Spinal Cord Injuries: The Basics Kadre Sneddon POS Rounds October 1, 2003
Anatomy Dorsal columntouch, vibration Corticospinal tract- UMN Anterior horn-lmn Spinothalamic tractpain, temperature (contralateral)
The Vertebrae
Mechanisms of Injury Cord injuries mainly result from vertebral fractures, subluxations and dislocations Can also occur in Ligamentous injuries Hyperextension in the presence of a narrow canal Disc herniation Penetrating injuries Result from axial loading, flexion, extension, rotation, lateral bending, and distraction
Symptoms and Signs to make you Suspicious Spine tenderness/pain Weakness Numbness or paresthesias Respiratory compromise Hypotension
Describing injuries Complete and incomplete No sensory or motor function below level is complete Tricks-sacral sparing, DTR, anal wink Usually no significant improvement Any sensory or motor function below level is incomplete Much better prognosis with some neurological improvement
Browne-Sequard Hemisection of cord Ipsilateral motor, position/vibration loss with contralateral pain, temperature loss 1-2 levels below injury Rare in classical form but variations seen Some recovery seen in non-penetrating trauma
Central cord syndrome Hyperextension in prior cervical canal stenosis resulting in vascular compromise (anterior spinal artery) Motor, pain, temp loss upper limbs, loss of bladder function Good prognosis
Anterior cord syndrome Paraplegia, loss of pain, temperature with preserved position/ vibration sense Infarction of the territory of the anterior spinal artery often caused by a ruptured disc Poor prognosis
Levels Neurologic level Most caudal segment of the spinal cord with normal sensory and motor function (3/5) Zone of partial preservation Dermatomes and myotomes Vertebral level Often discrepancy because the spinal nerves ascend and descend in the canal prior to joining the cord
Radiologic descriptions Fractures, fracture-dislocations Spinal cord injuries without radiographic abnormality (SCIWORA) Stable and unstable Often difficult to establish and experts often disagree All injuries are treated as unstable until an orthopod or neurosurgeon confirms stability
Atlas Atlanto-occipital dislocation Rare, bad, no traction Jefferson fracture (burst # C1) Axial loading Best seen on odontoid view Unilateral ring or lateral mass # Usually stable Rotary subluxation Seen in kids, RA On odontoid view
Axis Odontoid fractures 60% of C2 # Type 1-tip, type 2 base of the dens, type 3, base of dens and body Hangman s # (20%) Posterior elements of C2 (the pars interarticularis)
C3-7 C5-6 most common level of injury mobile fulcrum Vertebral body fractures Subluxation of articular processes Most likely to cause neurological injury Fractures of laminae, spinous processes, pedicles, or lateral masses Ligamentous injury
T-spine injuries (T1-T10) Wedge compression Axial loading with flexion Tend to be stable Burst injuries True vertical axial compression Fracture-dislocations Rare but bad because of narrow canal Chance fractures
Thoracolumbar Junction Fractures (T11-L1) Common because of mobility of L-spine against rigid T-spine Result from acute hyperflexion and rotation Fall from a height, restrained drivers Unstable, very sensitive to rotation Injury to the nerve roots of the cauda equina
Lumbar Fractures Distraction in flexion Seatbelt Chance fracture-splitting injury which begins posteriorly and proceeds anteriorly through the vertebral body or disc Injury to cauda equina so complete injury rare Associated retroperitoneal and visceral injuries
Diagnosis Clinical examination Plain films CT MRI
C-spine films Lateral film You must see all 7 Cs and T1 Swimmer s view PRN Odontoid view Especially if pain or suspicious lateral AP film for unilateral facet dislocation 92% sensitivity
Adjuncts CT If C-spines inadequate or + findings require delineation Flexion-extension views For occult instability or to determine instability in a known # Requires voluntary movement and expert supervision
T, L-spine films AP is preferred to lateral only because a cross-table AP provides better bony definition than a cross-table lateral
Treatment Principles Resuscitation Protect undamaged neural tissue Correct spinal alignment and achieve permanent stability Restore function to reversibly damaged neural tissue
Resuscitation Respiratory compromise Paralysis of the diaphragm above C3 Insufficient tidal volumes C4-6 lesions Paralysis of intercostal muscles also causes respiratory compromise
Neurogenic shock Occurs in lesions higher than T5 Denervation of the sympathetic system Increased venous capacitance and decreased return Careful fluid resuscitation and gentle pressors as needed Associated with bradycardia in C-spine injuries (no sympathetic input to heart) Will not have normal tachycardia
Immobilization All trauma patients need to be immobilized until a spinal injury is excluded Semirigid collar Backboard for transport but remove ASAP Sedate PRN Protect airway
Steroids ATLS currently recommends treatment with steroids if this can be started in the first 8 hours after injury for 23 hours 30 mg/kg over 15 minutes then 5.4 mg/kg/hr for 23 hours
Reduction and stabilization C-spine usually reduced through traction Skull tongs or halo are placed and then the patient is placed in traction while frequent xrays are obtained to assess reduction Reassessed frequently T, L spine fractures treated with bedrest immobilization Immobilization usually necessary for 3 months
Indications for OR Unsafe for traction (locked facet joints) Failure to reduce fracture Progressive neurological deterioration Cord compression by a intraspinal mass Penetrating injury Usually require immobilization post-op