Medicine for Managers. BSc MB BS BDS FDSRCSEng MRCS LRCP DRCOG MHSM FRSM. Stroke Revisited

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Johnathan French
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occurs as a result of disturbance in the blood vessels supplying blood to the brain. It is usually the result of a thrombosis (clot) or haemorrahage (bleed).

1 nhsmanagers.net Briefing 3 March 2017 Medicine for Managers Dr Paul Lambden BSc MB BS BDS FDSRCSEng MRCS LRCP DRCOG MHSM FRSM Stroke Revisited A stroke is a rapidly developing loss of brain functions which occurs as a result of disturbance in the blood vessels supplying blood to the brain. It is usually the result of a thrombosis (clot) or haemorrahage (bleed). It is a serious medical emergency and its consequences last more than twenty-four hours. The length of time distinguishes a stroke from related event called a transient ischaemic attack (TIA). The symptoms of a TIA are similar to those of a stroke but they resolve completely with twenty-four hours. There has been a concerted advertising campaign the last couple of years to raise the profile of the disease so that sufferers are identified quickly and treated speedily to reduce the extent of the damage. The acronym FAST has been used to educate the population and to emphasise the need for speed. It highlights the commonly-recognised symptoms of drooping of the FACE on one side, inability or difficulty in using the ARM or experiencing numbness on the affected side, SPEECH becoming slurred, confused or the individual being unable to utter words and TIME to emphasise the urgency of acting as swiftly as possible to seek help and treatment. The stroke itself produces unilateral (onesided) weakness (hemiparesis) or paralysis (hemiplegia) with some or all of the symptoms described in the advertising together often with loss of balance, loss of reflexes and disurbed sensation or numbness. The cause of a stroke is the restriction or cessation of blood flow to an area of the brain. Once deprived of blood, and therefore of oxygen and nutrients, brain cells rapidly start to die and the size of the area of destruction usually defines the extent of the loss of function As described the actual mechanism is a clot or a bleed. A clot is a mechanical blockage

of an artery. Between 80 and 85% of all strokes are the result of a blood clot. Blood Clot A bleed occurs when a blood vessel weakened, by some sort of damage bursts and leaks blood.

They include: Thrombotic (Ischaemic) Strokes: Atrial Fibrillation Raised Cholesterol and Lipids Diabetes Mellitus Obesity Smoking Heavy Alcohol Usage Haemorrhagic (bleed) Strokes: High Blood Pressure

2 of an artery. Between 80 and 85% of all strokes are the result of a blood clot. Blood Clot A bleed occurs when a blood vessel weakened, by some sort of damage bursts and leaks blood. Bleeding Artery There are a number of factors which predispose to a stroke. They include: Thrombotic (Ischaemic) Strokes: Atrial Fibrillation Raised Cholesterol and Lipids Diabetes Mellitus Obesity Smoking Heavy Alcohol Usage Haemorrhagic (bleed) Strokes: High Blood Pressure (hypertension) Excessive alcohol Stress, causing rise in blood pressure In a patient has atrial fibrillation, the heart ceases to beat regularly but develops an irregular irregularity which in turn causes eddy currents and areas of stagnation in the atria (upper chambers). The resulting slow blood movement results in the formation of clots which circulate from the heart to the brain to lodge in the first vessel encountered which is narrower than the clot. Increased blood cholesterol results in increased deposition of fatty cholesterol in the walls of arteries which causes narrowing and roughening of vessels with increased likelihood of clotting. Diabetes results in arterial onarrowing and smoking may increase blood viscosity as well as the nictine effect of causing arterial narrowing. Transient Ischaemic Attacks Some patients develop symptoms which are similar to, or indistinguishable from, a stroke but which may last only a few minutes or up to twentyfour hours before disappearing completely. Such an episode is called a transient ischaemic attack (TIA), colloquially known as a mini-stroke. TIAs should be treated seriously because they are a warning of increased risk of a full-blown stroke in the near future. As with a stroke the symptoms are the result of deprivation of oxygen and nutrients to an area of the brain. They occur as a result of thickening and narrowing of the arteries supplying the brain with blood and may be the result of a temporary further narrowing as a result of clot formation within the vessel. In such circumstances the clot dissolves spontaneously over a short period of time preventing any permanent damage. For patients who experience a TIA, contacting the medical services is a priority so that action can be taken to prevent the development of a stroke subsequently. Raised blood pressure results in increased strain on vessel walls increasing the risk of a blow-out.

