Qatar Foundation for Education, Science and Community Development, Weill Cornell Medical College in Qatar, and the New York Academy of Sciences
Stroke and Traumatic Brain Injury: Qatar Clinical Neuroscience Conference
Posted June 20, 2014
A recent epidemiological survey identified stroke and traumatic brain injury (TBI) as the most prevalent causes of adult-onset brain disorders in the United States, resulting in substantial mortality and disability as well as high economic costs. These disorders result from the damage or death of healthy, functioning cells and brain tissue. Stroke generally affects older adults, but TBI is also a leading cause of disability among young children, partially from sports-related injuries. Most current treatments for stroke and TBI target the consequences of brain injury, not the injury itself.
The Qatar Clinical Neuroscience Conference focused on two broadly defined categories of brain disorder. Track 2: Stroke and TBI convened experts in clinical neuroscience to discuss the imaging, diagnosis, and treatment of disorders caused by external conditions such as cerebrovascular disease, stroke, and TBI. The speakers assessed the evidence for current management guidelines; discussed new strategies for timely treatment; and presented data on the mechanisms of stroke and TBI, which may illuminate new targets for treating the pathology of brain injury.
Track 1 of the conference focused on affective disorders, debilitating mood-related psychiatric illnesses such as depression and bipolar disorder that result from an intrinsic or chronic dysfunction of the brain, either within the cells or in their connectivity. The Qatar Foundation for Education, Science and Community Development, Weill Cornell Medical College in Qatar, and the New York Academy of Sciences presented the conference on March 15–17, 2014, in Doha, Qatar.
Use the tabs above to find a meeting report and multimedia from this event.
Presentations available from:
Neeraj Badjatia, MD, MSc (University of Maryland School of Medicine)
Randall Matthew Chesnut, MD (University of Washington; Harborview Medical Center)
David Chiu, MD (Houston Methodist Hospital Neurological Institute)
Matthew E. Fink, MD (Weill Cornell Medical College)
Roger Härtl, MD (Weill Cornell Medical College)
Costantino Iadecola, MD (Weill Cornell Medical College)
Barry Kosofsky, MD, PhD (Weill Cornell Medical College)
Jose A. Pineda Soto, MD (Washington University School of Medicine; St. Louis Children's Hospital)
Glen Prusky, PhD (Weill Cornell Medical College; Burke Medical Research Institute)
Ashfaq Shuaib, MD (University of Alberta, Canada)
View the multimedia meeting report on Track 1 of the Qatar Clinical Neuroscience Conference at:
Affective Disorders: Qatar Clinical Neuroscience Conference eBriefing
- 00:011. Introduction; Stroke treatment and time factors
- 04:092. The IMS III Trial; Time to reperfusion; The FAST-MAG Trial
- 15:453. The CURE and SPS3 Trials; The CHANCE Study
- 22:274. The SAMMPRIS Trial; The POINT Study
- 31:455. Novel oral anticoagulants; Endovascular therapy trials; CREST II; Conclusion
- 00:011. Introduction; The physiology of thermoregulation
- 07:242. Ischemia; Timeline for hypothermic protection
- 11:023. Targeted temperature management after TBI; The NABISH studies
- 20:484. The Eurotherm Trial; Spreading depolarizatons; The Hopes Trial
- 26:435. ICP and ischemia; Summary and conclusio
- 00:011. Introduction
- 06:302. TBI and disability; Modulating environment to optimize recovery
- 14:393. Therapeutic interventions and secondary insults; Pediatric TBI guidelines
- 22:484. Monitoring and treatment; Improving the pipeline model; Potential challenges
- 26:565. Center characteristics; Neurophysiological thresholds
- 31:056. Conclusion
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Cerebral collaterals and acute stroke
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Imaging in transient ischemic attacks
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The Joint Commission accredits and certifies more than 20 500 health care organizations and programs in the United States. Joint Commission accreditation and certification is recognized nationwide as a symbol of quality that reflects an organization's commitment to meeting certain performance standards.
TEMPIS is a telemedical network founded in 2003 by two specialized stroke centers and 12 (now 15) regional hospitals in eastern Bavaria/Germany to provide modern stroke management and advanced stroke expertise in non-urban areas.
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Current therapy for TBI
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Peterson E, Chesnut RM. Static autregulation is intact in majority of patients with severe traumatic brain injury. J Trauma. 2009;67(5):944-9.
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Hypothermia for TBI
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Hyperosmolar therapy for brain edema
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Barkhoudarian G, Hovda DA, Giza CC. The molecular pathophysiology of concussive brain injury. Clin Sports Med. 2011;30(1):33-48.
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Diaz-Arrastia R, Kochanek PM, Bergold P, et al. Pharmacotherapy of traumatic brain injury; state of the science and the road forward: report of the Department of Defense Neurotrauma Pharmacology Workgroup. J Neurotrauma. 2014;31(2):135-58.
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Hypothermia for TBI
The Hypothermia for Patients requiring Evacuations of Subdural hematoma trial aims to find out if therapeutic hypothermia improves outcomes following TBI that requires surgery.
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Meta-analysis of IV t-PA Therapy
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The Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke trial is a randomized, double-blind, multicenter clinical trial to determine whether clopidogrel 75 mg/day (after a loading dose of 600 mg) is effective in improving survival free from major ischemic vascular events.
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Matthew E. Fink, MD
Matthew E. Fink is the Louis and Gertrude Professor and chair of the Department of Neurology at Weill Cornell Medical College. He is also neurologist-in-chief at New York Presbyterian Hospital/Weill Cornell Medical Center, chief of the Division of Stroke and Critical Care Neurology Center, and vice chair of the Medical Board. Fink holds an MD from the University of Pittsburgh and served as resident and chief resident in internal medicine at the Boston City Hospital. He trained in neurology at the Neurological Institute of New York/Columbia Presbyterian Medical Center and later joined Columbia University as associate professor of clinical neurology and neurosurgery and founding director of the Neurology-Neurosurgery Intensive Care Unit at New York Presbyterian Hospital. Fink has also served at the Beth Israel Medical Center and the Albert Einstein College of Medicine. He was a founding member and chair of the Critical Care Section of the American Academy of Neurology and the Research Section for Neurocritical Care of the World Federation of Neurology. Fink is the editor of Neurology Alert and past president of the New York State Neurological Society.
