Spinal Shock

What is Spinal Shock?

Spinal shock is a sudden, temporary loss or change in the function of the spinal cord after a severe injury. This loss affects movement, sensation, reflexes and body functions that we don’t usually think about, like heart rate and digestion. The term “spinal shock” was first coined by Hall in 1840, and Sherrington further explained it as a temporary loss of reflexes after a spinal cord injury.

The most common cause of spinal shock is high-impact injuries like car accidents or falls. However, secondary injuries such as poor blood flow (ischemia) or infection can also cause damage. Other causes could be diseases that affect the spinal cord due to immune reaction, infections, cancer, certain heart and blood vessel conditions, or inherited diseases.

Spinal shock lasts anywhere from a few days to a few weeks. Although it’s caused by a back injury, it’s considered a physiological process, meaning how the body deals with the injury, not a structural/anatomical problem with the spinal cord itself.

To diagnose spinal shock, doctors collect your medical history and the details about your injury, conduct a full physical exam and get imaging scans of your spine. Also, they will use standardized evaluation scales such as the Glasgow Coma Scale (GCS) and American Spinal Injury Association (ASIA) Scale.

Doctors have to make sure your airway is clear, you are breathing, your heart is beating, check for any disability, and exposure to any harmful stuff (ABCDE protocol). They make sure to keep the spine immobilized during this check-up and when moving you to prevent further injury. Initial symptoms include paralysis, lack of reflexes, trouble controlling bowel and bladder, and a loss of muscle tone in the rectum.

Spinal shock without a significant injury to the backbone itself generally has a better outcome than when a break is present. Treatment of severe spinal shock can be a challenge, but aggressive medical therapy can help lessen the impact on overall function. Treatments focus on maintaining a stable heart rate and breathing to prevent further damage and providing support as the body heals. Surgery to relieve pressure (decompression) might also be considered. However, even with the best care, some deficits following spinal shock could be permanent.

Usually, patients regain function in time, but lasting neurological impairment might indicate a more severe, structural spinal cord injury. Doctors need to be skilled in managing spinal shock, staying up-to-date in knowledge and strategies. This knowledge helps spot signs of spinal shock early and respond effectively to improve patient outcomes and reduce the risk of complications.

What Causes Spinal Shock?

Spinal shock is a temporary condition brought on by a sudden injury to the spinal cord. Spinal cord injuries are mainly categorized into two types. The main causes of primary spinal cord injuries are blunt force trauma, such as car or bike accidents, and pedestrian incidents, accounting for about half of all cases. For people over 65, falling is usually the cause. Other things that can cause primary spinal cord injuries include bullet or knife injuries, severing of the spinal cord, physical damage, pus-filled abscesses, and spreading disease from another part of the body.

Secondary spinal cord injuries, on the other hand, are mainly due to poor blood flow (ischemia) resulting from the blockage or damage of the arteries supplying the spinal cord. This results in the spinal cord not getting enough blood (hypoperfusion) and damage due to lack of oxygen (anoxic damage).

Among known risk factors, neck bone deterioration (Cervical spondylosis) is most often associated with spinal cord injury; it’s seen in 10% of such cases. Other risk factors include birth abnormalities of the spine like an unstable joint between the first two neck bones (atlantoaxial instability), fusion of neck bones at birth (congenital fusions), or a stuck spinal cord (tethered spinal cord). Also, temporary spinal shock was reported after the use of a specific spinal imaging agent (intrathecal iodinated contrast).

Risk Factors and Frequency for Spinal Shock

Spinal cord injuries, or SCI, are estimated to occur 15 to 40 times per million people globally each year. Many of these cases happen to young men following an accident or trauma. The upper part of the spine, known as the cervical region, is the most common area affected, accounting for about 55% of acute cases. Unfortunately, injuries in this area tend to have worse outcomes than those in other parts of the spine. This is reflected in lower reported numbers of cervical SCI in health statistics.

• Each year worldwide, there are around 15 to 40 spinal cord injury cases per million people.
• The majority of these happen to young men due to trauma.
• Approximately 55% of these injuries affect the cervical spine, the area near the neck.
• Cervical spinal injuries usually have a tougher recovery compared to other spinal injuries.
• In the United States, there are about 54 cases per one million people, which amounts to nearly 17,900 new spinal cord injury cases each year.

