Here's some information:
Occult Spinal Dysraphism:
Refers to a skin-covered subcutaneous mass on the back with a variety of lesions responsible for the mass.
Lesions = spinal lipomas, dermoid or epidermoid cysts, diastematomyelia, dermal sinus tract, meningoceles, and myelocystocele.
A common pathologic effect shared by these entities is the traction on the spinal cord referred to as the tethered cord syndrome
From the book
"Surgical Disorders of the Sacrum"
Doty and Rengachary
<<If the cord is also tethered is this what is called spina bifida occulta?>> No, tethered cord is a condition that is related to occult spinal dysphrasm, it isn't in itself called SBO. SBO and OSD are not the same thing. spina bifida occulta is when there is no nerve involvement ata ll- no neurological deficient. Occult Spinal Dysraphism (OSD) is when there is some kind of nerve involvement- when there is some neurological comprimise. OSD's are closed forms of spina bifida but they are involved and inhibit function at some point.
From an article called 'mgmt of tight filum terminal syndrome...."
"Maldevelopment in the neurulation process causes various congenital malformations such as myelomeningocele, meningocele, lipomyelomeningocele, split cord malformations and dermal sinus tract"
OSD lesions can include the following:
lipomeningomyelocele-spinal lipoma
spinal cord tethered by a thickened filum terminale
dermal sinus tracts w/ or w/o dermoid tumors
diastematomyelia-split cord malformations, often associated with hairy patch
meningocoele manque-dorsal spinal cord fixation associated with diastematomyelia
neurenteric cysts
terminal syringomyelia-CSF-filled cyst involving lumbar spinal cord, often associated with tethered cord
Another article defines Spinal dysraphisms as:
"a term that refers to all forms of developmental abnormalities occuring in the midline of the back - from the skin externally to the vertebral bodies internally. Although the true incidence of spinal dysraphism is unknown, authors of some studies have extimated an incidence of 0.05 to .25 per 1000 births. These abnormalities usually involve the lumbosacral spine, though lesions in the cervical and thoracic region do occur. Spinal dysraphism, which may result in a tethered spinal cord, exists in an open form, spina bifida aperta, and in a closed form, spina bifida occulta. The most commone expression of spina bifida aperta is the myelomeningocele. Common forms of spina bifida occulta include the lipomyelomeningocele and diastematomyelia.
Tethered cord syndrome
Tethered cord syndrome (TCS) usually occurs in children but can occur in adults. The bottom end of the spinal cord usually lies just below the junction between the thoracic (rib bearing) vertebrae and the lumbar vertebrae.
In TCS the bottom of the spinal cord is too low (below the second lumbar vertebra) indicating that it is tethered. This generally occurs in the presence of MM which will previously have been operated upon. It can also complicate a lipoma of the spine, a dermal sinus of the spine or spina bifida occulta. A thickened band passes from the end of the spinal cord to the bottom of the sacrum, the coccyx.
Problems TCS can cause
Problems occur in TCS during times of growth of the child.
When children grow their spine lengthens a lot but the spinal cord does not.
In adults, extreme movements of the spine can pull on the cord and can cause symptoms.
The spinal cord should be free to move relative to the growth of the spine but in TCS it is tethered so lengthening of the spine causes tension on the spinal cord and nerves. The symptoms include:
difficulty walking
leg weakness and muscle wasting
sensory loss in the legs
foot deformities (children only) pes cavus
bladder and bowel disturbance (incontinence)
back pain or leg pain (more common in adults)
scoliosis
Investigations for TCS
MRI scan of the back will demonstrate TCS.
Treatment of TCS
All spinal cords which appear tethered on a scan require treatment. However, if symptoms or neurological deterioration occur the cord should be untethered. In this operation the back is opened and the bottom of the spinal cord is freed from the surrounding tissues. The thickened filum terminale (bottom of the spinal cord) is cut. The spine can then lengthen without putting tension on the spinal cord.
The operation may need to be repeated as the child grows because scarring can lead to recurrent tethering. The risks of surgery include cord or nerve damage and meningitis
What is Tethered Spinal Cord Syndrome?
Tethered spinal cord syndrome is a neurological disorder caused by an abnormal stretching of the spinal cord. The course of the disorder is progressive. In children, symptoms may include lesions, hairy patches, dimples, or fatty tumors on the lower back; foot and spinal deformities; weakness in the legs; low back pain; scoliosis; and incontinence. Tethered spinal cord syndrome may go undiagnosed until adulthood, when symptoms such as sensory and motor problems and loss of bowel and bladder control emerge. This delayed presentation of symptoms is related to the degree of strain placed on the spinal cord over time. Tethered spinal cord syndrome appears to be the result of improper development of the neural tube, and is closely linked with spina bifida.
Is there any treatment?
In children, early surgery is recommended to prevent further neurological deterioration. If surgery is not advisable, spinal cord nerve roots may be cut to relieve pain. Other treatment is symptomatic and supportive.
What is the prognosis?
With treatment, patients with tethered spinal cord syndrome have a normal life expectancy. However, some neurological and motor impairments may not be fully correctable.
What research is being done?
The NINDS conducts and supports research on disorders of the spinal cord. The goals of this research are to find ways to prevent, treat, and cure these disorders.
<<does anyone know what surgery is involved for this and typically how long hospitalisation is>>
Surgery involves the NS opening up the back and releasing the tether. Hospitalization varies, but our experience is about 5 days. First 3 days in the prone (flat position), then slowly the child is permitted to sit up (for older children).