Javaid I. Sheikh, MD
Javaid I. Sheikh is the dean of Weill Cornell Medical College in Qatar (WCMC-Q), which he has led since January 2010. He previously served as associate dean and professor of psychiatry and behavioral sciences at Stanford University School of Medicine and chief of medical staff at the Stanford affiliate VA Palo Alto Health Care System. Sheikh is an authority on anxiety and aging. He conducted the first studies, in the 1990s, to delineate the impact of aging on anxiety disorders, with detailed phenotypic characterizations and identification of risk factors. His group has investigated the interface of central fear circuits and sleep architecture in patients with chronic anxiety disorders. It is now looking at biomarkers and risk factors associated with perinatal depression. At WCMC-Q, Sheikh initiated a comprehensive 5-year strategic plan for the school, with a view to establishing it as the premier academic medical institution in the MENA region. Sheikh holds an MD from King Edward Medical College in Pakistan and an MBA from Golden Gate University.
Melanie Brickman Stynes, PhD, MSc
The New York Academy of Sciences
Brooke Grindlinger, PhD
The New York Academy of Sciences
Jack D. Barchas, MD
Jack D. Barchas is the Barklie McKee Henry Professor and chair of the Department of Psychiatry at Weill Cornell Medical College and psychiatrist-in-chief at Weill Cornell Medical Center. Barchas was previously the dean for both research development and neuroscience at the University of California, Los Angeles, and a professor in the Department of Psychiatry and Biobehavioral Sciences. He obtained his MD at Yale University and then completed an internship at the University of Chicago, postdoctoral training at the National Institutes of Health, and a psychiatry residency at Stanford University. As faculty at Stanford he held the Nancy Friend Pritzker Professorship; directed the Pritzker Laboratory, an interdisciplinary program focused on behavioral neurobiology; and served as associate chair of the Department of Psychiatry and Behavioral Sciences. He has held chairperson appointments on the Board on Biobehavioral Science and Mental Disorders of the Institute of Medicine and the Board of Trustees of the New York Academy of Medicine. He currently chairs the board of the Association for Research on Nervous and Mental Disorders and is president of the Pasarow Foundation, which provides awards for extraordinary scientific achievement in neuropsychiatry, cardiovascular disease, and cancer. He has also directed the Pritzker Network and served as an editor of the Archives of General Psychiatry.
Alan F. Schatzberg, MD
Alan F. Schatzberg received his MD from New York University. He completed a psychiatric residency at the Massachusetts Mental Health Center and a clinical fellowship in psychiatry at Harvard Medical School. After serving in the United States Air Force, he joined the staff at McLean Hospital and the faculty of Harvard Medical School. He later became clinical director of the Massachusetts Mental Health Center and a professor of psychiatry at Harvard Medical School, while continuing with his research program on depression at McLean Hospital. In 1991 Schatzberg moved to Stanford University to become the Kenneth T. Norris Jr. Professor and chair of the Department of Psychiatry and Behavioral Sciences. Schatzberg has been an active investigator in the biology and psychopharmacology of depressive disorders. He has explored norepinephrine systems in depression as a means of subtyping these disorders, as well as biological mechanisms that underlie the development of delusions in major depression. Schatzberg is now investigating the clinical psychopharmacology of nondelusional depression, particularly chronic depression. He is co-editor-in-chief of the Journal of Psychiatric Research and past president of the American College of Neuropsychopharmacology. In 1998 he was awarded the Gerald L. Klerman Lifetime Research Award from the National Depressive Manic-Depressive Association.
Neeraj Badjatia, MD, MSc
Neeraj Badjatia is an associate professor of neurology, neurosurgery, and anesthesiology at the University of Maryland School of Medicine. He is also chief of neurocritical care at the R. Adams Cowley Shock Trauma Center and medical director of the Neurocritical Care Unit. He holds an MD from Northeastern Ohio University's College of Medicine and completed an internship at St. Elizabeth Medical Center, a neurology residency at Emory University School of Medicine, and a fellowship in neurocritical care and vascular neurology at Massachusetts General Hospital. He previously served as director of the Neurocritical Care Training Program at New York Presbyterian Hospital and as an assistant attending at Massachusetts General Hospital and Columbia University Medical Center. His clinical career has focused on merging principles of clinical neurology with critical care medicine, with a research focus on understanding the systemic metabolic consequences after brain injury. He has investigated the metabolic impact of therapeutic normothermia after brain injury, leading to a greater understanding of the metabolic cost associated with shivering during cooling. He is an associate editor of Neurocritical Care and an elected fellow of the American Neurological Association.
Randall Matthew Chesnut, MD
Randall Matthew Chesnut is a University of Washington professor based at Harborview Medical Center. He holds appointments in the Department of Neurological Surgery and the Department of Orthopedics and Sports Medicine. He has particular expertise in surgery and critical care for traumatic brain injury, spinal cord injuries, failed back surgery, and adult spondylolisthesis, as well as sports-related spine and brain injuries. Chesnut is conducting research to improve care for people with traumatic brain and spine injuries. He currently has funding from the National Institutes of Health for outcome studies in brain injury and trauma care systems in Latin America. He is also a leader in writing evidence-based practice guidelines for traumatic brain injury and spine surgery. He holds an MD from the University of Washington School of Medicine and completed fellowship and residency training at the University of California, San Diego, and an internship in the UW Department of Surgery
David Chiu, MD
David Chiu is medical director of the Houston Methodist Hospital Eddy Scurlock Stroke Center and a neurologist at the Methodist Neurological Institute. His active clinical practice benefits from his extensive translational research in extending the time and quality of life for stroke patients, focused on acute stroke treatment, stroke prevention after TIA, and stroke. He serves on the Board of Directors for the American Heart Association and is active in the American Academy of Neurology, the American Heart Association Stroke Council, the Texas Medical Association, and the Harris County Medical Association. He is also a reviewer for Stroke and the Journal of Neurology, Neurosurgery and Psychiatry. Chiu is an associate professor of clinical neurology at Weill Cornell Medical College. He received his MD from Yale University School of Medicine and completed a residency in neurology at the University of California, San Francisco, and a fellowship in cerebrovascular disease at University of Texas at Houston School of Medicine.
