The prognosis depends on the type of spina bifida occulta...
Spina Bifida Occulta refers to a group of conditions involving the spinal column—a structure made of bones called vertebrae. The spinal column is responsible for supporting the skeleton and protects the spinal cord, which is the cable of nervous tissue that transmits information between the brain and the body. Spina Bifida Occulta is a common condition, occurring in 10% - 20% of otherwise healthy people; it is often found incidentally during a radiogram (X-Ray) of the lower back. By definition “Spina Bifida Occulta” means “hidden split spine.” The term is misleading because it is used to describe several conditions. The most frequently seen form is considered harmless and is simply a variant of normal vertebral (bone) anatomy. In this condition, parts of the bones of the spine called the spinous process and neural arch appear abnormal on a radiogram. Usually, the spinal cord, and spinal nerves are not involved. Isolated bony Spina Bifida Occulta (without an underlying spinal cord abnormality) does not lead to problems with the nervous system. Some radiologists have resorted to calling this situation a vertebral fusion defect, thus taking away the reference to Spina Bifida.
However, there are related conditions (much less common) also called Spina Bifida Occulta that affect the spinal cord and can have potential health consequences. For a list see: