Spinal Cord Injuries
- Understanding of the complete neurological exam, including cranial nerves, sensorimotor pathways in the cord and nerve roots is essential to diagnosing injury.
- There are four classically described incomplete spinal cord lesions.
Anterior Cord Syndrome:
- Typically a cervical spine injury
- Characterized by alteration in the function of the long tracts in the white matter in the anterolateral aspect of the spinal cord.
- Mechanism of injury is usually typically a hyperflexion injury, commonly seen in diving injuries. Anterier cord is compressed
- Characterized by complete motor loss and loss of pain and temperature discrimination below the level of injury.
- The posterior columns are variously spared resulting in preservation of deep pressure and position sense below injury level
- The prognosis is the worst of the incomplete syndromes. Return of any muscle function below the level of injury is rare.
Posterior Cord Syndrome:
- Involves injury to the dorsal columns of the spinal cord
- Produces loss of proprioception vibrating sense while preserving other sensory and motor functions
- A rare syndrome that usually is caused by an extension injury
- Longterm outcomes are unpredictable.
Central Cord Syndrome:
- Most common incomplete spinal injury
- Destruction of the central portion of the spinal cord, both gray and white matter.
- The motor horn cells of the arms and the centrally located long tracts are most severely affected
- Mechanism of injury is usually a hyperextension injury in the elderly patient who has a more stenotic spine, producing a central hematomyelia (blood within the cord).
- Perianal sensation is preserved
- Return of motor and sensory in the lower extremities usually occurs early especially after placement of tong traction
- Prognosis varies
- Mechanism is a penetrating injury in which half of the cord is injured and the other half remains intact.
- Due to the crossing over of the spinal tracts, the clinical picture below the level of injury is different on each side.
- Ipsilateral side of the injury site: paresis (weakness) or paralysis
- Contralateral side of injury site: hypoalgesia (decreased sensation)
- Prognosis for recovery is the most promising of the incomplete syndromes. The weak side should become stronger and usually has normal sensation, whereas the contralateral side regains some sensibility and has good motor power.
Conus Medullaris and Cauda Equina Syndromes:
- There are two other syndromes seen with injury to the conus medullaris and the cuada equina.
- Conus medullaris is usually injury posterior to the vertebral bodies from T12 to L1, possibly involving T11 to L2.
- Produces loss of bowel and bladder control
- Signs/Symptoms are loss of perianal sensation and poor sphincter tone. The prognosis is poor for significant return of bowel and bladder control.
- Cauda equina is the spinal cord from L1 to L5 and is composed entirely of the lumbar and sacral nerve roots.
- Injury in this region does not produce a spinal cord injury but one more similar to a peripheral nerve injury.
- Physical findings are variable sensory and motor loss. Because of the peripheral nerve similarity, the prognosis for motor nerve recovery is good.
- Inquiry into any change in bowel or bladder continence is essential
- Considered a surgical emergency requiring emergent decompression of the cauda equina