Spinal Trauma Flashcards

1
Q

Pre-dental space

A

Transverse ligament rupture without an associated fracture can occur in older patients from a direct blow to the occiput. Radiographic diagnosis relies on measuring the predental space, which is the space between the posterior aspect of the anterior arch of C1 and the anterior border of the odontoid. A predental space of >3 mm on a lateral radiograph (2 mm for CT images) implies damage to the transverse ligament; >5 mm implies rupture of the transverse ligament.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Flexion teardrop fracture

A

(highly unstable) Extreme hyperflexion causes complete disruption of the spinal ligaments at the level of injury. The “teardrop” is the anteroinferior portion of the vertebral body that is separated and displaced from the vertebral body by the anterior spinal ligament. “Fanning” of the spinous processes may be present, with or without fracture. A sagittal fracture through the vertebral body may be seen on CT. Anterior spinal cord syndrome is associated with this injury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Unilateral facet dislocation

A

(stable unless associated with an articular mass fracture)

mechasim: Flexion-rotation

A unilateral facet dislocation occurs when the articular mass and inferior facet on one side of the vertebra are anteriorly dislocated. On a lateral radiograph, the involved vertebral body will be displaced <50% of its width. On the anterior view, the spinous process at the level of the rotation will be pointing toward the side that is dislocated.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Jefferson burst fracture of atlas

A

(potentially unstable)

Mechanism: vertical compression

[Reproduced with permission from Block J, Jordanov MI, Stack LB, Thurman RJ (eds): The Atlas of Emergency Radiology. McGraw-Hill, Inc., 2013. Fig 11-13.]

Vertical compression forces the occipital condyles downward and produces a burst fracture by driving the lateral masses of C1 apart. This is best seen as outward displacement of the lateral masses on the open-mouth odontoid radiograph or on CT. If displacement of both lateral masses (measured as offset from the superior corner of the C2 vertebral body on each side) is >7 mm when added together, rupture of the transverse ligament is likely, and the spine is unstable.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Traumatic spondylolisthesis (hangman’s fracture)

A

(unstable)

The hangman’s fracture is a fracture of both pedicles of C2, with the anterior displacement of C2 on C3. This was associated with the neck hyperextension from judicial hangings, where the noose knot is placed under the subject’s chin and snaps the head backward. Suicidal hangings do not usually cause extreme hyperextension and are not associated with the hangman’s fracture. Because the spinal canal at the level of C2 is large, a hangman’s fracture does not cause neurologic injury.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Odontoid (dens) fractures

A

(type II and III are unstable)

Frequently involves other injuries to the cervical spine and multisystem trauma. Conscious patients will usually describe immediate and severe high cervical pain with muscle spasm. The pain may radiate to the occiput. Neurologic injury is present in 18% to 25% of cases with odontoid fractures, ranging from minimal sensory or motor loss to quadriplegia. Odontoid fractures are classified according to the level of injury. CT can miss odontoid fractures if the fracture line is aligned with the cut of the CT (en face).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Primary vs Secondary Spinal Cord Injury

A

Damage to the spinal cord is the result of two types of injury. First is the primary injury from mechanical forces from traumatic impact. This insult sets into motion a series of vascular and chemical processes that lead to secondary injury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Complete vs Incomplete Injury and Spinal Shock

A

The severity of spinal cord injury determines the prognosis for recovery of function, so it is important to distinguish between complete and incomplete spinal cord injuries.

The American Spinal Injury Association defines a complete neurologic lesion as the absence of sensory and motor function below the level of injury. This includes loss of function to the level of the lowest sacral segment. In contrast, a lesion is incomplete if sensory, motor, or both functions are partially present below the neurologic level of injury. This may consist only of sacral sensation at the anal mucocutaneous junction or voluntary contraction of the external anal sphincter upon digital examination.

Complete lesions have a minimal chance of functional motor recovery. Patients with incomplete lesions are expected to have at least some degree of recovery. The differentiation between complete and incomplete spinal cord damage may be complicated by the presence of spinal shock.

