Current Developments in Stroke

A stroke occurs when blood flow to the brain is interrupted. The interruption may be due to build-up of fatty deposits on the inner walls of the blood vessels that supply blood to the brain (atherosclerosis and thrombosis), bleeding from a brain blood vessel (haemorrhage) or a blood clot that travels to the brain from a different part of the body (embolus). Cerebral thrombosis, cerebral haemorrhage and cerebral embolism are the three medical terms used to describe these three subtypes of stroke. Common symptoms of stroke include sudden weakness of the face, arm or leg, most often on one side of the body. Tobacco use, harmful use of alcohol, physical inactivity, unhealthy diet and air pollution are the main risk factors of atherosclerosis that lead to stroke. Noncommunicable Diseases (NCDs) (strokes, heart attacks, diabetes, cancer and chronic respiratory disease) share the same risk factors. Long-term exposure to these risk factors also cause raised blood pressure, diabetes and raised blood lipids, which increase the risk of developing strokes. The more risk factors a person has, the greater is the risk of stroke. Nearly two thirds of individuals who develop a stroke die or are disabled. After a first attack of stroke, medicines are required to prevent repeated attacks. Strokes are preventable if individual action is supported by health policies that reduce exposure of people to risk factors. Governments and political leaders have a vital role to play in the prevention of stroke and other NCDs through the implementation of public health policies to control tobacco use, harmful use of alcohol, unhealthy diet, physical inactivity and air pollution.

At present, there is a serious disconnect between medical advances in the field of stroke and its worldwide application. Implementation of new advances to treat stroke depends on country resources and capacity. Stroke (NCDs) cannot be prevented if exposure to risk factors is ignored and action is taken only to provide high technology treatment for strokes. Prevention of first and recurrent attacks of stroke in high risk people through a primary health care approach and affordable stroke unit care for stroke victims need to be prioritized. Governments have a responsibility and a fundamental role to play in prevention by protecting people from exposure to tobacco, harmful use of alcohol, unhealthy food and air pollution. Effective implementation of policies to reduce exposure to behavioural risk factors and air pollution is challenging and is often influenced by politics. The tobacco, alcohol and food industries use devious tactics to protect profits at the expense of the health of people. The general public could lobby to support government policies that protect the health of people.

Population ageing and increasing exposure to behavioural and environmental risk factors are increasing the worldwide burden of stroke. Since 1990, there has been a significant increase in absolute numbers of strokes and the number of deaths from stroke. The burden of stroke is higher in low- and middle-income countries and, in particular, increasing in the younger age groups. The major risk factors for stroke are well established, and many of these, particularly behavioural risk factors such as tobacco use, harmful use of alcohol, unhealthy diet and physical inactivity, are modifiable. Hence, stroke is a highly preventable disease. Primary prevention is the key strategy for reducing the global health impact of stroke. This chapter presents the most recent updates from the Global Burden of Diseases, Injuries and Risk Factors Study (GBD) 2013 studies and discusses stroke prevention strategies.

Treatment of stroke patients should occur in dedicated stroke units with experienced medical, nursing and allied health staff to minimize morbidity and mortality. Specific treatment strategies depend on the type of stroke, which is determined by urgent brain imaging. The key treatment for ischaemic stroke, caused by a blocked blood vessel, is to restore blood flow using clot-dissolving medicine or minimally invasive surgery via angiogram. Both treatments are time critical as effectiveness reduces rapidly over the first few hours after stroke onset. Specific treatment options for intracerebral haemorrhage (bleeding into the brain) are limited, but lowering blood pressure may have some benefit and research into minimally invasive surgery is ongoing. In addition to lifestyle modification, prevention of further strokes requires lowering blood pressure and, for ischaemic stroke, lowering cholesterol and medications to reduce clotting (e.g. aspirin). Access to proven stroke therapies is highly variable and gaps lead to unnecessary disability, death and health costs.

Thrombolysis (clot dissolving using medicine) and thrombectomy (clot removal via minimally invasive angiogram) are effective acute treatments for ischaemic stroke, but are expensive and time limited. Specialized stroke units are proven to manage stroke-related sequelae and complications effectively. They make stroke treatment quicker, easier and more accessible for a larger number of patients and have specialized staff, predefined protocols and better rehabilitation outcomes. These stroke units have proven benefits in countries that can afford them, but should be extended even to limited-resource settings when possible. Besides thrombolysis, thrombectomy and stroke unit care, ongoing research is exploring medications that may keep brain tissue in the region of a stroke alive for longer (cytoprotection), technological advances such as nanoparticles to increase the penetration of thrombolytic agents into the clot and stem cell therapies, all of which remain to be proven in large-scale randomized controlled trials. As a significant number of patients live with some level of disability, rehabilitation is important. Newer techniques to augment traditional rehabilitation such as robots and computer-based systems and virtual rehabilitation are some of the options currently being actively studied. These are easy to use and have shown positive results in small scale studies, but may be costly.

The 2030 Agenda for Sustainable Development is an ambitious initiative of the United Nations, with 17 goals and 169 targets, integrating health, economic development, elimination of extreme poverty, social inclusion, environmental sustainability and good governance. The 17 Sustainable Development Goals focus on: poverty; hunger; health education; gender equality; water and sanitation; energy; economic growth and employment; industry, innovation and infrastructure; inequality; sustainable cities; consumption and production; climate change; marine resources; terrestrial ecosystems; peace, justice and accountability; and global partnership for sustainable development. There is a mutually reinforcing relationship between health and the three dimensions of sustainable development – social, economic and environmental. The connectors are health systems, behavioural, biochemical and environmental risk factors, ecosystems and the social and structural determinants of health, including enabling legal environments, financing and governance. In recognition of the negative impact of NCDs including stroke on development, they have been specifically incorporated in Goal 3 of the Sustainable Development Goals. Goal 3 addresses all major health priorities, including stroke and other NCDs, integral for the attainment of the Sustainable Development Goals. The 2030 Agenda for Sustainable Development, integrating health with economic, social and environmental dimensions of development, offers an unprecedented opportunity to address stroke (NCDs) and their determinants through multisectoral and multidimensional approaches.

Direct and indirect costs of stroke (NCDs) adversely impact macroeconomic productivity and national and household income pose a significant financial burden on health-care budgets. The estimated global economic loss due to cardiovascular disease (stroke and heart disease) has been estimated at US$ 863.5 billion in 2010. It is estimated to increase by 22% and to US$ 1.04 billion in 2030. For the period 2011–2025, the cumulative lost output in low- and middle-income countries associated with cardiovascular disease (stroke and heart disease) is projected at more than US$ 3.76 trillion. The total cost of implementing a set of very cost effective interventions for prevention and management of stroke across all low- and middle-income countries for the period 2011–2025, is estimated at only US$ 170 billion. This amounts to an annual per person investment of under US$ 1 in low-income countries, US$ 1.50 in lower-middle-income countries and US$ 3 in upper-middle-income countries.