenesis of this process is poorly understood. We sought to characterize alterations in perilesional blood flow that occur during the acute phase of ICH and to determine whether progressive enlargement of edema surrounding ICH is related to increased or decreased perfusion.

METHODS

We performed paired consecutive CT and 99mTc-hexamethylpropylenamine oxime single-photon emission computed tomography (SPECT) scans during the acute (mean, 18 hours) and subacute (mean, 72 hours) phase of ICH in 23 patients. Hematoma and edema volumes were traced and calculated from CT images. SPECT-derived hypothetical flow deficit volumes (FDV) around each hematoma were calculated by measuring a "zero-flow" volume within a large perilesional region of interest (based on percent tracer count loss compared with the contralateral side) and subtracting the corresponding ICH volume. Patients with significant midline shift (>5 mm) or global blood flow reduction were excluded from the analysis.

RESULTS

ICH volume (18 mL) did not change, mean edema volume increased by 36% (from 19 to 25 mL, P<0.0001), and mean FDV decreased by 55% (from 14 to 6 mL, P=0.0004) between the acute and subacute phases. Edema volume on the second CT scan correlated positively with FDV on the first SPECT scan (Spearman's p=0.48, P=0.02), and with the volume of reperfused perilesional tissue (FDVacute-FDVsubacute) (Spearman's p=0.41, P=0.05). Perilesional edema on CT always corresponded topographically with perfusion deficits on SPECT. In 4 patients, delayed focal hyperemia was identified in more peripheral cortical regions, but these areas appeared normal on CT.

CONCLUSIONS

Perilesional blood flow normalizes from initially depressed levels as edema forms during the first 72 hours after ICH, and the eventual extent of edema correlates with the volume of reperfused tissue. These results suggest that the potential for perilesional ischemia is highest in the earliest hours after ICH onset and implicate reperfusion injury in the pathogenesis of perihematoma edema formation.

Effect of 5% albumin solution on sodium balance and blood volume after subarachnoid hemorrhage

OBJECTIVE

Subarachnoid hemorrhage (SAH) predisposes patients to excessive natriuresis and volume contraction. We studied the effects of postoperative administration of 5% albumin solution on sodium balance and blood volume after SAH. We also sought to identify physiological variables that influence renal sodium excretion after SAH.

METHODS

Forty-three patients with acute SAH were randomly assigned to receive hypervolemia or normovolemia treatment for a period of 7 days after aneurysm clipping. In addition to a base line infusion of normal saline solution (80 ml/hr), 250 ml of 5% albumin solution was administered every 2 hours for central venous pressure (CVP) values of < or =8 mm Hg (hypervolemia group, n = 19) or < or =5 mm Hg (normovolemia group, n = 24).

RESULTS

Both groups demonstrated relative volume expansion in base line measurements. The hypervolemia group received significantly more total fluid, sodium, and 5% albumin solution than did the normovolemia group and had higher CVP values and serum albumin levels (all P < 0.02). Cumulative sodium balance was even in the hypervolemia group and persistently negative in the normovolemia group, because of sodium losses that occurred on Postoperative Days 2 and 3 (P = 0.03). In a multiple-regression analysis of all patients, 24-hour sodium balance correlated negatively with glomerular filtration rate (GFR) and positively with serum albumin levels, after correction for sodium intake (P < 0.0001). Hypervolemia therapy seemed to paradoxically lower GFR (P = 0.10) and had no effect on blood volume, which declined by 10% in both groups. Pulmonary edema requiring diuresis occurred in only one patient in the hypervolemia group.

CONCLUSION

Supplemental 5% albumin solution given to maintain CVP values of >8 mm Hg prevented sodium and fluid losses but did not have an impact on blood volume in our patients, who were hypervolemic in base line measurements. The natriuresis that occurs after SAH may be mediated in part by elevations of GFR. In addition to acting as a colloid volume expander, 5% albumin solution lowers the GFR and promotes renal sodium retention after SAH. These properties may limit the amount of total fluid required to maintain a given CVP value and hence may minimize the frequency of pulmonary edema.