Matthew E. Fink, MD
Roger Härtl, MD
Roger Härtl is a professor of neurological surgery, director of spinal surgery, and co-director of the Weill Cornell Spine Center, affiliated with the Brain and Spine Center at Weill Cornell Medical College. He is also the neurosurgeon for the New York Giants Football Team. Härtl received his MD from the Ludwig-Maximillians University in Germany. He completed postdoctoral fellowships at Weill Cornell Medical College and the Charite Hospital of Humboldt University, Germany; a surgical internship and residency at Allegheny General Hospital in Pittsburgh; a neurosurgery residency at New York Presbyterian Hospital/Weill Cornell Medical Center and Memorial Sloan-Kettering Cancer Center; and specialized training in complex spine surgery at the Barrow's Neurological Institute. His scientific work focuses on the pathophysiology of traumatic brain injury and the treatment of brain edema and intracranial hypertension in brain-injured patients. His clinical interests focus on simple and complex spine surgery, minimally invasive spinal surgery, and neurotrauma. He is actively involved in improving neurosurgical care in developing countries as the leader of Weill Cornell's Global Health Neurosurgery Initiative in Tanzania.
Costantino Iadecola, MD
Costantino Iadecola is the Anne Parrish Titzell Professor of Neurology and director of the Brain and Mind Research Institute at Weill Cornell Medical College. He is a clinician-scientist who works on the cellular and molecular mechanisms of neurovascular function and on the overlap between stroke and dementia. Iadecola is a recipient of the Javits Award from the National Institutes of Health, the Willis Award from the American Heart Association, and of the Zenith Fellow Award from the Alzheimer's Association. He is on several editorial boards, including for the Annals of Neurology and the Journal of Cerebral Blood Flow and Metabolism, and is active in various editorial capacities for Stroke, for Hypertension, Circulation, for the Proceedings of the National Academy of Sciences, and for the Journal of Neuroscience. Iadecola is currently the principal investigator of four NIH-supported studies. He holds an MD from the University of Rome, Italy, and completed a postdoctoral fellowship and neurology residency at Cornell University.
Barry Kosofsky, MD, PhD
Barry Kosofsky is the Horace W. Goldsmith Foundation Professor of Pediatrics, chief of the Division of Pediatric Neurology, and director of the Horace W. Goldsmith Foundation Laboratory of Molecular and Developmental Neuroscience. He is also a professor of pediatrics and of neurology and neuroscience at Weill Cornell Medical College and an attending pediatrician at New York Presbyterian Hospital. Kosofsky holds an MD and PhD in neuroscience from Johns Hopkins University School of Medicine. He completed pediatric residency training at Children's Hospital in Boston, and then served as assistant resident/chief resident at Massachusetts General Hospital, where he also completed a postdoctoral fellowship in the East Molecular Neurobiology Laboratory. He joined Weill Cornell after 19 years at Harvard Medical School and Massachusetts General Hospital. He is co-chair of the Long Range Planning Committee for the Child Neurology Society. As a clinician-scientist Kosofsky studies animal models of diseases that affect human brain development, with a focus on understanding the consequences for the developing brain of intrauterine exposure to drugs of abuse.
Jose A. Pineda Soto, MD
Jose Pineda is an assistant professor of pediatrics and neurology and director of the Pediatric Neurocritical Care Program at Washington University School of Medicine in St. Louis. Following a residency in pediatrics at the University of South Florida, he completed training in pediatric critical care medicine at Duke University, including research training at the Multidisciplinary Neuroprotection Laboratory. Pineda joined the faculty of the Department of Pediatrics and the McKnight Brain Institute of the University of Florida, where he conducted laboratory and clinical research studies of traumatic brain injury (TBI). Pineda was recruited to Washington University because of his expertise as a pediatric intensivist and his clinical experience and interest in pediatric TBI. His research focuses on the mechanisms of TBI and potential new treatments for brain injury. He holds an MD from the Universidad Francisco Marroquin School of Medicine in Guatemala.
Glen Prusky, PhD
Glen Prusky obtained MSc and PhD degrees from Dalhousie University, Canada. Following postdoctoral training at Yale University, Prusky moved as faculty to the University of Lethbridge, Canada. He served as professor and chair of the Department of Neuroscience and as a principle investigator of the Canadian Stroke Network before being recruited to the Burke Medical Research Institute and the Department of Physiology and Biophysics at Weill Cornell Medical College in 2007. His research program focuses on understanding adaptive and maladaptive change in the nervous system over the lifespan. One research stream aims to understand the mechanisms underlying experience-dependent plasticity of vision. Another focuses on developing treatments for progressive visual decline arising from retinal degenerative disease, diabetic neuropathy, and aging. His team is also involved in the development of rehabilitative strategies for stroke.
Lee Schwamm, MD
Lee Schwamm is a professor of neurology at Harvard Medical School and vice chair of neurology at Massachusetts General Hospital, where he is the director of Acute Stroke Services. He is also director of the Partners TeleStroke Center, a network that provides acute stroke consultation services to 27 rural and community hospitals in Massachusetts and northern New England. His clinical interests are in cerebrovascular diseases, intensive care medicine, brain imaging, and applied health care technology. Schwamm is a recognized leader in acute stroke treatment, stroke advocacy, and the use of telemedicine and other technology strategies to improve the quality of stroke care. He has played a pivotal role in the development and leadership of the American Heart Association's National Get With the Guidelines–Stroke program and is currently chair of its national steering committee. He also serves as a consultant to the Massachusetts Department of Public Health, the Paul Coverdell National Acute Stroke Registry at the Centers for Disease Control and Prevention, the Joint Commission Primary Stroke Center, the National Quality Forum, and the Canadian Stroke Registry.
