SPINE AND SPINAL CORD TRAUMA

ADNAN ALI
BS EMERGENCY CARE TECHNOLOGY(KMU)
Spine injury, with or without neurological deficits, must always be considered in
patients with multiple injuries. Approximately 5% of patients with brain injury have
an associated spinal injury, whereas 25% of patients with spinal injury have at least
a mild brain injury. Approximately 55% of spinal injuries occur in the cervical
region, 15% in the thoracic region, 15% at the thoracolumbar junction, and 15% in
the lumbosacral area. Up to 10% of patients with a cervical spine fracture have a
second, noncontiguous vertebral column fracture.
In patients with potential spine injuries, excessive manipulation and inadequate
restriction of spinal motion can cause additional neurological damage and worsen
the patient’s outcome. At least 5% of patients with spine injury experience the
onset of neurological symptoms or a worsening of preexisting symptoms after
reaching the emergency department (ED). These complications are typically due to
ischemia or progression of spinal cord edema, but they can also result from
excessive movement of the spine. If the patient’s spine is protected, evaluation of the spine
and exclusion of spinal injury can be safely deferred, especially in the presence of systemic
instability, such as hypotension and respiratory inadequacy. Spinal protection does not require
patients to spend hours on a long spine board; lying supine on a firm surface and utilizing spinal
precautions when moving is sufficient.
Excluding the presence of a spinal injury can be straightforward in patients without
neurological deficit, pain or tenderness along the spine, evidence of intoxication, or
additional painful injuries. In this case, the absence of pain or tenderness along the
spine virtually excludes the presence of a significant spinal injury. The possibility of
cervical spine injuries may be eliminated based on clinical tools
However, in other patients, such as those who are comatose or have a depressed
level of consciousness, the process of evaluating for spine injury is more
complicated. In this case, the clinician needs to obtain the appropriate radiographic
imaging to exclude a spinal injury. If the images are inconclusive, restrict motion of
the spine until further testing can be performed. Remember, the presence of a
cervical collar and backboard can provide a false sense of security that movement
of the spine is restricted. If the patient is not correctly secured to the board and the
collar is not properly fitted, motion is still possible
Although the dangers of excessive spinal motion have been well documented,
prolonged positioning of patients on a hard backboard and with a hard cervical
collar (c-collar) can also be hazardous. In addition to causing severe discomfort in
conscious patients, serious decubitus ulcers can form, and respiratory compromise
can result from prolonged use. Therefore, long backboards should be used only
during patient transportation, and every effort should be made to remove patients
from spine boards as quickly as possible.
Anatomy and Physiology
The following review of the anatomy and physiology of the spine and spinal cord
includes the spinal column, spinal cord anatomy, dermatomes, myotomes, the
differences between neurogenic and spinal shock, and the effects of spine injury on
other organ systems.
Spinal Column
The spinal column consists of 7 cervical, 12 thoracic, and 5 lumbar vertebrae, as
well as the sacrum and coccyx. The cervical spine, because of its mobility and
exposure, is the most vulnerable part of the spine to injury.
The cervical canal is wide from the foramen magnum to the lower part of C2. Most
patients with injuries at this level who survive are neurologically intact on arrival to
the hospital. However, approximately one-third of patients with upper cervical
spine injuries (i.e., injury above C3) die at the scene from apnea caused by loss of
central innervation of the phrenic nerves.
Below the level of C3, the spinal canal diameter is much smaller relative to the
spinal cord diameter, and vertebral column injuries are much more likely to cause
spinal cord injuries.
Thoracic spine mobility is much more restricted than cervical spine mobility, and
the thoracic spine has additional support from the rib cage.
Hence, the incidence of thoracic fractures is much lower. Most thoracic spine
fractures are wedge compression fractures that are not associated with spinal cord
injury. However, when a fracture-dislocation in the thoracic spine does occur, it
almost always results in a complete spinal cord injury because of the relatively
narrow thoracic canal.
The thoracolumbar junction is a fulcrum between the inflexible thoracic region and
the more mobile lumbar levels. This makes it more vulnerable to injury, and 15% of
all spinal injuries occur in this region.
Spinal Cord Anatomy
The spinal cord originates at the caudal end of the medulla oblongata at the
foramen magnum. In adults, it usually ends near the L1 bony level as the conus
medullaris.
When a patient has no demonstrable sensory or motor function below a certain
level, he or she is said to have a complete spinal cord injury. An incomplete spinal
cord injury is one in which some degree of motor or sensory function remains; in
this case, the prognosis for recovery is significantly better than that for complete
spinal cord injury
Dermatomes
A dermatome is the area of skin innervated by the sensory axons within a
particular segmental nerve root.
