Overview of Vertebrobasilar Artery
Ischemia of the brainstem, cerebellum, and thalamus caused by stenosis or occlusion of the vertebrobasilar artery is characterized by vertigo, double vision, choking on drinking water, and weakness of the limbs, with the onset of symptoms related to atherosclerosis, embolism, small arterial lesions, and trauma, and is treated with pharmacologic and endovascular interventions.
Definition
Posterior circulation ischemia refers to the occurrence of stenosis, thrombosis or occlusion in the posterior circulatory system of the brain, causing ischemia and infarction in the posterior part of the brain and a series of clinical manifestations.
It often manifests as dizziness, double vision, unclear pronunciation, difficulty in swallowing, and uncoordinated limb movement.
The posterior circulation, also known as vertebrobasilar system, consists of vertebral artery, basilar artery and posterior cerebral artery, which mainly supplies blood to the brainstem, cerebellum, thalamus, occipital lobe, part of temporal lobe and upper spinal cord.
Types
Classification by duration
Transient ischemic attack: no substantial damage to brain tissue occurs, symptoms are transient and recurrent, lasting no more than 24 hours, and no lesions are found on imaging.
Cerebral infarction: Substantial damage to brain tissue occurs, symptoms last more than 24 hours, and lesions can be detected on imaging.
Categorized according to the diseased blood vessel and the site of injury
Basilar artery trunk occlusion syndrome: lesion of basilar artery or bilateral vertebral arteries, damage to the brain stem.
Basilar artery cusp syndrome: lesions of basilar artery branches, damage to the midbrain, thalamus, temporal lobe and occipital lobe damage.
Pontine infarct type: ischemia mainly involves the middle part of the pons.
Dorsolateral medulla oblongata syndrome: lesions of the posterior inferior cerebellar artery, injury to the medulla oblongata.
Others: cerebellar and occipital lobe injury.
Morbidity
Posterior circulation ischemia is a common cerebrovascular disease, accounting for 20% to 25% of all ischemic strokes.
There are 18 new cases per 100,000 people in China every year.
It is more common in middle-aged and old people, and is more common in men than women.
Causes
Causes
The following factors are closely related to the occurrence of posterior circulation ischemia.
Atherosclerosis
The most important cause of ischemia is atherosclerosis.
Atherosclerosis occurs in the vertebrobasilar artery system, forming plaques that narrow the vessels and are not compensated for by blood supply from other sources, causing ischemia in brain tissue.
Embolism
A thrombus from the inner wall of a large blood vessel in the body or from the heart dislodges and enters the vertebrobasilar system with the blood circulation, blocking the blood vessel and causing ischemia of the brain tissue.
When spontaneous fragmentation or dissolution of the thrombus occurs, blood flow is restored and symptoms are relieved.
Small Artery Lesions
High blood pressure can cause extravasation of blood components into the vessel walls of small arteries, causing damage, hardening and thickening of the vessel walls, leading to narrowing of the lumen of small vessels and affecting blood supply.
External factors
External force or trauma can also cause vascular damage to the vertebrobasilar artery, causing narrowing of the vessel and affecting blood supply.
Risk factors
People with any of the following risk factors are at high risk for this disease
Middle-aged or elderly.
Family history of the disease.
Long-term smoking, alcohol consumption, lack of exercise, high salt and high fat diet, obesity.
Hypertension, hyperlipidemia, diabetes mellitus, hyperhomocysteinemia.
Suffering from stroke, atrial fibrillation, coronary atherosclerotic heart disease.
Symptoms
Main Symptoms
Dizziness, nausea
Manifested as dizziness and inability to stand still.
Dizziness is often associated with changes in body position (including turning, flexing and extending the neck, etc.).
At the same time, there is often epigastric discomfort and vomiting.
Limb weakness
Weakness of the upper and lower limbs on one side, inability to hold things, inability to stand.
Sensory abnormalities
Decreased sensation in the face and limbs, decreased sensitivity to pain or hot and cold stimuli, and numbness can also occur.
Dysphagia
This is characterized by effort in swallowing, difficulty in swallowing or food regurgitation, choking and coughing after swallowing.
Dysarthria
It is characterized by difficulty in speaking, slurred pronunciation and hoarseness.
Unsteady walking or falling
Unsteady walking, staggering, like drunkenness, easy to lose balance and fall.
