With atrial fibrillation, with myocardial infarction, with prosthetics of the heart valves, with endocarditis of an infectious nature, an embol opens, which closes the lumen of the vessel and leads to ischemia of the brain tissue. With the occlusion of a small vessel with myocardial infarction, diabetes mellitus and high blood pressure, cavity portions of necrosis in the brain can form. Therefore, not large areas of ischemic damage to the cerebral hemispheres are formed, but small cavities, and this stroke is called lacunar. Most often, the symptoms of this form of the disease are erased.
This is a very serious disease - ischemic stroke, the causes of which can be reduced to the following:
- A blood clot or cholesterol plaque breaks away from the wall and, with a blood stream, enters a small vessel in the brain.
- A blood clot comes off the endocardium and closes the lumen of the cerebral artery.
- In case of hemodynamic impairment, heart failure and circulatory disorders, the embolus from the heart enters the carotid artery.
- Lacunar ischemia of the brain against the background of hypertension and severe diabetes.
- In trauma, arterial dissection may occur, leading to cerebral ischemia.
Ischemic stroke has three degrees of severity. Allocate cerebral symptoms and focal. Headache, pain in the eyeballs, which increases with their movement, nausea, dizziness and vomiting are common symptoms.
Its consequences depend on the patient’s age, location of vascular blockage, duration of occlusion, development of collaterals and blood pressure. The more time has passed since the blockage and the larger the lesion site, the faster irreversible processes occur. Signs of ischemic stroke depend on the localization of occlusion. When the anterior cerebral artery is blocked, the lower extremities are affected, severe weakness, paresis or paralysis develops, and speech is disturbed.
With damage to the posterior cerebral arteries , a violation of the functions of the cerebellum, brain stem, occipital and temporal lobes is observed. There is difficulty in swallowing, respiratory depression and serious heart disorders. Coordination of movements, sensitivity to pain and temperature may be impaired. Stunned consciousness up to a coma, a distortion of the face as a result of damage to the trigeminal and facial nerve, and paralysis of half the body are noteworthy. From the viewpoint, nystagmus, strabismus develops.
Ischemic stroke with blockage of the middle cerebral artery is characterized by impaired sensitivity and paralysis on the opposite side of the lesion. Sensitivity is impaired, paresis of the gaze, upper limbs and face develops.
With carotid thromboembolism, paresis develops on the opposite side and vision on the side of occlusion drops sharply.
With basilar artery occlusion, ischemic stroke can manifest itself in different ways, depending on the level of damage. There may be tinnitus and hearing loss up to its loss, nystagmus and dizziness, vomiting and nausea. With damage to the trunk of the basilar artery or vertebral arteries, complete paralysis, bilateral paresis of the gaze and coma can be observed.
The process of ischemia of brain tissue is reversible within 6-12 hours. It’s rare when you can count on a day. Therefore, it is extremely important to correctly and timely provide the necessary medical care to the patient if an ischemic stroke occurs. Provide him with peace, stabilize the work of the heart and lungs, and prevent complications. It is important to restore blood flow, protect the brain from further damage and support its normal nutrition.