How does the brain cause a respite

In 2001, strokes were the fourth leading cause of death in Germany. Strokes are far more common among older people than younger people because disorders such as vascular calcification that lead to such an event develop over time.
Depending on the cause, a distinction is made between ischemic ("bloodless") and hemorrhagic ("bloody") strokes.

Around 80 percent are ischemic strokes. A blood vessel is blocked either by arteriosclerotic deposits or a blood clot. Brain cells that are cut off from the blood supply as a result do not receive enough oxygen. Briefly insufficient blood flow to parts of the brain causes a transient ischemic attack (TIA), a temporary disorder of the brain. Since the blood supply quickly resumes, no brain tissue dies like it does in a stroke. A transient ischemic attack is often an early warning sign of a possible impending stroke and should be taken very seriously.

The other 20 percent of strokes that occur are hemorrhagic strokes. A blood vessel in the brain bursts, so that blood seeps into the brain tissue. This irritates the tissue and can lead to reactions that trigger a stroke.

The main risk factors for both types of stroke are atherosclerosis - narrowing of the arteries due to fat deposits in the arterial walls - high blood pressure, diabetes, and smoking.
Atherosclerosis plays a larger role in an ischemic stroke, while high blood pressure is important in a hemorrhagic stroke. Other risk factors for a hemorrhagic stroke are: the use of anticoagulants, aneurysms (bulges) of the arteries inside the skull, malformations of blood vessels and vascular inflammation.


How a stroke or a transient ischemic attack affects the body depends on exactly where in the brain the blood flow was interrupted or bleeding occurred. Each area of ​​the brain is supplied by specific blood vessels. For example, if a blood vessel in the area of ​​the brain that controls muscle movements in the left leg is blocked, muscle weakness or paralysis will result in the left leg. If the area that perceives touch sensations in the right arm is damaged, one no longer has any feeling in the right arm.

Because early treatment is very important, everyone should recognize the early symptoms of a stroke. A stroke is always an emergency that cannot be delayed and must be treated immediately!


Every hour counts.

The most common early symptoms of ischemic stroke include sudden muscle weakness and paralysis of the face and leg on one side of the body, slurred speech, sudden confusion with difficulty speaking and understanding what is being said, sudden clouding and loss of vision, especially in one eye, loss of balance and coordination, causing falls, sudden severe headache, and unusual or loss of sensation in one arm or leg or on one side of the body. The symptoms of a transient ischemic attack are the same, but they usually go away within minutes and rarely last more than an hour or two.

The symptoms of hemorrhagic stroke are similar to those of ischemic stroke, but it may include sudden severe headache, nausea and vomiting, temporary or persistent loss of consciousness, and very high blood pressure.

The blood supply to the brain

The brain is supplied with blood via large arteries, the internal carotid arteries and the vertebral arteries. The internal carotid arteries carry blood from the heart in front of the neck to the brain, while the vertebral arteries run over the neck. The vertebral arteries unite in the skull and form the base of the skull. The internal carotid arteries and the basal skull artery divide into several branches, including the cerebral arteries. These large arteries join a circle of other arteries, which thus form a connection between the vertebral arteries and the internal carotid arteries. Other small arteries lead from this circle like roads from a roundabout. These branches transport the blood to all areas of the brain.

When the large arteries that supply the brain are blocked, some people either have no symptoms or only have a mild stroke, while others with the same blockage have a massive stroke. The reason for this is that some people are born with arteries that can protect them from having a stroke. The arterial circle is key to this. If this artery is large in diameter, the circle can distribute blood throughout the brain even if one or even two of the large arteries are blocked. On the other hand, if the diameter is small or the circle is interrupted, redistribution of the blood is more difficult. In addition, some people have the innate ability to form new blood vessels (collaterals). When a carotid artery is blocked, it can form collateral vessels and bypass the blockage.





Why a stroke only affects one half of the body

A stroke usually only damages one half of the brain. As the nerves cross from one side of the brain to the other, the symptoms are felt on the other side of the body.