Which condition is characterized by the absence of vertical arches in the associated vertebrae, often seen in spina bifida?

The condition that is characterized by the absence of vertical arches in the associated vertebrae, often seen in spina bifida, is myelomeningocele. This form of spina bifida involves a defect in the closure of the neural tube, leading to a sac-like protrusion that contains both spinal nerves and membranes. The absence of the vertical arches in the vertebrae occurs due to the failure of development and fusion during the embryonic stage, which is a direct consequence of the neural tube defect.

In the case of myelomeningocele, the lack of structural integrity in the spine can lead to significant neurological deficits and other complications, highlighting the importance of early diagnosis and management. This is also why the other conditions mentioned do not typically involve the specific vertebral arch abnormalities associated with myelomeningocele. Spinal muscular atrophy, for example, primarily affects motor neurons and does not directly involve defects in the vertebrae. Hidden spina bifida refers to unnoticeable defects that do not typically present with the same severe structural anomalies. Occulta spina bifida generally involves a benign form of spina bifida, where the defect is covered by skin and is not associated with the absence of vertebral arches