Although there is no cure for stroke, recent advances in treatment mean patients have a significantly better chance of recovery compared to ten years ago, as Corinne Swainger reports
The latest audit by the Royal College of Physicians in 2012 showed that emergency care has significantly improved since the introduction in 2007 of the National Stroke Strategy. For example, 65 per cent of stroke patients received treatment on a dedicated stroke unit – up 18 per cent over 2011; while 67 per cent of patients, who were suitable for clot-busting drugs, received them – up 30 per cent compared to 2011.
In addition, 91 per cent of patients had a brain scan within 24 hours of arriving in hospital, allowing doctors to identify their specific type of stroke and administer the most suitable treatment.
Current stroke treatments are tailored to the needs of each patient. Treatments may include anti-platelet drugs, such as aspirin or anti-coagulants, and clot-dissolving drugs, if appropriate. Other drugs include statins to lower cholesterol, anti-hypertensive drugs that lower blood pressure and drugs designed to limit the extent of damage to brain tissue. Rehabilitation is also used to restore strength to the patient and help them adjust to their post-stroke lifestyle.
The brain can stay viable up to 48 hours after a stroke so it gives us more much-needed valuable time to treat the patient
An ischaemic stroke is caused by blood clots that cut off oxygen to the brain, which can cause fatal brain damage. Tissue plasminogen activator (TPA) is the primary clot-busting drug used to dissolve the blood clot causing the stroke.
Clot-busting drugs are most effective when administered within 90 minutes of the onset of stroke, but this treatment is only licensed for four-and-a-half hours, which offers a narrow treatment time. Physicians must, therefore, quickly evaluate the problem and decide if patients are eligible to receive the clot-busting drugs. Aspirin or anticoagulants are also used to help dissolve blood clots.
FIXED-DOSE ATRIAL FIBRILLATION TREATMENTS
Three new oral anticoagulation treatments – dabigatran, rivaroxaban and apixaban – have recently been approved in most major countries and are expected to replace warfarin for stroke prevention in atrial fibrillation (AF). While warfarin is effective, it has many limitations, including the need for monitoring and regular dose adjustments, as well as many interactions, which prevents its use in at least half of patients with AF.
The main advantage of the new drug rivaroxaban in particular is that it can be taken once a day which encourages patient compliance. Professor John Camm of St George’s, University of London, says: “The availability of a once-daily option that eliminates the need for routine coagulation monitoring is of significant importance for patients.”
EXTENDING TREATMENT TIME
Doctors in Scotland are now researching a new approach to determine when a patient actually suffered their attack. This can potentially extend the amount of time that brain tissue, known as the penumbra, can be treated around the “dead” area after a stroke.
Dr Celestine Santosh, a neuroradiologist at Southern General Hospital, Glasgow, who is leading the research, says: “One-third of all stroke patients don’t know the time of their onset of symptoms. However, research shows that the penumbra can stay viable up to 48 hours after a stroke so it gives us more much-needed valuable time to treat the patient.” Human stroke trials are expected to begin in Glasgow in 2015.
MECHANICAL CLOT-BUSTING DEVICES
A new generation of mechanical devices has been designed to remove blood clots in ischaemic strokes. The surgical technique was approved by the US Food and Drug Administration in March 2012 and could significantly change the way doctors treat the problem.
The new devices vary in design, but are inserted into blocked arteries, trapping and then removing the clot, and reopening the blocked blood vessel. By removing clots quickly and returning blood to the brain, patients could have a better chance of recovery.
In a recent medical trial using one such device, clots were removed in 50 per cent of patients given medication directly into the brain, compared with 5 per cent of patients receiving standard care.
Also known as therapeutic hypothermia, brain cooling has been shown to decrease swelling and reduce the amount of brain damage after acute stroke. This technique has proved highly effective in saving lives and preventing neurological damage after heart attack, and after oxygen deprivation in newborns.
Studies have involved the body of patients being cooled using ice cold intravenous drips and cooling pads applied to the skin. This lowers the body temperature to about 35C, slightly below its normal level. The treatment puts the body into a state of artificial hibernation, when the brain can survive with less blood supply, giving doctors vital time to treat blocked or burst blood vessels.
Deep vein thrombosis (DVT) is common in immobile patients with a recent stroke, and is a common cause of avoidable death and morbidity in these patients. While anticoagulant drugs can increase the risk of bleeding in the prevention of DVT, the recent CLOTS Trial has shown that the use of graduated compression stockings can reduce the risk of post-stroke DVT and is a potentially safe, useful treatment in pulmonary embolism in stroke patients.
CAROTID ARTERY STENTING
Approximately 25 per cent of strokes are due to carotid artery disease, which causes a narrowing of arteries that lead from the chest up to the brain, and can cause a transient ischaemic attack or mini stroke. The standard treatment is a surgical procedure called carotid endarterectomy where the artery is cut open and the plaque removed.
However, the improvement of stent platforms and embolic protection devices over the past decade, and the strong demand from patients for a less-invasive procedure, has made carotid artery stenting an equally efficient and safe procedure for the prevention of stroke.
UK POSTCODE LOTTERY
Stroke charities warn of a postcode lottery in stroke treatment. A patient’s prospects can vary significantly depending on where they live in the UK.
In London, eight hyper-acute centres were established with the aim of getting all stroke patients to specialist facilities for emergency care, before transferring them to one of 20 local stroke units for ongoing rehabilitation. These developments have transformed London into one of the best stroke service centres in the UK.
Professor Tony Rudd, consultant stroke physician at the Guy’s and St Thomas’ NHS Foundation Trust, says: “Mortality has come down quite significantly in London compared to the rest of the country. Many patients in other areas of the UK don’t have access to specialist stroke units or lifesaving thrombolytic treatments 24 hours a day, seven days a week.”