Clinical and radiological evaluation of caudal regression syndrome

Caudal regression syndrome is a form of segmental spinal dysgenesis involving the caudal spinal column, ranging from segmental coccygeal agenesis to extensive thoracolumbar agenesis with varying degrees of spinal cord dysgenesis. A majority of caudal regression cases are sporadic but maternal pre-gestational diabetes mellitus is an important risk factor. Imaging is an integral part of management of caudal regression syndrome. Antenatal diagnosis on obstetric ultrasound and evaluation with fetal MRI is ideal. Early postnatal diagnosis and/or detailed evaluation with MRI is essential for early management to improve outcomes. Pang classification categorizes caudal regression syndrome into two categories based on the position of the conus while Renshaw classification is based on the degree of vertebral column agenesis. Caudal regression syndrome may be associated with several additional anomalies, both spinal and extraspinal. A number of genitourinary and gastrointestinal anomalies have been described in association with caudal regression syndrome. The field of view of MRI of the lumbosacral spine in caudal regression syndrome needs to be extended to visualize the retroperitoneal structures without the use of a saturation band. Syndromic associations may be suspected, and additional imaging performed, based on findings of extended field of view MRI of the spine. Associated sacral masses and filar abnormalities need to be identified and may also require surgical treatment. The multisystem nature of this disease necessitates a multimodality approach to the evaluation and management of caudal regression syndrome with close cooperation between pediatric neuroradiologists and body radiologists as well as multiple clinical teams. Appropriate early management with surgical correction as necessary can significantly improve prognosis and survival in caudal regression syndrome.