What is Spinal Cord Injuries?
A spinal cord injury (SCI) is a complex condition that can happen when the spinal cord gets damaged directly or indirectly. The primary cause of SCI is acute trauma, such as car accidents, though it can also be brought about by slow-developing causes such as cancer or chronic infection from diseases like tuberculosis. An injury to the spinal cord can lead to permanent disability, severe health complications or even death. Severe spinal injuries often affect heart and lung function and need immediate medical attention.
The disruption to the nerves or axons in the spinal cord can result in loss of motor and sensory function below the point of injury. Young people under 30 are disproportionately affected by SCIs and can experience significant long-lasting physical impairment. The injury can also lead to many health, financial, and mental health problems over their lifetime. In fact, spinal cord injuries are thought to have a projected lifetime economic impact of $2 to 4 billion. Treatment strategies include initial emergency stabilization and advanced therapies like stem cell therapy, which requires a long-term commitment. As such, choosing the right treatment approach is crucial for all healthcare professionals involved in patients’ care.
The spinal cord is like a long cable of nerve fibers stretching from the base of the brain down to the spine. It relays sensory and motor signals between the brain and the rest of the body. The spinal cord is divided into segments that align with the spine’s levels. Each segment branches out into spinal nerves that cater to specific parts of the body. The primary structures within the spinal cord are the corticospinal and spinothalamic tracts and the dorsal columns—these are the main nerve pathways that facilitate communication between the brain and the body.
The corticospinal tract is mainly responsible for voluntary movement. It originates from the motor areas of the brain, passes through the brain stem, and travels down the spinal cord. Most of its fibers run alongside the spinal cord, forming the lateral corticospinal tract. The rest of the fibers make up the ventral corticospinal tract which does not extend to the lower thoracic segments of the spinal cord.
The spinothalamic tract is a sensory pathway that sends pain and temperature signals from the body to the brain. This nerve tract ascends through the front side of the spinal cord and makes a connection in the thalamus before projecting to the brain’s region responsible for receiving and interpreting sensory information.
The dorsal columns, also known as the posterior columns or dorsal funiculi, convey touch, pressure, and vibration sensations from the body to the brain. They ascend in the back area of the spinal cord and consist of the fasciculus gracilis and the fasciculus cuneatus.
The spinal cord is divided into different regions based on their corresponding spine levels. The cervical nerves (C1 to C8) supply the neck, shoulders, arms, and hands. Thoracic nerves (T1 to T12) supply the upper part of the arm’s inner side and the muscles of the trunk and abdomen. Lumbar nerves (L1 to L5) supply the lower back, buttocks and the lower limbs. Sacral nerves (S1 to S5) cater to the pelvic organs, buttocks, genitals, and lower limbs. The coccygeal nerve provides sensations to the skin overlying the tailbone and surrounding areas, as well as facilitating movement of the pelvic floor muscles. The distribution of these nerves is best represented by dermatome maps.
The “cauda equina” refers to the bundle of spinal nerve roots at the end of the spinal cord that appears like a horse’s tail. The “conus medullaris” is the lower end of the spinal cord, which is usually found at the levels of the first and second lumbar vertebrae. The “filum terminale” which extends from the conus medullaris, serves to hold the spinal cord and protective spinal sac in place by attaching it to the tailbone.
Spinal cord injuries can bring about a variety of symptoms, each requiring a different approach for management. For medical professionals to diagnose and manage neurologic conditions affecting movement and sensation, understanding the anatomy and organization of the spinal cord, including the locations of important nerve pathways, is essential.
What Causes Spinal Cord Injuries?
In the United States, the main cause of spinal cord injuries (SCI) is motor vehicle accidents (MVCs), which account for 38% of new injuries each year. Around 30% of these injuries result from falls. Violence causes 13% of the injuries, while sports-related accidents account for 9%. Lastly, 5% of these injuries are due to medical and surgical reasons.
Risk Factors and Frequency for Spinal Cord Injuries
Between 250,000 and 500,000 people worldwide experience spinal cord injuries (SCIs) every year. Most of these injuries are preventable and are often due to violence or motor vehicle crashes. In the United States, there are about 17,000 new cases of SCIs annually, and an estimated 282,000 people are currently living with these injuries. Males are most commonly affected, especially in cases related to sports. The age group at the highest risk for SCIs ranges from 16 to 30 years old.
- Every year, between 250,000 and 500,000 people worldwide experience spinal cord injuries.