3 Diagnosis of a Stroke Normally the clinical presentation enables a stroke to be diagnosed without difficulty. Forty years ago that was an end-point and there was little to be done other than to place the patient in a bed and provide nursing care. Now, the situation is very different. Blood tests will be important to check, in particular: Cholesterol Blood sugar Haematology (including clotting) Electrolytes and Urea Blood pressure. If the blood pressure is high it will be necessary to make immediate decisions about how it should be managed to reduce the risk of extension of, or further bleeding, without compromising the blood supply to any area. Another immediate stage in management is to establish the location and extent of the stroke. This is achieved with a brain scan. Scans enable the clinician to establish; Whether the stroke is Ischaemic or Haemorrhagic How extensive is the damage Which part of the brain is affected. The scan with normally be a computerised tomography (CT) or a magnetic resonance imaging (MRI) scan and the choice will depend on availability, complexity of the bleed, speed of access and degree of detail required. CT scans involve multiple X-ray images built up into a three-dimensional picture of the brain. They can be enhanced by the injection of dye into a vein. The dye travels round the body through the vessels, which are outlined, and areas of obstruction more clearly visualised. MRI scans produce the image by the creation of a magnetic field which is distorted by the presence of a body resulting in the image which, again by computer, is created into a threedimensional picture. Scanned images revolutionised the internal assessment of the body, producing as they do images of textbook quality. Other tests may involve the assessment of other vessels to review the degree of narrowing or the potential risk for a further stroke. For example, a carotid ultrasound scan may be

carried out to view the arteries in the neck which carry blood to the brain to assess whether they are fully patent or narrowed by disease.

Treatment of Stroke consists of: 1. Management of the acute event with reduction of damage where possible 2.

area. They are sometimes irritatingly called by the Americanism clot busters.

4 carried out to view the arteries in the neck which carry blood to the brain to assess whether they are fully patent or narrowed by disease. Echocardiography is an ultrasound technique used to assess the heart to assess whether there is damage or the presence of blood clots which could cause further compromise. Treatment of Stroke consists of: 1. Management of the acute event with reduction of damage where possible 2. Prevention of recurrence Ischaemic Strokes: Medication is a first line and may consist of: (a)thrombolytics These are drugs which can dissolve blood clots and restore and improve blood flow to an area. They are sometimes irritatingly called by the Americanism clot busters. It is vital to distinguish an ischaemic (clot) stroke from a haemorrhagic (bleeding) stroke before use because a thrombolytic drug will make a haemorrhagic stroke worse. Both carotid scanning and chocardiography employ ultrasound which consists of highfrequency sound waves which are fired through a probe into the body and bounce back from structures to produce an image. (b) Antiplatelet drugs. Common aspirin in low dose is frequently used. The aspirin stops platelets (the building bricks of blood clots in the blood) from sticking together to form clots. Physicians may alternatively prescribe either clopidogrel or dipyridamole, usually for a limited period before switching to aspirin (unless the patient is sensitive to the drug). (c) Anticoagulants are used to prevent the formation of new blood clots. Warfarin is the traditional anticoagulant but newer drugs such as rivaroxaban and dabigatran are increasingly used because of simpler administration.

5 (d) Other drugs are associated with risk reduction and may include antihypertensives to reduce the blood pressure and therefore the risk of recurrent damage, and statins to reduce the cholesterol level to minimise the buildup of plaques of atheroma on the vessel walls. Haemorrhagic Strokes: In haemorrhagic strokes medication is again important and lowering of blood pressure and other measures to prevent further strokes from occurring are vital. Surgery is occasionally used to drain a blood clot. Removal of clot reduces the pressure in the brain and therefore can diminish the degree of damage through pressure to brain cells in the vicinity. Of course, the immediate treatment, though it may be vital, is only the start of a long process of recovery and rehabilitation. Initial treatment may be supportive, including artificial feeding if the swallowing reflex has been compromised, oxygen if there is loss of respiratory effort, nutrition and fluids. Treatment, which may then continue for months, is about restoration of function through the use of physiotherapy and occupational therapy. Some patients have difficulty in speaking (dysphasia) or loss of speech altogether (aphasia) and speech and language therapists can work with stroke patients to restore communication ability. Feeding may continue to be a problem if swallowing is compromised during the stroke and patients may need either a tube from the nose to the stomach (a nasogastric tube) or the insertion of a feeding tube from the outside to the stomach by means of a small incision in the abdomen, a procedure done under local anaesthetic. The tube is called a percutaneous endoscopic gastrostomy PEG tube. Swallowing, like weakness and paralysis, and speech may improve over time with the crucial support of the medical team. The longer term may introduce a number of issues which may cause concern or inconvenience for the stroke sufferer. As recovery occurs the objective is to return as much as possible to normal living. Patients may need advice on such things as having sex (which does not increase the risk of a further stroke) and being able to drive (which depends on the nature of any disability and the type of vehicle which can be used). It is also important to remember that, following a stroke, the risk of a further stroke is increased and it is important to maintain a healthy lifestyle. Factors such as age, ethnicity and medical history are not changeable but factors such as having a healthy diet, exercise, cessation of smoking, reduction in alcohol consumption and effective management of any concomitant medical problems such as diabetes will considerably reduce the risk. When I qualified in the early seventies, medical wards would often be half-full of stroke patients for whom little was available. They simply laid in bed or sat in a chair able to do little and often largely unattended. That has all changed now with modern investigation, medication and supportive management. In another forty years who knows how much better stroke management will be and anything that minimises or eliminates this major cause of disability will be welcomed enthusiastically. paullambden@compuserve.com

E X P L A I N I N G STROKE

E X P L A I N I N G STROKE EXPLAINING STROKE Introduction Explaining Stroke is a practical step-by-step booklet that explains how a stroke happens, different types of stroke and how to prevent a stroke. Many people think a stroke