Signs and Symptoms of Spinal Shock

When dealing with a patient who has suffered from trauma, healthcare professionals need to assess for any potential spinal cord injuries (SCI). This assessment is usually done right after primary assessment, which follows the ABCDE protocol – Airway, Breathing, Circulation, Disability, Exposure. The patient’s spine should be immobilized during the assessment and transportation to prevent any additional injury. This immobilization can be done using a cervical collar, supportive blocks and straps on a backboard. When moving the patient, it is important to use the log-roll method. Often, this is done by emergency medical personnel at the scene.

If the injury is in the spinal cord region above the C5 bone, the patient may lose the ability to breathe on their own and require ventilatory support. However, this usually isn’t the case if the injury is below the T5 bone. If the patient needs to be put on a ventilator on an emergency basis, options include either rapid-sequence intubation with spinal immobilization or intubation over a flexible fiberoptic laryngoscope if the situation permits. It’s also common for these patients to have very low blood pressure which should be treated immediately with a blast of liquid crystalloid.

After initial stabilization, a more detailed examination can be conducted in the hospital. Such an examination includes getting past medical history if possible, as conditions like osteoporosis, and cervical spondylosis can increase risk for SCI or affect the neurologic exam, such as dementia or alcoholism. Clinicians should also check for signs of spinal and neurogenic shock. Spinal shock is characterized by sudden loss of spinal cord functions including motor, sensory, reflex, and autonomic neural systems, after a severe SCI. This can coincide with Neurogenic shock, which is characterized by low blood pressure, slow heartbeat, and low body temperature due to imbalance in the nervous system.

Physical exams should also evaluate the patient using the Glasgow Coma Scale and the American Spinal Injury Association scale to quantify the neurological impairment. Clinicians should visually inspect and palpate the spine for any signs of injury such as hematomas, bruising, bony injuries, midline deviation, and pain. If the patient has low blood pressure due to neurogenic shock, large amounts of fluids which can cause pulmonary edema are not recommended. Instead, medication to increase blood pressure should be used. Signs of urinary retention should be assessed, and a urinary catheter should be placed as soon as possible.

The duration of spinal shock, or the serquence of temporary loss of reflex activities, can vary from about an hour for superficial reflexes to several weeks or even months for deep tendon or autonomic reflexes. The reflexes tend to return in a certain order: delayed plantar reflex, bulbocavernosus reflex, cremasteric reflex, ankle jerk, Babinski sign, and knee jerk.

Clinicians should be aware of the four phases of reflex recovery:

• Phase 1: In the first 24 hours, the patient may experience areflexia or hyporeflexia, bradyarrhythmia, or hypotension due to motor neuron hyperpolarization.
• Phase 2: From day 1 to day 3, cutaneous reflexes become prominent, while deep tendon reflexes remain absent due to denervation supersensitivity and receptor upregulation.
• Phase 3: Between 4 days to a month, most patients recover deep tendon reflexes, and the Babinski sign may appear.
• Phase 4: Lasting from 1 to 12 months, now with long axon and synapses growth, patients will experience hyperactive cutaneous and deep tendon reflexes even with minimal stimuli.

Testing for Spinal Shock

If your doctor thinks you might have a spinal cord injury (SCI), one of the most important things they’ll do to check is run some imaging tests. First, they need to make sure your heart rate and blood flow are stable. Once that’s confirmed, they’ll move on to diagnostic imaging tests. These are usually required if you’ve had a serious injury, if you’re feeling pain anywhere along your spine, if there are signs of injury during a neurological exam, or if you’re unconscious.

Doctors usually start the diagnosis process with a computed tomography (CT) scan of your brain and neck, plus your chest, belly, and pelvic area. A CT scan uses X-rays to create detailed images of your body and can help identify any potential injuries. It’s recommended to scan the entire spine, as research indicates that around 20% of patients with trauma have multiple spinal injuries.

