What is Tethered Cord Syndrome (TCS)?

Tethered Cord Syndrome (TCS) is when the body tissue attaches itself to the spinal cord, resulting in limited movement of the spinal cord. This is a nervous system disorder that could cause the spinal cord to stretch abnormally. It may be caused by impaired growth of the neural tube, which later forms the brain and spine, while the foetus is still developing.¹ 

Patients may reach adulthood and only be diagnosed late in life. The delayed symptoms occur gradually over time due to  worsening strain on the spinal cord. 

How is it related to spina bifida?

It is related to the spina bifida condition, which is  the formation of a gap in the spine  due to the abnormal formation of the baby’s spine and spinal cord during pregnancy. This usually occurs in a certain type of spina bifida which is called myelomeningocele. In this condition, the spinal cord does not detach from the skin of the back during foetal development which prevents the spinal cord from rising normally. This causes it to be low-lying or tethered.² 

About one-third of myelomeningocele patients would need surgery for TCS during their childhood as the symptoms of spinal cord tethering increase during periods of rapid growth.³ 

Causes and Risk Factors

The most common causes or risk factors of TCS are:^1,4

• Spinal cord injury
• Pregnancy
• Ageing - the spinal column gets narrower
• Childbirth 

Signs and symptoms

The usual presentation of TCS includes one or more of these symptoms:^1,5

• A bump, discolouration, or hairy patch on the child’s back
• Back pain
• Leg pain
• Muscle weakness or numbness in the legs or feet
• Difficulties standing or walking
• No bowel or bladder control 

How is it diagnosed?

When a patient shows symptoms of TCS, doctors usually  perform a magnetic resonance imaging (MRI) to check the spine. An MRI scan can help observe the level of conus medullaris (a segment of the spinal cord measuring about 3cm), lesions, and plan for surgeries. It can also be used to check the thickness of the filum terminale - if it is thicker than 2mm, it  is considered abnormal in children.³ 

In addition, MRI can help to give a broad picture of the investigation, diagnosis, and treatment of the disease in association with spinal cord tethering. This includes myelomeningocele, lipomyelmeningocele, split cord malformation, etc.³

Testing the bladder is also important to diagnose TCS as sphincter dysfunction may show up  as a symptom at any age. The different evaluation tests for a bladder affected by  the nervous system include total bladder capacity and pressure, uninhibited contractions, leak point pressure, electromyelogram activity, sensation of the bladder, and bladder compliance. After spinal cord detethering surgeries, formal testing of the bladder is performed to ensure improvement or stability of the patient.⁴ 

Management and treatment options

Surgery

According to a study conducted, a group of 40 patients who had  undergone meningomyelocele surgery later developed symptoms of TCS, which was 88.9% of the study size. The likelihood of them getting TCS showed a 27.5% chance after one year, 40% chance after two years and 60% chance at 5 years. They had more foot and bladder control issues related to TCS. The results show a high consideration for de-tethering procedures in patients who had undergone repair of meningomyeloceles.⁶ 

The healthcare team will only consider untethering surgery if the patient's  health is deteriorating  due to signs and symptoms of TCS. The process of untethering involves opening the skin around the covering of the myelomeningocele (dura). A small section of the bony vertebrae (laminae) may be taken out to provide a better view of the spinal cord. Then, the myelomeningocele and spinal cord are carefully detached from the surrounding nerve roots. Once that is done meticulously, the dura and the surgical wound are closed by the surgeon.² 

In recent years, minimally invasive spinal surgery has been preferred due to minimal blood loss,  shorter hospital stay, and adequate pain control after the operation. This has been applied to minimally invasive surgery for TCS and results have shown that it is a safe and viable alternative to open surgery.⁷  

Rehabilitation and supportive care

After the surgical procedure for TCS is completed, patients usually stay for one to two nights in the hospital. Patients are encouraged to lie flat on the bed overnight to rest and prevent stress on the wound closure. Referrals to occupational or physical therapists may be recommended to relieve bowel and bladder problems, although follow-up for patients is difficult due to carers having to coordinate visits to various places.³ 

A paediatric tethered cord clinic was developed at a paediatric medical centre in Chicago, USA to improve the multidisciplinary care in TCS patients with occult spinal dysraphism (OSD). There have been successfully managed multidisciplinary spina bifida clinics,  so it should be similar for TCS patients. The results showed that it improves care, decreases the burden on families, and improves regular follow-up.⁸ This shows that rare and complex diseases should be routinely monitored especially after surgery as patients benefit from the clinic care  for the various symptoms present. 

Long-term  condition and complications

After having spinal cord untethering surgery, all patients showed  improvement in pain management, and about 70% of patients showed improvement in motor strength, better gait, and less muscle pain and spasms. Moreover, about 64% of patients showed better bladder control after the surgery.⁹ 

Unfortunately, every surgical procedure has risks and complications. The chances of there being complications from having the untethering surgery are  usually about 1 to 2%. The complications  include infection, spinal cord or myelomeningocele damage, and bleeding.² Damage to the spinal cord or myelomeningocele could cause bowel or bladder problems, or less muscle strength. Most children only need one surgery in their lifetime but as growth happens, about 10-20% of children might need surgery again.² 

The decision on whether to have surgical treatment depends on the doctor and patient. Patients and guardians should make informed decisions after weighing the risks and benefits. 

FAQs

What is the life expectancy of someone with tethered cord syndrome? 

Patients usually have normal life expectancy if they are treated, although they may not be able to move normally or have the best bowel and bladder control. 

Is TCS hereditary?

 Some patients may have gene defects that cause stretching of the spinal cord. Some patients could also have genes that  increase  the risk of developing the condition in rare cases.¹⁰

Summary

 It is evident that there is a relationship between TCS and spina bifida.  The significant impact of TCS on the management and outcome of patients with spina bifida has been discussed in this article.

Healthcare professionals need to recognise  the implications of TCS in the subset of spina bifida, which is myelomeningocele. They must adopt a comprehensive management approach that combines early detection, appropriate intervention, and ongoing support to benefit patient outcomes. 

 Continued efforts in raising awareness, enhancing diagnostic methods, and advancing treatment are essential to improve the quality of life for individuals affected by both TCS and spina bifida. Successful spina bifida clinics could pave the way for the formation of more specialised TCS clinics and improve patient support post-operation. Through collaborative research and clinical programs, we can strive towards better understanding, management, and ultimately, prevention of these conditions.