Visual disturbances
Seeing an object with double vision, also known as diplopia.
Not being able to see something or having a part of the visual field missing, also known as visual field defects.
Others
Headaches and memory loss may also occur.
Complications
Vascular dementia
Manifested by memory loss and quick forgetting of things that have happened.
Inability to speak fluently or coherently, sleeping during the day and awake at night.
Associated with repeated, persistent inadequate blood supply causing extensive brain tissue damage.
Lung Infections
Manifested by fever, cough, sputum, and dyspnea.
Associated with prolonged bed rest after the onset of illness, decreased respiratory defense function and body resistance, and inability to cough up sputum smoothly.
Upper gastrointestinal bleeding
If cerebral infarction occurs, it is easy to develop peptic ulcer in the acute stage, causing bleeding, vomiting blood and black stool.
It is manifested as vomiting blood, black stools, and when the bleeding volume is large, there may be pallor, lowered blood pressure or even coma.
Consultation
Department of Medicine
Neurology
If symptoms such as numbness, weakness of limbs and dizziness occur, it is recommended to seek medical treatment promptly.
Emergency Department
For sudden symptoms such as unclear speech, paralysis, headache, coma, etc., it is recommended to seek medical treatment as soon as possible or call 120 emergency number or go to the Emergency Department.
Preparation for medical treatment
Preparing for medical treatment: registration, preparation of documents, and common problems.
Tips for medical treatment
Before seeking medical treatment, it is recommended to rest in bed and minimize moving and activities.
Try to keep a record of symptoms, duration, etc. to give your doctor more information.
If you have the habit of monitoring and recording your blood pressure and blood sugar every day, you can provide the records to the doctor.
Preparation Checklist for Doctor’s Visit
Symptom list
Pay particular attention to the time of onset of symptoms, special manifestations, etc.
Any dizziness, nausea or vomiting?
Any weakness, numbness, or unsteady walking?
Choking on water, slurred speech, etc.?
Any memory loss?
When did the symptoms first appear and approximately how long did they last each time?
Any aggravating or relieving factors?
Medical History Checklist
Is there anyone in the family with this disease or stroke?
Is there any chronic smoking, alcohol consumption, lack of exercise, high salt and high fat diet, obesity?
Is there hypertension, hyperlipidemia, diabetes, hyperhomocysteinemia?
Are there any diseases such as stroke, atrial fibrillation, coronary atherosclerotic heart disease?
Checklist
Examination results in the last six months, which can be brought to the doctor
Imaging: cranial CT, MRI, cerebral angiography
Ultrasonography: transcranial Doppler, carotid ultrasonography, etc.
Laboratory tests: blood glucose, blood lipids, coagulation function, homocysteine, markers of myocardial injury, etc.
Medication list
Medication used in the last 3 months, if available in boxes or packages, bring with you to the doctor’s office
Antiplatelet aggregation drugs: aspirin, clopidogrel.
Lipid-lowering drugs: atorvastatin, fenofibrate, resuvastatin.
Antihypertensive drugs: nifedipine, metoprolol, captopril, chlorosartan.
Hypoglycemic drugs: glibenclamide, metformin, acarbose.
Diagnosis
Diagnosis
Diagnosis can be made on the basis of medical history, physical examination, laboratory tests, and imaging tests.
Medical history
History of hypertension, hyperlipidemia, diabetes mellitus, heart disease, smoking, and chronic alcohol consumption.
Family history of the disease or stroke.
Clinical manifestations
Symptoms
Dizziness, limb weakness, numbness, nausea or vomiting, choking on drinking water, diplopia and other symptoms.
Physical signs
The doctor uses a physical examination to see if there are any abnormalities in muscle strength, skin sensation, swallowing function, and nerve reflexes.
Muscle strength check: Observe whether you can complete movements such as lifting hands, sitting up, standing and walking, and whether you need assistance.
Skin sensory examination: Slide a cotton swab over the patient’s skin or lightly prick the skin with a blunt needle to assess the degree of sensory impairment according to the sensitivity to sensation.
Swallowing function examination: Observe whether there is choking when drinking water to assess swallowing function.
Tendon reflex examination: Observe the contraction of the forearm and thigh muscles when the tendons of the elbow and knee are struck to assess whether the nerve reflexes are abnormal.
