Neural Axis Abnormalities in Congenital Spine Deformity: Is a Screening MRI Necessary?

Purpose: The value of obtaining routine MRI study has been debated in recent literature. This study was undertaken to identify the incidence, type of intraspinal anomaly and validity of neurological (N/E) and radiographic evaluation in detecting these anomalies.

Methods: Ninety-seven patients (59 female, 38 male) with congenital spinal deformity seen in one institution between 1992 and 1999 who had screening MRI were studied. All medical records, plain radiographs and MRI studies were reviewed. Fiftyseven had congenital scoliosis, 27 congenital kyphoscoliosis and 13 congenital kyphosis. The mean age at presentation was 4+3 years (1 mo to 13 years)

Results: Twenty-four of 97 (24.7%) of the patients were found to have intraspinal anomalies on their MRI (27.1% of females and 21.1% of males). These anomalies included: Diastematomyelia (14), Tethered cord (11), Syringomyelia (4), Dural Ectasia (4) and Lipoma (1). There were 8 complex anomalies. Of 97 patients, 20 had abnormal neurological examination and 10 had abnormal radiographs. Of 24 patients with abnormal MRI, 16 had normal radiographs and 18 had normal neurological examination. The sensitivity of clinical and radiographic assessment in detecting intraspinal anomalies was 25% and 33.4% respectively. The specificity of assessments was also 81% and 97.3%. Anomalies were more frequent in lumbar spine (9) and mostly associated with unilateral bars. Eight patients (1/3) required surgical treatment for their underlying anomalies.

Conclusions: The yield for detecting neural axis anomalies based on clinical and radiographic evaluation is low. MRI is an integral part of the assessment of patients with congenital spinal deformity. Since 1/3 of patients require surgical intervention, it should be done early in the course of treatment to prevent further neurological deficit.