Ashfaq Shuaib, MD
Ashfaq Shuaib received his undergraduate medical education at Khyber Medical College in Pakistan, obtaining a MBBS degree. He completed postgraduate training in internal medicine and neurology at the University of Calgary, Canada, followed by specialized training in cerebrovascular research at the University of Western Ontario, Canada, and Duke University Medical School. He was a professor of medicine and neurology at the University of Saskatoon, Canada, before joining the University of Alberta as professor of medicine and director of the Division of Neurology in 1997. He later stepped down as divisional director but remained director of the Stroke Program. He moved to Doha, Qatar, in 2014 as director of the Qatar Neuroscience Institute. His major interests are in understanding the basic mechanisms of cerebral ischemia and in clinical trials for cerebrovascular diseases. He is on the editorial board of Heart.org, Faculty F-1000, Stroke, Frontiers in Neurology (associate editor), Neurohospitalist, and the Pakistan Journal of Neuroscience. He chaired the steering committees of the SAINT II and SENTIS trials and is a steering committee member for five current multicenter acute stroke trials. In Qatar, he has begun a clinical trial in patients with TIAs and minor stroke, with 10 participating sites in the Middle East.
Jennifer Cable lives in New York City, where she experiments with different outlets to communicate science. She enjoys bringing science to scientists and nonscientists alike. She writes for Nature Structural and Molecular Biology, Bitesize Bio, Under the Microscope, and the Nature New York blog. She received a PhD from the University of North Carolina at Chapel Hill for her research in investigating the structure/function relationship of proteins.
A recent epidemiological survey identified stroke and traumatic brain injury (TBI) as the most prevalent causes of adult-onset brain disorders in the U.S. While stroke primarily affects the elderly, TBI is the most common cause of childhood death and disability, with half of patients under 18 years old. In March 2014, clinical experts in stroke and TBI met in Doha, Qatar, to share current and future practices in the diagnosis, imaging, management, and treatment of these conditions.
Stroke is the second leading cause of death in the world and the leading cause of permanent disability. As the population ages, the number of stroke patients is increasing, despite the declining incidence of stroke over the past 30 years. Risk factors for stroke include demographic characteristics such as age and gender, behaviors like smoking, and medical conditions like hypertension.
Stroke is classified into two categories. Ischemic stroke results from a blockage in the vessels that supply the brain with blood and is further classified according to the origin of the blood clot. Hemorrhagic stroke results from a ruptured blood vessel that disrupts blood flow to part of the brain.
Ischemia activates a series of harmful pathways that lead to neuronal death. Protective pathways such as collateral flow, inflammation, decreased protein synthesis, and increased antioxidant production are activated to mitigate damage. Costantino Iadecola and Ashfaq Shuaib described processes that could be targeted to find new treatments for stroke. Iadecola described the conflicting role of inflammation in stroke as both a cause of damage and a critical component of tissue repair. Shuaib discussed the role of collateral blood flow in mitigating neurological damage.
Early treatment after stroke is critical to restore blood flow to the affected area and prevent permanent brain damage. David Chiu discussed recent trials in stroke demonstrating the benefits of early therapy to prevent neurological damage and recurrent stroke. Shuaib stressed the importance of early imaging in patients experiencing transient ischemic attacks (TIAs) to inform proper treatment and management decisions. Lee Schwamm showed how telemedicine can improve stroke care in small and/or rural hospitals that may not have a dedicated neurological staff on-site. Finally, Matthew E. Fink described pregnancy-related stroke and subarachnoid hemorrhage.
Traumatic brain injury
TBI is caused by sudden trauma to the brain during an incident such as a fall or motor vehicle accident. The sudden motion can cause the brain to move and twist within the skull, damaging brain tissue. TBI usually causes brain swelling, or edema, which can increase intracranial pressure (ICP) and decrease cerebral perfusion pressure (CPP), the pressure gradient that causes blood flow in the brain. Signs and symptoms of TBI include headache, fatigue, vomiting, increased sensitivity to light, irritability, and sleep problems. While the damage and symptoms of TBI are reversible in some patients, for others symptoms persist. There is currently no reliable method to determine which patients will experience ongoing symptoms.
Since little can be done to treat the initial injury, current therapies for TBI focus on mitigating the secondary effects of injury, such as increased ICP, hypotension, ischemia, fever, and seizures, to allow the brain time to heal itself. Treatment is focused on monitoring ICP and CPP. Randall Matthew Chesnut provided a historical perspective, describing how the guidelines for ICP and CPP monitoring evolved, and presented data from recent trials suggesting that the current thresholds may not be appropriate in all cases. Chesnut called for a more individualized approach to treating TBI that takes into account the underlying reasons for increased ICP and decreased CPP, which can vary among patients.
Neeraj Badjatia and Roger Härtl presented clinical evidence for the use of hypothermia and hyperosmolar therapy to decrease ICP and mitigate neuronal damage. Barry Kosofsky and Jose A. Pineda Soto focused on the unique needs and characteristics of pediatric TBI, with Kosofsky providing his approach for managing sports-related TBI in children.
Costantino Iadecola, Weill Cornell Medical College
Ashfaq Shuaib, University of Alberta, Canada
- Inflammation is a cause of tissue damage but is also critical to tissue repair in stroke patients.
- Good collateral blood flow can mitigate ischemic damage in stroke patients and identify patients who may respond to thrombolytic therapy outside the recommended time window.
- In patients with poor collateral blood flow, therapeutic interventions may be able to activate collateral circulation during acute stroke.
Inflammation in ischemic stroke
Ischemic stroke triggers several harmful pathways within neurons that result in apoptosis, inflammation, oxidative stress, and excitotoxicity. In turn, the brain attempts to minimize damage by activating protective pathways that increase collateral flow, decrease protein synthesis to save energy, and engage antioxidant defenses. Costantino Iadecola of Weill Cornell Medical College and Ashfaq Shuaib of the University of Alberta respectively discussed inflammation and collateral flow as means to understand the pathology of stroke, identify patients most likely to respond to therapy, and develop new therapies.
Inflammation has positive and negative effects in stroke patients. After the initial ischemic injury, a series of mechanisms result in the production of reactive oxygen species (ROS) and eventually inflammation. During the acute phase of stroke, inflammation can increase ICP and lead to secondary injury. However, within days to weeks after stroke, inflammation is critical to tissue repair.
