Overview of Vertebral Artery
Various reasons lead to blood into the vertebral artery arterial wall to form hematoma, so that the inner and outer walls of the vessel stripped, leading to the formation of vertebral artery tumor-like protrusion, lumen narrowing, rupture of the vessel to the back of the neck pain, headache, limb weakness, diplopia, choking on drinking water, unsteady walking or even impaired consciousness, etc., as the main manifestations of the pathogenesis is still unclear, and may be related to genetic factors, spontaneous vascular injuries, vascular trauma, the main anticoagulant, anti-platelet drug therapy, endovascular therapy or surgery. Anti-coagulant, anti-platelet drug treatment, endovascular treatment or surgery is also available.
Definition
Vertebral artery entrapment refers to various causes of blood entering the arterial wall of the vertebral artery to form a hematoma, or a spontaneous hematoma within the arterial wall of the vertebral artery, which strips away the intervascular wall, resulting in a narrowing of the lumen of the vertebral artery or a rupture of the blood vessel; if a verrucous protrusion is formed, it becomes an entrapment aneurysm.
The vertebral artery generally starts from the subclavian artery and passes through the transverse foramen of the cervical vertebrae and the foramen magnum of the occipital bone from below into the cranial cavity, and is responsible for the blood supply of the cervical spinal cord and the posterior part of the cerebellum, the brainstem, and the occipital lobe.
Common symptoms of vertebral artery entrapment include back neck pain or head pain, intermittent or persistent neurological dysfunction due to ischemia in the posterior circulation, such as diplopia, dysphonia, dysphagia, choking on drinking water, unsteady walking, limb weakness, numbness, and impaired consciousness.
Classification
Classification according to lesion site
Extracranial type VAD: the entrapment is located below the foramen magnum of the occipital bone to the subclavian artery.
Intracranial VAD: the entrapment is located above the foramen magnum of the occipital bone to the intersection of the two vertebral arteries.
Incidence
The incidence of vertebral artery entrapment is (1.0-1.5)/100,000, and young and middle-aged people between 30 and 50 years of age are the most prevalent [2-4].
There is no significant difference in the overall male-to-female ratio, but the male-to-female ratio varies in different parts of the body. The incidence of intracranial vertebral artery entrapment is 2.5 times higher in women than in men, while the incidence of extracranial vertebral artery entrapment is 2.5 times higher in men than in women.
Causes
Causes
Vertebral artery entrapment can be categorized etiologically into two main groups: spontaneous arterial entrapment and traumatic arterial entrapment [5].
Patients with spontaneous arterial entrapment often do not have an exact history of trauma, but there is an underlying structural weakness of the vessel wall. Such as hereditary diseases, atherosclerosis, syphilitic arteritis, and autoimmune diseases are associated.
Traumatic arterial entrapment can be caused by violence, sudden movement, etc. For example, violent neck pulling or twisting, violent neck massage, head tossing or strenuous exercise such as lifting weights or playing ball.
Both causes can also work together to trigger the disease.
Risk factors
Certain cerebrovascular risk factors are risk factors for vertebral artery entrapment, such as obesity, long-term use of oral contraceptives, migraine, fibromuscular dysplasia, and vasculitis.
Pathogenesis
The pathogenesis of vertebral artery entrapment is unclear and is related to the structure of the vessel wall.
The wall of the vertebral artery has three main layers, the inner, middle and outer membrane.
The outer membrane is mainly composed of dense connective tissue, which contains small branches of the carotid sympathetic nerves; the middle membrane layer is mainly composed of internal elastic fibers and smooth muscle, which contains the terminal branches of the carotid nerves; and the inner membrane is mainly composed of endothelial cells, which are normally closely connected to the three layers.
If the wall of the vertebral artery is torn for any of the above reasons, blood will flow into the wall to form a hematoma, causing arterial stenosis, occlusion, or aneurysm, resulting in ischemia of the spinal cord, the back of the cerebellum, and other vertebral artery-supplied areas, with corresponding neurological dysfunction.
Neck pain or head pain is mainly characterized by intermittent and episodic neurological dysfunction, such as diplopia, perioral numbness, dysphonia, dysphagia, numbness and weakness of limbs.
Symptoms
Main Symptoms
Pain
When vertebral artery entrapment is formed without rupture, there may be no obvious symptoms, or pain in the back of the neck and occipital area.
Pain is more common than carotid artery entrapment, and the pain can be in various forms, throbbing or tingling, and can be unilateral or bilateral.
If vertebral artery entrapment rupture can be secondary to subarachnoid hemorrhage, causing severe headache [6].
