MEDICAL MATTERS: Of the many unpleasant aspects of having a stroke, the impairment or loss of speech must be one of the most frightening. When a doctor examines a patient with a suspected stroke he must carefully assess speech. But listening to people's responses over the years, I have been struck by how cruel it must seem to the patient.
How would you like to be asked a question, only for the reply to emerge in the form of gibberish? Or perhaps worse, for no sound to come out of your mouth, followed by the realisation that you can no longer communicate verbally with those around you.
Aphasia is the medical term used to describe an inability to speak after a stroke, while the term dysarthria applies when there is a difficulty articulating words and sounds.
One of the first tasks in assessing a patient with speech difficulties is to establish whether they have an expressive or receptive dysphasia. In other words, can they understand what is being said, but are unable to express the appropriate words in response. Or has the stroke damaged that part of the brain that helps interpret incoming speech, leading to a condition called receptive dysphasia.
The term stroke has its origins in the Greek word apoplexia, meaning a seizure as a result of being "struck down". The word is a combination of apo (meaning away from) and plexe (a stroke). It comes from a belief at the time that anyone seized by a sudden disability was "struck down" by the gods.
A stroke is the result of a sudden and severe disturbance of blood flow to a part of the brain. Whether it causes a left- or right- sided weakness, speech, perception or visual problems can be accurately traced back to a precise area in the brain.
Most strokes (80 per cent) are caused by a process similar to a heart attack: the blood supply to a part of the brain is cut off leading to infarction or damage. Less commonly, a stroke may be the result of an uncontained bleed into the brain and is referred to as haemorrhagic stroke. When the injury and its effects persist for more than 24 hours, the event is called a cerebrovascular accident (CVA) or full-blown stroke. But if the neurological deficit resolves in 24 hours or less, it is called a transient ischaemic attack (TIA).
Writing in The Principles and Practice of Medicine, the renowned physician William Osler said: "the chief difficulty in deciding on a method of treatment [of stroke] is to determine whether the apoplexy is due to haemorrhage or to thrombosis".
While this difficulty has been largely resolved thanks to the advent of medical technology such as CAT and MRI scans, the treatment options since Osler wrote these words in the early 20th century have increased.
The current edition of a respected independent publication, The Drugs and Therapeutics Bulletin (DTB), addresses the issue of what drugs should be prescribed following a CVA or TIA in order to prevent a further vascular event. As the 10-year risk of stroke or a heart attack following a TIA or mini-stroke is 44 per cent, this is an important consideration for patients.
The first line of treatment is called anti-platelet therapy. Drugs such as aspirin can prevent platelets sticking together and so the risk of a further clot, either in the heart or the brain, is reduced. The research is convincing and shows that for every 1,000 people who have a stroke or a TIA, anti-platelet treatment taken for around three years prevents 25 non-fatal strokes, six non-fatal heart attacks and 15 deaths.
The DTB, having examined the literature carefully, recommends a daily dose of 75mg of aspirin as an adequate preventive measure. If the patient has a genuine hypersensitivity to aspirin, then a drug called clopidrogel is the recommended alternative.
All patients who have had a non-haemorrhagic stroke or TIA should be prescribed cholesterol-lowering treatment in the form of a statin. The DTB specifically recommends simvastatin 40mg daily. And it also suggests that such patients receive treatment to reduce their blood pressure "even for patients considered to have normal blood pressure". Rather than specify a particular drug, the authors state: "the reduction in vascular events associated with antihypertensive therapy appears to be an effect of blood pressure reduction and not specifically the drug used".
If you have had a stroke or a TIA recently, you should discuss these recommendations with your GP. Unfortunately, due to a short-sighted decision by the Health Service Executive, family doctors in the State no longer receive copies of the Drugs and Therapeutics Bulletin. However, both patients and doctors can access excellent evidence-based advice on this and other topics by consulting the Cochrane Library. Thanks to the efforts of the Health Research Board (HRB), this source can be accessed free via a link on the HRB website at www.hrb.ie
Dr Muiris Houston is pleased to hear from readers at mhouston@irish-times.ie but regrets he cannot answer individual queries.
