Occulta is Latin for “hidden”. This is the mildest form of spina bifida.
In the 17th century, Dutch anatomists provided the first descriptions and initiated surgical management efforts for spina bifida. In the 19th century, the term “spina bifida occulta” was coined and various presentations of spinal dysraphism were appreciated.
In occulta, the outer part of some of the vertebrae is not completely closed
The splits in the vertebrae are so small that the spinal cord does not protrude. The skin at the site of the lesion may be normal, or it may have some hair growing from it; there may be a dimple in the skin, or a birthmark.
Many people with this type of spina bifida do not even know they have it, as the condition is asymptomatic in most cases.The incidence of spina bifida occulta is approximately 10-20% of the population, and most people are diagnosed incidentally from spinal X-rays. A systematic review of radiographic research studies found no relationship between spina bifida occulta and back pain.
More recent studies not included in the review support the negative findings.
However, other studies suggest spina bifida occulta is not always harmless. One study found that among patients with back pain, severity is worse if spina bifida occulta is present.
Among females, this could be mistaken for dysmenorrhea.
Incomplete posterior fusion is not a true spina bifida, and is very rarely of neurological significance.
Current understanding of tethered cord syndrome first began with the understanding and management of spina bifida; this later led to the gradual recognition of spina bifida occulta and the symptoms associated with tethering of the filum terminale.
Spina bifida occulta (SBO) may occasionally be associated with diastematomyelia, tethered cord, lipoma, or dermoid tumor. When symptomatic from one of these associated conditions, the presentation is usually that of tethered cord.
Infants with classic cutaneous markers of occult spinal dysraphism (OSD), with progressive neurologic, skeletal, and/or urologic findings, present no diagnostic or therapeutic dilemma: they routinely undergo MRI and Spinal cord untethering (SCU). Conversely, in asymptomatic patients or those with fixed, minor abnormalities, the risk profile of these OSD cohorts should be carefully considered before SCU is performed. Irrespective of whether or not SCU is performed, patients at risk for progression should be followed carefully throughout childhood and adolescence by a multidisciplinary team 1).