Stroke is defined as a neurologic deficit caused by a focal injury to the central nervous system secondary to vascular disease, and includes ischemic stroke, intracerebral hemorrhage (ICH), and subarachnoid hemorrhage (SAH).1 Each year, approximately 800,000 new people develop a stroke in the United States.2 Stroke is the fifth leading cause of death in the United States and a leading cause of major disability in adults.2 Furthermore, the risk of recurrent stroke is as high as 20% at 5 years.3 There are 2 major types of stroke: ischemic and hemorrhagic stroke. Approximately, 87% of stroke in the United States is ischemic and the remaining is hemorrhagic.3 Hemorrhagic stroke can be further divided into ICH and SAH.4 This chapter aims to outline the current understanding of common stroke presentations, risk factors, pathophysiology, complications, and treatment.
ACUTE STROKE PRESENTATION
Acute stroke should be suspected in a presentation of acute neurologic deficits that could be attributed to a vascular distribution. The knowledge of stroke is intertwined with typical clinical presentation syndromes associated with large or small vessel occlusions. Anterior cerebral artery (ACA) lesions typically present with leg weakness or numbness, aphasia, and apraxia, while middle cerebral artery (MCA) lesions manifest as face or arm weakness more than leg weakness, with aphasia (left side involvement) and, at times, neglect (right side involvement). Posterior circulation strokes present with cranial nerve deficits such as diplopia and often with cerebellar features such as ataxia, nausea, and nystagmus. Presence of alteration in mental status, headache, nausea, and vomiting is usually more indicative of increased intracranial pressure (ICP) and hemorrhagic strokes.5
Modifiable risk factors and nonmodifiable vascular risk factors result in disparities in ischemic stroke risk factors between different populations. Age and sex are known to be strong nonmodifiable indicators of ischemic stroke risk. The risk of stroke increases by 9% every year for men and 10% for women.6 Men are at higher risk of ischemic strokes in the young and middle-aged groups; however, women have a higher ischemic stroke risk in their lifetime and tend to have worse mortality and morbidity outcomes.7
Ethnicity is another significant nonmodifiable risk factor for ischemic stroke. Blacks have a higher risk of ischemic stroke risk, especially in the young middle-aged group (between 45 and 54 years of age) with a black-to-white incidence ratio of 4.02.8 The risk remains higher in the older age group but becomes more attenuated. Another nonmodifiable risk factor is a family history of strokes. The Framingham study showed that history of parental stroke before the age of 65 increases risk 3-fold.9 Other hypercoagulable conditions have been linked to increased risk of ischemic stroke, including hereditary diseases such as sickle cell disease, Fabry disease, and homocystinuria,10 and acquired hypercoagulable conditions ...