The target of this course is doctors. Also bring some light to patients and their families. You have just been called to the emergency department to evaluate and treat a possible stroke patient. You ask yourself: What should I do first? How do I know it is a stroke? Is it too late to reverse the damage, and if not, how do I do it? How do I make sure that I do things correctly during the first day or so to prevent worsening? This course is designed to answer these real-life questions.

The term ‘‘stroke’’ usually refers either to a cerebral infarction or to non-traumatic cerebral hemorrhage. Depending on the population you are seeing (ethnicity, age, comorbidities) the ratio of infarcts to hemorrhages is about 4:1. As will be described later,  cerebral infarcts can be caused by a number of pathological processes, but all end with an occlusion of a cerebral artery or vein. If the arterial occlusion results in a reduction of blood flow insufficient to cause death of tissue (infarction), it is termed ‘‘ischemia.’’

3. Stroke in the emergency room

3.1 Is this a stroke?

3.1.2 Diagnosis

There is currently no 100% sensitive and specific test for cerebral infarction in the emergency department, so that the diagnosis is usually made on the basis of a characteristic history, exam, presence of comorbidities, and the absence of seizures or other stroke mimics.

All of the following may present similarly to a stroke. In all cases, the distinction can be made by an emergent MRI scan, which will show abnormal diffusion-weighted signal in most stroke cases, but not in mimics.