Stroke (or apoplexy) is a condition caused by a reduction in blood flow to the brain. This disease develops when blood flow is blocked or a blood vessel ruptures.
Ischemic stroke is the most common, accounting for about 85% of cases.
This is caused by a complete blockage of the arteries that bring the blood to the brain.
Usually older people are affected, but a stroke can also occur in children or adolescents.
Hemorrhagic stroke occurs when a blood vessel in the brain ruptures. There are two types of blood vessels that can rupture and lead to hemorrhagic stroke: aneurysms and arterio-venous malformations (AVM).
An arterio-venous malformation (AVM) is a genetic abnormality of a blood vessel. One of these vessels can rupture and cause bleeding in the brain.
An aneurysm is the swelling of a blood vessel. If it is not treated, the artery wall becomes weak until it tears.
Hemorrhagic stroke can occur in two ways:
- with a subarachnoid hemorrhage
- with a cerebral hemorrhage
Subarachnoid hemorrhage: The superficial arteries of the brain (on the outside of the arachnoid) rupture and the blood fills the space between the skull bone and the brain.
Cerebral hemorrhage: The blood vessels that run in the brain rupture and damage the nearby cells.
Type of stroke according to its localization
Posterior, if it occurs in the vertebro-basilar vascular ring, namely in the vertebral or basilar arteries.
Anterior, if it occurs in the median cerebral artery.
Lacunary, when only one of the arteries perforantes and profonda is affected.
The right-sided stroke in the brain causes symptoms on the left side of the body.
What is a TIA or transient ischemic attack?
The blood flow to the brain is interrupted only for a short moment. The symptoms are similar to those of ischemic stroke.
The brainstem (lower part of the brain) is called a bridge.
If the blood circulation is interrupted for only a few seconds, this can cause serious damage to the brain cells.
There are three main sections of the central nervous system:
- Brain stem.
The cerebrum is the largest part of the central nervous system and is divided into two halves: the right and left hemisphere.
Ischemia in the bridge area is caused by lack of blood in the brainstem.
The brainstem controls vital functions such as breathing, heartbeat and blood pressure.
A stroke in the bridge leads to serious problems of these functions.
Difference between Stroke and Heart Attack
Stroke: sudden death of some brain cells due to lack of oxygen. It occurs when blood flow in the brain is blocked due to occlusion or rupture of a blood vessel.
Heart attack: lack or insufficient blood supply to the heart. Often a myocardial infarction is caused by occlusion or narrowing of a coronary artery. The main symptom is chest pain.
Causes of hemorrhagic or ischemic stroke
About 85% of strokes are ischemic. Ischemia develops when the arteries of the brain become blocked by thrombi or embolism. This causes a reduction in blood circulation. Ischemias are caused by:
They occur when a blood clot (thrombus) forms in an artery that carries blood to the brain. The blood clot is caused by fatty deposits (plaques) that accumulate in the arteries and lead to a decrease in blood flow (atherosclerosis).
Atrial fibrillation favors the formation of blood clots and increases the likelihood of stroke.
Recently, it has been discovered that there may be a genetic predisposition.
They occur when a blood clot detaches (away from the brain), is carried away by the bloodstream and settles in the cerebral arteries. This coagel of blood is called an embolus.
Hemorrhagic stroke occurs when a blood vessel in the brain ruptures. Cerebral hemorrhages are caused by many diseases of the blood vessels, such as arterial hypertension (high blood pressure) and aneurysms.
A less common cause of cerebral hemorrhage is congenital malformation of blood vessels.
Cerebral hemorrhages can also occur outside the central nervous system:
Intracerebral (or cerebral) hemorrhage occurs when a blood vessel in the brain ruptures and the blood comes into contact with surrounding brain tissue. The result is damage to the neurons.
The brain cells are without oxygen and can die.
Diseases that lead to cerebral hemorrhage are the following:
- Vascular malformations
In this disease, an artery ruptures between the brain and the skull bone (outside of the arachnoid).
Most often, the affected person feels a severe and sudden headache.
Subarachnoid hemorrhage is caused by the rupture of a brain aneurysm. After the blood leaks, the blood vessels in the brain can dilate and narrow in irregular ways (vasospasm).
Vasospasm alters blood flow in the brain and can otherwise cause damage to neurons.
Transient ischemic attack (TIA)
A transient ischemic attack (TIA) (also called a mini-stroke) has symptoms similar to those of a stroke, but these disappear completely over the course of a few hours; usually they last no longer than five minutes.
Like ischemic stroke, TIA occurs when a blood clot decreases blood flow to the brain.
Signs and symptoms of acute stroke
The symptoms of stroke appear suddenly and without warning, mainly these are:
- speech disorders,
- comprehension problems,
- speech disorders (aphasia),
- crooked mouth due to facial paralysis on one side,
- tingling and pain in the face, arm or leg,
- loss of vision in only one eye,
- walking disorders,
- loss of balance,
- lack of coordination.
Symptoms depend on the localization of the stroke:
- Lobus frontalis: causes problems of movement and perception of the body in space;
- Temporal lobus: causes disturbances in hearing, speech and memory;
- Lobus parietalis: affects the ability to perceive the body and the environment;
- Lobus occipitalis: mainly affects vision and can cause visual hallucinations.
Diagnosis of hemorrhagic or ischemic stroke
examinations The first examination is a CT. It shows if there is bleeding in the brain. You can see whether it is ischemic or hemorrhagic stroke.
Other studies to clarify a stroke:
- Magnetic resonance imaging (MRI)
- Electrocardiogram (ECG) to check for heart problems
- complete blood count (BB)
- Blood sugar
- Liver and kidney function
- Prothrombin time (measurement of blood clotting time)
- Carotid Doppler sonography
- Angiography via magnetic resonance (MRA)
- Angiography in CT
If the stroke is the result of a heart problem, the following follows:
- 24-hour Holter ECG
- Telemetric test
Studies confirm that the risk factors for heart disease are also crucial for the prevention of stroke. A fulminant stroke can be fatal.
Mortality increases if the patient develops fever after the stroke.
Often a heart problem causes brain disease. Many people who suffer a stroke also have coronary artery disease.
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