Occult Spinal Dysraphism

Occult spinal dysraphism (OSD) comes with mild symptoms. This form of spina bifida is a closed type where the spinal nerves and or meninges are mixed up in some way with their surrounding structures and this involvement causes complications. This form of spina bifida can be hard to detect and not always has clear complications. This is why it is unclear how many people have it. There is an estimation of 1 in 250 people to 1 in 5,000 people. As science reveals more things this estimation may become more precise.

These are the signs of OSD:
As many as 80% of people with OSD have at least one of these outward signs or herald marks. The signs include:

• A hairy patch in the middle of the lower back
• A fatty lump over the bottom of the spine
• A stork bite or haemangioma (a reddish or purple spot) on the skin
• A dimple or sinus (hole) above the level of the crease in the buttocks (Dimples below the level of the crease are common in newborns and are usually no cause for alarm)
• A pigmented area or birthmark over the bottom of the spine.
• A small tail

OSD can be very complex because it is not just one condition. It represents a number of conditions which can occur separately or in combination. Some of these conditions are:

• A tethered spinal cord where the lower end of the spinal cord is stuck or attached to surrounding bone or other structures. The spinal cord is usually free (to some extent) to move up and down within the spinal canal.
• A lipoma which is a fatty lump whose tissues are often interwoven with those of the spinal cord, making them very difficult to separate. Lipomas can also tether the spinal cord.
• Diastematomyelia where the spinal cord is split in two usually by a piece of abnormal bone or cartilage. This can also tether the spinal cord.
• A dermal sinus which is a connection between the spinal canal and the skin of the back.

All of these conditions can affect the functioning of the spinal cord i.e. its ability to send messages to and from the brain. The cord can become stretched which causes pain and the blood supply to the cells in the spinal cord can be affected with the result that the nerves lose their ability to function properly.

These are complications of people with OSD:
Not everyone with OSD will have complications. Sometimes the onset of signs and symptoms will be so gradual that they may not appear until adulthood. For most though, there will be some indications early in the person’s life that the nerves in the spine are not working as they should.
Some of these are:

• Foot deformity
• Weakness in the legs
• Reduced feeling or numbness in the legs or feet
• Back or leg pain
• Bladder infections
• Bladder incontinence
• Constipation
• Scoliosis or other orthopedic deformities.

All of these symptoms can be caused by conditions other than OSD so it is important to see your doctor for thorough testing and an accurate diagnosis.
It is especially important to seek medical advice where the symptoms are progressing or getting worse. These changes may indicate that the spinal cord is tethered and an operation to untether the cord might be required.

Prevention:
There is no guaranteed prevention, but is has been shown that taking enough folic acid can reduce the risk of neural tube defects in baby by 70%. To help prevent OSD it is recommended to have enough folic acid in your diet one month before conception and all through out pregnancy. The recommended amount is .5 milligrams a day. If  history of neural tube defects is found in either the mother or father's history then it is recommended to have a larger dosage of 4 milligrams a day.

Information for this blog page was received from: http://www.mydr.com.au/babies-pregnancy/spina-bifida-occulta

and also from: Spina Bifida Hydrocephalus Queensland. Spina Bifida Occulta. July 2010. http://spinabifida.org/wp-content/uploads/2010/12/SBO-Booklet.pdf