Stroke Rehabilitation

Richard Wilson, Preeti Raghavan

• Publisher: Elsevier
• Year: 2018
• ISBN:
  9780323553827
• Topic: Medicine
• Subtopic: Physiotherapy, Physical Medicine & Rehabilitation

Practical and concise, Stroke Rehabilitation provides everyday clinical guidance on current methods, techniques, evidence, and controversies in this important area. This focused resource by Drs. Richard Wilson and Preeti Raghavan consolidates today's available information in an easy-to-navigate format for today's practicing and trainee physiatrists, as well as other members of the rehabilitation team.

Chapter 1

Stroke Epidemiology and Prevention

Bernadette Boden-Albala, MPH, DrPH, Noa Appleton, MPH, and Benjamin Schram, BS

Abstract

This chapter discusses the global burden of stroke and the methods utilized within the field of epidemiology to monitor stroke incidence, prevalence, and outcomes. Risk factors for stroke are numerous, many of which are modifiable, making stroke one of the leading preventable diseases worldwide. Prevention is therefore a critical component to reducing occurrence of both incident and recurrent strokes. Modifiable risk factors reviewed in this chapter include hypertension, diabetes, dyslipidemias, physical inactivity, smoking, diet, sleep, and alcohol use. Disparities in care, treatment, and health outcomes among racial and ethnic minority groups are highlighted in the chapter. Public health strategies targeting lifestyle changes, community engagement, and population level behavior change are detailed to convey the powerful potential of primary and secondary stroke prevention.

Keywords

Epidemiology; Interventions; Prevention; Risk factors; Stroke

Introduction

For many years stroke has been recognized as a leading cause of disability and mortality in the United States and other industrialized countries. Stroke is more disabling than fatal: the annual cost of direct and indirect stroke-related healthcare in the United States is estimated to be about 34 billion dollars measured in both healthcare dollars and loss of productivity.¹ Over the last few years stroke has emerged as a major global burden as well, especially with the increase of risk factors such as hypertension, diabetes mellitus, and obesity, and a growing burden in low and middle income countries (LMICs), which are experiencing both chronic and infectious disease.² Globally, the burden of stroke and other noncommunicable diseases is on the rise, and projections indicate they will continue to increase in prevalence, reaching epidemic proportions within the next decades.²

Awareness of the importance of stroke has led to a vast and accumulating literature on stroke risk factors, stroke etiology, and stroke outcomes. Stroke risk factors have been elucidated and clinical trials have indicated the benefits of treatment for persons with hypertension, atrial fibrillation, hypercholesterolemia, and asymptomatic carotid disease. In 1996, the first approved treatment for acute stroke, recombinant tissue plasminogen activator (rtPA), became available. Additionally, the pharmaceutical industry continues to actively pursue the development of “neuroprotective” agents to be used acutely for enhanced recovery from this disabling disease. Concurrently, over the last decade there has been important research looking at the contribution of devices, especially for clot retrieval, in the acute stroke period.

In the 21st century, technological advancements in the field of brain imaging, genotyping, and medical information systems have begun to facilitate epidemiological study designs that can elucidate stroke risk markers at the molecular level and risk factors at the subclinical level. Such advancements have provided researchers with more precision in stroke diagnosis and classification, including documentation and timing of events through the use of diffusion-weighted brain imaging techniques. Finally, as the relationship between genetic and environmental factors has become clearer, the role of precision medicine in prevention, treatment, and recovery has taken on a more central space.³

While improved technology has increased the precision and generalizability of data on stroke, epidemiologists who study stroke still struggle with critical issues. Despite recognition of and treatment modalities for modifiable stroke risk factors such as hypertension and cardiac disease, these risk factors remain highly prevalent. Additionally, overall stroke mortality rates are declining, but differentials continue to be reported between whites and other racial/ethnic groups including African-Americans, Hispanics, Alaska Natives, and Asian Pacific Islanders. In recent decades, the aging of the population and increasing prevalence of certain stroke risk factors have led to an increased absolute number of strokes per year (see Table 1.1), resulting in greater incidence, mortality, morbidity, and cost.^2,4

Clinical Definition of Stroke

A stroke is clinically defined as a focal neurologic deficit caused by a local disturbance in cerebral circulation—predominantly either an obstruction of cerebral blood (ischemic stroke) or a rupture to a vessel wall supplying blood to either the brain or spinal cord (intracerebral hemorrhage or subarachnoid hemorrhage, respectively). These three distinct etiological groups–ischemic stroke (IS), intracerebral hemorrhage (ICH), and subarachnoid hemorrhage (SAH)—comprise about 87%, 10%, and 3%, respectively, of all strokes annually.¹

From an epidemiological perspective, the establishment of standardized practical diagnostic criteria for defining stroke is critical. Agreement on a definition for stroke enables comparison of incidence and prevalence rates in studies throughout the world. A number of epidemiological issues arise in the enumeration of stroke cases. Diagnostic criteria for stroke and sensitivity of the diagnosis may differ from study to study. Indeed, early increases in stroke incidence may be attributed to the transition to universal use of CT imaging. Prior to the general use of CT imaging to confirm strokes, underdiagnosis or misclassification of strokes were more likely to occur. With better imaging and the ability to identify abnormalities associated with transient ischemic attack (TIA), we can move toward a more uniform definition of stroke overall.

TABLE 1.1

Absolute Number of Women and Men With Stroke (in Millions) in the World by Stroke Type in 1990 and 2013 (95% Uncertainty Limits Are in Brackets)

		Women		Men
		1990	2013	1990	2013
Ischemic stroke	Incident	2.14 (1.96–2.33)	3.28 (3.06–3.52)	2.17 (2.05–2.33)	3.62 (3.43–3.85)
	Prevalent	4.86 (4.56–5.19)	8.66 (8.32–9.00)	5.18 (4.93–5.46)	9.65 (9.27–10.05)
Hemorrhagic stroke	Incident	0.86 (0.79–0.92)	1.53 (1.42–1.63)	1.03 (0.96–1.09)	1.84 (1.72–1.94)
	Prevalent	1.78 (1.67–1.87)	3.36 (3.23–3.51)	2.11 (2.02–2.22)	4.00 (3.81–4.17)

Reprinted with permission from Feigin VL, Norrving B, Mensah GA. Global burden of stroke. Circ Res. 2017;120(3):439–448.

Over the years, there have emerged a number of different definitions of stroke and TIA. In 2013 the American Heart Association (AHA)/American Stroke Association (ASA) published a consensus statement, An Updated Definition of Stroke for the 21st Century, which incorporates clinical and tissue criteria.⁵ They defined central nervous system (CNS) infarction as “brain, spinal cord, or retinal cell death attributable to ischemia, based on neuropathological, neuroimaging, and/or clinical evidence of permanent injury.”⁵ Intracerebral hemorrhage and subarachnoid hemorrhage are also included in the broad definition of stroke. A TIA was originally defined as a neurological deficit lasting less than 24 hours. However, with the increased ability to image lesions with deficits lasting only a few hours, the AHA endorsed a revised, more operational definition of TIA as a “transient episode of neurologic dysfunction caused by focal brain, spinal ...