Continuing Education Activity

A spinal cord injury is a potentially crippling injury which often results in severe and permanent disability. Quite often when encountering multi-system trauma in a patient, the presence of spinal injury should be highly suspected. Moreover, up to 5% of patients with a head injury may also have an associated spinal injury, making it an injury with a need for time-sensitive intervention. Spinal cord injury involves various levels of the spine. The annual incidence of spinal cord injury is approximately 40 cases per million population. Adolescent boys are at highest risk for injuries. The non-accidental injury is an underreported mechanism; therefore, the true incidence of spinal injuries is underestimated. Amongst the various levels of injuries, cervical spine injuries are rare in children and occur in less than 1% of these patients due to underlying anatomical differences compared to adults. This activity examines when this condition should be considered in differential diagnosis and how to properly evaluate it. This activity highlights the role of the interprofessional team in caring for pediatric patients with spinal trauma.

Objectives:

• Describe the various type of spine injuries, most notably fractures, in light of pre-disposing factors inherent in pediatric patients.
• Summarize the diagnostic approach and evaluation criteria for potential spinal trauma in the pediatric population.
• Outline the treatment options for spinal injuries in pediatric patients based on injury type.
• Explain some possible interprofessional team strategies for improving care coordination and communication to advance the evaluation and treatment of spinal injuries in the pediatric population and improve outcomes.

Introduction

A spinal cord injury is a potentially crippling injury which often results in severe and permanent disability. Quite often when we encounter multi-system trauma in a patient, the presence of spinal injury should be highly suspected. Moreover, up to 5% of patients with a head injury may also have an associated spinal injury, making it an injury with a need for time-sensitive intervention. Spinal cord injury involves various levels of the spine. The rates of incidence are cervical (55%), thoracic (15%), the thoracolumbar junction (15%), and lumbosacral region (15%).[1][2][3][4][5]

Etiology

The etiology for spinal cord injuries is varied and most spinal injuries are due to blunt trauma. Motor vehicle accidents are a leading cause of spinal cord injury followed by falls particularly in children younger than eight years of age and in the elderly population). With advancing age, sports-related injuries become more common. Firearm injuries and other forms of violence in adolescents and young adults may also result in spinal cord injuries. Additionally, newborns additionally sustain birth injuries.[6][7]

Epidemiology

The annual incidence of spinal cord injury is approximately 40 cases per million population. Adolescent boys are at highest risk for injuries. The non-accidental injury is an underreported mechanism; therefore, the true incidence of spinal injuries is underestimated. Amongst the various levels of injuries, cervical spine injuries are rare in children and occur in less than 1% of these patients due to underlying anatomical differences compared to adults.

Pathophysiology

The pathophysiology of injury varies markedly in children compared to adults. Children differ from adults with respect to spinal cord anatomy as follows:

• Children have a different fulcrum due to a large head
• Children's vertebra is incompletely ossified
• Their ligaments are firmly attached to articular bone surfaces that are more horizontal.

Thus, the younger the age, the more flexible the spine is. Hence neural damage occurs in children much earlier than musculoskeletal injury. As age increases the likelihood of cervical cord injury decreases with up to 75% of injuries occurring in infancy up to 8 years old because the fulcrum of cervical mobility moves progressively downward with the child’s increasing age.

• Younger than eight years: C1 and C3
• Eight to 12 years: C3 and C5
• Older than 12 years: C5 and C6

The mode of injury occurrence can be classified as primary and secondary. Primary injury results from mechanical forces directly due to traumatic impact. Secondary injury occurs due to various vascular and chemical processes resulting from a primary injury.

Before one evaluates a patient, a basic review of spinal cord anatomy can yield a rapid diagnosis. The three most important tracts in the spinal cord are corticospinal tracts, spinothalamic tracts, and dorsal (posterior) columns.

The corticospinal tract is a descending motor pathway. Damage involving this tract causes ipsilateral clinical findings including muscle weakness, spasticity, increased deep tendon reflexes, and Babinski sign.

The spinothalamic tract is an ascending pathway that transmits pain and temperature sensation. Damage to this tract results in loss of pain and temperature sensation on the opposite side of the body.

The dorsal columns are also descending motor pathways which transmit vibration and proprioception. Damage to one side of the dorsal columns causes ipsilateral loss of vibration and position sensation. A light touch is transmitted by both the spinothalamic tracts and the dorsal columns. Therefore, a light touch is preserved to some extent unless there is involvement of both the spinothalamic tracts and the dorsal columns. 

