Hardik Amin

Acute Central Retinal Artery Occlusion Treated with Intravenous Recombinant Tissue Plasminogen Activator

Central retinal artery occlusion (CRAO) causes ischemic stroke of the eye. We report a case of CRAO that was successfully treated with intravenous recombinant tissue plasminogen activator (rt-PA) and review the current literature. A 64-year-old right-handed man presented to the emergency department with acute left eye amaurosis. An ophthalmologic assessment revealed a left afferent pupillary defect, minimal visual acuity, macular edema with a cherry red spot, and multiple emboli in the inferotemporal arcade of the left eye. A neurologic examination was otherwise nonfocal; neuroimaging was normal. Acute CRAO was diagnosed, and rt-PA was administered intravenously 185 minutes after symptom onset. A repeat examination 4.5 hours after treatment found improved vision, reduced macular edema, and no emboli. An ophthalmologic evaluation 10 days later found a visual acuity of 20/200 in the left eye and bilateral arterial sclerosis without evidence of retinal emboli or macular edema. This case illustrates that intravenous rt-PA may be an effective therapeutic option for CRAO in select patients. Given the current literature and the recommended established safety window for thrombolytics in acute ischemic cerebral stroke, it is reasonable to administer intravenous treatment for CRAO within 4.5 hours after symptom onset. Nevertheless, it is critical that a prospective clinical trial confirm the efficacy, safety, and time window for treatment.

Cardioembolic Stroke: Practical Considerations for Patient Risk Management and Secondary Prevention

Abstract Cardioembolic (CE) stroke constitutes approximately 20% of all occurrence of ischemic stroke in patients. Atrial fibrillation remains the most common and most studied mechanism underlying CE stroke events. Cardioembolic strokes carry high morbidity and are associated with early recurrence in patients. Our understanding of other patient mechanisms associated with CE stroke, including valvular disease, left ventricular dysfunction, and patent foramen ovale, continues to grow. Our review summarizes the diagnosis and management of patients who have sustained CE stroke as a result of the aforementioned cardiac mechanisms. Advances in primary and secondary risk management for prevention of CE stroke are also highlighted in our article—specifically, emerging data regarding monitoring of patients with atrial fibrillation, new anticoagulation therapy, and management of patients with decreased ejection fraction.

Cryptogenic Stroke—The Appropriate Diagnostic Evaluation

Opinion statementIschemic strokes are a significant cause of morbidity and mortality in the United States. They may be due to large artery atherosclerosis, small vessel occlusion, cardioembolism, or other less common mechanisms such as toxins, hypercoagulable disorders, and vasospasm. Each mechanism carries its own risk of recurrence and prognosis. Strokes without an identifiable cause despite a complete work-up are described as cryptogenic. Cryptogenic stroke therefore is a diagnosis of exclusion, and one that should not be arrived at haphazardly. One must complete a thorough, and frequently challenging, stroke work-up prior to this diagnosis. Challenges in determining stroke etiology include the transient nature of precipitating events such as vasospasm or cardiac arrhythmias, variable durations of cardiac monitoring, and unclear significance of certain cardiac structural anomalies. Many consider cryptogenic stroke to be a heterogeneous combination of paroxysmal and occult conditions that create such diagnostic difficulties. The diagnosis of cryptogenic stroke itself carries with it specific outcomes and prognosis. This article will provide an overview of the definition and epidemiology, recommendations for diagnostic evaluation, and risks of recurrence of cryptogenic stroke.

Intra-Arterial Treatment of Acute Ischemic Stroke: The Continued Evolution

Opinion statementThe devastation caused by acute ischemic strokes is evident in every intensive care unit across the world. Although there is no doubt that progress has been made in treatment, it has been slow to come. With the emergence of new technologies in imaging, thrombolysis and endovascular intervention, the treatment modalities of acute ischemic stroke will enter a new era. In this review, we present the concept of the seven evolutionary phases in the treatment of acute ischemic stroke to date.

On- versus Off-Hour Patient Cohorts at a Primary Stroke Center: Onset-to-Treatment Duration and Clinical Outcomes after IV Thrombolysis.

BACKGROUND The symptom onset-to-treatment (OTT) duration predicts symptomatic intracerebral hemorrhage (sICH) and adverse outcomes after ischemic stroke. Previous studies found disparities in OTT durations and clinical outcomes between stroke patients with symptom onset during on-hours versus off-hours, which led to the initiation of nationwide efforts to provide consistent 24-hour stroke care. GOAL Our objective is to compare OTT durations and clinical outcomes in ischemic stroke patients whose symptoms originated during on- versus off-hours at a primary stroke center. METHODS We analyzed clinical data from 210 consecutive patients receiving intravenous recombinant tissue plasminogen activator therapy between January 2009 and December 2013 at Yale-New Haven Stroke Center, a primary stroke center. Stroke severity was assessed by baseline National Institutes of Health Stroke Scale (NIHSS) scores. Clinical outcomes were assessed by presence of sICH and by stroke-related fatalities. OTT durations and clinical outcomes were compared using Mann-Whitney tests, 2-sample tests of proportions, and 2-sample t-tests after testing for equal variance. FINDINGS We found no significant differences in OTT durations between on-hour and off-hour patient cohorts (137 minutes versus 145 minutes, P = .53). There were also no differences in stroke severity (mean NIHSS score 12.4 versus 11.3, P = .27), sICH rates (4.6% versus 6.5%, P = .56), or stroke fatality rates (9.2% versus 9.8%, P = .89) between the 2 cohorts. CONCLUSIONS Our results represent progress in emergency response and acute stroke care, and reinforce ongoing nationwide efforts to increase stroke awareness and provide consistent quality care for patients with acute stroke.

