Tethered spinal cord syndrome is a rare neurological disorder where the spinal cord is attached, or tethered, to the tissues around the spine. This tethering of the spinal cord restricts its movements and prevents it from keeping up with its ongoing growth as the body grows. This causes the spine to stretch and elongate abnormally, which may cause nerve damage and extreme pain.
Tethered cord syndrome has been linked to spina bifida and scoliosis. Roughly 20% to 50% of children who were diagnosed with spina bifida at birth and have undergone surgery to correct its impacts on their body may need surgery later in life to untether the spinal cord as well.
Some children are diagnosed with tethered cord syndrome at birth (what's known as a congenital condition), whereas others get symptoms of the condition as infants or during their early childhood. In some cases, people with tethered cord syndrome show no visible sign of the condition until they become adults.
Most incidents of tethered cord syndrome are developmental — that is, they unfold as the child grows older. This happens as fibrous connective tissue builds up in the filum terminale, which typically runs from the L1 vertebra of the spinal cord up to the beginning of the coccyx, or tailbone.
These fibrous tissues are non-elastic and are part of the neural tube. The neural tube is formed in the embryonic stage and later forms the spinal cord. The fibrous tissue comes out of the neural tube and attaches itself to the spine when the neural tube doesn't close completely. This is what restricts the movement of the spinal cord.
Because tethered cord syndrome is a physiological condition, it can be reversed if doctors are able to detect it in its early stages and perform surgery soon after.
What Causes Tethered Cord Syndrome?
Two conditions are primarily responsible for tethered cord syndrome — myelomeningocele and lipomyelomeningocele.
The lower end of the spinal cord is located opposite the disc between the first and second lumbar vertebrae (known as the L1 and L2 vertebrae). With myelomeningocele, the spinal cord doesn't separate from the skin in the back region as the child grows.
The spinal cord stores fat in the lower end of the spine. In lipomyelomeningocele, this fat in the spinal cord gets intertwined with the fat in the thecal sac (the sac that the spinal cord floats within) and limits the spinal cord's movement.
Other conditions that are known to cause tethered cord syndrome include:
Symptoms of Tethered Cord Syndrome
The persistent stretching of the tissues due to the continuous growth of the child leads to several neurological symptoms as well as other kinds of symptoms. As the growth rates of the body and the spinal cord are different from one child to another, it’s difficult to determine the exact signs of this condition.
Some of the symptoms of tethered cord syndrome in children include:
- Fatty tumor or a deep indentation in the lower back
- A wound or lesion in the lower back
- Severe back pain that increases with activity
- A hairy patch or discolored skin on the lower back
- Pain in the legs, especially on the rear side
- Deformities of the legs
- A fragile spine
- Scoliosis (sideways curving of the spine)
- Bowel or bladder issues
- Numbness or a tingling sensation in the legs
In very rare cases, people with tethered cord syndrome may go into adulthood without being diagnosed with this condition. This could lead to immense strain on the spinal cord and cause growing sensory and motor problems and a total loss of bladder and bowel control.
Treatment for Tethered Cord Syndrome
Treating tethered cord syndrome typically involves surgery to release the spinal cord from the tissue. This surgery is called a laminectomy and usually involves removing a few parts of the bones (called bone spurs) or tissues from the lower part of the spinal cord. This process enables the surgeons to access the area around the spinal cord and enlarges the spinal canal, which relieves pressure on the cord and the nerves around it.
The surgeons free the spinal cord either by gently moving it or by completely cutting it away from the spinal fat that restricts the motion. After completing the surgery, surgeons usually patch the area they operated on to prevent the loss of blood and cerebrospinal fluid. Neurosurgeons may rely on techniques such as neuromonitoring to help them observe the progress of the surgery.
Sometimes, as the child grows, the spinal cord will reattach itself to the tissue even after a successful surgery. This can restrict the child's movements once again. In these cases, they may need additional or multiple surgeries to release the spinal cord.
Around 10% to 20% of children with this condition need more than one surgery as the symptoms of tethering occur during growth phases.
Children are usually able to get back to their normal activities within a few weeks of a successful surgery. How much muscle and bladder function the child regains after surgery depends on the impact of the condition before the surgery.
Complications after surgery include infections, bleeding, and damage to the spinal cord, which could lead to reduced muscle strength or limited bladder and bowel function. In some cases, the children may need to undergo some sort of physical therapy following surgery. This can help the healing process and gradually improve muscle strength in the areas of the body that weren't previously used because of the condition.
If surgery doesn't happen early, tethered cord syndrome may lead to serious consequences, such as deteriorating motor and sensory functions. In some cases, it may also lead to paralysis of the lower body and the total loss of bowel and bladder functions.