Introduction
A stroke describes a circulatory disorder of the brain. It can be caused by calcification of the vessel walls or by a blood clot that blocks the vessels. A cerebral haemorrhage can also lead to a reduced supply of blood to the brain.
Consequently, the cells die and the tissue is destroyed. The stroke can affect different areas of the brain. If the visual center is damaged, a visual disturbance results, which can even lead to blindness.
The accompanying symptoms
A visual disturbance can be caused by damage to the so-called occipital lobe. In this area visual stimuli are processed and vision becomes possible. This area is supplied by the posterior cerebral artery.
If the artery closes on one side, the visual field is lost. The field of vision can only be perceived to a limited extent. If the artery closes on both sides, complete blindness results.
If the posterior cerebral artery is severely blocked, the thalamus is damaged. The thalamus is a part of the diencephalon and is used for information processing. This is where the stimuli are received, processed and then transmitted to the cerebrum.
The damage causes a loss of consciousness and contralateral hemihypaethesia. This means that a reduced sensation of touch or pain does not occur on the side of the damaged thalamus, but on the opposite side. Furthermore, memory disorders and problems with learning can occur.
Psychological changes, such as depressive behavior with fatigue, are also frequently observed. You can find general information on this topic here: Visual disturbancesIf the posterior cerebral artery closes early, arteries leading to the cerebellum can also be affected. The cerebellum has different functions.
These include the coordination and fine-tuning of movement sequences and the maintenance of balance. Muscle tone is also regulated by the cerebellum. In the event of a stroke, the tissue in the cerebellum is no longer supplied with blood and the nerve cells die.
As a result, neurological deficits such as balance disorders occur. The affected patients walk uncoordinated and very shakily. The dizziness can also be caused by damage to the cerebellum.
If the stroke affects the A. cerebri posterior in the early course, the nerve cells of the cerebellum die. In addition to coordinating movement, the cerebellum also regulates the fine motor skills of the eye muscles. Consequently, the gaze can no longer be stabilized.
The combination of these functional failures leads to uncoordinated eye movements and an uncertain gait pattern. The body no longer knows which position it is in. This loss of information causes dizziness. A further cause can be incorrect blood pressure regulation. The blood pressure is lowered too much, which is especially noticeable when moving.
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