History and Physical

It is the severity of spinal cord injury which determines the prognosis for recovery of function. The American Spinal Injury Association classifies spinal cord injury into complete spinal cord injury which includes the complete absence of sensory and motor function below the level of injury, and incomplete spinal cord injury in which a patient has partial sensory function, motor function, or both below the neurologic level of the injury. However, this distinction may not be possible to make until spinal shock has resolved, as patients in spinal shock may lose all reflexes below the area of injury. While a physician entertains a diagnosis of spinal cord injury, the following history and physical exam findings are pertinent to explore.[8][9]

History

• The presence of midline pain
• A distracting injury that may take attention from the spinal area, for example, a rapidly bleeding open fracture
• Paresthesias, the older the child, the more likely the child will report these symptoms
• Loss of consciousness may indicate head trauma, but one must not be distracted in ruling out concomitant spinal cord injury
• Urinary or fecal incontinence indicate lower spinal level injury

Physical Examination

• Determine the mental status using the Glasgow coma scale
• Attempt to delineate the level of the spinal cord injury or level of sensory loss
• Test for proprioception or vibratory function to examine posterior column function
• The anogenital reflexes should be tested. If anogenital reflexes are preserved, an incomplete spinal cord injury is suspected despite complete sensory and motor loss. This evaluation should include bulbocavernosus reflex, anal wink reflex, cremasteric reflex, and rectal tone
• A careful evaluation of the entire spine should be performed even if a cervical injury is detected early
• It is important to perform a serial neurologic examination to document neurologic improvement or deterioration in patients with suspected or diagnosed spinal injuries
• Beware that children with cervical and high thoracic spinal cord injuries are also at risk for respiratory failure and neurogenic shock.

The following are incomplete spinal cord syndromes which have typical presentations.

Central cord syndrome is the most common incomplete spinal cord injury which manifests as symmetric incomplete quadriparesis. There is disproportionately greater motor impairment in upper compared to lower extremities, bladder dysfunction, and a variable degree of sensory loss below the level of injury. The typical mechanism is hyperextension injury. The hallmark of this condition is greater damage to the middle portion of the cord than to the periphery. It may be related to the somatotopic organization of the corticospinal tract within the spinal cord. The lamination of the corticospinal tract is organized with the most lateral being the sacral components and advancing medially with the lumbar, thoracic, and cervical components toward the central spinal canal. Professionals believe that injury seen in central cord syndrome predominantly involves white matter.

Anterior cord syndrome is characterized by complete motor paralysis and loss of pain and temperature sensation, with sparing of proprioception and vibration sensation. However, the motor loss is greater in the lower extremities than the upper extremities. The typical mechanism is hyperflexion and axial loading. In this scenario, damage primarily involves the anterior two-thirds of the spinal cord and therefore affects the corticospinal tract and spinothalamic tracts. This damage results in motor paralysis and loss of pain and temperature sensation. Proprioception and vibration are spared because the posterior third of the spinal cord containing the dorsal columns is not involved. This condition has a poor prognosis with only 10% to 15% of patients demonstrating functional recovery.

Brown-Séquard syndrome is characterized by ipsilateral hemiplegia, ipsilateral loss of proprioception, and contralateral loss of pain and temperature. This syndrome usually occurs due to penetrating trauma resulting in physiologic hemisection of the spinal cord. This injury affects the lateral half of the cord and frequently occurs in the cervical spine. This causes damage to the fibers within the descending lateral corticospinal tracts and the ascending dorsal columns. They both decussate in the medulla, resulting in ipsilateral hemiplegia and ipsilateral loss of proprioception, respectively.

Posterior spinal cord syndrome is a type of injury in which there is a preservation of motor function, pain, and temperature, but proprioception and vibration sensations are lost below the level of the injury. The posterior portion of the spinal cord can be damaged either by direct trauma or because of a secondary injury involving the posterior spinal arteries. This syndrome is linked to injuries associated with hyperextension of the neck. Patients with this injury may ambulate, but since they lose proprioception and vibratory sensations, direct visualization of their feet is required during walking. Therefore, they may not be able to ambulate in the dark.

Cauda equina syndrome. Since cauda equina contains lumbar, sacral, and coccygeal nerve roots, injury to cauda equina causes peripheral nerve injuries. Although it is not a direct spinal cord injury, this entity still requires emergency neurosurgical intervention. The following clinical features may be present: bowel and/or bladder dysfunction, decreased rectal tone, asymmetric sensory loss in the lower extremities, weakness of the lower extremities, decreased lower extremity reflexes, and saddle anesthesia, which is characterized by sensory deficit over the perineum, buttocks, and inner thigh.

Spinal shock is the temporary loss of spinal reflex activity with motor and sensory losses. This loss results from loss of sympathetic vascular tone resulting in paradoxical bradycardia with hypotension. During spinal shock, patients appear physiologically completely paralyzed but may show significant recovery after the initial phases of spinal shock have resolved. 

Evaluation

Following are the investigations to pertinent for aiding in the diagnosis of spinal cord injury.[1][10][11][12][13]

Plain radiographs

In alert patients, three views, the lateral, anterior-posterior, and odontoid, of the cervical spine can be obtained. An adequate lateral cervical spine x-ray should include all seven cervical vertebrae and the superior border of the first thoracic vertebra. An adequate lateral cervical spine film may identify up to 90% of bony injuries. Since physical examination is not adequate for the detection of cervical spine injuries, decision rules can be used to decide when to obtain imaging.