A CT scan can provide a lot of helpful information, but it’s not perfect. Sometimes, it might miss fractures. That said, CT scans have a better chance of finding spinal fractures than regular X-rays. If a fracture is found on a CT scan, your doctor will likely call for a consultation with a spinal surgeon. If the scan doesn’t show a fracture but an SCI is still suspected, a neurology expert may be asked to assist with further examination and treatment. If a blood vessel related injury in the brain is suspected, a CT angiogram may be performed.

Another test that might be used is magnetic resonance imaging (MRI). This test is usually more accurate at spotting spinal injuries than a CT scan, but may be difficult and time-consuming to perform, particularly if the patient is unstable. If a CT scan doesn’t show any sign of SCI but your doctor still has suspicions, an MRI might be recommended. A recent study revealed that out of 1550 patients with no signs of SCI on a CT scan after serious injuries, MRI found spinal irregularities in 182 of the patients. This led to the conclusion that a CT scan alone can’t completely rule out an SCI, especially in patients who are unconscious or who cannot be examined for other reasons. Therefore, an MRI is commonly advised for further evaluation, surgical preparation, and to help determine the likely outcome. However, if emergency surgery is required, it should not be delayed to perform an MRI.

Treatment Options for Spinal Shock

Spinal shock is a short-term physical response typically improving within days to weeks. The focus of medical management isn’t on curing spinal shock itself but on minimizing spinal cord harm and avoiding further complications. This is usually done through careful management of blood pressure and breathing, alongside supportive care measures including physical therapy and managing pain. In some instances, surgery might be an option.

Patients experiencing spinal shock may have low blood pressure and a slow pulse because of disruptions to their nervous system. This often happens after injuries to the neck and upper spine because the normal control of blood vessels is lost, leading to reduced blood pressure. A slow pulse happens due to the heightened influence of the body’s rest-and-digest nervous system. It’s crucial to maintain ample blood flow to the spine to avoid any further harm due to insufficient blood supply. Careful fluid management is needed to avoid fluid buildup and swelling. Most patients might need medication to raise their blood pressure. In cases where the pulse is dangerously slow, certain medications or temporary pacing can be used.

Patients with neck and upper spine injuries often need help breathing due to suppressed respiration. Additionally, trauma often leads to severe lung inflammation requiring breathing support to stabilize the patient. Patients also have a high chance of getting pneumonia due to a decreased ability to cough and clear out secretions. Chest physical therapy, involving things like chest percussion, incentive spirometry, and deep suctioning, should be used to minimize this risk. Flu and pneumococcal vaccinations are also recommended.

While glucocorticoid treatment, a type of anti-inflammatory medication, has been used in the past to reduce inflammation and swelling, it is not recommended for routine use due to insufficient supporting data. One study did find that patients treated within 8 hours of injury had some improvement in motor function if they received high dose glucocorticoids. However, more serious side effects like infection were also noted in these patients, thus discouraging the use of this medication in most cases.

For some patients with spinal fractures, surgery within 24 hours of the injury might be performed to relieve pressure on the spinal cord and prevent further harm due to insufficient blood supply. The potential benefits of surgery need to be weighed against common surgical risks and the possibility of further vascular damage. The ideal timing for this type of surgery is not clear, as limited studies have been carried out.

Alongside other management plans for spinal shock, supportive therapies are also recommended to lessen patient impact. These include:

– Preventing blood clots: Due to immobility and trauma, all patients need precautions taken to prevent blood clots. This usually includes treatment with low-molecular-weight heparin and intermittent pneumatic compression devices.

– Managing bowel and bladder: Depending on the level of injury, patients may experience a combination of bowel and bladder retention or incontinence. Medical professionals should customize the patient’s bowel regimens, and urinary catheterization is also needed due to urinary retention.

– Preventing pressure ulcers: Due to decreased sensation and immobility, pressure ulcers are common. The standard of care is to turn and reposition patients every 2 hours to prevent this complication.

– Managing nutrition: Maintaining good nutrition is crucial to promote healing and prevent weight gain. Patients’ changing metabolic and dietary needs should be evaluated and treated.

– Managing pain: Pain, depression, and anxiety are common after spinal cord injury and should be treated accordingly.

– Physical therapy: This is recommended as soon as the spine has been stabilized, with the primary goal being functional recovery.

What else can Spinal Shock be?