Iadecola discussed the molecular mechanisms that promote inflammation after stroke. Briefly, ischemia-induced apoptosis releases cell fragments that bind to and activate CD36, a receptor involved in innate immunity that is found on the surface of microglia, macrophages, and endothelial cells. Activation of CD36 results in the expression of several inflammatory genes, including the immunological form of nitric oxide synthase (iNOS), which downregulates mitochondrial activity and DNA synthesis via the production of nitric oxide (NO) and is upregulated following stroke.
According to Iadecola, the molecules involved in inflammation provide attractive therapeutic targets; however, therapeutic strategies should focus on the downstream effectors of inflammatory damage and should be carefully timed as the negative effects of inflammation manifest during acute phases of the disease.
Collateral circulation in ischemic stroke
Collateral circulation is another mechanism the brain uses to minimize damage after stroke. Blood flow is maintained in the brain via a network of collateral arteries (several arteries that supply the same area with blood). Approximately one-third of people are born with poor collateral flow, which decreases universally with age and is negatively affected by hypertension and diabetes. Shuaib stressed the importance of evaluating collateral flow during acute stroke to assess treatment response and prognosis. In patients with good collateral flow, ischemic damage progresses more slowly because blood can reach the affected area of the brain via collateral vessels. These patients may benefit from thrombolytic therapy administered after the recommended 4-hour time window.
The SENTIS (Safety and Efficacy of NeuroFlo Technology in Ischemic Stroke) trial investigated whether collateral flow can be enhanced via transient aortic occlusion in patients experiencing stroke. The goal of aortic occlusion is to divert blood from the lower limbs to the brain, thereby increasing cerebral blood flow (CBF) and improving collateral flow. The trial used the CoAxia NeuroFlo catheter to partially occlude the aorta for 45 minutes. Among 515 patients randomized to undergo either aortic occlusion or conventional treatment, aortic occlusion did not decrease disability but was associated with a significantly lower rate of mortality—particularly among elderly patients over 70 years old, patients who had moderately severe stroke, and patients who were treated within 5 hours of stroke.
David Chiu, Houston Methodist Hospital Neurological Institute
Ashfaq Shuaib, University of Alberta, Canada
Lee Schwamm, Harvard Medical School; Massachusetts General Hospital
- Early treatment is critical to prevent neurological damage and reduce the risk of recurrent stroke.
- In patients experiencing transient ischemic attacks, early, detailed MR imaging can identify those at risk for recurrent stroke.
- Telemedicine can connect primary stroke centers with smaller hospitals to increase and improve treatment in stroke patients.
Benefits of early treatment in acute stroke
In the emergency room, one of the first tests performed in stroke patients is a CT scan to identify the stroke as ischemic or hemorrhagic. For ischemic stroke, thrombolytic therapy may be indicated to break up the blood clot and restore blood flow to the affected region. Thrombolytic therapy can be dangerous in hemorrhagic stroke because it can increase the risk of further hemorrhage. Current guidelines recommend administering thrombolytic therapy no more than 4.5 hours after the onset of symptoms, when the risk of hemorrhage generally begins to outweigh the benefit of therapy.
Several recent trials have demonstrated the importance of early thrombolytic therapy to prevent neurological dysfunction and recurrent events in ischemic stroke patients. If administered within 90 minutes of symptom onset, thrombolytic therapy is 18.5 times more likely to be beneficial than harmful; if administered 360 minutes after symptom onset, it is more likely to cause harm than benefit.
David Chiu of Houston Methodist Hospital Neurological Institute described several studies of treatment regimens after stroke. In the IMS III (Interventional Management of Stroke III) trial, adding intra-arterial endovascular therapy (intra-arterial delivery of thrombolytic therapy to the clot site or mechanical removal of the clot via a thrombectomy device) to intravenous thrombolytic therapy conferred no significant advantage in mortality or in incidence of intracerebral hemorrhage. However, the analysis demonstrated the importance of early therapy: every 30-minute delay in intra-arterial therapy decreased the likelihood of a good clinical outcome by 10%. Chiu asserted that future trials in acute stroke should target earlier time windows.
Chiu also described two clinical trials comparing the efficacy of dual antiplatelet therapy (aspirin and clopidogrel) to aspirin monotherapy. Antiplatelet therapies prevent blood clot formation and are often used to prevent recurrent stroke. In the SPS3 (Secondary Prevention of Small Subcortical Strokes) study, which initiated therapy 2 weeks after the initial stroke, 8 years of follow-up demonstrated no difference in the rate of recurrent stroke. In contrast, a study in China called CHANCE, which initiated therapy within 24 hours of symptom onset, found a 32% lower risk of recurrent stroke in the dual therapy group compared to the aspirin monotherapy group. A similar study, the POINT (Platelet-Oriented Inhibition in New TIA and minor ischemic stroke) trial, is underway in the U.S. to determine whether similar results can be achieved in a different patient population.
Benefits of early imaging in transient ischemic attacks
Ashfaq Shuaib discussed the importance of early imaging in patients with transient ischemic attacks (TIAs), brief (less than one-hour) episodes in which there is a temporary lack of blood flow to a confined region of the brain. Approximately 10.5% of TIA patients experience a second stroke, half within 2 days. However, early treatment can reduce the risk of recurrent stroke by 80%.
Scoring systems based on age, diabetes status, duration of TIA, weakness, speech impairment, and blood pressure can help identify patients at high risk of recurrent stroke, but Shuaib also stressed the necessity of early CT and MR imaging. CT scans, standard for acute stroke patients, are ubiquitous and fast. However, Shuaib recommended that clinicians also perform MR imaging because it is more accurate and can detect ischemic stroke earlier, which is especially important for patients experiencing brief ischemic episodes.
Shuaib recommended performing MR imaging in the ER to determine when to admit patients and/or administer aggressive treatment. For infarctions that are below the detection of standard diffusion-weighted MRI technology, he recommended more sensitive MRI techniques, such as diffusion-tensor imaging (DTI) and perfusion-weighted imaging (PWI).
One outstanding question in the field is how long patients should receive therapy. To help answer this question, Shuaib is currently involved in a study comparing 10-day and 30-day treatment of dual antiplatelet therapy to investigate whether treatment duration can be reduced in patients experiencing TIAs.
