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Cerebral Microbleeds: A Risk Factor for Intracranial Hemorrhage and Worse Outcomes After Thrombolytic Therapy for Acute Ischemic Stroke

Mark R. Etherton, MD PhD

Charidimou A, Turc G, Oppenheim C, Yan S, Scheitz JF, Erdur H, et al. Microbleeds, Cerebral Hemorrhage, and Functional Outcome After Stroke Thrombolysis: Individual Patient Data Meta-Analysis. Stroke. 2017

In this entry, I discuss the recent meta-analysis, using individual patient data, by Andreas Charidimou and colleagues on cerebral microbleeds (CMB) and the risk of intracerebral hemorrhage (ICH) and poor functional outcomes after intravenous thrombolytic therapy for acute ischemic stroke.

Prior to this study, a recent meta-analysis had demonstrated that the mere presence of pre-treatment CMBs was associated with increased odds of symptomatic intracerebral hemorrhage (sICH) after intravenous thrombolytic therapy for acute ischemic stroke (Charidimou et al. Stroke. 2015). Building on this study, the authors performed a pooled, individual patient data meta-analysis to evaluate several hypotheses pertaining to the presence, quantity, and location of pre-treatment CMBs in relation to ICH risk and post-stroke outcomes.

By |September 20th, 2017|clinical|0 Comments

Beyond Drip and Ship: The Role of Baseline Vascular Imaging for Referring Hospitals in Acute Ischemic Stroke Triage for the Endovascular Era

Danny R. Rose, Jr. MD

Boulouis G, Siddiqui K, Lauer A, Charidimou A, Regenhardt R, Viswanathan A, et al.  Immediate Vascular Imaging Needed for Efficient Triage of Patients With Acute Ischemic Stroke Initially Admitted to Nonthrombectomy Centers. Stroke. 2017

The landmark publication of multiple positive endovascular thrombectomy (EVT) trials in 2015 was a pivotal moment for treatment of acute ischemic stroke. The most significant development in acute stroke treatment in the nearly twenty years since the FDA approval of tissue plasminogen activator in 1996 has led to much discussion with respect to improving stroke systems of care to be able to provide this treatment to as many eligible patients as possible. Reflecting this new development in acute stroke treatment, the American Heart Association released a focused update to their guidelines on acute stroke treatment that recommended endovascular therapy be offered to patients who present within 6 hours of last known normal and have a favorable imaging profile and a National Institutes of Health Stroke Scale (NIHSS) of 6 or greater.

Just as the time-sensitive nature of intravenous thrombolytic administration led to the development of prehospital stroke scales and the stroke alert process, the most effective way to triage and treat patients with suspected emergent large vessel occlusions (LVO) amenable to endovascular treatment is a topic of ongoing research and debate. An important facet of this discussion concerns the most effective method to triage and transfer patients with suspected LVO to a thrombectomy-capable stroke center. A cohort by Sarraj et al. presented at the 2017 International Stroke Conference showed comparably good outcomes for patients transferred to thrombectomy-capable centers as compared to patients who presented directly to the facility, suggesting that the “drip and ship” transfer paradigm can be successfully augmented to accommodate endovascular therapy.

Author Interview: Søren Bache, MD

Søren Bache

Søren Bache

A conversation with Søren Bache, MD, from the Neurointensive Care Unit, Department of Neuroanaesthesiology and Centre for Genomic Medicine, Rigshospitalet, University of Copenhagen, Denmark, about microRNA changes after subarachnoid hemorrhage.

Interviewed by José G. Merino, MD, Associate Professor of Neurology, University of Maryland School of Medicine.

They will be discussing the paper, “MicroRNA Changes in Cerebrospinal Fluid After Subarachnoid Hemorrhage,” published in the September 2017 issue of Stroke.

​Dr. Merino: Thank you for agreeing to the interview. First, I would like you to explain some things about delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH) for our readers: How common is it? How soon after SAH does it develop? How does it affect outcome after SAH?

