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

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.