Journal de colonne vertébrale et de neurochirurgie

Occipitalisation of Atlas with Sudden Onset

Riccardo Ciarpaglini, Patrick Sutter, Philippe Otten and Gianluca Maestretti

Occipitalisation of Atlas with Sudden Onset

Occipitalization or assimilation of the atlas, atlanto-occipital fusion and occipito-cervical synostosis are synonyms and indicate a fusion of C1 to the base of the skull. This condition was initially described by Rokitansky in 1844 and was demonstrated radiologically by Schuller in 1911. Atlo-occipital fusion can be complete or partial, unilateral or bilateral and bony or fibrous. Its incidence is reported from 0.14 to 3.63% according to different authors in the whole population, with equal repartition in both sexes and it is considered the most common anomaly of the cranio-cervical junction.