Spinal cord injury without radiologic abnormality (SCIWORA)

Introduction

• SCIWORA (spinal cord injury without radiologic abnormality) originally referred to spinal cord injury without radiographic or CT evidence of fracture or dislocation
  • With advent of MRI, term has become ambiguous
  • "Spinal cord injury without neuroimaging abnormality" more correct name
• Following findings on MRI have been recognized as causing primary or secondary spinal cord injury:
  • Intervertebral disk rupture
  • Spinal epidural hematoma
  • Cord contusion
  • Hematomyelia
• Prognosis of SCIWORA is actually better than patients with spinal cord injury and radiologic evidence of traumatic injury

History

• 1969:
  • Mentioned for the first time in medical literature
  • Described as a unique syndrome in study of 29 children with traumatic paraplegia where 16 had no x-ray findings
  • Study done at NSIC Aylesbury, Buckinghamshire, England
• 1982:
  • Term "SCIWORA" first coined by Pang and Wilberger
  • Defined as "objective signs of myelopathy as a result of trauma" with no evidence of fracture or ligamentous instability on plain spine radiographs and tomography

Definition

• Acute traumatic myelopathy
• Normal plain radiographs
• Normal computed tomography (CT)

Prevalence

• Mostly in pediatric population (range: birth to 16 years old)
• Inherent elasticity in pediatric cervical spine can allow severe spinal cord injury to occur in absence of x-ray findings
• The true incidence is probably close to 20% of all pediatric spinal cord injuries
  • Up to 30% of severe cervical injuries in children 8 years of age and younger
  • 10% in children 9-16 years old
• Common in cervical and thoracic region
• Rare in lumbar region

Mechanism of Injury

• MVA (motor vehicle accident)
• Motor vehicle - pedestrian accident
• Fall
• Sports injury
  • Football
  • Diving
  • Wrestling
  • Gymnastics

Pathogenesis

• Hyperextension injury to spine whose vertebral canal diameter is already compromised by spondylosis has a high risk of cord injury
• Excessive anterior buckling of ligamentum flavum into canal, already compromised by posterior vertebral body osteophytes, probably is the cause of central cord syndrome
• Pathophysiologic mechanisms
  • Direct spinal cord injury (traction)
    • Longitudinal cord traction
    • Root traction/avulsion
  • Direct spinal cord compression (extreme flexion/hyperextension)
    • Transient compression
      • Ligamentous bulging
      • Reversible disc protrusion
      • Transient subluxation of vertebrae
    • Persistent compression (potentially requires operative intervention)
      • Occult fracture with cord compression
      • Spinal epidural hematoma
      • Persistent disc herniation
      • Occult subluxation/instability
  • Indirect spinal cord injury
    • Transmission of externally applied kinetic energy to spinal cord
    • Known as SCC (spinal cord concussion)
  • Vascular/ischemic injury
    • Vascular occlusion, dissection, cord infarction
    • Vasospasm
    • Hypotension, impaired cord perfusion

Diagnosis

SCIWORA is mainly a diagnosis of exclusion.

Typical Clinical History

A 2 1/2-year-old boy presented with a 2-day history of paucity of movement of both legs, inability to bear weight on his legs, and inability to pass urine. The previous afternoon, he had fallen from a tractor. There was no history of any injury to head, unconsciousness, bleeding from ear nose or throat, or any seizures. The child was moving his legs after he fell and there was no deformity of legs or spine.

The next day when the child woke up, the parents noted that he was not moving his legs and was not able to sit without support. There was no history of fever or vomiting, no history of any paucity of movement or weakness in the upper limbs, or any history suggestive of cranial nerve involvement. He did not have difficulty breathing or bowel incontinence.

On general examination, there was pallor. No evidence of any fracture of limb bones, lacerations, or deformity or tenderness over the spine was found. Neurologic examination revealed a conscious child with normal cranial nerves and upper limbs. There was gross hypotonia in the lower limbs, 0/5 power and areflexia. Abdominal reflex, cremasteric, and anal reflex were absent. The bladder was palpable and urine could be expressed out on abdominal pressure. There were no meningeal or cerebellar signs.

Neurologic Presentation

• Wide spectrum of neurologic dysfunction, ranging from mild, transient spinal cord concussive deficits to permanent, complete injuries of the spinal cord; incidence and severity are related to the patient's age
  • Higher incidence of SCIWORA in young children
  • Transient neurologic deficit (ie, paraparesis or quadriparesis) or persistent subjective symptoms (ie, numbness or dysesthesias) suggest a SCIOWORA diagnosis
• Pang and Wilberger described a "latent" period from 30 minutes to 4 days (mean 1.2 days) before the onset of objective sensorimotor deficits in 13 of 24 children they studied.