Myasthenic crisis: clinical features, mortality, complications, and risk factors for prolonged intubation

We retrospectively reviewed the hospital records of 53 patients admitted for 73 episodes of myasthenic crisis at Columbia-Presbyterian Medical Center over a period of 12 years, from 1983 to 1994. Median age at the onset of first crisis was 55 (range, 20 to 82), the ratio of women to men was 2:1, and the median interval from onset of symptoms to first crisis was 8 months. Infection (usually pneumonia or upper respiratory infection) was the most common precipitating factor (38%), followed by no obvious cause (30%) and aspiration (10%). Twenty-five percent of patients were extubated at 7 days, 50% at 13 days, and 75% at 31 days; the longest crisis exceeded 5 months. Using survival analysis and backward stepwise Cox regression, we identified three independent predictors of prolonged intubation: (1) pre-intubation serum bicarbonate > or = 30 mg/dl (p = 0.0004, relative hazard 4.5), (2) peak vital capacity day 1 to 6 post-intubation < 25 ml/kg (p = 0.001, relative hazard 2.9), and (3) age > 50 (p = 0.01, relative hazard 2.4). The proportion of patients intubated longer than 2 weeks was 0% among those with no risk factors, 21% with one risk factor, 46% with two risk factors, and 88% with three risk factors (p = 0.0004). Complications independently associated with prolonged intubation included atelectasis (p = 0.002), anemia treated with transfusion (p = 0.03), Clostridium difficile infection (p = 0.01), and congestive heart failure (p = 0.03). Three episodes of crisis were fatal, for a mortality rate of 4% (3/73); four additional patients died after extubation. All seven deaths were due to overwhelming medical comorbidity. Over half of those who survived were functionally dependent (home or institutionalized) at discharge. In addition to prospective controlled studies of immunotherapies, the prevention and treatment of medical complications offers the best opportunity for further improving the outcome of myasthenic crisis.

Electrocardiographic markers of abnormal left ventricular wall motion in acute subarachnoid hemorrhage

A reversible and presumably neurogenic form of myocardial dysfunction may occur following subarachnoid hemorrhage (SAH), but the relationship of this finding to electrocardiographic abnormalities remains unclear. To clarify this issue, serial electrocardiograms (ECGs, mean 6.2 per patient) and echocardiograms (mean 3.4 days after SAH) were obtained in 57 SAH patients without preexisting cardiac disease. The goal was to determine which specific electrocardiographic changes, if any, reflect abnormal left ventricular wall motion in acute SAH. Wall motion abnormalities were identified in five (8%) of 57 patients. Four of these affected patients experienced hypotension (systolic blood pressure < 100 mm Hg) and three exhibited pulmonary edema within 6 hours of SAH, compared to none of the 52 patients with normal wall motion (p < 0.0001). Patients with abnormal wall motion were more likely than patients with normal echocardiograms to have symmetrical T wave inversion (five of five vs. seven of 52, p < 0.001) and severe (> or = 500 msec) QTc segment prolongation (five of five vs. three of 52, p < 0.001) on serial ECGs. These associations maintained their significance with analysis limited to single ECGs performed on or near the day of echocardiography. Abnormal wall motion was also associated with borderline (2% to 5%) creatine kinase MB elevation (five of five vs. three of 52, p < 0.001) and poor neurological grade (p < 0.0001). Although no combination of findings on a single ECG resulted in 100% sensitivity for abnormal wall motion, the presence of either inverted T waves or severe QTc segment prolongation on serial ECGs was associated with 100% sensitivity and 81% specificity. These results demonstrate an association between reduced left ventricular systolic function, mild creatine kinase MB elevation, and electrocardiographic repolarization abnormalities in acute SAH. Symmetrical T wave inversion and severe QTc segment prolongation best identified patients at risk for myocardial dysfunction and may serve as useful criteria for echocardiographic screening following SAH.

Noninvasive monitoring of cardiac output by Doppler echocardiography in patients treated with volume expansion after subarachnoid hemorrhage

OBJECTIVE

To assess the validity and potential clinical utility of cardiac output monitoring using Doppler echocardiography in patients treated with volume expansion after subarachnoid hemorrhage.

DESIGN

Observational study of patients in a randomized, clinical trial.

SETTING

Neurologic intensive care unit.