In a few patients, unilateral upper limb pain can be manifested due to C5-C6 cervical nerve root ischemia.
Posterior circulation ischemia
Vertebral artery entrapment can cause transient ischemic attacks and cerebral infarction in the brainstem, medulla oblongata, cerebellum, and upper spinal cord.
Patients mainly present with dizziness, headache, vomiting, numbness, limb weakness, impaired consciousness, blurred vision, visual loss, unsteady walking or falling.
Dorsolateral medullary syndrome
Cross-cutting sensory disorder: e.g. left vertebral artery entrapment can cause right limb hyperalgesia and numbness.
Cerebral nerve palsy: vomiting, eructation (hiccups), dysphagia, hoarseness, choking on drinking water caused by damage to the vagal nucleus, nucleus of suspicion and reticular formation.
Horner’s syndrome: the main manifestations are pupil constriction, eyeball invagination, upper eyelid ptosis and less sweat on the side of the affected side.
Cerebellar injury symptoms: balance disorder, uncoordinated limb movement, nystagmus.
Cervical spinal cord symptoms
Rarely, it may present with decreased muscle strength of limbs, sensory numbness and other manifestations.
Complications
Subarachnoid hemorrhage
Rupture causing subarachnoid hemorrhage occurs in up to 70% of patients with vertebral basilar artery entrapment, most commonly in intracranial vertebral artery entrapment [7].
It manifests as severe symptoms such as sudden severe headache, nausea and vomiting, epilepsy, coma, etc., and may even cause sudden death.
Consultation
Department of Medicine
Emergency department
When symptoms such as posterior neck pain, headache, limb weakness, diplopia, etc. occur without a cause or after an external force on the head and neck, it is important to consult the emergency department or neurology in a timely manner.
Neurology, Neurosurgery, Interventional Medicine
After diagnosis, if endovascular intervention or surgical treatment is required, referral to the Department of Neurology, Department of Neurosurgery or Department of Interventional Medicine is necessary for further consultation.
Preparation
Preparation for the consultation: registration, preparation of documents, common problems
Tips for medical treatment
It is recommended to consult a doctor as soon as possible to avoid delay in diagnosis and treatment.
Prepare relevant medical records before consultation.
Preparation List
Symptom list
Pay special attention to the time of onset of symptoms, special manifestations, etc.
Is there any mechanical force, massage or sudden pulling on the head and neck?
Is there pain in the back of the neck or head?
Is there diplopia?
Are there any sunken eyes?
Is there ptosis of the eyelids?
Is there perioral numbness?
Is there limb weakness?
Is there hoarseness of voice, difficulty in swallowing, choking on water?
Is there unsteady walking? Vertigo?
Is there any impairment of consciousness?
List of medical history
Is there a history of head and neck trauma, massage, etc.?
Any history of atherosclerosis, syphilitic arteritis, hereditary disease, autoimmune disease, etc.?
Checklist
Examination results in the last six months, which can be brought to the doctor’s office
Imaging tests: Cranial magnetic resonance examination (MRI+MRA), CT angiography (CTA), digital subtraction angiography (DSA).
Other tests: carotid artery ultrasound.
Medication list
Medication used in the last 3 months, if available in boxes or packages, carry with you to the doctor’s office
Antiplatelet drugs: aspirin, clopidogrel, etc.
Anticoagulants: warfarin, etc.
Diagnosis
Diagnosis based on
Medical history
The patient may have a history of atherosclerosis, syphilitic arteritis, hereditary diseases, autoimmune diseases, etc.
Patients may have head and neck trauma, etc.
Clinical manifestations
Symptoms
The main manifestations include pain in the back of the neck and occipital region.
Dizziness, vertigo, numbness of limbs/head and face, limb weakness, headache, vomiting, diplopia, impaired consciousness, visual disturbances, unsteady walking or falling.
Difficulty in swallowing, hoarseness, choking on water.
Physical examination
The doctor will find out about muscle tone, muscle strength, sensation, brain nerve function, nerve reflexes, and ataxia through physical examination.
Muscle tone: To find out which parts of the muscle tone change by feeling with the hand the blockage of the patient’s joints in passive flexion and extension.
Muscle strength check: Observe whether the patient can complete movements such as lifting hands, sitting up, standing and walking, and whether he/she needs assistance.
Sensory examination: Slide a cotton swab over the patient’s skin or use a blunt needle to gently prick the skin to assess the degree of sensory impairment based on the sensitivity to sensation.
Cerebral nerve function examination: Cooperate with the doctor to complete a series of movements and tests such as eye movements, opening and closing the eyes, puffing up the cheeks, swallowing, etc., to determine whether the cranial nerve function is impaired.
