Intracranial Artery Stenosis
Stenosis of the carotid arteries is a narrowing of the lumen of the vessels that are responsible for the blood supply to the brain. Pathology is dangerous and coward: there are no symptoms for a long time, but there can be dangerous complications.
When carrying out diagnostics and treatment, it is necessary to establish the localization of damage, the degree of stenosis, and its causes. Therefore, patients are assigned a wide diagnostic program and treatment methods – today, they are diverse and effectively eliminate the problem.
Most often, the disease affects the extracranial vessels, but the pathology of the intracranial arteries also occurs. This condition is the cause of 50% of the clinical cases of ischemia of the medulla and about 30% of strokes. The doctor must distinguish between complete and incomplete obturation of the vascular lumen, which leads to a violation of the blood supply.
Normally, the common carotid arteries depart the left from the aortic arch and the right from the brachiocephalic trunk. They are directed vertically and located on either side of the cervical spine. Further, there is a division into the external and internal carotid arteries. The branches of the arteries supply blood to the intracranial regions, arteries, parts of the face, organs of the head, and neck.
Why does intracranial artery stenosis develop?
The disease does not have a single cause. Most often, this is a combination of risk factors. With their prolonged action, sufficient intensity, and the tendency of the organism, the disease develops. This complicates the situation since there is no single factor that needs to be eliminated to correct the situation. Let’s consider the possible reasons:
This is the most common condition that leads to intracranial arterial stenosis and can cause complete interruption of blood flow. Atherosclerosis is a violation of fat metabolism, in which the amount of cholesterol and saturated fatty acids in the blood increases, leading to the formation of plaque on the vessel wall. It interferes with the normal rheological properties of the blood – its flow slows down. The larger the fatty accumulation becomes, the more blood elements accumulate on it, increasing in size. From platelets and red blood cells, which adhere to the site of damage to the wall, a thrombus is formed, which can lead to embolism. Sometimes atherosclerotic formations can become covered with small ulcers, violate the integrity of the vessel, and sometimes block its lumen, stopping the blood flow.
- Specific pathology
Narrowing of the arterial vessel is observed with a disease of the connective tissue that forms the stroma of the intracranial artery; this is called fibromuscular dysplasia – the vessels cease to maintain their tone and collapse, stopping blood flow. Intracranial artery stenosis can accompany some inflammatory diseases of the vascular wall – arteritis, systemic vasculitis, Takayasu’s disease, Horton’s disease. There are rare pathologies, such as moyamoya disease, in which there is a slow, progressive narrowing of the lumen of the arteries.
- Hard blow, concussion
After some traumatic brain injuries, a special hematoma is observed – subintimal, which has an appropriate localization. A thrombus, which forms with increased blood clotting, rare types of anemia, can block the lumen. There is an antiphospholipid syndrome, in which young patients experience heart attacks and strokes precisely because of increased coagulation. Blood clots are formed in case of heart rhythm disturbances while taking certain medications.
- Congenital features of the structure of blood vessels – they are tortuous, hypoplastic. Vascular pathology accompanies systemic diseases, diabetes, obesity, and metabolic disorders.
Manifestations and diagnostics of stenosis of the carotid arteries
What manifestations are accompanied by pathology?
The clinical manifestations of the disease depend on where the problem is. In the early stages of the disease, compensatory mechanisms are always included. For example, if the blood flow is partially disturbed, a collateral system develops, which will provide alternative pathways for the blood supply to the brain. The lack of oxygen supply is also compensated – pulse and respiration become more frequent, and intracellular processes change; this is sufficient for short-term conditions but not for serious pathology. In such cases, the symptoms develop. With a sharp onset and significant intracranial artery stenosis, compensatory forces do not work, and the clinic has a pronounced character, which indicates a stroke.
- One of the first alarms is transient cerebral ischemia. These are short-term episodes of impaired blood supply, which can be compensated for by collateral blood flow.
- The condition can be recognized by a decrease in sensitivity and motor activity and experiencing visual disturbances.
- At some localizations, corresponding violations occur – speech, hearing, swallowing difficulties, asymmetry of the face, severe pain.
- The more common symptoms are dizziness, feeling unwell, weakness, and seizures.
- Also, the symptoms of occlusion overlap with the symptoms of the tumor process, dementia; this is indicated by increased irritability, depressive disorders, mood swings, increased sleepiness, decreased memory, and mental abilities.
Diagnostic program for disease
The doctor begins the diagnosis of stenosis of the carotid arteries by interviewing the patient and general clinical research. If there are neurological symptoms, a doctor checks reflexes, sensitivity, physical activity, muscle. Instrumental techniques used include:
- Ultrasound of stenosis of the carotid arteries of the head and neck with Doppler ultrasound – triplex scanning;
- Functional tests during ultrasound examination;
- Computed tomography angiography – visualization of blood flow through the vessels using a contrast agent;
- Magnetic resonance imaging of the brain.
To diagnose atherosclerosis, a laboratory method is used – the patient donates blood for a blood lipid profile. The pulse and blood pressure are measured accurately. To identify systemic vasculitis, specific laboratory tests and immunological studies are used.
- How is intracranial artery stenosis treated?
The most advanced and least traumatic way of treating carotid stenosis is stenting. Stenting is the placement of a stent, which is a metal tube made of cells, into the narrowed part of the artery.
- Why is intracranial artery stenosis dangerous?
Damage to the intima of the carotid artery can lead to traumatic occlusion of the vessel and the cessation of blood circulation in its basin – such injuries are assessed as life-threatening and can be fatal.
- Why is vascular stenosis dangerous?
Arterial stenosis is an extremely dangerous condition that, if untreated, can become a threat to human life. Depending on which artery is blocked, certain vital organs may suffer – the brain, heart, kidneys, lungs, etc.
- What risks does intracranial artery stenosis surgery take?
Violation of blood circulation in the brain (stroke) with paralysis of the arms and/or legs, speech impairment as consequences of disease and its complications. More often, the reason for this is the detachment of a piece of plaque during manipulations on the carotid artery and getting it into the arteries of the brain, less often the blockage of the carotid artery with blood clots. The risk is very low, at 1-3%.