Stroke continues to be a major cause of morbidity and mortality in adult populations worldwide. More than 795,000 patients are diagnosed with new or recurrent stroke each year in the United States alone, and this entity is the fourth most frequent cause of death among adults, ranking behind heart disease, cancer, and chronic lower respiratory disease.1 Ischemic stroke comprises 87% of all strokes. This disease is a leading cause of disability in the adult population. More than 50% of stroke sufferers will be left with permanent disability, 25% will require some assistance with activities of daily living, and 25% of patients will remain in an institutional setting 6 months poststroke.2
The management of acute stroke had been strictly supportive until 1995, when the National Institute of Neurological Disorders and Stroke (NINDS) rt-PA Stroke Study Group published their trial of recombinant tissue plasminogen activator (rt-PA) in the treatment of acute ischemic stroke.3 The availability of an effective therapy triggered a renewed interest in treatment of acute ischemic infarction as well as the development of specialized “stroke centers” in an attempt to improve outcome in patients with cerebral ischemic infarction. These interventions have improved the outcomes in acute ischemic infarction; however, the 30-day mortality following acute stroke is still unacceptably high at 15% to 30%.4 The recent positive outcome of multiple endovascular trials introduces a new paradigm for treatment of ischemic stroke with proximal vessel occlusion and a significant penumbra. The door has opened for the determination of best practice combining systemic lytic and intra-arterial therapies.
It is now even more important for the emergency physician to be able to recognize acute ischemic infarction, order appropriate imaging studies, initiate intravenous (IV) thrombolytic therapy and rapidly consult neurologists and interventional specialists. This paradigm is akin to the treatment of ST-elevation myocardial infarction (STEMI). This chapter will review (1) basic neurologic syndromes as localized by their arterial distributions (i.e., anterior cerebral artery [ACA], middle cerebral artery [MCA], posterior cerebral artery [PCA], basilar artery, etc.) as an effort to simplify recognition of large-vessel infarctions, (2) new imaging modalities, (3) initial medical management, and (4) interventional management.
RECOGNIZING ACUTE ISCHEMIC INFARCTION
Because computed tomography (CT) scans do not “rule out” acute ischemic infarctions, the non-neurologist must perform a detailed neurologic examination. Identifying these patterns can assist in the identification of stroke syndromes that can be treated with thrombolytic therapy, as opposed to stroke syndromes that do not follow vascular territories such as hemorrhages; venous infarctions (extremely rare); or stroke mimics such as extreme ranges of blood sugar, seizures, or tumors. The history of a sudden onset of neurologic deficit and the time of onset are paramount to making diagnosis and treatment decisions.
The presentation of acute stroke follows distinctive anatomic patterns that are predictive of the involved arterial territory. Here are the anatomic structures and associated syndromes as ...