Swallowing function test: Observe whether there is choking when drinking water to assess the swallowing function.
Nerve reflex examination: Observe the contraction of forearm and thigh muscles when knocking the tendons of elbow and knee to assess whether the nerve reflex is abnormal.
Ataxia examination: Observe the accuracy and speed with which the patient accomplishes specific movements to assess whether ataxia exists. For example, the patient uses the pointer finger to point toward the doctor’s fingertips and the tip of his or her nose, or slides the heel of one side of the foot from the knee along the anterior aspect of the calf in the supine position to the foot.
Laboratory tests
Lipids, blood glucose, blood homocysteine, alpha-1 antitrypsin, ENA, ANCA, STD, etc. need to be perfected to look for the presence of risk factors for vascular injury.
Precautions: Fasting is required, and some items need to be checked regularly in order to monitor the health condition and evaluate the treatment effect.
Imaging
Ultrasound of neck vessels
It can directly observe the condition of arterial walls, and in a few cases, it can show double lumen changes of blood vessels (blood enters the vessel walls, forming true and false lumens), non-echoic hematoma signals between the vessel walls, and floating endothelium in the arterial lumens [8], which is the preferred screening method for this disease.
The vertebral arteries are small and multisegmental, and ultrasound is easy to detect lesions in the transverse foraminal segment of the vertebral arteries, but it is relatively difficult to detect lesions above the transverse foraminal segment, and requires a combination of other examination methods.
Ultrasound is economical, convenient, non-invasive and repeatable, but the results are highly dependent on the experience of the physician.
Patients should not wear high-necked or tight-necked clothing, and there is no need for special preparations such as fasting or holding urine.
Head and Neck Magnetic Resonance Imaging (MRI) and Angiography (MRA)
MRI can detect changes in cerebral infarction caused by vertebral artery entrapment at an early stage, and axial MRI can observe the vessel wall or lumen to some extent. It is particularly suitable when acute cerebral infarction is suspected and can show the area of the lesion several hours after the onset of the disease.
MRA shows the vertebral arteries more clearly, with the characteristic crescent sign, can dynamically show the direction of blood flow, and is more intuitive for the display of collateral circulation. Combined with MRI images, it can more sensitively detect small infarction foci in the posterior circulation.
Note: MRA results may magnify the degree of stenosis of the vertebral artery, and it is not possible to determine the stent restenosis; patients wearing metal dentures, cardiac stents, pacemakers and other metal objects in the body should consult with the doctor before the examination to determine whether the examination can be performed.
Head and neck CT angiography (CTA)
Helps to detect signs of arterial vessel wall changes, stenosis, occlusion, pseudoaneurysms, and bilinear lumens [9].
Precautions: the test is radioactive and is usually not recommended for pregnant women; it requires the use of contrast media and an iodine allergy test before the test.
Digital subtraction angiography (DSA)
It is the gold standard for the diagnosis of arterial entrapment, which manifests as bead-like stenosis or vessel occlusion on DSA.
Cautions: Cannot accurately show plaque components, attached wall thrombus, etc. It is an invasive test and is not routinely performed, usually in conjunction with endovascular interventions. The test is radioactive and is usually not recommended for pregnant women; it requires the use of contrast media and an iodine allergy test before the test.
Diagnostic criteria
The diagnosis of vertebral artery entrapment usually refers to the Japanese SASSY diagnostic criteria [11]. Vertebral artery entrapment can be diagnosed when the results of vertebral artery imaging meet any one of the following criteria.
CTA and MRA examination reveals vascular double lumen sign, endocardial flap sign and intramural hematoma.
DSA examination shows bead sign, flame sign and rat-tail sign.
Ultrasound reveals vascular double lumen changes, floating intima-media in the lumen, and reverse blood flow signals.
Differential diagnosis
Vertebral artery entrapment is mainly differentiated from migraine and vertebral artery stenosis.
Migraine
Similarity: patients may have headache, dizziness and other manifestations.
Differences: Migraine attacks may be preceded by triggers and prodromal symptoms, such as exertion, menstruation, etc., mainly manifested as unilateral throbbing or pulsating pain, often accompanied by nausea, vomiting, photophobia and phonophobia; recurrent attacks. There are usually no imaging abnormalities.
Vertebral artery stenosis
Similarities: patients can have manifestations of posterior circulation ischemia, such as dizziness, unsteady walking, and numbness and weakness of the limbs [12].
