The spinal cord is the portion of the CNS that extends from the base of the skull/foramen magnum → L1/L2 (conus medullaris) after which it continues as the cauda equina (L1-S5) for our lumbosacral nerves.
Injury to our spinal cord can be both traumatic and non-traumatic:
Pathophysiology
The most common cause of C-spine injuries are RTAs and collisions which both can be considered whiplash injuries. Whiplash is injury to the neck due to forcible hyperextension/hyperflexion. This most commonly occurs due to rear-impact collision where the individual gets pushed forward but the inertia of the head causes the neck to hyperextend, followed by a subsequent hyperflexion. This mechanism of whiplash injury results in cervical spine flexion, compression, extension, distraction and shearing very rapidly. The level of the spine affected is most commonly C6-C7.
Other causes of spinal cord injuries include:
- Falls
- Assaults
- Gunshot wounds
- Sports
- Spontaneous injury - neoplasms, osteoporosis, metabolic disorders.
- Degenerative stenosis
🔢 Classification
The American Spinal Injury Association impairment scale (ASIA impairment scale) is the most widely used classification system of SCIs. They divide them into 5 different categories.
- A: Complete - no motor, sensory or sacral sparing
- B: Incomplete sensory - no motor but sensory function is preserved at least in the sacral segments.
- C: Incomplete motor - 50% of muscles below the neurological level has < grade 3 motor function.
- D: Incomplete motor - 50% of muscles below the neurological level has > grade 3 motor function.
- E: Normal - prior injury with now normal sensory and motor function.
A grade 3 motor function means there is active movement, full range of motion and movement against gravity.
These will be discussed in more detail in neurology in year 4, however, we can briefly differentiate them into a few types such as:
- Central cord syndrome
- Brown-Sequard syndrome
- Anterior cord syndrome
- Conus Medullaris syndrome
- Causa Equina syndrome
Some types of SCIs that may occur include:
- Contusion
- Swelling
- Intramedullary haemorrhage
- Transection
- Extrinsic fractures
😷 Presentation
The more cranial the injury the greater the concern. Some signs and symptoms include:
- Quadriplegia
- Paraplegia
- Motor weakness
- Motor function loss - especially in arms, legs and chest.
- Breathing issues - due to impaired diaphragmatic function (C3-C5 damage).
- Sensory loss - in arms chest and legs
- Incontinence
- Pain - especially in the back.
🔍 Investigations
We will discuss the assessment of traumatic spinal injuries and how to check for spinal injuries then we will discuss imaging studies needed.
On arrival at the scene, we will use a modified A-E assessment known as the C-ABCDE assessment:
- C: Catastrophic haemorrhage
- A: Airway with in-line spinal stabilisation
- B: Breathing
- C: Circulation
- D: Disability - look for neurological signs and symptoms.
- E: Everything else - exposure and environment.
The C-spine should be secured at all stages and the remainder of the spinal column should also avoid movement. The C-spine is of greatest concern as damage to it may cause cessation of breathing which will ultimately lead to a much faster death.
Check if the patient:
- Has any significant injuries?
- Is under the influence of drugs or alcohol?
- Is confused or uncooperative?
- Has reduced consciousness?
- Has any spinal spain?
- Has hand or foot weakness?
- Has altered/absent sensation in hands or feet?
- Has priapism? (Due to damage of the sympathetic tracts).
- Has history of spinal problems, previous spinal surgery or conditions affecting the spine (e.g. ankylosing spondylitis).
The Canadian C-spine rule is to be used if the patient has a GCS of 15 and is stable, but C-spine injury is a concern. It stratifies patients into high and low risk, where high risk patients mandate a high-resolution CT scan while low-risk patients require no imaging.
High risk
- Age >65 years
- Dangerous mechanism of injury
- Paraesthesia
Low risk
- Minor rear-end motor vehicle collision
- Comfortable in a seated position
- Ambulatory (walking) at any time since the injury.
However, if they are unable to rotate their neck 45º left and right then they require a high resolution CT as well.
It is important to assess if these factors apply to the patient:
- Age >65 years
- Dangerous mechanism of injury
- Pre-existing spinal pathology or risk of osteoporosis (for example with chronic steroid use).
- Suspected spinal fracture in another region of the spine
- Neurological symptoms - such as paraesthesia, weakness, numbness.
On examination:
- Abnormal neurological signs - motor or sensory deficits.
- New deformity or bony midline tenderness
- Midline or spinal pain - on coughing for example.
- Pain or abnormal neurological symptoms on mobilisation.
C-spine injuries:
- Adults
- Trauma patient with high-risk according to the Canadian C-spine rules
- Trauma patient with low-risk but inability to rotate neck 45º left and right
- GCS <13
- Inability to cooperate
- Distracting injuries present which make clinical assessment unreliable.
- Children
Urgent CT scan within 1 hour if:
MRI to be done in children (<16 years old) if there is suspicion of cervical spine/column injury.
Thoracic, lumbar, sacral injuries:
X-ray is first-line for suspected injuries between T1-L3. If there is any abnormality on X-ray then CT may be requested.
🧰 Management
Suspected C-spine injury:
- 🥇C-ABCDE
- 🥇 Analgesia - is first-line.
- IV morphine
- Intranasal diamorphine or ketamine - if IV access cannot be established.
Confirmed C-spine injury:
- 🥇 Analegesia
- IV morphine
- Urgent referral to neurosurgery
- C-ABCDE
- Spinal motion restriction (SMR)
- Analgesia
- IV morphine