Anterior Spinal Artery Syndrome (Spinal Stroke)

What is Anterior Spinal Artery Syndrome (Spinal Stroke)?

Anterior spinal artery syndrome, also known as anterior cord syndrome or ventral cord syndrome, is a medical condition affecting the nervous system. It causes paralysis, pain, loss of temperature sensation and sometimes impacts the body’s automatic functions due to a blockage in the anterior spinal artery. This particular artery is responsible for supplying blood to the majority of the spinal cord and extends all along the front part of the spinal cord.

When the anterior spinal artery is blocked, it limits the flow of blood and can lead to damage in the spinal cord. This can result in weakening or paralysis of the legs, and loss of ability to perceive pain and temperature. The symptoms a patient experiences can vary based on which part of the spinal cord is affected and how quickly they receive treatment. Along with these symptoms, patients may also experience back pain or disorders of the autonomic system, which controls bodily functions like blood pressure control, bowel or bladder control, and sexual function.

The degree of paralysis can range from inability to move the lower body to complete paralysis of all limbs, depending on the extent and location of spinal cord involvement. Typically, patients suffering from this condition retain their sense of body position, ability to sense vibrations, and the sense of light touch. The loss of bodily functions usually occurs below the location of spinal cord involvement due to the anatomical distribution of the spinal cord.

The anterior spinal artery originates from arteries in the neck and runs all the way through the front part of the spinal cord. Along its course, smaller arteries join in and contribute to its blood supply. The anterior spinal artery mainly provides blood to important areas controlling movement and relaying sensory information in the spinal cord. If there’s not enough blood flow to these areas due to issues with the anterior spinal artery, that’s when we see the symptoms typically associated with this syndrome.

This particular syndrome is a rather unusual cause of sudden spinal cord damage, but when it comes to spinal cord strokes or infarcts, it’s reported to be the most common cause. This syndrome is triggered by any factors that affect or diminish blood flow to the anterior spinal artery. The leading causes are complications from aortic surgery and clogged arteries due to fatty deposits. Diagnosis is typically made based on distinct clinical features and confirmed through brain scans or similar imaging tests.

Unfortunately, the prognosis isn’t great since there’s no immediate treatment available. Doctors focus on addressing the root cause and preventing further complications. Currently, the treatment protocol for this syndrome follows the guidelines used for brain strokes, clogged arteries, and major spinal cord injuries.

What Causes Anterior Spinal Artery Syndrome (Spinal Stroke)?

Anterior spinal artery syndrome happens when there is direct or indirect damage to the front part of the spinal cord. This direct damage can happen when the spinal cord is physically crushed or squeezed, such as from a growing pool of blood. The syndrome is mainly caused by indirect damage – less blood flow to the front part of the spinal cord due to a blockage in the arteries that provide blood to it. In particular, blockage often occurs at the Adamkiewicz artery, a major branch.

It might surprise you to learn the important role the aorta (the main blood vessel leaving the heart) plays in the health of the front part of your spinal cord. The aorta leads to other big arteries, eventually reaching the anterior spinal artery that keeps the front two-thirds of the spinal cord alive and functioning. So, if anything harms the aorta (like a tear in the aorta wall), this can indirectly affect the spinal cord.

Certain risk factors can make someone more likely to get anterior spinal artery syndrome. These include things like smoking, high blood pressure, diabetes, high cholesterol levels, and having a personal or family history of strokes. The syndrome can also be caused by accidental damage to the aorta during surgery, specifically, surgery that involves trying to repair blood vessels or if the aorta has been clamped for a long time. Lesser common causes of blockages, leading to the syndrome, include blood clots or fatty deposits in the arteries that supply the front of the spinal cord.

The front part of the spinal cord is especially prone to blood supply problems because its arteries don’t usually connect with other arteries. There can be a blockage of the major artery that supplies blood to the lower part of the spinal cord, due to conditions like aneurysms (a ballooned blood vessel), trauma, or arteries damaged by syphilis. Other less common causes of this syndrome include low blood pressure, venous blockages, multiple sclerosis, and spinal cord compression from a fracture.