There are several medical conditions that can show symptoms similar to spinal shock. These include:

• Cardiogenic shock (a condition where your heart can’t pump enough blood)
• Hypovolemic shock (a severe fluid or blood loss)
• Septic shock (a serious infection spreading throughout the body)
• Malignancy (a disease process typically leading to cancer)
• Spinal infection like epidural abscess
• Epidural hematoma (a blood clot outside the brain)
• Disk herniation (occurs when a disc in the spine bursts)
• Spinal stenosis (narrowing of the spinal canal)

What to expect with Spinal Shock

The biggest threats to the health of those with spinal cord injuries (SCI) are heart disease and breathing problems which can lead to pneumonia, heart disease, severe infections in the bloodstream, clotting in the lungs, and unintentional injuries. The likelihood of recovering from a condition called ‘spinal shock’, which often follows SCI, is generally poor. This can be affected by existing health issues, the severity and location of the SCI, associated injuries, the patient’s age, and the nature of the injury. For instance, patients with an injury to the first three vertebrae of their neck are at 6.6 times higher risk of death than those with paralysis in their lower bodies.

Recovery of reflexes in the initial phase can potentially be a sign of recovery from spinal shock after SCI, although research on this is still limited.

In a large study in Germany, it was found that patients with multiple injuries (polytrauma) could often have spinal cord injuries. They discovered that for every 13 patients with multiple injuries, one would likely have SCI. Interestingly, more than half of these patients had complete spinal cord injuries with spinal shock. Although the SCI itself did not tend to massively increase the chance of death, these patients often had complications from multiple organ failure, severe infections, and longer hospital stays.

Possible Complications When Diagnosed with Spinal Shock

Spinal shock, a result of spinal cord injury, can lead to various complications within the body. These complications can range from sores caused by constant pressure on the skin, blocked veins due to blood clots (aka VTE), widespread infection (sepsis), pneumonia to bladder and bowel issues. There can even be events that affect heart health.

Another issue tied to spinal cord injury is cardiovascular complications. These are the most common cause of deteriorating health and death in both the early (acute) and later (chronic) stages of spinal cord injury. During the initial phase post-injury, spinal shock can often lead to drastic drops in blood pressure and disturbances in the nervous system that controls bodily functions. When spinal cord injury reaches a chronic state, it can result in a condition known as autonomic dysreflexia, where simple triggers can cause sudden severely high blood pressure. It’s also possible for someone to experience orthostatic hypotension (a sudden fall in blood pressure when standing up) in both the acute and chronic stages of injury.

Moreover, individuals with spinal cord injuries may also experience an elevated risk of developing deep vein thrombosis (blood clots deep in veins), systemic atherosclerosis (hardening and narrowing of the arteries), and heart diseases. Species of these conditions are more frequently noticed in this group than in people of the same age without spinal cord injuries. For men in the acute phase of spinal shock, a condition called priapism, or prolonged and painful erection, can occur as well.

When it comes to the complications of spinal shock other than those related to blood vessels, one of the significant issues is functional disability due to spinal cord injury. This disability is a major contributing factor to the deteriorating health and death among these patients. It’s worth noting that information about motor axonal excitability, or how well the motor nerves that control muscles work, remains limited. Hence, clear indicators that could predict the degree of functional recovery are still unidentified. Some research suggests rapid deterioration in peripheral motor axonal excitability and function during early spinal shock. What triggers eventual recovery and the factors that determine the degree of recovery remains unknown.

Preventing Spinal Shock

Spinal cord injuries and spinal shock can drastically alter a patient’s life. It’s important for patients to understand their medical condition, potential risks, likely outcomes, and the steps they can take to prevent these problems. This plays a key role in their treatment plan. Occupational and physical therapy, which includes strengthening exercises, improving mobility, and preventing falls, are essential in helping patients achieve the best possible results.

Looking after the skin, preventing blood clots (VTE prophylaxis), and keeping the urinary system and bowels working properly are key to avoiding complications such as urinary infections, a blocked bowel, and severe infections (sepsis). Also, problems in these systems can often set off a dangerous condition called autonomic dysreflexia – an abnormal overreaction of the body to certain stimuli. This condition can potentially be prevented if these harmful stimuli can be avoided.