In the Gambia, the number of hypertensive patients is on the rise. This led to an increase in the number of people suffering from strokes. Even though hypertension is not the only cause of stroke but it is definitely one of the major causes. It is very common and almost everyone around has heard of at least one or two cases.
Clinically, it is called a cerebrovascular accident (CVA). This is any incident which causes a decrease or cessation of blood flow to a part of the brain or the whole brain. This can be referred to as an ischemia. Ischemia of the brain tissue can lead to reversible or irreversible brain damage. When blood supply is compromised for less than 30 seconds, the brain damage is reversible. This is called a transient ischemic attack or TIA and in this case the symptoms of stroke last for about 1 or 2 hours. This happens because brain tissue can only survive for about 30 seconds without oxygen. However, if it exceeds 30 seconds the brain damage is irreversible and that part of brain tissue dies. This causes the symptoms seen in patients with stroke.
Strokes are mostly due to a defect of blood vessels. The origin can be thrombotic, embolic or haemorrhagic. A thrombus occurs because of an activation in the normal clotting process, this leads to the formation of a blood clot within a vessel. This clot can attract small blood components called platelets and this can increase its size. A gradual increase in size leads to complete or partial occlusion of the blood vessel leading to a part of the brain. Consequently, brain tissue in that part dies off and the symptoms of stroke appear.
An embolus is a detached intravascular solid, liquid, or gaseous mass that is carried by the blood to a site distant from its point of origin. So if the mass is carried to the brain, this leads to cerebral ischemia and if prolonged, it leads to a stroke. Thrombi and emboli can cause infarcts which is localized tissue death due to an obstruction of blood supply. These two are the main causes of ischaemic stroke.
The clinical outcome of a severe hypotensive episode that produces global cerebral ischemia varies with the severity of the insult. In mild cases, there may be only a transient post ischemic confusional state, with eventual complete recovery and no irreversible tissue damage. On the other hand, irreversible damage to brain tissue does occur in some patients who suffer mild or transient ischemic insults.
In the case of a haemorrhagic stroke, there is rupture of a blood vessel or an abnormal vascular structure which leads to bleeding into the brain. I can occur within brain tissue (cerebral hemorrhage) or outside the brain but within the skull and this compresses brain matter ie. Subarachnoid hemorrhage. Both types of hemorrhagic stroke compromise the blood supply in parts of the brain leading to the symptoms of stroke.
There are signs present which indicate a stroke. The patient should be taken to the nearest health facility as soon as possible. The signs should be checked FAST.
Face: Does it look uneven? You can ask them to smile.
Arm: Does the arm drift down? Ask them to lift both arms.
Speech: Does it sound strange? Ask them to repeat a phrase.
Time: brain cells die every second, rush them to the nearest health centre.
A stroke or TIA often requires emergency care. An ischemic stroke, if detected within three to four and half hours, may be treatable with a medication that can break down the clot that’s why its important to take patients to the hospital as soon as possible.
Other signs and symptoms that can be identified in people with stroke are an inability to move or feel one side of the body, loss of vision in one or both eyes or sides, difficulty swallowing and a severe headache in the case of a hemorrhagic stroke. Long-term complications may include pneumonia or loss of bladder control .
Since hypertension is one of the major causes of stroke, anything which predisposes to hypertension will pose some risk to developing a stroke. Some of them are tobacco smoking , obesity , high blood cholesterol, diabetes etc. Other risk factors include a previous Transient Ischemic Attack (TIA) and atrial fibrillation. Prevention of strokes is mainly achieved by a reduction of these risk factors. Drugs like aspirin and statins and surgery to open up the arteries to the brain in those with problematic narrowing are also other ways to reduce the occurrence of strokes. It is important to note that no medication should be taken without a valid prescription.
Several things can be done by health personnel to ascertain that a patient has a stroke, these are called investigations an they lead to a diagnosis. Diagnosis is typically with medical imaging such as a CT scan or magnetic resonance imaging (MRI) scan along with a physical exam. Other tests such as an electrocardiogram (ECG) and blood tests are done to determine risk factors and rule out other possible causes.
After all that is explained in the above paragraphs, it is very important that we try reduce our risk of developing hypertension by abandoning things that could lead to it. These are physical inactivity, smoking, alcoholism etc. Hypertension has many complications (stroke included) and effort should be made to reduce them. Stand up for your health, reduce the effect of strokes!!
By Fanta Fofana