Dr. Bache: The reported prevalence of DCI after SAH varies, but newer randomized clinical trials have found a risk of 21–38% in patients who survive the initial bleeding and aneurism-securing surgery. The variation in calculated risk may be due to discrepancies both in case definition (i.e. the numerator) and in the definition of which patients are entered into the denominator. Today, most researchers base their case definition of DCI on the criteria suggested by Vergouwen et al. (Vergouwen MD, et al. Stroke. 2010). Before this consensus work, the definition varied even more, and many used their own criteria for DCI, delayed ischemic neurological deficits (DIND) or cerebral vasospasm. However, not all patients are conscious enough to be assessed clinically for a deterioration in consciousness, and such patients may be either included or excluded in the total number of patients; hence, the variation in the denominator. Based on Vergouwen’s criteria, in our center, we found a prevalence of 23% in 450 patients admitted from 2009–12 with SAH (unpublished data). These patients all receive prophylactic nimodipine, which lowers the risk of DCI; therefore, one should expect publications from the pre-nimodipine era to report a higher prevalence of DCI (Dorhout Mees SM, et al. Cochrane Database of Systematic Reviews. 2007).

Delayed cerebral ischemia occurs a median of 6–7 days after hemorrhage, but this varies, with a typical reported range from 3 to 14 days. DCI may be reversible, but in some cases it progresses to permanent brain injury, thereby affecting outcome.

Predicting Stroke Outcome with Multimodality CT

Kevin S. Attenhofer, MD

Dankbaar JW, Horsch AD, van den Hoven AF, Kappelle LJ, van der Schaaf IC, van Seeters T, et al. Prediction of Clinical Outcome After Acute Ischemic Stroke: The Value of Repeated Noncontrast Computed Tomography, Computed Tomographic Angiography, and Computed Tomographic Perfusion. Stroke. 2017

A significant aspect of stroke care is the long-term ramifications with respect to a patient’s ability to manage their activities of daily living. Part of the physician’s role is to help the patient navigate this challenge to maintain as much independence as possible. Understanding likely outcomes helps set the stage for realistic expectations and goals. Today, the most commonly used metric to score outcomes is the modified Rankin scale (mRS) performed well after the index event (often 90 days).

In stroke research, follow-up imaging markers such as computed tomographic angiography (CTA) recanalization and computed tomographic perfusion (CTP) reperfusion are sometimes used as proxy measurements for clinical outcomes. In this study, Dankbaar et al. used multimodality commuted tomography to predict mRS at 90 days.

By |September 11th, 2017|clinical, prognosis|0 Comments

Taking Patients Directly to Comprehensive Stroke Centers May Be Feasible for Patients and Hospitals

Neal S. Parikh, MD 
@NealSParikhMD

Katz BS, Adeoye O, Sucharew H, Broderick JP, McMullan J, Khatri P, et al. Estimated Impact of Emergency Medical Service Triage of Stroke Patients on Comprehensive Stroke Centers. An Urban Population-Based Study. Stroke. 2017

Whether all acute stroke patients should be taken to a comprehensive stroke center (CSC) remains unclear. However, there is mounting computer modeling and clinical data that support transporting acute stroke patients directly to CSCs, especially when the additional travel time is not excessive. The American Heart Association recommends transporting patients directly to CSCs if additional travel time does not exceed 15–20 minutes.

Brian Katz and colleagues performed an analysis to examine real-world EMS transport practices in the Greater Cincinnati/Northern Kentucky (GCNK) region. They performed computer modeling to evaluate the implications of adhering more closely to AHA recommendations. The authors identified patients with acute stroke from the GCNK Study who were transported by EMS in 2010. The GCNK region has 1 CSC and a total of 14 primary stroke centers (PSC) and acute stroke ready hospitals (ASRH). Patients’ addresses were geocoded, and software was used to estimate travel distances to each patient’s initial presenting hospital and also to the CSC.

Statins and Carotid Artery Stenting

Tapan Mehta, MBBS, MPH

Hong JH, Sohn SI, Kwak J, Yoo J, Chang HW, Kwon OK, et al. Dose-Dependent Effect of Statin Pretreatment on Preventing the Periprocedural Complications of Carotid Artery Stenting. Stroke. 2017

In this entry, I discuss a recent publication by Dr. Jeong-Ho Hong and colleagues regarding effectiveness of statin pretreatment on preventing the periprocedural complications of carotid artery stenting (CAS).

CAS as a procedure has evolved significantly in the past two decades. Previous studies have shown increased periprocedural complication risk with CAS compared to carotid endarterectomy (CEA). Invention of new endovascular devices, distal embolization protection systems and antiplatelet medications, along with increasing operator experience, have contributed in reduction of periprocedural complications. Recently published CREST trial data can be considered an important example of this. As there is already data available on statin pretreatment reducing periprocedural complication risk for CEA and percutaneous coronary intervention, this study importantly extends the possibility of benefit with pre-procedural statin use for patients undergoing CAS.

