The silent menace of stroke | Action Medical Research

Touching Lives - June 2007

The silent menace of stroke

The wrong way

Action Medical Research has funded a study into the problem of food going down the ‘wrong way’.This inhalation of food without overt coughing is a process called ‘silent aspiration’ and researchers have developed a new test that should help doctors assess a patient’s ability to swallow and the likelihood of them silently inhaling food.

Researchers led by Dr David Smithard at the William Harvey Hospital, East Kent Hospitals Trust and GKT, London (King’s College), studied stroke patients being admitted to hospital, looking at their ability to swallow and the frequency of aspiration, particularly silent aspiration.

Dr Smithard says, “It had not been clear from previous research how often this silent aspiration happens, and whether or not patients who inhale food silently have a poorer outcome than those who can still cough normally. Without the coughing reflex, the swallow can appear normal and problems may remain undetected until they have caused complications.

“We modified the existing test and used a dye which would show up on a chest X-ray if it went into the airways, to highlight exactly what was happening. If food was shown to be going to the lungs it would give doctors a better idea of how to feed a stroke patient safely and would put them on alert for possible health risks.”

The team wanted to see how frequent silent aspiration actually is and recruited a number of stroke patients who used the new dye test and whose progress was followed up for six months.

Dr Smithard says, “It went very well, and has certainly raised awareness of what is a considerable problem for stroke patients. We estimate that up to one in ten stroke patients may aspirate silently and our research has demonstrated the need for more detailed assessment of swallowing.

“These patients need careful management as food and liquid inhaled into the lungs can have serious health implications and they can end up staying in hospital for longer than they should.


“We don’t have all the answers yet, but our trials have shown that our new test is safe and can now be used on a wider group of patients including the most severely affected stroke patients, who are potentially most at risk from silent aspiration and food inhalation.”

The £131,070 three-year grant from Action Medical Research has been crucial in enabling this study to take place. The potential implications of the research are enormous, given that stroke is the third commonest cause of death in the UK.

Dr Smithard says,”We could not have gone ahead without the support of Action Medical Research.We now have a new test, which may be particularly useful to smaller hospitals that may not have access to the most sophisticated camera equipment, which can be used to investigate the problem. It should make it easier for doctors to make important decisions on feeding in the first days after a stroke.”

Dr Smithard is not only on the receiving end of money from Action Medical Research — he also helps to raise it! He has been an enthusiastic participant in several of our fundraising cycle rides, including the epic London to Paris bike ride.

He says, “It is good to get involved in fundraising, though sadly I have had an injury that has stopped me training recently.Work commitments on the weekend of this year’s Bristol ride will keep me out of that event, which I had been hoping to do, but I’ll be back — hopefully with my two youngest children as well!” TL

Stroke facts

Research into the causes of stroke and into the care of those who have suffered a stroke is vital, given the extent of the problem and the UK’s ageing population. There are more than 250,000 people in the UK living with disabilities caused by a stroke and many patients require prolonged hospital stays and then long-term support at home after discharge. Muscle weakness, paralysis and loss of balance are the most common symptoms of stroke, and often just one side of the body is affected. Stroke can make even the most ordinary day-to-day tasks difficult — and communication problems caused by impaired speech are a huge cause of frustration for patients and their families. Most strokes are caused when a blood clot blocks an artery that carries blood to the brain. Less common are the strokes caused by a bleed, when a blood vessel actually bursts, leaking blood into the brain.Warning signs can include numbness and weakness in the body, trouble with vision, severe headache, confusion and difficulty speaking; but most strokes happen very suddenly, coming on before the victim can report any symptoms at all. Some people may have a transient ischaemic attack (TIA).This is a temporary interruption of blood supply to the brain and may produce stroke-like symptoms that disappear within 24 hours. A TIA is a warning and needs investigation because anyone who has a TIA is at risk of suffering a more severe stroke in the following weeks. There are many risk factors for stroke: the risk of stroke increases from age 55, then both sexes are affected equally; smoking increases the chances of having a stroke, as does high blood pressure. High cholesterol and diabetes are also bad news, and obesity is known to increase the risk. Heart disease and heavy drinking of alcohol can be contributing factors, and a family history of stroke is also a risk. Anyone suspected of having a stroke will be admitted to hospital for tests, which may include a brain scan to check for problems in the brain; blood tests to identify possible causes of the stroke, electrocardiogram (ECG) and chest X-ray to check for heart or lung problems that may have caused the stroke, and ultrasound to look at the arteries in the neck. Stroke can mean long-term hospital care and for all patients, the first few weeks are critical, with most people showing some improvement as the brain recovers, regaining lost movement over weeks and months. Even so, stroke often results in long-term disability, and many people never fully regain their movement, balance and speech.

Additional information from The Stroke Association and NHS Direct

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