Protocols

• Standards: Insufficient evidence to support diagnostic standards
• Guidelines: Insufficient evidence to support diagnostic guideline

Work up

• Plain spinal radiographs of the region of injury
  • Plain radiographs of the entire spinal column may be considered
  • Beware of pseudo-subluxation; apparent anterior displacement may be up to 4 mm
• CT scan of suspected level of neurological injury
• MRI of the suspected region of neurological injury may show
  • Hemorrhage
  • Edema
• SSEPs (somatosensory evoked potentials)
  • Electrophysiologic response of nervour system to sensory stimulation
  • Tests neurologic function, can relate any decrease or absence of impulse transmission
  • Not used diagnostically
  • Helpful for follow up; obtained within 24 hours of admission and compared in follow up analysis
• Not recommended:
  • Angiography
  • Myelography

Differential diagnosis

• Traumatic compressive myelopathy (compression by fractured vertebrae, disc herniation, etc.)
• Acute disseminated encephalomyelitis
• Transverse myelitis

Treatment

Protocols

• Standards: Insufficient evidence to support treatment standards
• Guidelines: Insufficient evidence to support treatment guidelines
• Consider external immobilization of the spinal segment of injury for up to 12 weeks
  • A collar or a more rigid brace can be used.
  • Immobilization is maintained until confirmation of spinal stability by flexion and extension radiographs
• Consider avoidance of "high-risk" activities for up to 6 months
  • Avoid activities that encourage flexion and extension of neck for additional 12 weeks; associated with less chance of recurrent injury
  • Gradually increase range of motion once deficits have resolved
  • To avoid risk of recurrent injury, activity should be strictly limited for at least 3 months
• High-dose steroids
  • Methylprednisolone bolus of 30 mg/kg IV within 8 hours of injury, followed by infusion at 5.4 mg/kg/hr for the next 23 hours beneficial in improving the outcome ⁷
    • Outcome at 6 weeks and 6 months better when drug given over 48 hours, according to recent study.⁸
• Emerging role of stem cell transplant

Nursing Management

• Spine stabilization
• Counseling and education for patient and parents
• Regular neurologic assessment
• Caution in changing positioning
• Suctioning
• Prevention of complications
  • Pressure ulcers
  • Pulmonary adverse effects
  • Contractures

Prognosis

• MRI of region of neurologic injury may provide useful prognostic information about neurologic outcome following SCIWORA
• Children < 8 years old have worse prognosis
• Poor prognostic signs:
  • Delay in onset of neurologic symptoms
  • Deterioration of neurologic symptoms
  • Recurrent injury

References

1. Bracken MB, Shepard MJ, Collins WF, Holford TR, et al: A randomized trial of methylprednisolone or naloxone in the treatment of acute spinal cord injury: Results of the second National Acute Spinal Cord Injury Study (NASCIS II). N Engl J Med 322:1405-1411,1990.
2. Davis PC, Reisner A, Hudgins PA, Davis WE, O'Brien MS: Spinal injuries in children:Role of MR. AJNR 14:607-617-1993.
3. Dickman CA, Zabramski JM, Hadley MN, Rekate HL, Sonntag VKH: Pediatric spinal cord injury without radiographic abnormalities. J Spinal Disorders 4:296-305,1991.
4. Eleraky MA, Theodore N, Adams M, Rekate HL, Sonntag VKH: Pediatric cervical spine injuries: report of 102 cases and review of the literature. J Neurosurg (Spine) 92:12-17, 2000.
5. Grabb PA, Pang D: Magnetic Resonance imaging in the evaluation of spinal cord injury without radiographic abnormality in children. Neurosurgery 35:406-414, 1994.
6. Hadley MN, Zabramski JM, Browner CM, Rekate H, Sonntag VKH: Pediatric spinal trauma. J Neurosurg 68:18-24,1988.
7. Hamilton MG, Myles ST: Pediatric spinal injury: review of 174 hospital admissions. J Neurosurg 77:700-704, 1992.
8. Osenbach RK, Menezes AH: Spinal cord injury without radiographic abnormality in children. Pediatr Neurosci 15:168-175, 1989.
9. Osenbach RK, Menezes AH: Pediatric spinal cord and vertebral column injury. Neurosurgery 30:385-390, 1992.
10. Pang D, Wilerger JE: Spinal cord injury without radiographic abnormalities in children J Neurosurg 57:114-129, 1982.
11. Pang D, Pollack IF: Spinal cord injury without radiographic abnormality in children-The SCIWORA syndrome. J Trauma 29:654-664, 1989.
12. Pollack IF, Pang D, Sclabassi R: Recurrent spinal cord injury without radiographic abnormalities in children. J Neurosurg 69:177-182, 1988.
13. Rathbone D, Johnson G, Letts M: Spinal cord concussion in pediatric athletes. J Ped Orthop 12:616-620, 1992.
14. Ramon S, Dominguez R, Ramirez L, Paraira M, Olona M, Castello T, Garcia-Fernandez L: Clinical and magnetic resonance imaging correlation in acute spinal cord injury. Spinal Cord 35:664-673, 1997.
15. Rossitch E, Oakes WJ: Perinatal spinal cord injury. Pediatr Neurosurg 18: 149-152, 1992.
16. Ruge JR, Sinson GP, McLone DG, Cerullo LJ: Pediatric spinal injury: the very young. J Neurosurg 68:25-30, 1988.
17. Turgut M, Akpmar G, Akalan N, Ozcan OE: Spinal injuries in the pediatric age group. EurSpine J 5:148-152, 1996.