Strokes occur when the brain is not getting enough blood, which can lead to oxygen and nutrient deficiency, brain damage and death.
Ischaemic stroke, the most common, results from a blood clot blocking the normal blood flow, while haemorrhagic strokes involve brain damage from a burst blood vessel. A “mini-stroke”, or transient ischaemic attack (TIA), can happen if the brain is temporarily starved of blood. These are often a precursor to a full-blown stroke.
Some stroke risk factors are unavoidable. Three quarters of strokes occur in people aged over 65. People with South Asian, African or Caribbean backgrounds have a predisposition to diabetes and heart diseases, which can lead to strokes.
However, there are controllable risk factors. More than two to three units of alcohol daily for women and three to four units for men can lead to high blood pressure and an irregular heartbeat, which increase the likelihood of strokes. Smoking narrows the arteries and brings a risk of blood clots.
High cholesterol in the blood brings higher stroke risk. Food that contains high amounts of saturated fat raises cholesterol levels, while small amounts of unsaturated fat in oily fish, avocados and olive oil lower cholesterol. Overweight people tend to have high blood pressure, so maintaining a healthy weight is essential.
The development of specialist stroke units, with better facilities and highly skilled staff, has also improved survival rates after a stroke
Adjusting these risk factors is a major challenge for some patients, says Stewart Findlay, a GP from Durham with an interest in stroke care. “Once adults have developed addictive habits, it’s extremely difficult to get them to change. There are some who do not change even with access to smoking cessation services or personal trainers.”
People with long-term conditions and those over 65 should have regular pulse checks to check if their heartbeat is irregular, adds Dr Findlay. An irregular heartbeat could be a sign of a heart condition called atrial fibrillation, which increases people’s risk of a stroke. “We can give them medication at this stage. People can even check their own pulse,” he says.
When a stroke occurs, quick treatment can prevent major damage and disability. The Department of Health introduced its FAST campaign in 2009 to emphasise this. The acronym – Face, Arms, Speech, Time – refers to simple checks to determine whether someone may be having a stroke: drooping on one side of the face, an inability to raise arms above their head and keep them there, slurred speech – and emergency action.
Stroke care has improved significantly in recent years. The rate of strokes fell 30 per cent between 1999 and 2008, according to an analysis published in the journal BMJ Open last October. The study also showed that the proportion of people dying within two months of a first stroke fell from 21 per cent in 1999 to 12 per cent in 2008. Improved drug treatment, both before and after the stroke, is the likely reason, including the use of blood cholesterol and blood pressure-lowering drugs, the researchers concluded.
The development of specialist stroke units, with better facilities and highly skilled staff, has also improved survival rates after a stroke. Professor Tony Rudd, clinical lead for stroke care for NHS London, says: “Before we had these units, we had 31 hospitals giving stroke care and the quality ranged from excellent to pretty poor. Survival rates are better now because the patients get higher quality assessment.”
The units are open around the clock to assess, diagnose and treat people within 30 minutes. The benefits are already being seen. Patients in London are 25 per cent more likely to survive now than before the units opened. This equates to about 214 fewer deaths a year within 30 days of a stroke.
In 2009 only 174 London patients received essential clot-busting drugs, but the figure rose to 587 in the first five months of 2010 after the units were set up. These drugs are vital because they can limit the extent of disabilities following a stroke, meaning a more positive outlook for thousands of people who have a stroke every year.