Reducing the time to treatment: telemedicine in stroke care
Although the importance of early stroke treatment has been demonstrated in several clinical studies, many patients do not receive timely therapy. In a pooled analysis of 6 trials of neuroprotective therapies for acute stroke, only 0.2% of patients were treated within the first hour of brain ischemia, whereas 92.3% were treated after 3 hours. Because up to 70% of stroke patients arrive at hospital by ambulance, engaging paramedics in stroke treatment can significantly reduce the time to treatment. New models of care in which ambulances are equipped with CT scanners are being investigated in Berlin, Germany, and in Houston, Texas.
Lee Schwamm described the TeleStroke program at Massachusetts General Hospital, which uses telemedicine to provide stroke patients with high-quality, timely care. Physicians at certified stroke centers evaluate patients via video, review CT or MRI scans, and perform neurological exams, such as the NIH Stroke Scale (NIHSS). A primary purpose of TeleStroke is to determine whether a patient meets the requirements for thrombolytic therapy. Eligibility depends on CT and MRI scans, neurological function, and the time since symptom onset. Not all hospitals have the experienced personnel needed to evaluate such criteria.
Schwamm advocated a "hub and spoke" model of telemedicine, with the TeleStroke system located at a hub hospital, often an academic medical center or large tertiary hospital, and close-by spoke hospitals that can call for consultation and transfer patients if necessary. In a study by Schwamm of 38 hospitals with a TeleStroke program, 80%–90% of spoke hospitals were either rural or small hospitals.
Treatment and evaluation of acute stroke patients via telemedicine is cost-effective, and several studies show both that telemedicine increases the use of thrombolytic therapy and that thrombolytic therapy administered based on evaluation via telemedicine is as effective and well tolerated as therapy administered at a certified stroke center.
Matthew E. Fink, Weill Cornell Medical College
- Although representing a small fraction of strokes, subarachnoid hemorrhages significantly contribute to the cost and mortality rate of stroke.
- Pregnancy is a risk factor for stroke that may be overlooked by many hospitals. The risk of pregnancy-related stroke may be higher in older women.
Aneurismal subarachnoid hemorrhage
Approximately 2%–4% of healthy people have a benign, unruptured aneurysm, a ballooning of a weakened region of a blood vessel. If left untreated, aneurysms can rupture, causing hemorrhagic stroke. Subarachnoid hemorrhage (SAH) occurs in the area between the brain and the thin tissues that cover it.
Matthew E. Fink of Weill Cornell Medical College discussed treatment and care for aneurismal SAH. There are approximately 30 000 cases of SAH in the U.S. each year. Unlike that of other types of stroke, the incidence of SAH has remained relatively stable over the past 30 years, at 10.5 per 100 000 person years. Although SAH represents a small fraction of strokes, it contributes significantly to the morbidity and mortality of stroke. SAH has one of the highest mortality rates of any naturally occurring disease, with an acute fatality rate of up to 51%, compared to 5% for myocardial infarction. In addition, 46% of survivors have long-term cognitive dysfunction and approximately one-third will require lifelong care.
Fink stressed the importance of proper screening and prevention for SAH and called for genetic studies of high-risk groups to better understand its causes. The PHASES aneurysm risk score published early 2014 in Lancet Neurology was developed from a meta-analysis of six trials of unruptured cranial aneurysm in 8000 patients. The score takes into account the size and location of the aneurysm as well as patient characteristics such as age, hypertension, and nationality. While the score can be used to eliminate high-risk aneurysms, the risks of complications due to therapy increase with age; therefore, a small aneurysm in an older patient may not be worth treating.
Among patients with SAH, 25% die as a direct result of the hemorrhage. Other causes of death include vasospasm, rebleeding, hydrocephalus, intracerebral hematoma, surgical complications, and medical complications. According to Fink, all these conditions are either preventable or treatable and there is significant opportunity for physicians to reduce the morbidity and mortality associated with hemorrhage. Fink argued for a multidisciplinary approach that includes neurologists, neurosurgeons, anesthesiologists, and critical care and emergency medical specialists.
Treatment for SAH includes early surgery (within 12 hours of arrival at the hospital) to eliminate the aneurysm and prevent rebleeding. Other therapies include CSF drainage, hemodilution, intravascular volume expansion, induced arterial hypertension, inotrope infusion, and calcium channel blockers. In a study by Fink at the Neurological Institute of New York, the 30-day mortality rate in patients after SAH decreased from 50% to less than 20% after these therapies were instituted in the late 1980s.
Blood clotting factors increase during normal pregnancy, putting pregnant women at risk of thromboembolitic complications, including venous thrombosis, pulmonary embolism, subarachnoid hemorrhage, cerebral infarction, and myocardial infarct. While the risk of stroke in the U.S. has generally decreased over time, from 1994–5 to 2006–7 the risk of pregnancy-related stroke increased by 47% and 83% during antepartum and postpartum periods, respectively. The primary reason for this trend is a higher rate of childbirth at older ages; another reason is the increased prevalence of diseases such as hypertension, heart disease, diabetes, and obesity. Women who experience a pregnancy-related stroke are not at increased risk of stroke in the future.
Most cases of pregnancy-related stroke occur postpartum or peripartum, defined as the two days before and one day following delivery. The risk of ischemic stroke increases 2-fold during pregnancy, 9-fold during the postpartum period, and 34-fold during the peripartum period. While risk of brain hemorrhage does not increase during pregnancy, there are 95- and 47-fold increased risks for intracranial hemorrhage (ICH) and SAH, respectively, during the peripartum period, and 12- and 2-fold increased risks during the postpartum period.
According to Fink, pregnancy-related stroke is often missed because it is relatively rare and may not be accompanied by the usual warning signs, such as blurry vision or dizziness or sudden weakness, numbness, or paralysis. Furthermore, the types of stroke that occur during pregnancy and postpartum differ from the most common types in the general population. For example, hemorrhagic stroke is more common than ischemic stroke in pregnant women, and carotid atherosclerosis, which is the most common cause of stroke among elderly patients, is rare. Fink recommended prenatal screening for thrombophilias, such as factor V Leiden mutation and elevated factor VIII levels. These conditions affect blood coagulation, increasing the risks of blood clot formation, ischemic stroke, and cerebral venous thrombosis. He also recommended aggressive blood pressure management in pregnant patients.
