Occipitalization of the Atlas - A Case Report

Occipitalization is a congenital synostosis of the atlas to the occiput, which is a result of failure of segmentation and separation of the most caudal occipital sclerotome and the first cervical sclerotome during the first few weeks of fetal life. Occipitalization of atlas is associated with abnormalities as a result of narrowing of the foramen magnum, compressing the spinal cord or the brain stem. However, this anatomical variation may often go unnoticed. One of the human skull of Indian origin collected from Department of Anatomy, DM wayanad Institute of Medical Sciences, Wayanad Kerala, India, showing occipitalization of Atlas. Although atlanto-occipital fusion is a congenital condition, many patients do not develop the symptoms until the second decade of life. This may be due to a gradual increasing degree of ligamentous laxity and instability with aging.