PATIENTS

Simultaneous, blinded measurements of cardiac output by thermodilution and Doppler echocardiography were performed in 48 patients 1 or 2 days after aneurysmal clipping. Follow-up Doppler echocardiography was performed an average of 3.9 days later (range 3 to 6) in 15 patients assigned to normovolemia and 24 patients assigned to hypervolemia.

INTERVENTION

Patients received supplemental 5% albumin in order to maintain increased (hypervolemia) or normal (normovolemia) cardiac filling pressures.

MEASUREMENTS AND MAIN RESULTS

The overall degree of correlation between the two measures was moderate (r = .67, r2 = .45, p < .0001). Bias and precision calculations (-0.75 +/- 1.34 L/min) showed a tendency for Doppler echocardiography to underestimate thermodilution, particularly when cardiac output was very high. Although hypervolemia patients received more 5% albumin than normovolemia patients, mean percent change in Doppler echocardiography cardiac output did not differ between the two groups. Multiple regression analysis showed that the percent change in Doppler echocardiography cardiac output correlated strongly with changes in heart rate (p < .0001), but not with daily net fluid balance or 5% albumin administration.

CONCLUSIONS

Agreement was poor between Doppler echocardiography and thermodilution measurements of cardiac output, and trends reflected variations in heart rate rather than fluid status. Monitoring of cardiac output by this technique cannot be recommended in patients treated with volume expansion after subarachnoid hemorrhage.

Progression of multiple cryptic vascular malformations associated with anomalous venous drainage. Case report

The case of a young girl with a pericallosal venous malformation associated with multiple cryptic vascular malformations (CVM's) is described. The presenting cryptic malformation, which hemorrhaged, was completely excised, but the venous malformation was not. Routine follow-up magnetic resonance images obtained over the past 9 years have documented the development of multiple new cryptic malformations along the radicles of the venous malformation. Magnetic resonance imaging and cerebral angiography revealed venous outflow obstruction at the junction of the venous malformation with the straight sinus. The association of CVM's with anomalous venous drainage patterns and the role of venous hypertension in the pathogenesis of cryptic malformations are discussed. This case suggests that CVM's associated with a venous malformation may recur and new ones may develop if the venous malformation is not excised, particularly if venous hypertension is also present. The likelihood of a surgical cure in these patients may depend on complete excision of both anomalies, which is rarely feasible because of the potentially devastating results of resecting a venous malformation. Alternative treatments for patients with both types of lesions are discussed.

Cardiac injury associated with neurogenic pulmonary edema following subarachnoid hemorrhage

OBJECTIVE

To describe the clinical features of cardiac injury associated with neurogenic pulmonary edema (NPE) in patients with acute subarachnoid hemorrhage (SAH).

BACKGROUND

NPE is generally viewed as a form of noncardiogenic pulmonary edema related to massive sympathetic discharge.

METHODS

Case series.

RESULTS

We found echocardiographic evidence of reduced global and segmental left ventricular (LV) systolic function in five women (mean age, 44; range, 36 to 57) with SAH and NPE. None had a history of heart disease. Four patients were Hunt/Hess grade III and one was grade IV. All five patients experienced (1) sudden hypotension (systolic blood pressure < 110 mm Hg) following initially elevated blood pressures, (2) transient lactic acidosis, (3) borderline (2 to 4%) creatine kinase MB elevations, and (4) varied acute (< 24 hours) electrocardiographic changes followed by widespread and persistent T wave inversions. Pulmonary artery wedge pressures were normal in 3/3 patients at the onset of pulmonary edema but reached high levels (> 16 mm Hg) in all four patients studied beyond this period. Reduced cardiac output and LV stroke volume were identified in three patients; the fourth patient demonstrated normal values on high doses of intravenous pressors. Cerebral infarction due to vasospasm occurred in four patients and resulted in two deaths. Follow-up echocardiography performed 2 to 6 weeks after SAH revealed normal LV function in all three survivors.

CONCLUSIONS

A reversible form of cardiac injury may occur in patients with NPE following SAH and is associated with characteristic clinical findings. Impaired LV hemodynamic performance in this setting may contribute to cardiovascular instability, pulmonary edema formation, and complications from cerebral ischemia.