The left thoracic curve pattern: a strong predictor for neural axis abnormalities in patients with "idiopathic" scoliosis.

STUDY DESIGN

A prospective trial of MRI study in patients with "idiopathic" left thoracic scoliosis.

OBJECTIVE

To investigate the prevalence of neural axis abnormalities in asymptomatic patients with "idiopathic" left thoracic scoliosis.

SUMMARY OF BACKGROUND DATA

Some patients with neural axis abnormalities have scoliosis as the only presenting sign, and they might be given a diagnosis of "idiopathic" scoliosis. These neural axis abnormalities are risk factors for neurologic injury during spine correction. With the development of MRI, neural axis abnormalities are increasingly being found in patients with "idiopathic" scoliosis. However, there are few reports on the prevalence of neural axis abnormalities in asymptomatic patients with "idiopathic" left thoracic scoliosis.

METHODS

A total of 68 patients with presumed "idiopathic" left thoracic scoliosis were examined for neural axis abnormalities, using MRI.

RESULTS

Neural axis abnormalities were detected in 37 (54%) patients, including Chiari 1 malformation in 15 patients, Chiari 1 malformation with syringomyelia in 10, Chiari 1 malformation with syringomyelia and tethered cord in 1, Chiari 1 malformation with syringomyelia and diastematomyelia in 1, syringomyelia in 8, syringomyelia with tethered cord in 1, and arachnoidal cyst in cerebellomedullary cistern in 1 patient. There were statistically significant differences between patients with and without neural axis abnormalities regarding gender and curve severity (P < 0.05).

CONCLUSION

When a left thoracic curve pattern is present in patients with "idiopathic" scoliosis, especially in male patients or patients with severe curve, strong consideration should be given to the possibility of the presence of neural axis abnormalities, and acquisition of an MRI scan considered.