Modest Association between the Discharge Modified Rankin Scale Score and Symptomatic Intracerebral Hemorrhage after Intravenous Thrombolysis

BACKGROUND Thirty- and 90-day modified Rankin Scale (mRS) scores are used to monitor adverse outcome or symptomatic intracerebral hemorrhage (sICH) in ischemic stroke patients after intravenous (IV) thrombolytic therapy. Discharge mRS scores are more readily available and could serve as a proxy for 30- or 90-day mRS data. Our goal was to evaluate agreement between the discharge mRS score and sICH. Additionally, we tested for correlations between the discharge mRS score and 8 clinical scores developed to predict sICH or adverse outcomes based on 90-day mRS data. METHODS Clinical data were analyzed from 210 patients receiving IV thrombolysis from January 2009 till December 2013 at the Yale New Haven Hospital. Agreement between sICH and the discharge mRS score was assessed using linear kappa. Eight clinical scores were calculated for each patient and compared with the discharge mRS score by univariate logistic regression. Goodness of fit was tested by receiver operating characteristic (ROC) analysis and by Hosmer-Lemeshow statistics. RESULTS We found only modest agreement between sICH and unfavorable discharge mRS scores (mRS ≥ 5), with kappa .22, P = .0001. All 8 clinical scores tested showed good agreement with discharge mRS score of 5 or more (ROC area >.7). CONCLUSIONS The discharge mRS score shows only modest agreement with sICH and therefore cannot be recommended as a proxy for 30- or 90-day mRS data. However, the discharge mRS score correlates strongly with clinical scores predicting long-term adverse outcome; therefore, assessment of discharge mRS scores may be of some clinical benefit.

Stroke Systems of Care

This material is not likely to be on your boards; however, knowledge about the evolving landscape of the delivery of stroke care is important for the practicing vascular neurologist. Years after IV t-PA was approved by the FDA in 1996, studies showed that the medication was vastly underutilized with mixed outcomes. In turn, the Brain Attack Coalition (BAC) made the initial recommendations for the development of Primary Stroke Centers to promote better standardization of safe and effective acute stroke care. Since then, there has been an emphasis by the American Heart Association/American Stroke Association (AHA/ASA), The Joint Commission (TJC), and Centers for Medicare and Medicaid Services (CMS) to evaluate specific stroke measures and hospital outcomes. In search of faster, more effective administration of lytics, many investigators have focused on the prehospital setting.

Stroke Treatment and Management

The major breakthrough in acute stroke treatment occurred in 1995, when it was published that IV t-PA was effective in reducing disability in acute ischemic patients within 3 h after onset of symptoms. Attention has since shifted to acute stroke being at the centerpiece of stroke management. Twenty years later, stent retrieval devices were demonstrated to be effective in reducing disability in select patients. Despite the proven efficacy of these interventions, most stroke patients will not have access to these treatments for a number of reasons. Regardless, most strokes are attributed to modifiable risk factors, and primary and secondary prevention for cerebrovascular disease should be equally championed. The comprehensive stroke neurologist needs to be skilled at not only evaluating diagnostic and therapeutic options for patients that present early to the hospital but also patients that present past the window for acute intervention. Updates and recommendations for management guidelines are endorsed by the American Heart Association should be reviewed (http://my.americanheart.org/professional/index.jsp).

Initial Stroke Evaluation

The acute stroke evaluation can be stressful. When a patient arrives at an Emergency Department, they will be surrounded by EMS, nurses, techs, ED physicians, and students. As a stroke neurologist, it is your job to phase out the noise and focus on the patient. It is important to remember that it is a very systematic evaluation requiring only an abbreviated history and physical examination, with the initial goal of deciding if the patient is a candidate for thrombolysis. Your evaluation must be done calmly and efficiently, because ultimately it is only your opinion that matters!

Epidemiology and Risk Factors

Stroke poses a significant global health burden. Many modifiable and nonmodifiable risk factors have been studied. Controlled trials have shown that interventions that affect many modifiable risk factors (HTN, lipids, carotid stenosis, and atrial fibrillation) can reduce stroke risk. Both internists and stroke physicians must evaluate and treat these risk factors in outpatient setting. Many putative risk factors such as insulin resistance are being studied. An appreciation of individual stroke risk is required to significantly affect the future burden of stroke.