What is stroke?

Most of us must have known a relative, friend or fellow worker who has had stroke. As the name implies and simply put, it is a catastrophic loss of power and movement in one half of the body in a person who was otherwise ‘healthy,’ from a disturbance of the blood supply to the brain. Stroke occurs when the brain is deprived of blood supply. The disturbance of blood supply could be due to blockage (ischaemic stroke) or rupture of the blood vessel (haemorrhagic stroke).

As a result of this, because of lack of blood and oxygen, the affected brain cells are damaged or die, and their function is thus also affected. For example, the person may suddenly lose the ability to speak or move a body part (e.g. the face, arm and leg). In some cases, the pressure within the brain, because of the bleeding, results in sudden very severe headaches with vomiting, and loss of consciousness or even sudden death.




What are the causes of stroke?
As human beings, we are the products of our genes (nature) and environment (nurture). We are born with genetic attributes that play out with the environment to determine the diseases we succumb to. In the case of stroke, these are termed non-modifiable or modifiable. The commonest cause is high blood pressure (hypertension) in 80 percent of cases, followed by diabetes mellitus, cholesterol abnormalities, sickle cell disease, heart diseases, sedentary lifestyle, old age, obesity, excessive alcohol consumption and cigarette smoking.

Unfortunately, most victims of stroke are not aware of the above risk factors, which are largely preventable. Thus, if taken in context of the fact that stroke is the second leading cause of death and a major cause of disability globally, control of these factors is smarter and cheaper. Low-income countries, with per capita income of $825 have over taken high-income countries with per capita income of $10,066 over the past four decades in the incidence and case fatality of stroke. There has been a 42 percent decrease in stroke incidence in high-income countries and greater than 100 percent increase in low to middle income countries. Consequently, it is the low-income countries, with poor resources, that are bearing the burden of stroke in increasing magnitudes with average annual incidence of 117/100,000 and case fatality of 26.6 percent to 40 percent.

The burden of stroke is very high, as stroke is a leading cause of death and disability all over the world. For instance, it is estimated that one in five women and one in six men all over the world will have a stroke in their lifetime. According to the World Health Organisation and data available from experts worldwide, about 17 million people suffer a stroke every year. Of these, at least 200,000 strokes occur in Nigeria alone.

Stroke is the most common medical emergency in all the teaching hospitals across Nigeria, and certainly one of the top leading non-communicable causes of death. In fact, worldwide, stroke kills more people each year than AIDS, tuberculosis and malaria put together. Stroke affects everyone – it occurs in children and adults, but beyond the directly affected persons, it can devastate families, care givers, friends, the workforce, and communities.

How can stroke be prevented?
The majority of strokes can be prevented by making individual changes based on the risk factors, making healthier choices with respect to our diet and exercise, and having regular medical checkups to detect and treat any risk factor. Even when someone has survived a stroke, it is important to intensify these preventive measures to reduce the likelihood of recurrence. In line with the global world stroke campaign recommendations, beyond individual changes, everyone must become involved in advocating globally and locally for policies that will ensure that we are altogether healthier.

What are the consequences of stroke?
About 23 to 30 percent of stroke victims die in the first 30 days of the ictus. About 40 per cent will go home and be independent, 20 per cent will need some form of assistance for activities of daily living and 20 per cent will need institutional care. So, as you can see, the consequences of stroke are devastating, particularly in low-income countries.

What are the possible treatments?
Stroke treatment is a multidisciplinary endeavour that involves many specialists, who apply their expertise and treatments that are based on evidence of being effective (from research and experience). The most important thing is that when a stroke is suspected, the person must be taken to a hospital immediately. This will ensure that more accurate diagnosis is made and treatment started. On the part of doctors, we must all stay abreast of the warning signs and be able to quickly recognise and diagnose stroke, and refer patients appropriately if the expertise is not available in our own practice.

In the acute stage, survival partly depends upon time lapse from event to hospital (‘door to hospital’ time.) Medical technology can now restore blood supply to dying brain tissue (penumbra,) if the stroke victim reaches hospital within three to four and a half hours of the event. This is where the rudimentary or non-existent medical emergency service in low-income countries poses a serious challenge. As a result, many patients die before reaching hospital. The event can be easily recognised by observers (relatives and friends) from the following: Facial asymmetry, arm and leg weakness on one side, speech difficulty, and the time of occurrence. These are popularly called “FAST.”

In high-income countries, ‘brain attack’ teams convey victim within the hour to hospital emergency units, where intravenous or intra arterial recombinant Tissue Plasminogen Activator (rTPA) is given after a CT-Scan has excluded haemorrhagic stroke. If it is a haemorrhagic stroke with raised intracranial pressure, decompressive neurosurgery could be life-saving. Equally, an ischaemic stroke patient with severe oedema also benefits from decompressive surgery. Multimodal CT-Scan (CT angiography and CT-Perfusion Scan) or Multimodal Magnetic Resonance Imaging (Diffusion Weighted MRI & Perfusion Weighted MRI) could be used to further refine the identification of patients with ischaemic stroke that are likely to benefit from tPA therapy. The clinical selection protocol for tPA therapy is very stringent to guard against haemorrhage and is difficult to fulfil in non-specialised centres and is not practised in Nigeria.

However, a centre like the National Hospital Abuja has all the potentials that could be organised to deliver tPA therapy for acute ischaemic stroke that often presents within the four and a half hour time limit.

If a patient survives the acute stage, then rehabilitative physiotherapy plays a crucial role in restoring him/her to normal function, as much as possible. The degree of disability anchors on activities of daily living that we take so for granted. Such actions as turning in bed, getting out of bed and going to the toilet that we do on reflex without thinking become very important, when we are unable to perform them. Relatives and spouses of stroke victims know this very well.

Various disability rating and outcome scales have emerged over time with proven reliability and validity. The common ones include the National Institute of Health Stroke Scale (NHISS), which is useful for early determination of severity, prognostication and serial assessment, while the Barthel Index (BI) is useful for planning rehabilitative strategies. The Modified Rankin Sale (mRS) and Glasgow Outcome Score (GOS) are measures of outcome and useful in considering early intervention. The NHISS method is quick to administer by the bedside in seven minutes and is a 13 item scoring system. It integrates neurologic exam components CN (visual), motor, sensory, cerebellar, inattention, language and level of consciousness. Maximum score is 42, signifying severe stroke and minimum score is 0 (a normal exam). Scores greater than 15 to 20 are more severe.

Thus, community surveys should be done to identify and treat the risk factors. Health education should be given for early detection and referral to hospital (FAST). The staffing and infrastructure of hospitals should be improved for optimal management of victims of stroke. Modification of risk factors remains central in control of the disease, which should be pursued by public and private partnership. The partnership should engage in individual and population based education, screening and management of causal factors detected, such as hypertension, which is responsible for 80 percent of strokes. Prevention is better, smarter and cheaper than cure. So, it is important that people eat right, behave right and exercise right.

Stroke affects everyone — we all have a reason to prevent it. Stroke is preventable – learn how it can be prevented, and also practise the preventive strategies.

Learn the warning signs of stroke. If you notice someone having a stroke, say something and do something – get them to hospital, FAST!
To our government: support the development of coordinated systems of care, including specialised stroke units and stroke care teams, and support excellence in stroke research.