Baseline Blood Pressure and Intra-Arterial Therapy Outcomes

Brian Marcus, MD

Mulder MJHL, Ergezen S, Lingsma HF, Berkhemer OA, Fransen PSS, Beumer D, et al. Baseline Blood Pressure Effect on the Benefit and Safety of Intra-Arterial Treatment in MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands). Stroke. 2017

It is known that extremes in blood pressure lead to worse functional outcomes in stroke patients. This article by Mulder et al. looks to see if similar extremes in blood pressure lead to worse outcomes in patients receiving intra-arterial treatment. They performed a post hoc analysis of the MR CLEAN study in the Netherlands and measured blood pressure at baseline and before intra-arterial treatment and compared this with the patient’s modified Rankin scale at 90 days. In addition to looking at modified Rankin scale, the authors also looked to see how blood pressure prior to therapy was related to imaging findings, changes in the NIHSS, TICI score, and the Barthel index.

By |August 28th, 2017|clinical|0 Comments

Optimal Timing of DWI for TIA

Hatim Attar, MD

Shono K, Satomi J, Tada Y, Kanematsu Y, Yamamoto N, Izumi Y, et al. Optimal Timing of Diffusion-Weighted Imaging to Avoid False-Negative Findings in Patients With Transient Ischemic Attack. Stroke. 2017

MRI scans are the gold standard imaging modality for diagnosing acute cerebrovascular injury. The purpose of performing them in Transient Ischemic Attack (TIA) patients is to determine presence of infarction, which lends information on prognosis and risk of recurrence. This novel Japanese study has investigated Diffusion Weighted Imaging (DWI) latency from symptom onset and false negative MRI scans in TIA patients. Shono et al have determined the optimal timing of obtaining MRI scans in TIA patients to limit false negative results.

By |August 16th, 2017|clinical|0 Comments

Author Interview: Robert G. Kowalski, MD, MS

Robert G. Kowalski

Robert G. Kowalski

A conversation with Robert G. Kowalski, MD, MS, Principal Investigator, Craig Hospital, and Assistant Clinical Professor of Neurology and PM&R, University of Colorado School of Medicine, about stroke following traumatic brain injury.

Interviewed by José G. Merino, MD, Associate Professor of Neurology, University of Maryland School of Medicine.

They will be discussing the paper, “Acute Ischemic Stroke After Moderate to Severe Traumatic Brain Injury: Incidence and Impact on Outcome,” published in the July issue of Stroke.

Dr. Merino: Thank you for agreeing to the interview. Can you first briefly describe the methods and main findings of the analysis published in Stroke?

Dr. Kowalski: The study was a research collaboration between the Centers for Disease Control and Prevention (CDC) and the Traumatic Brain Injury Model Systems (TBIMS) program. It was led by researchers at Craig Hospital in Englewood, CO. Investigators studied more than 6,400 traumatic brain injury (TBI) patients over a 7.5-year period to evaluate risk factors for onset, incidence, and predictors of outcome in ischemic stroke occurring acutely after TBI. We found that 2.5% of individuals who experience a moderate to severe TBI also suffer an acute ischemic stroke (AIS) at the time of the injury. In half of these cases, the individuals experiencing stroke concurrent with brain trauma were age 40 or younger. Additionally, the study found the risk of acute ischemic stroke immediately following traumatic brain injury was 10 times the risk of ischemic stroke in the general population.

The Complex Relationship Between Statins and Intracerebral Hemorrhage Outcomes

Mark R. Etherton, MD, PhD

Siddiqui FM, Langefeld CD, Moomaw CJ, Comeau MJ, Sekar P, Rosand J, et al. Use of Statins and Outcomes in Intracerebral Hemorrhage Patients. Stroke. 2017

In this entry, I discuss a recent publication by Fazeel Siddiqui and colleagues regarding the use of statins and outcomes after intracerebral hemorrhage (ICH).

The current evidence suggests a complex relationship between serum cholesterol levels, statin use, and outcomes after ICH. Low serum cholesterol levels have been associated with increased incidence of ICH, as well as hematoma expansion. However, a prior meta-analysis demonstrated antecedent statin use was associated with decreased risk of mortality and increased likelihood of a good outcome after ICH (Jung et al. Int J Stroke. 2015). The authors, therefore, set out to investigate the relationship of statin use with ICH outcomes by evaluating 3-month disability, mortality, and hematoma size/expansion.