Isolated cervical spinal canal stenosis at C-1 in the pediatric population and in Williams syndrome

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>Isolated cervical canal stenosis at the level of the atlas (C-1) is a rare cause of cervical myelopathy in the pediatric population. It has been associated with several genetic disorders including spondyloepiphysial dysplasia congenita, Down syndrome, and Klippel-Feil syndrome. The purpose of this study is to highlight the authors' experience with 4 additional pediatric cases, review the literature, and report a new association of this disease with Williams syndrome.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>The medical records and radiological imaging studies of 4 patients treated at Texas Children's Hospital for symptomatic hypoplasia of the atlas were retrospectively reviewed. Pertinent patient demographic data, clinical presentation, imaging findings, and outcomes after surgery were recorded. A thorough literature review was performed, allowing the authors to compare and contrast their 4 cases to surgical cases already published in the literature.</jats:p></jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>There were 11 boys and 1 girl in the aggregate series. The average age of the patients was 7 years (range 13 months–14 years), and the duration of symptoms prior to presentation was 6 months (range 0–36 months). The mean sagittal diameter of the spinal canal at the level of the atlas measured from the posterior aspect of the dens to the anterior aspect of the arch of C-1 was 11.9 mm (range 8.3–16 mm) in the aggregate series. In 2 new pediatric patients with hypoplasia of the atlas the disease was associated with Williams syndrome, which has not been previously described. Patients in the aggregate series were followed for an average of 18 months (range 3–50 months). Laminectomy of C-1 provided neurological improvement in all patients who presented.</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>Isolated cervical spinal canal stenosis at the level of the atlas is a rare cause of cervical myelopathy. The authors hope that this report will prompt clinicians to consider it when searching for the origin of signs and symptoms of cervical myelopathy, especially in children.</jats:p></jats:sec>

Congenital malformed posterior arch of atlas with fusion defect: a case of developmental canal stenosis causing cervical myelopathy

“…The midsagittal canal diameter at the level of atlas in the present case was 6.36 mm, whilst the normal sagittal diameter at the level of atlas is reported to be 16-25 mm (2,3,16). While significant cervical cord compression occurs if the sagittal canal diameter is <14 mm at the level of atlas; myelopathic signs and symptoms develop when the diameter falls <10 mm (17,18). Such a degree of severe stenosis, as seen in the present case, predisposes the patient to a progressive myelopathy as well as a high risk of severe spinal cord injury even after trivial trauma (12,17).…”

Pediatric Craniovertebral Junction Surgery

“…4,8,9) Abnormal ossification of the C1 laminae can result in C1 hypoplasia. 10,11) Os odontoideum, a well-known cause of AAD especially in Down syndrome, is an isolated circular bone fragment separated from a small odontoid. It is once regarded as congenital origin but currently its cause is thought to be unrecognized fracture around the base of odontoid process before the age of 4.…”

“Dynamic” Rotational Canal Stenosis Caused by Osteoma of the Atlas: A Case Report and Review of Literature

“…Cervical canal stenosis related to the atlas has been associated with ossification of its transverse ligament, 2,3) hypoplasia of the atlas, 4–13) atlantoaxial instability, 11,12) and genetic disorders including Down syndrome, 12,13) Klippel–Feil syndrome, 14) and Williams syndrome. 15) On the other hand, canal stenosis caused by neck rotation has been reported in correlation with the hypertrophic atlantal anterior arch 16) and bilateral C-2 nerve root tumors. 17) …”