Spina Bifida Occulta (SBO) is the mildest and most frequent form of Spina Bifida, often remaining hidden for a lifetime and discovered incidentally during imaging for an unrelated condition. The term “occulta” means “hidden,” reflecting that the condition is usually asymptomatic and does not present with the visible sac associated with more severe forms. The question of whether SBO qualifies as a disability is complex, depending less on the diagnosis itself and more on the presence and severity of any resulting functional limitations. This article explores the anatomical reality of SBO, its potential for symptoms, and the specific criteria used to determine legal disability status.
Understanding Spina Bifida Occulta (SBO)
Spina Bifida Occulta is a congenital defect that arises when the neural tube, which forms the brain and spinal cord, does not fully close during the first month of embryonic development. The condition is characterized by a small bony defect in one or more of the vertebrae, typically in the lower lumbosacral region. Unlike Meningocele or the more severe Myelomeningocele, SBO is defined by the fact that the spinal cord and its protective membranes, the meninges, remain intact and within the spinal canal.
This structural difference makes SBO the mildest type of Spina Bifida, as the nervous system tissue is not exposed or damaged at the time of birth. The small gap in the bony covering is covered by skin. An estimated 10% to 20% of the population may have SBO, and for the vast majority, the condition causes no symptoms and is never diagnosed.
Symptom Presentation and Functional Impact
The typical experience of someone with Spina Bifida Occulta is complete absence of symptoms, with no need for medical intervention or lifestyle changes. The condition is so often benign that its discovery on an X-ray performed for back pain is frequently coincidental. Most individuals with SBO lead full, active lives without ever knowing they have the condition.
A small fraction of people with SBO, estimated to be about 1 in 1,000, do experience neurological symptoms that can lead to functional limitations. These symptoms are not caused by the bony defect directly but by associated conditions, collectively known as occult spinal dysraphism, which may include a tethered cord or lipomas.
Tethered cord syndrome is the most frequent complication, occurring when the spinal cord is abnormally attached to the surrounding tissues, restricting its movement. As a person grows, a tethered cord can become stretched, leading to nerve damage and neurological dysfunction.
This complication can manifest as progressive back or leg pain, muscle weakness in the lower extremities, and changes in gait. Importantly, it can also cause dysfunction of the nerves controlling the bladder and bowels, resulting in incontinence or difficulty controlling elimination. It is these rare, secondary complications and the resulting nerve damage that create true physical impairment, not the simple bony gap of SBO alone.
Determining Disability Status
Determining whether Spina Bifida Occulta constitutes a legal disability depends on the specific functional impact the condition has on an individual, not merely the diagnosis itself. Disability is generally defined by the inability to engage in substantial gainful activity due to a medically determinable physical or mental impairment that is expected to last for a specified duration. SBO, in its most common, asymptomatic form, does not meet this definition because it causes no functional limitation.
For an individual with SBO to be granted disability status, the application must demonstrate that the condition has resulted in a severe, medically documented impairment. This means the person must provide evidence of the complications, such as severe, intractable back pain, significant motor dysfunction, or profound bladder or bowel control issues caused by a tethered cord or other associated neurological damage. The diagnosis of SBO serves as the underlying cause, but the disability determination is based on the measurable severity of the resulting impairment, which is evaluated against specific criteria for neurological or musculoskeletal disorders.
The focus of the review is on residual functional capacity—what the person can and cannot do in a work environment or, for a child, in age-appropriate activities. Simply having the bony defect is not sufficient; the claim must prove that the complication results in limitations severe enough to prevent full-time work or normal development. Medical records, including imaging studies like Magnetic Resonance Imaging (MRI) and nerve conduction studies, are necessary to document the extent of the nerve damage and functional loss required for a successful claim.
Medical Monitoring and Long-Term Outlook
For the many individuals whose Spina Bifida Occulta is discovered incidentally and who have no symptoms, specialized medical monitoring is generally not required. The defect is simply noted, and routine pediatric or adult care continues as normal, with no need for further evaluation or treatment. The long-term outlook for this large group is excellent, with no reduction in life expectancy or quality of life.
If symptoms such as pain, weakness, or bladder changes do develop, a thorough evaluation by specialists like a neurosurgeon or neurologist is necessary to check for a tethered cord or other occult conditions. This evaluation often involves an MRI to visualize the spinal cord and surrounding structures. If a tethered cord is confirmed, surgical intervention may be recommended to release the cord and prevent further nerve damage.
The vast majority of people with SBO, even those who require surgical correction of an associated condition, are able to lead independent and fulfilling lives. The prognosis remains positive because the spinal cord itself is usually normal, and the functional problems are localized and often treatable.