Patients in spinal shock lose all reflex activities below the area of injury, and lesions cannot be deemed truly complete until spinal shock has resolved.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Spinal Cord Anatomy - tracts

A

corticospinal tracts

spinothalamic tracts

dorsal (posterior) columns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Corticospinal Tract

A

The corticospinal tract is a descending motor pathway

In the lower medulla, approximately 90% of the fibers cross to the side opposite that of their origin and descend through the spinal cord as the lateral corticospinal tract.

Damage to the corticospinal tract neurons (upper motor neurons) in the spinal cord results in ipsilateral clinical findings such as muscle weakness, spasticity, increased deep tendon reflexes, and a Babinski’s sign.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Spinothalamic Tract

A

The two major ascending pathways that transmit sensory information are the spinothalamic tracts and the dorsal columns.

The spinothalamic tract transmits pain and temperature sensation.

When the spinothalamic tract is damaged, the patient experiences loss of pain and temperature sensation in the contralateral half of the body.

The (pain and temperature) sensory loss begins one or two segments below the level of the damage.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Dorsal Columns

A

The dorsal columns transmit vibration and proprioceptive information.

Injury to one side of the dorsal columns will result in ipsilateral loss of vibration and position sense.

The sensory loss begins at the level of the lesion. Light touch is transmitted through both the spinothalamic tracts and the dorsal columns.

Therefore, light touch is not completely lost unless there is damage to both the spinothalamic tracts and the dorsal columns.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Naming of spinal nerve roots

A

Each spinal nerve is named for its adjacent vertebral body.

In the cervical region, there is an additional pair of spinal nerve roots.

The first seven spinal nerves are named for the first seven cervical vertebrae, each exiting through the intervertebral foramen above its corresponding vertebral body.

The spinal nerve exiting below C7, however, is referred to as the C8 spinal nerve, although no eighth cervical vertebra exists.

All subsequent nerve roots, beginning with T1, exit below the vertebral body for which they are named.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Cauda Equina anatomy

A

During fetal development, the downward growth of the vertebral column is greater than that of the spinal cord.

Because the adult spinal cord ends as the conus medullaris at the level of the lower border of the first lumbar vertebra, the lumbar and sacral nerve roots must continue inferiorly below the termination of the spinal cord to exit from their respective intervertebral foramina.

These nerve roots form the cauda equina.

A potential consequence of this arrangement is that injury to a single lower vertebra can involve multiple nerve roots in the cauda equina. For example, an injury at the L3 vertebra can involve the L3 nerve root as well as the lower nerve roots that are progressing to a level caudal to the L3 vertebra.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Spinal Injury and airway / breathing concerns

A

The higher the level of spinal injury, the more likely is the need for early airway intervention.Unstable spine lesions above C3 can cause immediate respiratory arrest.

Lesions affecting C3-C5 can affect the phrenic nerve and diaphragm function.

Delayed respiratory compromise can occur if spinal cord edema from more caudal lesions progresses rostrally to cause phrenic nerve paralysis.

Many patients can initially support ventilatory function using intercostal muscles or abdominal breathing, but they eventually tire and subsequently develop respiratory failure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Neurogenic Shock

A

Neurogenic shock

  • state of hypoactivity of the sympathetic nervous system in patients with quadriplegia or high paraplegia
  • the higher the lesion, the greater the effects

Main features

•bradycardia

-heart rate usually 50 - 60 /min.

•hypotension

-systolic BP usually 90-100 mmHg

•poikilothermia

Associated with

  • flaccid paralysis of skeletal muscle
  • paralytic ileus
  • flaccid paralysis of bladder
17
Q

Motor Grading 0 -5

A

GradeMovement

0 No active contraction

1 Trace visible or palpable contraction

2 Movement with gravity eliminated

3 Movement against gravity

4 Movement against gravity plus resistance

5 Normal power

18
Q

Spinal Injury Level assessment

A

Determine the level of sensory loss), and investigate proprioception or vibratory function to examine posterior column function.

