11.4 Spinal Cord Injuries Flashcards
Spinal Cord Injuries
- Commonly effects both sensory and motor tracts
- Highest risk is 16-30 due to risky behavior
- Motor vehicle accidents is highest cause
- Mortality is highest in the first year of injury.
Vertebral Column Injury
- Commonly caused by acceleration/deceleration injuries, deformation forces, usually applied at a distance.
- Forces compress, pull, or sheer tissue so that they glide into one another
Fracture - Can lead to bone fragmentation
Dislocation or Subluxation - Causes displacement and prevents correct alignment of vertebral column.
Flexion Injury - Caused by head bending forward such as being struck in the back of the head
Extension Injury - Caused by hyperextension of the spine usually caused by a blow to the chin or face
- FLEXION AND EXTENSION INJURIES ARE MOST COMMON IN C4-C6
Acute Spinal Cord Injury
Most Common Areas
- C1-C2, C4-C7, T10-L2
Pathogenesis of ASC Injury
- Small hemorrhages in gray matter cause necrosis
- Edema in white matter impair microcirculation of the spinal cord which causes decreased perfusion and ischemia and loss of oxygen to the area of injury
- Damaged area can cause damage 2 cord segments above and below the site if injury
- Cord swelling also causes dysfunction but once the swelling goes down it function will return.
36-48 hours after injury
- Phagocytes enter area
- Reabsorption of hemorrhage
- Degenerated axons are engulfed by macrophages
4 Weeks
- Traumatized cord is replaced with collagen tissue (scar tissue)
- Meninges thicken due to scarring
Dermatomes
- Test to assess sensation
- A dermatome is an area of skin that is supplied by a single spinal nerve
- Each nerve relays sensation from a particular region of skin to the brain
- Can help us measure injury and monitor improvement
Phrenic Nerve
- Located in the neck (cervical) spine.
- Supplies movement to diaphragm and chest/upper abdomen.
- If this is damaged it is crucial in respiratory process.
Spinal Cord Tests
- Touch/pinprick sensations are tested for each dermatome
L2 - Hip flexion
C4 - Shoulder shrug
C5 - Elbow flexion
C6 - Wrist extension
C7 - Elbow extension
Classification of Spinal Cord Injury
- Complete injury with no motor or sensory function
- Incomplete injury with sensation but no motor function
- Motor function preserved below neurological level and more than half key muscles “active movement and full range of motion)
- Same as 3
- Both motor and sensory scores are normal.
Incomplete/complete Injury
Incomplete
- Partial loss below level of injury (sensory and motor)
Complete
- Total loss below level of injury (irreversible)
- Quadriplegia
INCOMPLETE CORD SYNDROMES
Central Cord Syndrome
- Most common type
- Older patients with degenerative bone changes of cervical spine are at highest risk
- Central cord controls upper extremities and lateral cord controls lower extremities
Recovery Order
- Legs, bladder, arms, hands
- Patients can use lower extremities but not upper extremities
Causes
- Hyperextension of central cord
- Patients have a favorable prognosis
Anterior Cord Syndrome
Causes
- Compression of acute disc herniation or hyperextension
Symptoms
- Loses pain and temperature sensation
- Maintains touch, vibration and proprioception (sensation of body position)
- Patients have an unfavorable variable prognosis
Brown-Sequard Syndrome
- Caused by penetrating injuries
Ipsilateral - same side as injury
Contralateral - opposite side of injury
Symptoms
- Ipsilateral (Paralysis and loss of proprioception)
- Contralateral (Pain and temperature sensation loss)
Cauda Equina Syndrome
- Compression of lumbar roots below L1 (only affects lumbar). Commonly seen in large disk herniations
- Effects lower extremities
SCIWORA
- Spinal cord injuries following a traumatic event without signs of fractures, dislocations, or ligament injuries
Manifestations
- Pain/stinging
- Loss of movement/sensation
- Loss of bowel/bladder control
- Exaggerated reflexes/spasms
- Changes in sexual function
- Difficulty bleeding, coughing, or clearing secretions.