Myotomes
Each segmental nerve root innervates more than one muscle, and most muscles
are innervated by more than one root (usually two).
Neurogenic Shock versus Spinal Shock
Neurogenic shock results in the loss of vasomotor tone and sympathetic
innervation to the heart. Injury to the cervical or upper thoracic spinal cord (T6 and
above) can cause impairment of the descending sympathetic pathways. The
resultant loss of vasomotor tone causes vasodilation of visceral and peripheral
blood vessels, pooling of blood, and, consequently, hypotension. Loss of
sympathetic innervation to the heart can cause bradycardia or at least the inability
to mount a tachycardic response to hypovolemia. However, when shock is present,
it is still necessary to rule out other sources because hypovolemic (hemorrhagic)
shock is the most common type of shock in trauma patients and can be present in
addition to neurogenic shock.
The physiologic effects of neurogenic shock are not reversed with fluid
resuscitation alone, and massive resuscitation can result in fluid overload and/ or
pulmonary edema. Judicious use of vasopressors may be required after moderate
volume replacement, and atropine may be used to counteract hemodynamically
significant bradycardia.
Spinal shock refers to the flaccidity (loss of muscle tone) and loss of reflexes that
occur immediately after spinal cord injury.
Effects of Spine Injury on Other Organ Systems
When a patient’s spine is injured, the primary concern should be potential
respiratory failure. Hypoventilation can occur from paralysis of the intercostal
muscles (i.e., injury to the lower cervical or upper thoracic spinal cord) or the
diaphragm (i.e., injury to C3 to C5).
Documentation of Spinal Cord Injuries
Spinal cord injuries can be classified according to level, severity of neurological
deficit, spinal cord syndromes, and morphology.
Level
The bony level of injury refers to the specific vertebral level at which bony damage
has occurred. The neurological level of injury describes the most caudal segment of
the spinal cord that has normal sensory and motor function on both sides of the
body. The neurological level of injury is determined primarily by clinical
examination. The term sensory level is used when referring to the most caudal
segment of the spinal cord with normal sensory function. The motor level is
defined similarly with respect to motor function as the lowest key muscle that has
a muscle-strength grade of at least 3 on a 6-point scale. The zone of partial
preservation is the area just below the injury level where some impaired sensory
and/or motor function is found.
Frequently, there is a discrepancy between the bony and neurological levels of
injury because the spinal nerves enter the spinal canal through the foramina and
ascend or descend inside the spinal canal before actually entering the spinal cord.
Determining the level of injury on both sides is important.
Severity of Neurological Deficit
Spinal cord injury can be categorized as:
• Incomplete or complete paraplegia (thoracic injury) • Incomplete or complete
quadriplegia/ tetraplegia (cervical injury)
Any motor or sensory function below the injury level constitutes an incomplete
injury and should be documented appropriately. Signs of an incomplete injury
include any sensation (including position sense) or voluntary movement in the
lower extremities, sacral sparing, voluntary anal sphincter contraction, and
voluntary toe flexion. Sacral reflexes, such as the bulbocavernosus reflex or anal
wink, do not qualify as sacral sparing.
Spinal Cord Syndromes
Characteristic patterns of neurological injury are encountered in patients with
spinal cord injuries, such as central cord syndrome, anterior cord syndrome, and
Brown-Séquard syndrome. It is helpful to recognize these patterns, as their
prognoses differ from complete and incomplete spinal cord injuries.
Central cord syndrome is characterized by a disproportionately greater loss of
motor strength in the upper extremities than in the lower extremities, with varying
degrees of sensory loss. This syndrome typically occurs after a hyperextension
injury in a patient with preexisting cervical canal stenosis. The mechanism is
commonly that of a forward fall resulting in a facial impact. Central cord syndrome
can occur with or without cervical spine fracture or dislocation. The prognosis for
recovery in central cord injuries is somewhat better than with other incomplete
injuries. These injuries are frequently found in patients, especially the elderly, who
have underlying spinal stenosis and suffer a ground-level fall.
Anterior cord syndrome results from injury to the motor and sensory pathways in
the anterior part of the cord. It is characterized by paraplegia and a bilateral loss of
pain and temperature sensation. However, sensation from the intact dorsal column
(i.e., position, vibration, and deep pressure sense) is preserved. This syndrome has
the poorest prognosis of the incomplete injuries and occurs most commonly
following cord ischemia.