Laboratory Tests
Includes routine blood tests, blood glucose, blood lipids, coagulation function, homocysteine, and markers of myocardial injury.
Purpose: To detect the presence of high-risk factors, assess the overall physical condition, and help determine the treatment plan.
Results: Elevated blood glucose, blood lipids, homocysteine, abnormal coagulation function, and myocardial damage can be detected.
Precautions: During the course of treatment, some of the items may need to be checked periodically in order to monitor the body’s condition and assess the effectiveness of treatment.
Imaging Tests
Magnetic Resonance Imaging (MRI) of the brain
The preferred imaging method, including standard MRI and vascular imaging MRA
Can detect ischemia and infarction in the brainstem, cerebellum, occipital lobe, and other areas.
MRI can show areas of lesions with low T1 signal, high T2 signal, and limited DWI diffusion several hours after onset.
MRA can directly measure the internal diameter of blood vessels and observe the three-dimensional alignment of blood vessels, which is important for the diagnosis of posterior circulation ischemia.
The reliability of MRA in observing small arterial branches is poor.
Brain CT scan
CT scan includes scanning CT and cerebral angiography CTA.
Scanning CT can quickly identify early cerebral infarction and cerebral hemorrhage.
CTA can reconstruct the intracranial and extracranial arterial system in three dimensions, which can clearly show the travel of blood vessels and measure the internal diameter of blood vessels.
Scanning CT is often affected by the bone quality at the base of the skull in the cerebellum and brainstem.
CTA cannot dynamically observe the compensation of intracranial blood flow and evaluate the secondary and tertiary collateral circulation.
Ultrasonography
This includes transcranial Doppler ultrasound (TCD) and carotid ultrasound.
It can detect stenosis and occlusion of large intracranial arteries.
Can assess collateral circulation and monitor microemboli, and assess cerebral blood circulation.
Can show atherosclerotic plaques, vessel stenosis and occlusion.
Cerebral Angiography (DSA)
DSA is recognized as the best means of diagnosing vascular lesions in the vertebrobasilar system.
It can directly observe the three-dimensional course of arteries and measure the internal diameter of blood vessels.
Dynamic observation of vascular lesions, blood flow changes, and judgment of the open path of collateral circulation provide a reliable basis for subsequent intervention or surgical treatment.
DSA is invasive, expensive, time-consuming and cannot show the distal end of occluded vessels.
It is risky and not the first choice.
Differential diagnosis
Posterior circulation ischemia should be distinguished from facial nerve palsy and Meniere’s disease.
Facial nerve palsy
Similarities: unilateral facial paralysis, numbness.
Differences
Facial nerve palsy does not have unfavorable limb movement, double vision, swallowing disorder, etc. It is mostly caused by viral infection.
There is no atherosclerosis in TCD examination and no brain lesions in MRI and CTA.
Meniere’s disease
Similarities: both may present with symptoms such as vertigo and vomiting.
Differences
Ménière’s disease tends to last more than 24 hours per attack, and there are no neurologic signs other than nystagmus.
There are no atherosclerotic manifestations on TCD examination, and no brain lesions on MRI and CTA.
Treatment
Aim of treatment: improve cerebral circulation, so that ischemic brain tissues restore normal blood flow before necrosis.
Treatment principle: drug treatment mainly, and interventional therapy if necessary.
General treatment
Bed rest: keep optimistic, ensure sleep, and the room should be quiet.
Nasogastric feeding: If unable to eat, nutritional supplements can be given via nasal feeding tube.
Respiratory management
If there is consciousness disorder or manifestation of hypoxia, give oxygen and assist ventilation treatment.
Turn over, pat the back and suction regularly to prevent pneumonia.
Cardiac monitoring: If there is unstable blood pressure, heart rate, pulse, coma, give cardiac monitoring.
Medication
Intravenous thrombolytic therapy
Indications: acute cerebral infarction caused by posterior circulation ischemia and within the time window of thrombolysis.
Commonly used drugs: alteplase, urokinase, etc.
Time window: intravenous alteplase within 4.5 hours of onset, and possibly urokinase within 4.5-6 hours.
Adverse effects: caution in the presence of bleeding or bleeding tendency, thrombocytopenia.
Antiplatelet therapy
May prevent new thrombosis and avoid worsening of symptoms.
Common drugs: aspirin, clopidogrel, etc.
