Cervical Myelopathy Caused by a Split Atlas Anomaly: A Case Report

Abstract

An 18-year-old male presented with a 6-month history of paresthesia of both arms and legs after a minor neck trauma. CT scan revealed a partial aplasia of the anterior and posterior arches of the C1 vertebra resulting in a split atlas. MRI showed an intramedullary high-signal area. We performed a posterior decompressive laminectomy and occipitocervical fusion. The bony defect into the posterior arch was replaced by a connective tissue cord, resulting in a compression of the dural sheath. The symptoms recovered completely 1 month after surgery. Knowledge of this rare malformation is crucial to the correct management of these cases.

Imaging of Developmental Malformations Affecting Craniocervical Junction

“…Congenital atlas abnormalities are rare malformations. They include aplasia/ hypoplasia and arch clefts and may be asymptomatic [14] . In the study conducted by Meddeb et al [15] , isolated hypoplasia of the anterior arch has been reported up to 0.7%, while in our study only one case had anterior arch atlas detect, however it was in a case of Chiari malformation and the patient suffered from hydrocephalus Bipartite atlas (Split atlas) is a rare malformation consisting of partial/ complete defect between the posterior and the anterior arches of C1 vertebrae body (figure3).…”