Stroke Test

Concerns have been raised about a new service known as Strokecheck, being offered in certain pharmacies in Australia. These pharmacies host general practitioner consultations where the person is questioned about the risk factors for stroke and if they are significant. A free ultrasound of the carotid arteries is offered. Strokecheck appears to be significantly promoted on social media and has also combined with a gym, a university and a large company to promote the service.

But, this has raised significant concerns within the medical profession. The president of the Australia and New Zealand Society of Vascular Surgeons, Dr Bernard Bourke said, “I am concerned the group is disease-mongering and masquerading as a charity to make money out of Medicare. It’s a rip off”, he said. “They’re putting the fear of God into people”.

Dr Bourke went on to say that “there was absolutely no evidence that people without symptoms of stroke should be getting screened for the stroke risk and having ultrasounds. This decision should be made by consultation with their regular general practitioners”.

Dr Bourke quoted a recent review by the US Preventive services task force which concluded that general screening in the population using ultrasounds of the carotid arteries for stroke risk caused more harm than good.

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So, what is the reality here? Firstly, it is my strong opinion that any ultrasounds should be performed by highly trained technicians and reported by specialists in the area who are reading these all of the time. The results of carotid ultrasounds can often be over-interpreted leading the patients to believe they have more issues than is really the case.

Also, an important point left out of the debate in the article published in the Sydney morning Herald on March 25th is that carotid atherosclerosis is only one cause of stroke and a normal carotid scan does not mean you are free of risk. Secondly, many people over the age of 60 will have a degree of carotid atherosclerosis which will never cause them any issues.

Let me make the point that the two major risk factors for stroke are hypertension and atrial fibrillation. The presence of significant hypertension which is typically long-standing, poorly controlled high blood pressure or atrial fibrillation will immediately alert a doctor that the sufferer has a higher risk for stroke, requiring further investigation and management.

These two major factors aside, there are five categories of stroke that need to be considered as the underlying factors which need investigation and management.

1) Carotid atherosclerosis — this is a major cause of stroke and the reason the carotid scanning is being offered. In my opinion, however, it is being offered in the wrong setting by the wrong people.

2) Lacunar infarction-this is typically a different type stroke with a very dramatic presentation but in many cases, almost complete recovery or the person being left with minimal disability. The real cause here is a bout of poorly control blood pressure. The management is of course better control of the blood pressure.

3) Cerebral embolism-although there are many causes of cerebral embolism, the major factor is atrial fibrillation. Atrial fibrillation is where the top chambers of the hearts develop a chaotic rhythm where these chambers quiver without effective contraction. Because there is then sluggish flow within these chambers, small clots can form which may then break away and travel up to the brain potentially causing a stroke.

4) Paradoxical embolism-the commonest cause of this condition is a Patent Foramen Ovale. In utero, this communication between the right and left atrium in the heart is open because we derive our blood supply and oxygen from the umbilical vessels. When we take our first breath, the pressure on the left side of heart increases typically closing the flap but in around 30% of cases a small communication is left. If a clot forms on the venous side of our circulation with situations such as prolonged immobilisation, it may break away and travel up towards the lungs. If it is going through the right atrium at the wrong time and for some reason the pressure increases on the right side of the heart such as is seen with straining, coughing or sneezing, the small clot can be forced across this patent flap and again can travel up to the brain where it may cause a stroke.

5) The final relatively common cause of stroke is a disorder of blood clotting. Any condition that makes the blood thicker may precipitate the formation of a clot and thus a subsequent stroke, if this occurs in the cerebral circulation. There are eight relatively common genetic causes of excessive blood thickness, the commonest cause being a condition known as Factor Five Leiden but there are also acquired causes that typically occur as one ages. This is especially so over the age 50 and is commonly associated with medical therapy such as hormone replacement therapy, chronic inflammatory conditions and even cancer.

There are a number of other rarer causes of stroke which are outside the scope of this article but clearly having a screen in a pharmacy is not, by any means, an adequate assessment and in some cases, may cause excessive worrying about something that is purely a normal aspect of ageing (such as minor carotid atherosclerosis) but in other cases may falsely reassure someone that they are not a stroke risk and therefore the person involved does not seek proper medical attention.

As always, these matters should be managed by a competent physician.