Adverse reactions: headache, dizziness, flushing, gastrointestinal upset, gastrointestinal bleeding.
Control of underlying disease
Hypertensive patients need to test blood pressure and control blood pressure with drugs such as nifedipine and betalactam.
Diabetic patients need to monitor blood glucose and cooperate with insulin, metformin and other drugs to control blood glucose.
Patients with hyperlipidemia need to have their blood lipids checked regularly, and cooperate with drugs such as atorvastatin and resuvastatin to lower blood lipids and stabilize atherosclerotic plaques.
Endovascular treatment
Indications: Severe stenosis of vertebrobasilar artery system and inability to compensate for blood supply through other arterial systems.
Purpose of the procedure: to open up the blood vessels and restore blood flow by placing stents in the vessels.
Surgical approach: mainly vertebral artery stenting.
Contraindications: presence of coagulation disorders, inability to tolerate surgery and anesthesia due to severe underlying diseases.
Prognosis
Cure
Posterior circulation cerebral infarction has a poor prognosis, with a mortality rate of about 3% to 4% and a disability rate of about 18%.
When the infarct is large, death may occur within hours or days.
Small infarcts, such as brainstem infarcts caused by penetrating artery occlusion, have little effect on life expectancy.
It tends to leave sequelae such as limb weakness, slurred speech, and difficulty in swallowing.
Harmfulness
If acute cerebral infarction occurs suddenly, it is easy to cause paralysis and abnormal sensation of limbs, which will seriously affect the quality of life.
When the infarction involves the brainstem and cerebellum, it may be life-threatening.
Motor disorder: manifested by paralysis of one or both limbs and inability to walk.
Cognitive impairment: can lead to impairment in comprehension and memory.
Dysarthria and swallowing disorders: paralysis of the facial and throat muscles, leading to disorders in speech and eating.
Vertigo, blurred vision, and limb weakness can lead to accidents and injuries, such as falls, burns, and traffic accidents.
Daily
Daily Management
Dietary management
Balance diet and choose a variety of food to achieve reasonable nutrition to ensure adequate nutrition and appropriate body weight.
Use more cooking methods with less salt and oil, such as steaming, boiling, mixing, water skimming and simmering, which are easy to digest and absorb.
Eat more vegetables, fruits and whole grains. Vegetables can be cooked in less time or cold.
Avoid foods that contain a lot of salt, such as salted meat, salted vegetables and other foods.
Avoid spicy and stimulating foods, such as chili peppers, coffee and strong tea.
For those who have difficulty in swallowing, eat pureed or pasty food.
Quit smoking and drinking.
Life management
Appropriate exercise can be done under the guidance of physician after the disease is stabilized.
Blood pressure, blood sugar, blood lipid and other indicators should be strictly controlled to reach the ideal range.
Avoid exertion and take rest.
Avoid fluctuation of blood pressure due to excessive emotional fluctuation, which may aggravate cerebral ischemia.
Disease monitoring
Monitor the changes of symptoms such as dizziness, muscle weakness and sensory loss every day.
Monitor and control blood pressure, blood lipid and blood sugar.
Gastrointestinal bleeding may occur during treatment and should be observed for abdominal pain and dark stools.
Follow-up review
Follow the doctor’s instructions for regular review, generally 1 to 3 months need to review, in order to adjust the treatment program.
The main review items include blood lipid, blood glucose, homocysteine, etc., transcranial Doppler ultrasound, and nuclear magnetic resonance.
Prevention
Low-salt and low-fat diet, eat more fruits and green leafy vegetables, cereals and crude fiber food, avoid overeating and binge drinking.
Quit smoking and drinking.
Live a regular life, get enough rest and avoid overwork.
Be able to have more than 5 days of physical exercise per week, and do 30 to 45 minutes of aerobic exercise every day, such as brisk walking and jogging.
Maintain ideal body weight, so that the body mass index (BMI = weight (kg)/height2 (m)) is 18.5～23.9kg/m2.
Have regular medical checkups to monitor blood pressure, blood glucose, blood lipids, TCD and carotid ultrasound.
If there has been a stroke, aspirin and clopidogrel should be taken as prescribed to reduce the risk of recurrence.
Attention should be paid to safety in daily life, avoiding sudden and vigorous activities of the head and neck to avoid causing loss of consciousness and vertigo, which can cause falls and create danger.