Test for “saddle anesthesia,” which is sensory deficit in the region of the buttocks, perineum, and inner aspect of the thighs

Test for “saddle anesthesia,” which is sensory deficit in the region of the buttocks, perineum, and inner aspect of the thighs.

Test deep tendon reflexes along with anogenital reflexes because “sacral sparing” with preservation of anogenital reflexes denotes an incomplete spinal cord level, even if the patient has complete sensory and motor loss.

To test the bulbocavernosus reflex, squeeze the penis to determine whether the anal sphincter simultaneously contracts. Assess rectal tone at the same time.

Test the cremasteric reflex by stroking the medial thigh with a blunt instrument. If the scrotum rises, some spinal cord integrity exists.

Document rectal tone and sensation around the anus. An “anal wink reflex” (contraction of the anal musculature when the perianal region is stimulated with a pin) indicates some sacral sparing.

Conversely, priapism implies a complete spinal cord injur

19
Q

Spinal Cord Injury Terminology

A

Neurological level

•the most caudal segment with normal sensory and motor function on both sides

Sensory level

•the most caudal segment with normal sensory function on both sides

Motor level

•the most caudal segment with normal motor function on both sides

Skeletal level

•radiographic level of greatest vertebral damage

Degree

•complete or incomplete

-an incomplete C5 lesion means there is an incomplete lesion below the level of C5 i.e. normal at the level of C5

20
Q

Central cord syndrome

A

•common in the elderly following hyper-extension injury

-causes buckling and central haematoma of the cord

•incomplete paralysis

  • weakness greater distally than proximally
  • weakness greater in arms than legs
  • proximal decrease in sensation
  • variable reflexes
  • sensation
  • reduced pain and temperature sensation in arms, often with hyperaesthesia
  • normal vibration sense and proprioception in limbs

•usually good outcome

-50% with severe initial involvement will ambulate, have bowel / bladder control and some hand movement

21
Q

Anterior cord syndrome

A

Damage to the corticospinal and spinothalamic pathways, with preservation of posterior column function.

Loss of motor function and pain and temperature sensation distal to the lesion.

Vibration, position, and tacticle sensation are preserved.

May occur following direct injury to the anterior spinal cord. Flexion of the cervical spine may result in cord contusion or bone injury with secondary cord injury.

Alternatively, thrombosis of the anterior spinal artery can cause ischemic injury to the anterior cord.

Anterior cord injury can also be produced by an extrinsic mass that is amenable to surgical decompression.

The overall prognosis for recovery of function is poor.

22
Q

Brown - Sequard lesion

A

The Brown-Séquard syndrome results from hemisection of the cord.

It is manifested by ipsilateral loss of motor function, proprioception, and vibratory sensation, and contralateral loss of pain and temperature sensation.

The most common cause of this syndrome is penetrating injury. It can also be caused by lateral cord compression secondary to disk protrusion, hematomas, spine fractures, infections, infarctions, or tumors.

23
Q

Spinal Shock

A

SPINAL SHOCK

Spinal shock is not neurogenic shock; the two terms have very different meanings and are not interchangeable.

Spinal shock is the temporary loss or depression of spinal reflex activity that occurs below a complete or incomplete spinal cord injury.

The typical presentation involves flaccidity, loss of reflexes, and loss of voluntary movement.

The lower the level of the spinal cord injury, the more likely it is that all distal reflexes will be absent.

Loss of neurologic function that occurs with spinal shock can cause an incomplete spinal cord injury to mimic a complete cord injury.

Therefore, cord lesions cannot be called complete until spinal shock has resolved.

The delayed plantar and bulbocavernosus reflexes are among the first to return as spinal shock resolves.

The duration of spinal shock is variable; it generally lasts for days to weeks but can persist for months.