- These injuries are mostly preventable, often resulting from violence or car accidents.
- About 17,000 new SCIs occur annually in the U.S., and around 282,000 people are living with these injuries.
- SCIs related to sports mostly happen in males.
- People aged 16 to 30 are at the highest risk for SCIs.
Signs and Symptoms of Spinal Cord Injuries
People with a spinal cord injury (SCI) may experience a severe condition, such as shock or cardiovascular arrest, especially if there’s been a major accident or if the upper part of the spinal cord is affected. To stabilize the patient, immediate action is needed to assess their breathing, heart function, disability and general condition.
SCIs usually happen because of car accidents, falls, sports injuries, or puncture wounds. Patients typically report symptoms like muscle weakness, tingling, or loss of feeling in certain body parts below the injury site. They may also feel pain, which can range from a localized discomfort to radiating pain depending on the severity and location of the injury. Other signs can include difficulty moving limbs, challenges with performing everyday activities, and bladder or bowel incontinence. Shortness of breath or difficulty coughing may happen when the injury involves the neck or chest portion of the spinal cord.
Chronic SCI can develop from ongoing traumatic cord injuries, cancer, or infections. These patients may consistently feel back pain, which can get worse at night or with activities that put weight on the back. Other symptoms can include unexplained weight loss, occasional fever, lack of appetite, and general weakness. The back might feel stiff and movement may be restricted. Feeling unusual sensations like tingling, known as paresthesia, in certain areas can be an early sign. As the condition worsens, motor weakness may develop, followed by difficulty with grip, walking, and bladder and bowel control. High spinal injuries can lead to breathing or heart complications. Risk factors include chronic smoking, previous cancer treatment, migration from tuberculosis-endemic regions, recent surgeries, and a weakened immune system.
During a physical examination, health professionals often find evidence of nervous system issues below the injury site. This can include decreased motor strength, altered sensation, and abnormal reflexes. Patients with acute trauma may display multiple injury signs, such as fractures in the skull and limbs, scrapes, bruises, bleeding, confusion, tenderness in the chest and abdominal area, low blood pressure, and difficulty breathing.
On the contrary, chronic SCI patients may show muscle wasting or shrinkage in paralyzed areas due to lack of use, along with spine deformities like an unusual curve, tenderness, or noticeable bone irregularities. Skin changes, such as redness, blisters, or sores over parts of the bone that are close to the skin due to immobility might be observed. The pattern of injury to the spinal cord depends on the location and extent of the damage.
Testing for Spinal Cord Injuries
Spinal Cord Injuries (SCIs) usually happen due to severe trauma or accidents. When this happens, it’s essential to carry out a thorough examination to identify any other possible injuries. This includes checking how well you can move and feel things – this helps to categorize the type of injury.
We use a system created by the American Spinal Injury Association (ASIA) to determine the extent of SCIs. This system labels injuries from A to E, with A being the most severe and E being normal:
* ASIA A: This is a complete injury which means you’ve lost all your ability to move or sense feelings.
* ASIA B: This is an incomplete injury where you can still feel things but can’t move.
* ASIA C: Another incomplete injury where you can still move parts of your body below the injury point. However, these muscles are quite weak.
* ASIA D: Again, an incomplete injury where you have maintained some motor function and at least half the muscles affected still retain a little strength.
* ASIA E: Normal motor and sensory function.
Imaging, such as X-rays, CT scans, and MRIs are critical for accurately identifying these injuries. On the one hand, you have plain radiographs (X-rays), which have been around for a long time. More recent imaging methods include CT (or CAT scans) and MRIs, which are now more widely used.
CT scans are great for showing possible fractures in more detail than X-rays. They can also highlight potential SCI. However, they might miss minor damaging effects on the soft tissues, in which case, we need better equipment.
And, this is where MRI comes in handy. MRI is better at showing injuries to soft tissues, including SCIs. This method can precisely point to the spot where the SCI is located. MRIs can also help anticipate the future condition of the patient. For instance, they can show particular findings that hint towards specific prognoses. In immediate SCIs, you might observe spinal cord compression, a bruise (contusion), swelling (edema), transection, and bleeding, and bulging of the flavum ligament. As time passes, subacute findings might become visible, including spinal cord swelling, myelopathy, and syrinx.
Situations like disc dislocation or spinal hyperextension often show up as disc herniation, which is visible on an MRI. Here, the disc material, including the soft inner part (nucleus pulposus) and the tough outer layer (annulus fibrosus), gets displaced.
