Pediatric Neurosurgery

PEDIATRIC SPINE AND SPINAL CORD INJURIES

SPINE INJURY

• Introduction
• Incidence
• Types of Head Injury
• Current Knowledge & Management
• Long-term Sequellae
• Prevention

INTRODUCTION

• Motor vehicle crashes #1 cause of TBI, SCI, and seizures
• 600-700 children die each year
• 75,000 children are injured

INCIDENCE

• Trauma is the leading cause of death in children
• 11,000 children die from trauma annually
• Of those, >80% had a severe head injury
• Of those, approximately 10% have a spinal cord injury
• In children ages 1-15, more died from trauma than all other causes… COMBINED

PEDIATRIC CONSIDERATIONS

• Structural differences between pediatric and adult cervical spines alter injury patterns and cause distinct pathology in young children.
• The more elastic intervertebral ligaments and more horizontally aligned facet joints in young children predispose them to subluxation of the cervical spine without bony injury.
• Immature neck muscles and a proportionally large head further compound this effect, making pediatric cervical spines act like a fulcrum and increasing the chance of injury.
• This fulcrum starts in the upper cervical levels and changes progressively to lower levels as the pediatric cervical spine matures, until it reaches adult levels at C5 and C6. Most injuries occur at the C1-C3 levels in children younger than 8 years.

BIRTH TRAUMA

• More often brachial plexus injuries, e.g Erb's palsy, than spinal cord injury
• Incidence of Erb's palsy 1:1000
• Incidence of permanent disability from Erb's palsy 1:10,000
• Acute work-up includes cervical spine X-rays and shoulder/clavicular X-rays

MOTOR ASSESSMENT

• Assess all extremities, as many muscle groups as possible
• Grade strength using British Muscle Movement Scale
  • 0 - Flaccid
  • 1 - Tone but no joint movement
  • 2 - Able to move joint horizontally but not against gravity
  • 3 - Able to move joint against gravity but not against active resistance
  • 4 - Weak but able to overcome light active resistance
  • 5 - Normal

AUTONOMIC ASSESSMENT

• Hypotension (Vasodilation)
• Priapism
• Lack of Sphincter
• Reflexes (Absent in acute injury and lower motor neutron injury, increased in chronic upper motor neutron injury)

PROGNOSIS

• Much worse prognosis if:
  • Injury is complete (no function distal)
  • Autonomic signs are present
  • Hypotension
  • Hypoxia

SUSPICIONS SHOULD BE RAISED REGARDING SPINAL CORD INJURY WHEN:

• Child abuse
• Vehicular ejection
• Peds vs car
• Child holding head rigid
• Apnea following trauma
• Any neurological deficit
• Seatbelt sign
• Subcutaneous emphysema
• Crepitance about spinous processes
• Heart rate <80 with hypotension (spinal shock)

RISK FACTORS FOR ERB'S PALSY

• Macrosomia
• Prolonged labor
• Gestational Diabetes
• Breech delivery
• Cephalopelvic disproportion

STEROIDS

• Start them as soon as there is a high level of suspicion for spinal cord injury
  • High dose Solumedrol protocl
    • Bolus 30mg/kg given over 15 minutes
    • Wait 45 minutes
      • Begin infusion of 5.4mg/kg/hr for total treatment time of 48 hours (barring complications)

ERB'S PALSY

• If the patient is still symptomatic and at least 3 months old, need to proceed to MRI of cervical spine and brachial plexus to rule out nerve root avulsion
• If improving clinically, observe until at least 6-9 months of age.
• If no improvement, consider surgical exploration/repair when 4-8 months old

1. Laurent, Neurosurgical correction of upper brachial plexus birth injuries. J Neurosurg. 1993;79:197-203

OCCIPITO-CERVICAL DISLOCATION

• Wackenheim's Clival baseline
• Powers ratio (distance from to the basion to the posterior arch of C1 divided by the distance from the opisthion to the anterior arch of C1)
• More common in certain syndromes, e.g. Down's syndrome¹

1. Trumble, Atlanto-axial Subluxation in a Neonate with Down's syndrome. Pediatric Neurosurgery 21(1): 55-58, 1994.

C1-2 ROTATORY SUBLUXATION

• More common in children due to ligamentous laxity and horizontal angle of C1-2 facets (until approximately 8yo)
• Ligamentous injury seen by jumped facets at C1-2
• Presents with acute onset of torticollis and neck pain, rarely with neurological deficit
• Stable injury
• Requires dynamic CT for diagnosis

TREATMENT OF C1-2 ROTATORY SUBLUXATION

• Conservative, palliative
  • Soft cervical collar
  • Prn pain medications
  • Scheduled muscle relaxants, e.g. Valium
  • Rest
  • Follow-up in 2-4 weeks with repeat dynamic CT¹

1. Myseros & Trumble, Conservative Treatment of Atlanto-Axial Rotatory Subluxation. Proceedings of AANS. 1995, 342.

ATLANTO-AXIAL SUBLUXATION

• C2 is the most common site of spinal cord injury in children
  • Anatomy is different
    • C2 synchondrosis(not completely ossified until 8 years old)
    • Similar to Type II odontoid fractures
    • Need to be immobilized

IMMOBILIZATION

• If able to reduce fracture such that displacement of dens and C2 is <3mm, most will fuse with 3 months of Halo immobilization
• If distraction is too great, or ligamentous injury too much to tolerate upright, will need surgical fixation
  • Usually sublaminar wires with bony fusion
  • If child large enough, may consider trans-articular or odontoid screws

AFTER IMMOBILIZATION

• Need to confirm stability by supine and upright cervical spine films
• Remember to re-torque the halo pins
• (lower pressures for thinner skulls)

PEARLS

• Most spinal column injuries in children, either ligamentous or osseous, can heal with external immobilization only
• Outcome is most dependent on severity of injury
• Speed of treatment/recognition of diagnosis is next most important variable