Options for how the arteries that supply the front part of the spinal cord can become blocked (and lead to this syndrome) are many, thus leading to reduced blood supply and causing damage to the spinal cord. These include:

• Surgery on the aorta: Increased risk comes with low blood pressure, clamping the aorta for a long time, increased pressure around the spinal cord and blockage of small spinal blood vessels, which reduces blood flow and causes damage.
• Arteries being blocked by fatty deposits or clots: A common cause of the syndrome.
• Splitting of the aorta: This often causes blockage in small spinal blood vessels.
• Stopping heart: It can stop or decrease blood flow to the artery supplying the front part of the spinal cord.
• Embolisms, or clots originating from the heart: This happens but rarely, and can cause blockages in the artery or other important spinal blood vessels.
• Inflammation of blood vessels, a condition known as vasculitis: It sometimes causes this syndome.
• Degeneration of spine disease under rare conditions, such as in patients with cervical spondylitis or thoracic disc herniation.
• Fracturing of the vertebra: This might cause the syndrome by compressing the artery from a piece of broken bone.
• A condition known as fibrocartilaginous embolic myelopathy, or sometimes idiopathic transverse myelitis, migration of certain materials into blood vessels supplying the artery.
• Low blood pressure: It may precipitate this syndrome.
• Certain forms of aortitis: It was common at one time but is rare today.
• Minimal invasive spine surgery, such as percutaneous balloon kyphoplasty.
• Abnormal connections of arteries and veins, known as arteriovenous malformations.
• A procedure known as digital subtraction angiography is a rare but potential cause.
• Sickle cell disease: It can lead to the syndrome due to clotting.
• Other conditions that cause clotting.
• Cocaine use: Because it produces restricting blood vessels, inflamed blood vessels or clots, it could lead to the syndrome developing.

Risk Factors and Frequency for Anterior Spinal Artery Syndrome (Spinal Stroke)

Anterior spinal artery syndrome is quite uncommon and so, there isn’t a lot of data available on how often it occurs. Still, we know that about 5% to 8% of severe spinal cord injuries are due to problems with the blood vessels, like spinal cord strokes. In fact, these kinds of strokes make up 1.2% of all strokes and occur in about 3.1 out of every 100,000 people in the United States each year.

When it comes to spinal cord strokes, anterior spinal artery syndrome is the most common type, making up as many as 87.2% of cases in some studies. Most people who experience this are between 50 and 70 years old.

• Anterior spinal artery syndrome is a rare condition.
• 5% to 8% of severe spinal cord injuries are due to problems with blood vessels, like spinal cord strokes.
• Spinal cord strokes make up 1.2% of all strokes and occur in about 3.1 out of every 100,000 people in the United States each year.
• In spinal cord strokes, the most common type is anterior spinal artery syndrome.
• It’s usually found in people who are between 50 and 70 years old.
• No data shows if it’s more common in men or women, but some studies suggest that older women with the syndrome have the worst outcomes.

As of now, more research is needed to gain a better understanding of this syndrome because of its rarity and the limited amount of data available.

Signs and Symptoms of Anterior Spinal Artery Syndrome (Spinal Stroke)

Anterior spinal artery syndrome is a condition caused by lack of blood flow to the front part of the spinal cord. Its symptoms are typically noticeable right away, showing up as motor problems and a loss of pain and temperature sensation below the level of the spinal cord injury. In most cases, the first symptom people notice is a sudden back pain that’s typically around the area where the spinal cord is injured. This is followed by loss or malfunction of movement and feeling below the level of the injury, but people usually retain a sense of body awareness, vibration perception, fine touch, and the ability to distinguish between two separate points touching the body. These symptoms are usually felt on both sides of the body. Depending on where the blood flow is blocked, patients might experience complete or partial paralysis from the neck down or the waist down.