Brown-Séquard syndrome results from hemisection of the cord, usually due to a
penetrating trauma. In its pure form, the syndrome consists of ipsilateral motor
loss (corticospinal tract) and loss of position sense (dorsal column), associated with
contralateral loss of pain and temperature sensation beginning one to two levels
below the level of injury (spino-thalamic tract). Even when the syndrome is caused
by a direct penetrating injury to the cord, some recovery is usually achieved.
Morphology
Spinal injuries can be described as fractures, fracture dislocations, spinal cord injury
without radiographic abnormalities , and penetrating injuries. Each of these
categories can be further described as stable or unstable. However, determining
the stability of a particular type of injury is not always simple and, indeed, even
experts may disagree. Particularly during the initial treatment, all patients with
radiographic evidence of injury and all those with neurological deficits should be
considered to have an unstable spinal injury. Spinal motion of these patients should
be restricted, and turning and/or repositioning requires adequate personnel using
logrolling technique until consultation with a specialist, typically a neurosurgeon or
orthopedic surgeon.
Specific Types of Spinal Injuries
Spinal injuries of particular concern to clinicians in the trauma setting include
cervical spine fractures, thoracic spine fractures, thoracolumbar junction fractures,
lumbar fractures, penetrating injuries, and the potential for associated blunt
carotid and vertebral vascular injuries.
Cervical Spine Fractures
Cervical spine injuries can result from one or a combination of the following
mechanisms of injury: axial loading, flexion, extension, rotation, lateral bending,
and distraction. Cervical spine injury in children is a relatively rare event, occurring
in less than 1% of cases. Of note, upper cervical spine injuries in children (C1–C4)
are almost twice as common as lower cervical spine injuries. Additionally,
anatomical differences, emotional distress, and inability to communicate make
evaluation of the spine even more challenging in this population.
Specific types of cervical spine injuries of note to clinicians in the trauma setting
are atlanto-occipital dislocation, atlas (C1) fracture, C1 rotary subluxation, and axis
Thoracic Spine Fractures
Thoracic spine fractures may be classified into four broad categories: anterior
wedge compression injuries, burst injuries, Chance fractures, and fracture-
dislocations. Axial loading with flexion produces an anterior wedge compression
injury. The amount of wedging usually is quite minor, and the anterior portion of
the vertebral body rarely is more than 25% shorter than the posterior body. Due to
the rigidity of the rib cage, most of these fractures are stable.
Burst injury is caused by vertical-axial compression.
Chance fractures are transverse fractures through the vertebral body. They are
caused by flexion about an axis anterior to the vertebral column and are most
frequently seen following motor vehicle crashes in which the patient was
restrained by only an improperly placed lap belt. Chance fractures can be
associated with retroperitoneal and abdominal visceral injuries.
Due to the orientation of the facet joints, fracturedislocations are relatively
uncommon in the thoracic and lumbar spine. These injuries nearly always result
from extreme flexion or severe blunt trauma to the spine, which causes disruption
of the posterior elements (pedicles, facets, and lamina) of the vertebra. The
thoracic spinal canal is narrow in relation to the spinal cord, so fracture
subluxations inthe thoracic spine commonly result in complete neurological
deficits.
Thoracolumbar Junction Fractures
Fractures at the level of the thoracolumbar junction are due to the immobility of
the thoracic spine compared with the lumbar spine. Because these fractures most
often result from a combination of acute hyperflexion and rotation, they are
usually unstable. People who fall from a height and restrained drivers who sustain
severe flexion with high kinetic energy transfer are at particular risk for this type of
injury.
The spinal cord terminates as the conus medullaris at approximately the level of L1,
and injury to this part of the cord commonly results in bladder and bowel
dysfunction, as well as decreased sensation and strength in the lower extremities.
Patients with thoracolumbar fractures are particularly vulnerable to rotational
movement, so be extremely careful when logrolling them.
Lumbar Fractures
The radiographic signs associated with a lumbar fracture are similar to those of
thoracic and thoracolumbar fractures. However, because only the cauda equina is
involved, the probability of a complete neurological deficit is much lower with
these injuries.
Penetrating Injuries
Penetrating injuries often result in a complete neurological deficit due to the path
of the missile involved (most often a bullet or knife). These deficits also can result
from the energy transfer associated with a highvelocity missile (e.g., bullet) passing
close to the spinal cord rather than through it. Penetrating injuries of the spine
usually are stable unless the missile destroys a significant portion of the vertebra.
General management
General management of spine and spinal cord trauma includes restricting spinal
motion, intravenous fluids, medications, and transfer
Thanks