Final answer:
The mildest form of spina bifida without herniation is spina bifida occulta. It involves incomplete closure of the vertebral bones around the spinal cord but usually has no functional symptoms. Early surgery and adequate folate during pregnancy can help manage this and more severe forms of the condition.
Step-by-step explanation:
The form of spina bifida associated with the failure of the bony spinal canal to close but without any herniation is known as spina bifida occulta. This is the mildest classification of spina bifida and is characterized by a defect in the closure of the vertebral bones surrounding the spinal cord, yet the spinal cord and the nerves within it remain untouched. As such, there may be no noticeable functional impairments, showing why the term 'occulta', meaning hidden, is applied to this condition.
Spina bifida occulta differs from other forms of spina bifida, such as meningocele and myelomeningocele, both of which involve more severe protrusions and potential neurological symptoms. Often, early surgical intervention is necessary to prevent additional damage or infection, especially in cases of meningocele and myelomeningocele where cysts or the defective neural tissue are present.
Lack of adequate folate during early embryonic development is a known risk factor for the neural tube's failure to close properly, leading to disorders like spina bifida. This underlines the importance of proper maternal nutrition during pregnancy to support the normal development of the nervous system.