In Uganda, stroke is one of the top five causes of adult death and accounts for 3.7 % of all admissions in Uganda’s hospitals. However, it should be noted that data on risk factors and outcomes from hemorrhagic and ischemic strokes in urban Ugandans are limited yet up-to-date data are required to estimate the current impact of the disease.
Stroke is a disease that affects the arteries leading to and within the brain. Strokes occur when a blood vessel that carries oxygen and nutrients to the brain is either blocked by a clot or bursts (or rupture). When that happens, part of the brain cannot get the blood (and oxygen) it needs, so it and brain cells die. The good news, however, is that upto 80% of strokes may be prevented.
In 80% of cases, a stroke is due to the occlusion of a blood vessel by a blood clot (ischemic stroke). Less frequently (20% of cases), it is caused by the rupture of a vessel, which results in a cerebral hemorrhage (hemorrhagic stroke). Transient ischemic attack (TIA) is caused, in the same way as an ischemic stroke, by the presence of a blood clot that temporarily obstructs the cerebral blood flow. In the case of a TIA, the symptoms usually last less than an hour and no brain injury is visible upon the radiological examinations.
Ischemic stroke is the commonest type of stroke not only in Uganda but also worldwide. It happens when an artery in the brain is blocked by a blood clot or a plaque fragment, usually in the heart or the large arteries leading to the brain and then moves through to the brain were blockage can occur leading to stroke, or a thrombotic form where a clot forms inside an artery that supplies blood to the brain. The clot then interrupts blood flow and causes a stroke. If an artery in the brain or one that goes to the brain is blocked for a short time, blood flow slows down or stops, causing a transient ischemic attack, sometimes called a mini-stroke.
This type of stroke presents suddenly with, numbness, weakness or paralysis of the face, and or leg usually on one side of the body; loss of vision in one or both eyes or even double vision; trouble speaking or difficulty in understanding others; loss of balance or co ordination and severe headache with no identifiable cause, all these resolve within an hour, in contradiction to ischemic and hemorrhagic case which goes on for a while or even permanent. 20 % of strokes (hemorrhagic) happen when a blood vessel in the brain burst and spills blood into or around the brain tissue. High blood pressure and aneurysms can make blood vessels weak enough to burst.
Stroke is the leading cause of disability worldwide and the second leading cause of death. Global stroke factsheet released in 2022 revealed that lifetime risk of developing a stroke has increased by 50% over the last 17 years and now 1 in 4 people are estimated to have a stroke in their lifetime. From 1990 to 2019, there has been a 70% increase in stroke incidence, 43% increase in deaths due to stroke, 102% increase in stroke prevalence and 143% increase in disability adjusted life years (DALY). The most striking feature is that the bulk of the global stroke burden (86% of deaths due to stroke and 89% of DALYS) occur in lower and lowermiddle – income countries.
The key signs of stroke are facial drooping, arm weakness on one or both sides and speech difficulties like slurring or not making sense. People may also experience changes in their vision and loss of balance and or dizziness. Knowing the signs of stroke and seeking immediate emergency medical care can save lives and improve the outcome for survivors.
Knowing your risk factors for stroke is the first step in preventing a stroke. You can change (modifiable) or treat some risk factors, but others you cannot (non modifiable). By having regular medical checkups and knowing your risk, you can focus on what you can change and lower your risk profile. Modifiable risk factors include high blood pressure, smoking, diabetes, high cholesterol levels, physical inactivity and obesity, heart and artery diseases and excessive alcohol intake.
Non modifiable factors include age, heredity, and race, history of prior stroke. High blood pressure stands out as the single most important risk factor for stroke. Normal blood pressure ranges between 100 – 120 systolic and 60 – 80 mmHg diastolic. Diagnosed with high blood pressure, work with your health care provider to reduce it. Among the 10 most leading risk factors for stroke , hypertension standout with a 56% risk, followed by obesity and diabetes at 24% and 20% respectively while low physical activities stands at lowest with 2% risk. Constantly high or elevated blood pressure makes the circulatory system work harder beyond capacity. This extra work causes damage like hardening and narrowing of blood vessels (atherosclerosis) increasing the risk of blockage in the brain vessels. Atherosclerosis can also increase the pressure the blood use to flow through vessels in the brain causing them to burst and bleed, leading to stroke.
Diabetes is also a well established risk factor for stroke. It can cause pathological changes in blood vessels at various locations and can lead to stroke if cerebral vessels are directly affected. Additionary, mortality is higher and post stroke outcomes are poorer in patients with stroke with uncontrolled glucose levels. Controlling diabetes and other associated risk factors are effective ways to prevent initial strokes as well as stroke recurrence.
Smoking is among the most significant risk factors for stroke, with a rise in chances over 18% for both active and passive smokers to be affected by the stroke. Tobacco smoke contains thousands of harmful chemicals which are transferred from your lungs to your blood stream. These chemicals change and damage cells and affects the normal body function. These changes mostly affect the circulatory system and increase your risk of stroke. Smoke from cigarettes contains carbon monoxide (CO) and nicotine. CO reduces the amount of oxygen in blood, while nicotine increases the heart rate which in turn increases the blood pressure which is a leading factor for stroke.
Though alcoholic consumption poses a 6% risk for stroke, this is more marked in individuals consuming abnormally large amount. While the experimental evidence is exciting and provocative, epidemiological evidence suggests a link between alcohol consumption and stroke. Regular alcohol ingestion is associated with hypertension, fatal and non fatal intracranial hemorrhage. Recent less stringently controlled studies suggest that alcohol consumption is a risk factor for cerebral infarction in young adults with occasional ethanol intoxication and middle aged women and young men with occasional alcohol intoxication and regular heavy drinking.
The most effective way to prevent stroke is to avoid risk factors associated with the disease. While age, sex, race and family history are non- modifiable risk factors, the modifiable ones like cigarette smoking, maintaining a healthy weight, eating more fruits and vegetables, consuming alcohol moderately, if at all and being physically active, they can be worked upon. Lifestyle modification that lower risk and identification and treatment of underlying disease such as atrial fibrillation are the main forms of secondary prevention strategies. Keeping hypertension under control involves quitting smoking and reducing exposure to environmental tobacco smoke, losing weight through a healthy diet, reducing one’s dietary salt intake and complying with a prescribed medication regimen all these can curb the risks of stroke.
Tertiary stroke preventive measures address the care of persons who have already suffered a first stroke episode. Physiotherapy and continuous medical assessments is the key in this part. Every year Uganda joins the rest of the world to observe a stroke day on 29th of October to emphasize the serious nature and high rates of stroke, plus rising of the awareness about the prevention and treatment of stroke. Last year, the theme was “together we are greater than stroke” with an indication of nearly 90% of strokes being preventable as long as we address the risk factors.
This article is written by Dr. Matovu Richard and sponsored by Specialist Doctors International