Moreover, we are now beginning to use new forms of MRI, which help us understand the smaller structural characteristics of nerve cells. These aspects include whether the nerve covering (myelin sheath) is intact and if there’s nerve degeneration or regeneration. A type of MRI known as Diffusion tensor tractography, or DTT, recreates significant nerve bundles in 3D. By doing this, DTT helps distinguish between healthy tissues and those with damage or deformation. This provides further insight into the extent of the SCI and aids doctors in planning for future surgical procedures.
Treatment Options for Spinal Cord Injuries
Treatment for acute spinal cord injuries (SCI) begins right at the site of injury, where paramedics and emergency medical staff play a crucial role in ensuring that the patient is stable before transferring them to a suitable healthcare facility. Immobilization, or preventing movement, is essential to avoid worsening any injuries that exist. Any life-threatening injuries or traumas need to be handled immediately. Furthermore, quick action is necessary if the patient is experiencing low blood pressure (hypotension) and shock, as these conditions can worsen the SCI and affect the chances of recovering neurologically. In some cases, immediate surgery may help minimize the injury by stabilizing the spine and relieving any compression caused by a herniated disc, blood clot, or foreign body.
The American Association of Neurological Surgeons and Congress of Neurological Surgeons recommends maintaining a systolic blood pressure of at least 90 mm Hg and a mean arterial pressure around 85 to 90 mm Hg. The aim is to provide sufficient blood flow to the spinal cord to prevent further injury. Steroid administration is a contentious issue in SCI treatment, with some studies suggesting potential benefits, but subsequent research has not confirmed these advantages.
Early intubation, a process of opening the airway through a tube, may be needed for patients with high-level SCI or complete paralysis. If mechanical ventilation is needed for more than 2 weeks, tracheostomy, a surgical hole in the windpipe, may be beneficial.
Patients who cannot empty their bladder (acute urinary retention) may need a urinary or suprapubic catheter, a tube that helps drain urine from the bladder to relieve discomfort. Clean intermittent catheterization, which involves periodically inserting a tube to empty the bladder, can result in fewer issues, such as urinary tract infections, and can facilitate spontaneous voiding. Proper training in clean intermittent catheterization can help patients better tolerate the process.
The Neurocritical Care Society recommends starting treatments to prevent deep vein thrombosis, a blood clot in a deep vein, as soon as possible, and no later than 72 hours after SCI. The Consortium of Spinal Cord Injury recommends using low-molecular-weight heparin, a blood thinner, but a daily check for bleeding risks is important. Enoxaparin is found to be superior to regular heparin in preventing pulmonary embolism, a dangerous lung condition, in patients with SCIs.
People with SCIs usually receive the best care in neurological intensive care units, where staff members are skilled in managing such injuries. Extensive physical rehabilitation therapy, led by physiatrists, physical therapists, and occupational therapists, can significantly improve patient outcomes.
Several medical interventions attempted for SCI, using medications such as nimodipine, gacyclidine, thyrotropin-releasing hormone, minocycline, etc., have not shown significant positive results. As of now, the primary treatment for acute SCI continues to be high-dose steroids.
Stem cell therapies for SCIs can include supportive and loading therapies. Supportive therapy uses nonneural stem cells from bone marrow, umbilical cord, and body fat. These cells release healing factors but have limited ability to regenerate nervous system cells. Loading therapy, on the other hand, employs stem cells capable of producing neural cells, offering a greater chance of replacing lost nerve cells, though it involves more complex processes.
For chronic SCIs, treatment depends on the cause of the injury. It needs to address both the neurological deficits and the primary disorder causing the deficits. Potential complications like pressure ulcers, secondary bacterial infection, and urinary dysfunction must be managed. Rehabilitation and comprehensive care play a key role in improving the quality of life and functional outcomes for people with chronic SCI.
What else can Spinal Cord Injuries be?