Diagnostic evaluation and treatment for pregnancy-related and other types of stroke are similar. However, Fink highlighted special considerations for women experiencing stroke during pregnancy, based on potential risk to the fetus. MRI should be avoided during the first trimester and warfarin treatment for ischemic stroke should be avoided during the first and second trimesters. Although thrombolytic therapy is not approved in pregnant patients, many centers use it because the drug does not cross the placenta, and no fetal injury has been reported.
Because the incidence of pregnancy-related stroke is rare, a single medical center may only encounter one case per year. Fink stressed the importance of creating a prospective registry of pregnancy-related stroke cases to collect sufficient data for future studies.
Randall Matthew Chesnut, University of Washington; Harborview Medical Center
Roger Härtl, Weill Cornell Medical College
Neeraj Badjatia, University of Maryland School of Medicine
- Current guidelines provide thresholds for ICP and CPP in patients experiencing TBI; however, a more individualized approach may be warranted.
- Current guidelines recommend the use of mannitol to decrease ICP in TBI patients. The data for hypertonic saline are not robust enough to provide any recommendation for its use.
- Although hypothermia has been shown to reduce ICP, randomized trials have failed to demonstrate a benefit in TBI patients.
Pathophysiology of TBI
Traumatic brain injury can result from a sudden blow to the head. As the head experiences abrupt acceleration or deceleration, contact between the frontal cortex and the skull can damage brain tissue. The motion also stretches the fibers that connect the cortex to the brain stem, causing further damage. TBI leads to brain swelling, which results in increased intracranial pressure (ICP), decreased cerebral perfusion pressure (CPP), decreased CBF, ischemia, and edema, all of which can exacerbate the initial injury.
Signs and symptoms of TBI can be physical, cognitive, and emotional. Physical symptoms include headaches, light sensitivity, noise sensitivity, nausea, vomiting, fatigue, numbness, tingling, and impaired vision and balance. Cognitive problems include impairments in concentration, memory, and attention. Emotional problems include irritability, sadness, and nervousness. Patients may also experience sleep problems, including drowsiness or trouble falling asleep.
Therapy for severe TBI
According to Randall Matthew Chesnut of the University of Washington and Harborview Medical Center, there is a mismatch between the pathophysiology of brain injury and current treatments. Current strategies such as ICP and CPP monitoring aim to treat the symptoms of brain injury while giving the brain time to heal itself and avoiding secondary injuries. Chesnut described some of these treatments.
After the initiation of ICP monitoring, the mortality rate for TBI decreased from 50% to between 18% and 36%. However, as Chesnut pointed out, correlation must not be confused with causation. A randomized trial comparing a protocol that monitored ICP and a protocol that did not failed to reveal a difference in efficacy. Chesnut asserted that advances in rehabilitation, imaging, trauma surgery, emergency care, and pre-hospital care may have also contributed to the decrease in mortality.
Current guidelines recommend maintaining ICP below 20 mm Hg. However, Chesnut argued that this threshold, developed in the 1960s and 1980s when care was managed differently, may not be as relevant today. In a case study, a patient whose ICP rarely fell within the acceptable range, increasing to as high as 60 mm Hg, showed no neurological changes. By day 7, the patient's ICP had fallen to within the acceptable range. This unusual case illustrates that the threshold for treating ICP can be tailored to individual patients. Chesnut emphasized that treatment modification should be done carefully and under close observation.
With regard to CPP, higher pressure is often thought to be better. However, in a retrospective review of pediatric patients with TBI, among patients with CPP above 40 mm Hg no correlation was found between increased CPP and improved mortality, suggesting a threshold effect. In a 1997 study, Chesnut showed that patients who did not receive CPP management but had no hypotension did as well as those who received CPP management. The major advantage of CPP management may be to reduce cerebral ischemia, but high CPP is not necessarily better because it carries a risk of damaging the blood–brain barrier and of toxicity caused by vasopressors and hypervolemia. Chesnut recommended keeping CPP within a normal range to normalize CBF, rather than focusing only on increasing CPP, but stressed that cerebral hypotension must be avoided.
Chesnut cautioned that there are no "magic numbers" with regard to TBI; the goal of current strategies is to allow the brain time to heal itself while avoiding secondary injuries. In the future, he hopes for more targeted therapies that address the pathophysiology of TBI and primary brain injury instead of secondary effects like ICP and CPP.
Hyperosmolar therapy for TBI
Roger Härtl of Weill Cornell Medical College described the use of mannitol and hypertonic saline to decrease ICP. Both substances are unable to cross the blood–brain barrier, creating an osmotic effect that draws fluid out of the brain. In a case-controlled study, Härtl compared mannitol and hypertonic saline treatment in over 3000 patients with severe TBI over 10 years. Hypertonic saline was the more effective treatment for lowering cumulative and daily ICP; however, although the treatment reduced the number of days spent in the ICU, it did not reduce 2-week mortality.
There are no recommendations for the use of hypertonic saline in the adult guidelines for TBI because current data are not sufficiently robust. Härtl asserted that it is difficult to draw conclusions and make recommendations based on the current studies comparing mannitol and hypertonic saline, which include a small number of patients and vary in study design and in the concentrations and combinations of mannitol and hypertonic saline used.
Hypothermic therapy for TBI
In TBI patients, increased ICP and inflammation can cause brain temperature to be elevated as much as 4°C above body temperature. Clinicians may induce hypothermia at the time of injury in an effort to decrease ICP. Mild hypothermia—a body temperature of to 32°C–34°C—has produced neuroprotective effects in several ischemic brain injury models.
Neeraj Badjatia of the University of Maryland School of Medicine reviewed clinical trials investigating the efficacy of hypothermia in brain injury. Although two clinical trials, NABISH-I and NABISH-II, failed to show any improvement in disability among patients with TBI, a meta-analysis of several studies revealed hypothermia treatment reduced the risk of poor neurological outcomes and death. Badjatia hypothesized that the application of a fixed duration of hypothermia, regardless of whether ICP had returned to normal, may have contributed to the failure of previous trials. He is optimistic that hypothermia may benefit patients after brain injury, because it has been demonstrated to reduce ICP. Two ongoing trials, EUROTHERM and HOPES, are investigating the efficacy of hypothermia therapy when ICP is used to determine when body temperature should be returned to normal.