• Sudden back pain at the injury site
• Loss or difficulty of movement and sensation, usually on both sides
• Retained sense of body awareness, vibration perception, fine touch, and two-point distinguishing ability
• Complete or partial paralysis from the neck down or the waist down (depending on the injury site)

Often, this condition can affect the sides of the spinal cord, from the base of the neck to the lower back, leading to issues with the systems of the body that function automatically, like the bladder and bowel, blood pressure control, heart rate, and sexual function. If the injury happens at a high neck level, it can interfere with the function of the phrenic nerve which controls the diaphragm and that leads to a possibility of respiratory failure. Symptoms that appear several days or weeks after the initial injury, such as muscle stiffness, overactive reflexes, bladder and bowel issues, and sexual dysfunction, are common features of this condition since there isn’t an immediate treatment for it.

• Uncontrolled bladder and bowel
• Low blood pressure
• Slow heart rate
• Sexual dysfunction
• Potential respiratory failure if spinal cord injury is at a high neck level
• Stiff muscles, overactive reflexes, bladder and bowel issues, and sexual dysfunction appearing days or weeks after the initial injury

Testing for Anterior Spinal Artery Syndrome (Spinal Stroke)

Anterior spinal artery syndrome is primarily diagnosed based on specific clinical features and specialized imaging of the brain and spinal cord.

Magnetic resonance imaging, or MRI, is considered the best diagnostic test for this condition. Although an MRI may initially show negative results during the first 24 hours, it’s an essential tool for confirming the syndrome. On an MRI, the syndrome is typically represented by a bright intensity signal in the anterior horns in the T2-weighted image.

Other diagnostic imaging studies can also be beneficial. MRI angiography or computed tomography (CT) angiography can offer insight into the condition of the blood vessels. Although CT angiography involves some radiation exposure and possibly harmful agents, it can also rule out issues in the aortic or vertebral artery. If necessary, digital subtraction angiography can also be used, mostly if an interventional procedure is required.

Besides imaging tests, laboratory studies are often performed to screen for conditions that could cause vessel damage. This can include diabetes, atherosclerosis, substance abuse, and high cholesterol. Blood tests for these conditions, as well as for various infectious diseases, are generally conducted.

As for treatment, it’s mainly supportive and focuses on managing the symptoms and underlying conditions. Efforts to control fever, manage blood sugar, and provide essential blood pressure support in an acute setting are also critical. If low blood pressure is a problem, it can be raised with certain medications.

Although high-dose steroid treatment for patients with anterior spinal artery syndrome is usually ineffective, in some instances where blood vessel disease is the underlying cause, treatment with intravenous clot-busting drugs within 4.5 hours of symptom onset has been reported to significantly improve the patient’s condition.

Other supportive treatments might be required to manage acute and late symptoms or complications. For instance, low blood pressure due to nerve damage, phrenic nerve impairment and diaphragm dysfunction in high cervical lesions might require treatment. Similarly, preventative measures might be needed to avoid ulcers, deep venous thrombosis, and pressure sores.

Since the most common cause of anterior spinal artery syndrome is aortic surgery, part of the treatment should focus on preventing it in the context of surgical procedures. Effective strategies include increasing blood flow and placing a lumbar drain to reduce spinal cord pressure.

Treatment Options for Anterior Spinal Artery Syndrome (Spinal Stroke)

The current treatment for anterior spinal artery syndrome, a condition that affects the arteries supplying the spinal cord, primarily involves supportive care. This includes managing conditions that narrow or block the arteries, injuries to the spinal cord, and managing symptoms related to inadequate blood supply to the brain. The timeliness of addressing the root cause of the problem is crucial to the prognosis as there is currently no known treatment to reverse this condition.

Primary actions focus on symptom control such as fever and blood sugar management, medication to prevent blood clots, and maintaining adequate blood pressure. In emergency situations, it is crucial to protect the patient’s airway and maintain blood pressure support. If blood pressure is low, it can be increased using certain medications. On the other hand, if blood pressure needs to be reduced, medications such as labetalol, esmolol, and nicardipine can be used.

High-dose corticosteroids have been found mostly ineffective in treating this syndrome. Patients whose condition is caused by conditions, such as the narrowing or blockage of arteries, and who have received a treatment involving the dissolving of blood clots within 4.5 hours from the onset of symptoms, have shown considerable improvement with minimal complications.