Typically, spinal cord injuries (SCIs) are diagnosed based on a patient’s experience, which often includes a history of trauma. However, if the condition’s onset and preceding events are unclear, the doctor must consider other possible causes of the symptoms, especially for weakened sensorimotor skills. They should include the following conditions in their differential diagnosis or list of potential causes:
- Central Nervous System Pathologies:
- Stroke
- Post-seizure paralysis (also known as Todd’s paralysis)
- Migraine that causes one-sided paralysis (Hemiplegic migraine)
- Multiple sclerosis
- Peripheral Nerve Pathologies:
- Guillain-Barré syndrome
- Transverse myelitis
- Paralysis caused by ticks
- Neuromuscular Junction Pathologies:
- Myasthenia gravis
- Poisoning by organophosphates
- Botulism
- Other Pathologies:
- Low blood sugar (Hypoglycemia)
- Periodic paralysis due to low potassium levels (Hypokalemic periodic paralysis)
- Low calcium levels (Hypocalcemia)
- Nerve damage caused by diabetes (Diabetic neuropathy)
- A mental condition where a person has blindness or other neurologic symptoms that cannot be explained by medical evaluation (Conversion disorder)
To rule out these conditions and accurately diagnose SCI, doctors will need to conduct a careful clinical examination and use diagnostic tests wisely.
What to expect with Spinal Cord Injuries
The prognosis, or outlook, for spinal cord injuries (SCI) is sadly not very good. None of the current treatments can lead to a full recovery. Less than 1% of people with spinal cord injuries regain their full function before they leave the hospital. The disability a person experiences directly relates to the level of injury. In simple terms, the higher up the injury on the spinal cord, the more disability a person may have and the more complications they might experience.
People with acute, or sudden, spinal cord injuries also have a significant increase in their risk of mortality, or death, in the first year after the injury. Those who survive the first year oftentimes have a shorter lifespan. Only 12% of people are able to get a job after their injury, and less than half get married.
For chronic, or long-term spinal cord injuries, the outlook depends on things like the severity of the injury, how quickly they get treatment, and the underlying cause of the injury. People who have complications due to delayed treatment or who have a severe underlying reason for their spinal cord injury usually have a worse outlook.
Possible Complications When Diagnosed with Spinal Cord Injuries
Spinal cord injuries can lead to several problems. These include urinary tract infections (UTIs), pressure sores, deep vein thrombosis (DVT), autonomic dysreflexia, and chronic pain. Autonomic dysreflexia is a condition that affects people with spinal cord injuries at or above the T6 level. It can often cause symptoms of orthostatic hypotension, which means low blood pressure when standing up.
These symptoms can be tough to manage. However, some options include using abdominal binders, elastic stockings, certain medications like midodrine and fludrocortisone, and increasing salt intake. These solutions can help control symptoms by expanding blood volume.
Consequently, spinal cord injuries can incur substantial indirect costs. These include lack of mobility, being unable to work, and putting a heavy load on caregivers.
The most common causes of death from spinal cord injuries are pneumonia and sepsis.
Simplified breakdown:
- Potential complications of spinal cord injuries
- Urinary tract infections
- Pressure sores
- Deep vein thrombosis
- Chronic pain
- Autonomic dysreflexia
- Orthostatic hypotension symptoms
- Solutions include medications, abdominal binders, elastic stockings and increased salt intake
- Indirect costs, such as lost mobility
- Inability to work
- Heavy burden on caregivers
- Common causes of death: pneumonia and sepsis
Preventing Spinal Cord Injuries
Preventing Spinal Cord Injuries (SCIs) primarily involves spreading awareness about factors that could cause such damage. These can include car accidents or falls. It’s also important to foster a culture of safety, for example, always ensuring to wear seatbelts and helmets. Part of this involves advocating for laws that uphold these safety standards. Altering our environment to be more secure, such as by adding handrails or improving lighting, can also help prevent accidents at places like parks, offices, and homes. In a broader perspective, centers that focus on accident prevention help reduce factors that lead to serious physical injuries. They work to improve car safety, gun control, and also put in place programs to prevent violence. Stopping smoking, maintaining workplace safety, and having regular health check-ups can also reduce the risk of SCIs becoming a chronic condition.
Secondary measures to prevent SCIs involve getting immediate medical care andproperly securing the spine after an injury to stop the condition from getting worse. Educating patients is a crucial part of clinical care. This includes discussions about what to expect in the future, possible complications, and the likely results of the injury. Patients should start rehabilitation programs, like physical and occupational therapy, early. This can help regain function and reduce potential disability.
Regular health check-ups, proactive management of complications such as bed sores and urinary track infections (UTIs), access to assistive devices, and strong support networks can improve movement, self-sufficiency, and overall happiness for people with SCIs. Support groups are also beneficial for dealing with social and emotional issues like anxiety, frustrations, feeling alone, and depression. This guarantees that patients receive the holistic support and guidance they need throughout their SCI experience. By implementing these preventative steps, healthcare professionals and communities can work together to reduce the rate and severity of SCIs. This ultimately improves the safety and quality of life for those affected.