Jose A. Pineda Soto, Washington University School of Medicine; St. Louis Children's Hospital
Barry Kosofsky, Weill Cornell Medical College
- TBI is the leading cause of childhood death and disability in the U.S.
- The primary causes of TBI in children are motor vehicle accidents and sports injuries.
- Current guidelines for TBI treatment in children focus on preventing secondary brain injury.
Guidelines and treatment for pediatric TBI
Of the 1.74 million people who suffer from TBI each year, half are under the age of 18. In the U.S., TBI is the leading cause of childhood death and disability. The most common causes of TBI among children are motor vehicle accidents and sports injuries. Children who experience significant TBI can demonstrate delayed development in IQ, language, motor function, and memory. Several characteristics of children differentiate pediatric TBI from adult TBI. Children's brains are more plastic than adults' brains, which may enable children to recover more completely, though often less quickly, but may also make them more vulnerable to injury. Specifically, infants and children have higher brain water content, decreased brain myelination, and less neck strength, all of which render infants' brains more susceptible to mechanical damage.
Jose A. Pineda Soto of Washington University School of Medicine and St. Louis Children's Hospital reviewed guidelines for the treatment of pediatric TBI. The current guidelines by the Brain Trauma Foundation target secondary injuries, such as hypotension, intracranial hypertension, fever, and seizures. In a retrospective study at his institution, Pineda investigated the success of the recommended approach, finding a 70% decrease in mortality in pediatric TBI patients after the guidelines were applied. In particular, the guideline-recommended implementation of earlier and more aggressive ICP monitoring and treatment was related to better outcomes. He is currently investigating how other variables, including CPP, MAP, CVP, glucose, and temperature management, impact pediatric outcomes.
Pediatric sports injuries
There are approximately 35 million youth athletes in the U.S. at risk for sports-related concussion or TBI. Sports concussions can be particularly difficult to treat because there is no clear evidence or research to support treatment guidelines in children. Most sports-related head injuries are mild and reversible. However, as Barry Kosofsky of Weill Cornell Medical College explained, 20%–30% of injuries falling into the mild TBI category may result in ongoing symptoms, such as headache, attention and memory deficits, and emotional problems. Unfortunately, current diagnostic tests such as MRI, neuropsychology, and EEG are unable to differentiate between patients who will have persistent symptoms and those who will recover. Kosofsky stressed the need for biomarkers that can identify patients at risk for ongoing brain damage.
In the absence of such biomarkers, Kosofsky outlined his approach to treating children experiencing TBI and concussion. Cognitive and neuropsychiatric assessments, such as ImPACT, a test used to determine when an athlete can return to the field, are not very reliable. If a patient has not fully recovered from the initial brain injury, there is an increased risk of subsequent injury. Kosofsky recommended a graded approach in which the patient slowly returns to mental and then to physical exercise. If an increase in mental or physical activity causes symptoms, the patient should return to previous activity levels for 2 to 3 days and should not attempt to "power through" a headache. Eventually, the patient can return to the field and then gradually increase physical activity.
Glen Prusky, Weill Cornell Medical College; Burke Medical Research Institute
Costantino Iadecola, Weill Cornell Medical College
- Diabetes causes neuronal dysfunction, possibly resulting from defects in mitochondrial function.
- Therapies that restore mitochondrial function may reverse the effects of neuronal damage in diabetes.
- The vasculature plays a key role in dementia, including in Alzheimer's disease.
Neuronal dysfunction in a mouse model of diabetes
Patients with diabetes are at increased risk of stroke, dementia, and Parkinson's disease. Glen Prusky of Weill Cornell Medical College and Burke Medical Research Institute described his work to elucidate the effect of diabetes on the nervous system in a mouse model. Prusky measures neurological dysfunction in mice by monitoring the visuomotor response. Briefly, researchers monitor deficits in the mouse's ability to track a rotating visual stimulus.
In a mouse model, diabetes resulted in defects in the visuomotor response, which appear before other symptoms of diabetes, such as weight gain and abnormal glucose levels. Because mitochondrial dysfunction is a marker of several neurological disorders, Prusky administered a peptide called MTP-131 that increases ATP production while reducing the production of reactive oxygen species (ROS) in the mitochondria. In control animals, MTP-131 had no effect on visuomotor function; however, in diabetic mice, it increased visuomotor function to normal levels. The effect of MTP-131 was restricted to visuomotor function—it had no effect on weight or glucose levels.
Prusky hopes to identify behavioral markers of nervous system dysfunction in the early stages of metabolic disease, contending that agents that improve mitochondrial efficiency, such as MTP-131, are promising candidates for treating such neuronal dysfunction.
Hypertension and dementia
Costantino Iadecola discussed the link between hypertension and dementia. Normally, the brain maintains a stable CBF despite changes in blood pressure by changing the diameter of blood vessels through a process known as autoregulation. Hypertension promotes hardening of the artery walls and plaque buildup, which can interfere with autoregulation.
For every 10 mm Hg increase in blood pressure, there is a significant decline in cognitive ability—even for blood pressure values that are considered normal. However, blood pressure must be managed with care. High blood pressure causes remodeling of the blood vessels; therefore, a decrease in blood pressure could decrease the supply of blood to the brain, resulting in ischemia.
The role of the vasculature in Alzheimer's disease
Alzheimer's disease is the most common form of dementia and is most commonly associated with the deposition of amyloid plaques comprised of Aβ peptide. Aβ peptide can damage neurons, but it has also been shown to damage blood vessels. Iadecola described the role of the brain's vasculature in Alzheimer's disease. In a mouse model of Alzheimer's disease, CBF decreased before any sign of neuronal dysfunction, which increased the susceptibility to ischemic injury. When researchers induced an ischemic stroke in Alzheimer's disease mice, the mice suffered from a greater decrease in blood flow and a higher infarction volume than non-Alzheimer's disease mice.
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