SPINAL CORD INJURY WITHOUT OBVIOUS RADIOGRAPHIC ABNORMALITY
SCI WORA in children has been a known entity since at least the early 20th century (12), though the acronym did not come about until 1982 in an article by Pang and Wilberger (13). The initial definition focused on children with traumatic SCI, who did not have evidence of vertebral column injury on spine x-rays, conventional and computed tomographic studies, myelograms, or dynamic flexion/extension studies. This excluded injuries caused by penetrating trauma, electrical shock, obstetric complications, and congenital spinal anomalies. In 2004, Pang published a review on what is now known about SCIWORA (14). Incidence of SCIWORA ranges between 5% and 67% of cases of pediatric SCI, with an average of 34.8%. The incidence is much higher in children 9 years and younger. Pooled data indicated an incidence of SCIWORA of 63.1% in younger children and only 19.7% in older children. Most injuries occur in the cervical cord, most commonly with C5 to C8 lesions. Thirteen percent of injuries were in the thoracic cord. This injury is thought to be primarily present in children due to the unique physiology of the developing spine, being much more mobile, without resulting in bony fractures, but causing stretch injury to other tissues. This increased mobility was thought to result in damage to the soft tissue structure of the spine, including ligamentous and neural structures, which cannot be demonstrated on radiographic studies. The advent of more advanced imaging techniques has demonstrated these soft tissue injuries. It should be noted that SCIWORA occurs in adults as well (15).
SCIWORA has been reported to cause complete and incomplete SCI, as well as central cord and Brown-Sequard syndromes. Pang classified ASIA-B/C as severe injuries and ASIA-D as mild. From this pooled data, SCIWORA results in ASIA-A22.1%, ASIA-B/C 12.6%, ASIA-D 23.2%, central cord syndrome 29.4%, and Brown-Sequard 12.7% (14).
With the development of MRI, damage to the soft tissue structures in the spinal column is readily apparent. This information was recently reviewed by Yucesoy and Yuksel (16). These authors suggest that in the MRI era, SCIWORA may be an ambiguous term and that those with no lesions on neuroimaging be classified as "real SCIWORA" or spinal cord injury without neuroimaging abnormality (SCIWNA). In the strict sense, radiographs do not include MRI, yet in standard use, most practitioners would consider most imaging to fall into the category of radiograph, regardless of the nature of the physics involved in the imaging process.
PROGNOSIS FOR NEUROLOGIC RECOVERY
One of the most challenging aspects of rehabilitation medicine is talking with patients and families regarding prognosis for recovery. We must be able to present the best available information regarding prognosis (which is often not good) in a manner that people with varied levels of education and sophistication can understand and that can offer a reasonable and realistic degree of hope. SCI is truly devastating, and as rehabilitation specialists, we must take the impact of that into account when communicating with patients and families. We must also be aware that during these times of stress, communication may not always be effective. We must also be clear that neurologic recovery can be markedly different from functional recovery.
A complete SCI examination is necessary for any discussion of prognosis. Examination at least 72 hours after injury has been determined to be a better prognostic indicator than earlier examinations (17-19). (This does not mean earlier examinations are not necessary, only that they are of less prognostic value, as they may be limited for a variety of reasons.)
Most recovery from SCI occurs during the first 6 months, with a plateau reached around 9 months postinjury, though later recovery can occur. Neurologic recovery after a complete injury is poor. Ninety-six percent of those with complete paraplegia and 90% with complete tetraplegia at 1 month will remain ASIA-A. Muscle groups with a grade of 0 at initial examination, more than two neurologic levels below the level of injury, are unlikely to regain functional strength. Seventy percent of individuals with tetraplegia and a complete SCI can expect the myotome below the neurologic level to regain at least antigravity strength (20). Muscles with grades 1 to 2 have a 64% chance of increasing to functional strength in paraplegia and 97% in tetraplegia. Incomplete paraplegia has an average motor score increase of 12 points at 1 year post-injury. Seventy-six percent of those with incomplete paraplegia became community ambulators. For incomplete tetraplegia, 46% became community ambulators at 1 year (21).