While there are similarities between spinal cord and brain strokes, treating them in the same way is not currently the standard approach due to the need for more research. Care for these patients primarily involves dealing with short-term and long-term symptoms or complications. For example, low blood pressure due to nerve damage is treated with intravenous fluids and medications that constrict blood vessels. If the condition has resulted in diaphragm dysfunction or bladder issues, medical interventions such as mechanical ventilation and bladder catheterization are utilized. Additional supportive treatments might include the prevention of blood clots, ulcers, and pressure sores, along with physical, occupational, and psychological therapy.

If the syndrome occurs due to aortic surgery, it is important to focus on preventing it. A protocol for this has been established which involves techniques to increase the blood supply to the anterior spinal artery and decrease pressure on the spinal cord. Additionally, it is essential to rule out any underlying causes that may prevent the use of treatments to dissolve blood clots.

What else can Anterior Spinal Artery Syndrome (Spinal Stroke) be?

When trying to diagnose anterior spinal artery syndrome, multiple conditions may present similar symptoms and need to be considered:

• Transverse myelitis tends to come on more slowly
• Multiple sclerosis can appear the same on an MRI, but patients usually also have issues with their skull and eyes
• Venous congestive myelopathy might show particularly large blood vessels in the brain with changes around the center and edges of the brain’s white matter when imaging is done
• Spinal cord tumors usually develop more slowly
• Spinal cord arteriovenous malformations
• Disk herniation
• Bleeding between the spinal cord and its protective covering (epidural hematoma)
• A puss-filled area inside the spine (epidural abscess)
• Conditions that cause compression in the spinal cord
• Central cord syndrome
• Dorsal cord syndrome
• Brown-Séquard syndrome
• Guillain-Barré syndrome – nervous system disorder
• Lower part of the spinal cord condition (Conus medullaris syndrome)
• Condition that affects the bundle of nerve roots at the lower end of the spinal cord (Cauda equina syndrome)

Each of these conditions need to be examined to ensure an accurate diagnosis is made.

What to expect with Anterior Spinal Artery Syndrome (Spinal Stroke)

The long-term outlook for people with anterior spinal artery syndrome isn’t well-documented, but general consensus indicates that it’s usually not favorable. However, one study suggests that spinal strokes may have a more positive outcome compared to brain strokes, which often come with additional cognitive impairment.

The cause of this syndrome is a key factor in determining how successful the outcome might be. Lesser known causes like disc herniation, when identified and treated fast, can even result in full recovery from symptoms.

Spinal cord infarction, a condition related to this syndrome, has a mortality rate ranging between 9% to 23%, often occurring soon after the injury. One study reported that out of a group of spinal cord infarction patients, 24% saw no improvement, and only 20% saw significant improvement. Two other studies indicated a relatively low full recovery rate – between 1% and 5%.

It’s important to note that survivors often continue to experience varying degrees of motor and sensory dysfunction. More severe cases and those not showing improvement within the first 24 hours tend to have a worse prognosis. Conversely, milder cases may see a positive outcome, with some patients even regaining their walking ability. For some, functional improvement can occur over several years.

There are several factors that can influence prognosis. Some conditions, like tears or ruptures in the main body artery or high neck lesions, increase the risk of fatal outcomes. The severity of symptoms at the beginning also plays a role – those with worse symptoms often have worse outcomes. Similarly, lack of improvement in the initial 24 hours, being female, or being an older adult are known to correlate with worse outcomes.

Possible Complications When Diagnosed with Anterior Spinal Artery Syndrome (Spinal Stroke)

People suffering from anterior spinal artery syndrome often face many complications due to the significant spinal cord injury involved. What trouble occurs can largely depend on the specific area of the spinal cord that has been damaged. Life-threatening complications from anterior spinal artery syndrome typically begin shortly after the injury or during the hospital stay. The complications include:

• Hypotension: If the lateral horns from T1 to L2 spinal levels are harmed, this may lead to shock, potentially resulting in fatal consequences if left untreated.
• Respiratory failure: Damage to the phrenic nerve (C3 to C5) due to high cervical-level injury may necessitate the need for prolonged artificial ventilation.
• Bradycardia: This could cause cardiac arrest, which may require the patient to be placed on atropine or to have a permanent pacemaker implanted.
• Infections: These can include urinary tract infections, pneumonia, and bacteremia (blood infection).
• Electrolyte imbalances
• Renal (kidney) failure
• Depression