Differences: Vertebral artery stenosis often occurs in middle-aged and elderly people, especially in the presence of hypertension, diabetes mellitus and other underlying diseases. Ultrasonography and magnetic resonance examination can determine the presence of atherosclerotic plaque and the thickness of the middle layer of the arterial intima.
Treatment
Aim of treatment: to close the arterial entrapment, restore nerve function and prevent complications.
Treatment principle: early treatment, mainly antiplatelet or anticoagulation, endovascular treatment or surgery if necessary.
Supportive treatment
For patients with transient ischemic attack or acute cerebral infarction, blood pressure and blood glucose should be adjusted in time to ensure the stability of the internal environment [13-14].
Drug therapy
Anticoagulant drugs
Commonly used drugs are heparin and warfarin.
Anticoagulation is recommended when vertebral artery entrapment presents with severe stenosis, the presence of unstable thrombus or pseudoaneurysm.
Anticoagulant drugs help to reduce thrombosis and lower the risk of cerebral infarction.
Note that they are contraindicated when the patient has a bleeding tendency, severe hepatic impairment, or recent intracranial hemorrhage, and a common adverse effect is an increased risk of bleeding [16].
Antiplatelet agents
Commonly used drugs are aspirin and clopidogrel.
Antiplatelet agents can be used when vertebral artery entrapment is accompanied by large cerebral infarction, severe neurologic impairment, or when anticoagulants are contraindicated [15-16].
By inhibiting platelet aggregation, the formation of thrombus is reduced, and the risk of stroke is reduced.
Note that antiplatelet drugs are contraindicated when patients have acute gastrointestinal ulcers, bleeding constitution, severe cardiac, hepatic, and renal failure, and common adverse drug reactions are increased risk of bleeding and gastrointestinal discomfort.
Surgery
If the patient still has cerebral infarction manifestations after the ineffective active antithrombotic treatment, endovascular interventions such as arterial balloon dilatation and stenting can be considered [17].
Surgery for vertebral artery entrapment is high risk and is less commonly used today, only as an alternative to failure after interventional therapy, and is appropriate for sites with limited lesions and easy surgical access.
Prognosis
Cure
Most patients with vertebral artery entrapment recover well with aggressive antithrombotic therapy, but recurrence occurs in a few cases.
Prognostic factors
Patients with the following factors have a poorer prognosis:
Transient cerebral ischemia and cerebral infarction occur.
Severe neurologic dysfunction.
Combined arterial occlusion, carotid artery entrapment.
Advanced age.
Bad habits such as smoking and drinking.
Presence of cerebrovascular risk factors such as hypertension, hyperlipidemia, diabetes mellitus.
Hazards
Accidental injuries can occur due to symptoms such as vertigo, blurred vision, and limb weakness, such as falls, burns, and traffic accidents. Sequelae such as limb paralysis and speech and swallowing disorders may occur.
Can cause severe subarachnoid hemorrhage leading to death.
Daily
Daily Management
Dietary management
Supply sufficient protein, vitamins and other nutrients, eat food with high quality protein, fresh fruits and vegetables.
While taking the oral anticoagulant warfarin, you need to maintain a steady intake of vitamin K. This means consuming essentially the same amount of vitamin K-rich foods such as liver, spinach, celery, and citrus every day.
Cessation of smoking and tobacco use.
Exercise management
After recovering from the disease, resume normal activities in a gradual manner, maintain a reasonable amount of exercise, and avoid strenuous exercise such as basketball, tennis, skating and swimming.
Daily life
Prevent trauma to the head and neck.
Avoid excessive force when coughing, sneezing or defecating.
Avoid violent head shaking, roller coaster rides or other forms of play that involve strenuous movements.
Neck massage and acupressure treatment must go to regular medical institutions, and violence is prohibited.
Psychological support
Family members should cooperate with doctors to guide patients to correctly understand the disease, accept the disease, and establish confidence in the treatment of the disease.
Encourage the patient to participate in social and family activities and do what he/she can to enhance self-confidence.
Disease monitoring
Pay attention to observe whether symptoms such as back neck pain, diplopia and limb weakness are relieved.
When applying antiplatelet and anticoagulant drugs, pay attention to observe whether there is bleeding and other conditions.
During the administration of warfarin, review the International Normalized Ratio (INR) regularly.The normal reference value of INR is 0.8-1.5, and it is usually required to keep the INR value at 2-3.
Prevention
Change bad habits, do not smoke or drink alcohol.
Control cerebrovascular risk factors, such as hypertension and hyperlipidemia, to minimize damage to arterial walls.
Avoid various triggering factors, such as strenuous exercise, forceful coughing or sneezing, riding roller coasters or other amusement park facilities, and violent neck thrust therapy.