A stroke is a very serious acute (short-term) event, caused by a sudden impairment in the blood supply to the brain, which can damage the brain tissue.1
A stroke (also called ‘brain attack’) occurs when a blood vessel that brings oxygen and nutrients to the brain either bursts (haemorrhagic stroke) or is clogged by a blood clot or some other mass (acute ischaemic stroke; approximately 85% of all strokes). When a stroke occurs, it kills brain cells in the immediate area. This usually happens within a few minutes.
Stroke is a major health problem. It frequently causes long-term functional and mental disabilities, and more than half of all stroke survivors are left dependent on others for everyday activities. According to the National Stroke Association, 10% of stroke survivors recover almost completely, 25% recover with minor impairments, 40% experience moderate to severe impairments that require special care, 10% require care in a nursing home or other long-term facility, and 15% die shortly after the stroke.
The stroke market is characterised by significant high unmet market and clinical needs. In the acute stroke setting, a patient’s treatment options and recovery prospects are a function of time, where time is measured in hours at best and minutes at worst. The risk of stroke is influenced by a number of factors. The most important ones are previous stroke or transient ischaemic attack (a ‘mini-stroke’), high blood pressure, physical inactivity, advanced age, diabetes, heart disease and smoking.
Stroke symptoms typically start suddenly, over seconds to minutes. The symptoms depend on the area of the brain affected. The more extensive the area of brain affected, the more functions are likely to be lost. The American Stroke Association identifies the following symptoms/warning signs, often referred to as ‘the suddens’:
- Sudden numbness or weakness of the face, arm or leg, especially on one side of the body.
- Sudden confusion, trouble speaking or understanding.
- Sudden trouble seeing in one or both eyes.
- Sudden trouble walking, dizziness, loss of balance or coordination.
- Sudden, severe headache with no known cause.
According to the World Health Organisation, each year approximately 15 million people worldwide suffer a stroke. Of these, 5 million die and another 5 million are permanently disabled, making stroke the second most common cause of death and a major cause of disability.
Stroke can affect people of all ages and genders. However, around the world, the majority of strokes occur in those over 65 years of age; for each decade of life after age 55, the stroke rate doubles in both men and women.
Based on reports across seven countries (the US, France, Germany, Italy, Spain, the UK and Japan), stroke occurs in an average of 214 out of 100,000 people per year, with the incidence growing annually by 1.9% due to an aging population. This means that in the US, for instance, every 40 seconds someone has a stroke, which is about 2,200 people per day.
Stroke, as the most important cause of morbidity and long-term disability, imposes an enormous economic burden. In the US, the total annual cost of stroke was estimated at $65.5 billion in 2008. In the EU, the total annual cost of stroke is estimated at €27 billion.
Seeking diagnosis and care
Anyone suspected of having a stroke should be taken to a hospital immediately to receive professional medical care. Stroke is a medical emergency, and the chances of recovery are greater if the person receives rapid treatment. Successful care of an acute stroke victim depends on a six-step chain (the ‘6 Rs’):
- Recognise: rapid recognition of stroke warning signs.
- React: call emergency medical services immediately.
- Respond: triage (establishing treatment priorities) and transport to an appropriate resource with advance notification.
- Reveal: rapid and accurate diagnosis with assistance from advanced imaging techniques.
- Rx: treatment at the hospital.
Over the last two decades, the management of stroke has improved. Key developments are:
- Routine management in special stroke care units in hospital.
- The availability of medications known as ‘thrombolytics’, which dissolve blood clots to treat acute ischaemic stroke.
- The introduction of methods to help prevent strokes.
These improvements have led to a higher proportion of patients receiving treatment and, alongside developments in imaging technology, have greatly improved treatment outcomes.
1. National Institute of Neurological Disorders and Stroke (NINDS). Stroke: Hope through research. 2011. www.ninds.nih.gov/disorders/stroke/detail_stroke.htm. Accessed 13/09/11.
2. Mackay J, Mensah G (eds.). The atlas of heart disease and stroke. Global burden of stroke. World Health Organisation (WHO) 2004. www.who.int/cardiovascular_diseases/en/cvd_atlas_15_burden_stroke.pdf. Accessed 13/09/11.
3. Roger VL, Go AS, Lloyd-Jones DM, et al. Heart disease and stroke statistics – 2011 update: a report from the American Heart Association. Circulation 2011; 123 (4): e18–e209.
4. National Stroke Association (NSA). Rehabilitation therapy after stroke. info.stroke.org/site/PageServer?pagename=REHABT. Accessed 13/09/11.
5. American Stroke Association. Warning signs. Last updated 2007. www.strokeassociation.org/STROKEORG/WarningSigns/Warning-Signs_UCM_308528_SubHomePage.jsp. Accessed 13/09/11.
6. Di Carlo A. Human and economic burden of stroke. Age Ageing 2009; 38 (1): 4–5.
7. Feigin VL, Lawes CM, Bennett DA, Anderson CS. Stroke epidemiology: a review of population-based studies of incidence, prevalence, and case-fatality in the late 20th century. Lancet Neurol 2003; 2 (1): 43–53.
8. Searles JW, Avodele L, Kuhlmann GL. Acute ischemic stroke. Decision Resources.Waltham,Massachusetts,USA: 2009.
9. National Institute of Neurological Disorders and Stroke (NINDS). Stroke proceedings: Pepe overview. 2011. www.ninds.nih.gov/news_and_events/proceedings/stroke_proceedings/pepeover.htm. Accessed 13/09/11.