The chance of recovering from anterior spinal artery syndrome is low, which often leads to unfavorable outcomes. Many complications come about because a majority of the patients don’t recover their ability to move and feel, leading to prolonged periods of immobility. These complications can include:

• Permanent muscle weakness or paralysis, either partially or fully.
• Deep vein thrombosis.
• Pulmonary embolism.
• Pressure sores, with a 50% lifetime risk.
• Neurological bowel or bladder issues.
• Sexual dysfunction.
• Neuropathic pain.
• Stomach stress sores.
• Gastrointestinal movement issues.
• Chronic pain, affecting 79% of the patients.
• Increased risk of osteoporosis due to prolonged immobility.
• Spasticity.
• Psychological issues including depression.
• Economic challenges.
• Being dependent on others for everyday activities.

Recovery from Anterior Spinal Artery Syndrome (Spinal Stroke)

For long-term success in managing anterior spinal artery syndrome, a thorough rehabilitation program before and after discharge is pivotal. The main goals of this rehabilitation are to improve the patient’s quality of life, help them regain independence, and prevent further complications. This often involves a variety of therapies aimed at improving motor function, such as physical, occupational, vocational, and neuropsychological therapies.

Post-surgery treatments for this condition are frequently ineffective, so it’s important to take steps to prevent spinal cord damage during the operation. Strategies include preventing anemia and low blood pressure, as well as avoiding extreme stretching or bending during positioning for surgery. Also, care must be taken to limit any surgical mishaps that may lead to blood vessel damage. If the surgery involves the aorta in the chest and abdominal area, testing for early signs of impaired spinal cord blood flow can be done using special techniques while the patient is anesthetized or awake.

The inability to move the arms and legs is a serious outcome of ventral cord syndrome, resulting in significant personal and societal costs. As there’s currently no treatment to reverse anterior spinal artery syndrome, patients need to engage in rehabilitation efforts aimed at enhancing their independence and quality of life while warding off subsequent problems. Various types of rehabilitation, like physical, occupational, vocational, and neuropsychological therapies, may be suitable for different patients.

Preventing Anterior Spinal Artery Syndrome (Spinal Stroke)

Anterior spinal artery syndrome can’t be prevented or reversed usually, but it’s often triggered by preventable conditions like aortic aneurysm or atherosclerosis. It’s key to educate patients about preventing diseases linked to major risk factors like high blood pressure, abnormal cholesterol, diabetes, and smoking. This can be achieved through promoting healthy eating, regular physical activity, and quitting smoking. If a patient develops health problems from these risk factors, having them under medical management is crucial to avoid worsening the condition or recurrence.

When a patient is in the hospital, they should receive guidance on adapting to life after being diagnosed with this syndrome. Subsequent visits to the doctor can offer support and further patient education. Adjusting to disability is a long-term process, and it requires the patient to reach the best possible balance between their personal abilities and their environment. The patient should be coached by the medical team, focusing on teaching them effective coping strategies.

A study found that patients who underwent a coping training program were less depressed and anxious than patients who received standard care only. When a patient is ready to leave the hospital, it’s a good chance for doctors and other health professionals to educate not only the patient but also their family and caregivers. The medical team needs to evaluate what kind of assistance the patient may need, like medical equipment, and how they can facilitate their patients’ return to society. Planning for emergencies, setting up follow-up visits and support, and providing the necessary medical tools should be considered when discharging a patient.

Patients also need help strengthening the personal resources that can support their successful adjustment, like abilities, skills, knowledge, experience, strengths, and adaptable behaviors. Patients should be advised on how participating in sports and exercise can benefit their health. But before starting any physical activity regime, patients have to be screened to determine the type of exercise they should do, any necessary precautions to take, and modifications to the exercise. Education should also focus on other parts of their life, like work and social relationships, by assessing and offering transport choices and adjustments.