Tethered cord explained...

First I wanna say, do not take this as medical advice. This is just how I understand what my daughter is going through, from my research on the internet.

When a fetus is formed, it goes through some pretty amazing processes. From a few cells that forms into a little body with all the organs intact, limbs attached, a head with a brain inside, and, of course the back with the spinal cord. These processes are very delicate and a certain number of things have to happen in the right order, at precisely the right time. If anything interrupts this process, there could be a defect in the fetus. Sometimes the defect is big enough so that a natural miscarriage follows, and sometimes the defect is so small that not even an MRI can pick it up.

One of the very early processes, is when a certain layer of cells (which later also forms the skin) forms the top part of the spinal cord. This process is called neurulation, and happens on the 18^th to the 22^nd day after conception. Thus, in around week 5 of pregnancy (14 days is added before pregnancy that leads up to conception. So at 6 weeks pregnancy, the fetus is 4 weeks “old”, and at 20 weeks pregnancy, the baby is 18 weeks “old”).

The bottom part of the spinal cord is formed by a process called canalization, starting around the 28^th day. The 2 parts of the spinal cord, formed by neurulation and canalization fuse together, and a 3^rd process starts. Around the 45^th day, the regression process takes place, forming the conus medularis (the pointed tip of the spinal cord) as well as the cauda equinae (the nerves that dangle from the spinal cord tip). The regression process has one last part. The lower end of the spinal cord degenerates, to form a fibrous band that extends from the very tip of the spinal cord down to the sacrum (very low back) where it is attached. This band is called the filum terminale, and the formation of it happens during the 45^th to the 48^th day. The 9^th week of pregnancy.



Source: http://en.wikipedia.org/wiki/Filum_terminale

 Because the degeneration that forms the filum terminale isn't a precise process, defects are more likely to happen than at the other processes. When degeneration fails, the result is a tight filum terminale.

Tight filum terminale means that the spinal cord is tethered to the bottom of the spine more tightly than it should've been. The spinal cord needs to float freely in the spinal canal. When the cord is tightened, it cannot float freely and this influence the nerves sprouting from the bottom of the spinal cord. These nerves serves the bowels, bladder and legs. As the person bends during normal daily activities, the cord is stretched tightly, instead of the filum terminale that should've stretch like an elastic band. When the cord is stretched, nerves are being damaged.

There are different pathologies that can cause a tethered cord. Tight filum is just one such possibility. Others include lipomas (fatty growths), scar tissue, bony spurs, dermal sinus tracts, etc.

Possible symptoms of a tethered cord (caused by a tight filum or other cause):

• Outward markers on the back, like a birthmark, hairy patch, dimples, etc.
• Scoliosis (curvature of the spine)
• Back Pain
• Gait, feet or leg abnormalities
• Drop foot
• Leg length discrepancy
• Feet length discrepancy
• Abnormal gait (stumbling, lifting legs too high, difficulty walking, etc.)
• Leg weakness
• Sensory abnormalities/paresthesia (skin numbness, pins and needles, etc.)
• High foot arches
• Clawed toes
• Toe-in (toes point sharply towards other foot)
• Pain in legs
• Tight or stiff leg muscles
• Muscle atrophy
• Bowel problems
• Loss of bowel control
• Constipation
• Impaction
• Bladder problems
• Incontinence
• Frequent infections
• Urgency
• Frequency
• Renal reflux with possible kidney damage

The list probably isn't complete, as it's such an individual thing. Depending on which nerves, and to what extend, it is being damaged by the traction. I've highlighted Boeboe's symptoms. Some of it is small symptoms, like the toe-in, the leg pain, high foot arches, and leg length discrepancy. It could/would almost be normal, if she didn't have all the other symptoms as well. The biggest problems we have with her, is of course the urinary and bowel problems. Of which she has nearly every possible symptom. That is why we've fought so hard to get her diagnosed.

Once a child is diagnosed with a tethered cord, surgery is nearly always indicated. The main goal is to stop more damage to the nerves by releasing the cord (detethering). Sometimes, the child is fortunate enough to experience improvement in some symptoms. We are hoping that since Boeboe has an occult tethered cord (meaning, it wasn't stretched out so much that the conus was lower than normal), she would be lucky and will have at least some improvement. Usually, pain and bowel symptoms improve after detethering. Unfortunately, urinary symptoms has the least likelihood of improving, though some studies had between 60-80% of people with occult tethered cord that experienced at least some urinary improvement.

Best case scenario would be if Boeboe could end up continent, in both bowel and bladder, and not experience the severe constipation or bladder spasms anymore. As well as an improvement in her dropfoot, so that she doesn't fall so much. I know that this scenario is highly unlikely, but we can hope, can't we?