These terms refer to a transient loss of motor sensory function of the spinal cord that recovers within minutes or hours but may persist in mild form for days or more. In most instances, the symptoms are rapidly diminishing and few neurologic abnormalities are found at the time of the first examination. There are a number of such transient syndromes: bibrachial weakness; quadriparesis (occasionally hemiparesis); paresthesias and dysesthesias in a similar distribution to the weakness; or sensory symptoms alone (“burning hands syndrome”). In the first and last of these, transient dysfunction of the central gray matter of the cervical cord is implicated. It is assumed that the cord undergoes some form of elastic deformation when the cervical spine is compressed or hyperextended; however, the same effects can be produced by direct blows to the spine or forceful falls flat on the back and occasionally, by a sharp fall on the tip of the coccyx. Little is known of the physiologic mechanisms that underlie these reversible syndromes.
Spinal cord concussion from direct impact is observed most frequently in athletes engaged in contact sports (football, rugby, and hockey). An incomplete and reversible myelopathy is referable to the site and level of the injury. A congenitally narrow cervical canal is thought to predispose to spinal cord concussion and to increase the risk of recurrence. As with cerebral concussion, particularly if there have been previous concussions, a difficult decision arises—whether or not to allow resumption of competitive sports. There are no reliable data on which to base this decision, only guidelines that tentatively allow continued participation, after an unspecified period of rest, if the deficit has been brief. It is, however, advisable in most cases to be certain that spinal instability has not been induced by the injury. This can be ascertained from flexion and extension x-ray images of the affected spinal region. The subject is reviewed by Zwimpfer and Bernstein. In athletic contact injury, unilateral arm and hand paresthesias are more common than symptoms of both arms, but they are usually from stretching of the brachial plexus on one side (a “stinger”), rather than from a cord injury.
Central cord syndrome (“Schneider syndrome”) and cruciate paralysis A special from of acute cervical cord injury implicates mainly central cord damage, resulting in the loss of motor function solely or more severely in the upper limbs than in the lower ones, and it particularly affects the hands. Bladder dysfunction with urinary retention occurs in some cases and sensory loss is often slight (hyperpathia over the shoulders and arms may be the only sensory abnormality). Many of these instances are reversible but damage to the centrally situated gray matter may leave an atrophic, areflexic paralysis of the arms and hands and a segmental loss of pain and thermal sensation from interruption of crossing pain and thermal fibers. Retroflexion injuries of the head and neck are the ones most often associated with the central cord syndrome, but other causes include hematomyelia, fibrocartilaginous embolism, and infarction from dissection of the vertebral artery in the medullary-cervical region as mentioned earlier in the chapter.
According to Dickman and colleagues, approximately 4 percent of patients who survive injuries of the very rostral cervical cord demonstrate a very limited form of the central cord syndrome, recognized by Nielson and named by Bell, “cruciate paralysis.” The weakness is very selective, being practically limited to the arms, a feature that is attributable to the segregation within the pyramidal decussation of corticospinal fibers to the arms (being rostral) and to the legs (more caudally situated). The arm weakness may be asymmetrical or even unilateral and sensory loss is inconsistent. The patients described have had contusions of the C1-C2 region. Whether the lesion lies strictly within the decussating corticospinal tract or involves central gray matter is not always clear; MRI findings have implicated the latter, as described by Inamasu et al.
Management of Spinal Injury