National Emergency X-Radiography Utilization Study (NEXUS)

NEXUS includes five clinical criteria which determine whether cervical spine imaging is warranted. If the following are present, imaging may not be necessary:

1. The absence of midline cervical tenderness.
2. A normal level of consciousness.
3. No evidence of intoxication
4. Absence of focal neurologic deficit
5. Absence of distracting injury.

Although there is no validated prediction rule for cervical spine imaging in children, certain factors that warrant imaging are:

• Altered mental status
• Focal neurologic finding
• Neck pain, torticollis 
• Significant torso injury 
• Condition predisposing to spinal cord injury (Down syndrome, Klippel-Feil syndrome)
• Diving, high-risk mechanisms such as acceleration or deceleration injury.

If the initial radiographs are inconclusive, the spine should remain immobilized until the practitioner reliably excludes injuries.

CT Scan

The CT scan is more sensitive and specific for evaluating the cervical spine, particularly at the craniocervical and cervicothoracic junctions, where the sensitivity of plain films is limited. The scan should be obtained in unconscious patients with significant blunt trauma; however, it is not clear whether a negative CT scan in an unconscious patient is adequate or a subsequent MRI should be obtained.

Beware that an absence of radiographic abnormality cannot exclude injury, particularly in children. In children younger than eight years of age, stretching of the spinal cord can cause spinal cord injury without radiographic abnormality (SCIWORA). This may be due to the horizontal orientation of the facet joints and elastic type of intervertebral ligaments. This may cause upper cervical spinal elements to shift rather than break when force is applied.

Treatment / Management

Prehospital

The important goals in the prehospital setting are as follows:

• Recognition of patients who are at risk for spinal cord injury. 
• Cervical spine immobilization. 
• Triage to an appropriate facility.

Emergency Department

The important goals in the emergency department setting are as follows:

• Every resuscitation should begin with ABCDE
• Airway maintenance with cervical spine protection
• Breathing and ventilation
• Circulation with hemorrhage control
• Disability (Neurologic evaluation)
• Exposure (Environmental control).

The priority is to protect the airway. Beware that the higher the level of spinal injury, the greater the chance that early airway intervention will be required. Lesions above C3 have a potential for immediate respiratory arrest. Also, lesions involving C3 to C5 can influence the phrenic nerve and diaphragm function. Therefore, early endotracheal intubation should be considered if an injury at or above C5 is present. During intubation, in-line spinal stabilization should be maintained. Monitor vital signs including heart rate, blood pressure, respiratory status, and temperature. Capnography may be useful to monitor respiratory status, particularly in the emergency department.

If hypotension is present in patients with spinal cord injury, neurogenic shock should be suspected. Hypotension and relative bradycardia are typical manifestations. However, blood loss should be suspected if hypotension is present in spinal injury patients until proven otherwise. Remember that a systolic blood pressure less than 80 mmHg is rarely due to neurogenic shock alone. A careful evaluation should be performed to search for the source of bleeding even if a spinal cord injury is present. Also, hemorrhagic shock may co-exist with neurogenic shock.

Other Considerations

Corticosteroid Use

Practitioners have treated patients with blunt spinal cord injuries with high-dose methylprednisolone. In the National Acute Spinal Cord Injury Study (NASCIS), improved neurologic function was demonstrated in patients who received high-dose corticosteroids within eight hours of injury. A loading dose of 30 mg/kg of methylprednisolone was administered over a 15-minute period. This was followed by an infusion of 5.4 mg/kg/hr and continued for 24 hours in patients treated within three hours of injury, or 48 hours in patients treated three to eight hours after injury. No benefit was demonstrated when steroids were administered eight hours or more after injury. It is not indicated for penetrating injuries. It is not adequately studied in children under 13 years of age. Risks associated with steroid use are as follows:

• Gastrointestinal hemorrhage
• Wound infection
• Severe sepsis
• Severe pneumonia.

Differential Diagnosis

• Acute torticollis 

• Cauda equina and conus medullaris syndromes

• Cervical strain

• Hanging injuries and strangulation 

• Neck trauma

• Septic shock

• Spinal cord infections

• Spinal cord injuries 

• Spinal cord neoplasms

• Thoracic outlet syndrome imaging

Pearls and Other Issues

Neurological injury is known to have a better prognosis in children when compared to adults. Incomplete lesions have a better prognosis compared to complete lesions. Ten percent to 25% of patients recover after complete spinal cord injuries. Sixty-four percent showed partial recovery.

Enhancing Healthcare Team Outcomes

The mmanagement of pediatric spinal trauma is with an interprofessional team that includes a trauma surgeon, emergency department physician, nurse practitioner, neurologist, neurosurgeon, orthopedic surgeon and an intensivist. The initial steps include following the ATLS protocol and then assessing the patient for any secondary injuries. Once spinal trauma has been diagnosed, the majority of patients are treated with supportive care. The outlook of children is signficantly better than in adults but the recovery can be prolonged. Those with severe neurological deficits at presentation may have residual deficits evern after full recovery.[14][15]