Introduction
Spina bifida is a condition that occurs due to the abnormal development of the spinal cord in the womb. Transitional spinal dysraphism (TSD) is a rare, subtler form of spina bifida, which is present from birth but may be found incidentally later in life. Characterised by certain structural changes in the spine found by imaging studies, some symptoms range from the presence of a hairy or discoloured patch on the back, to difficulties in walking or lower back pain.1 Read on to understand the implications and causes of this diagnosis in detail.
Understanding spina bifida
First, Let us talk about Spina Bifida. Embryos have special cells that are precursors to the various organs that develop in our body. Some of these cells form a tube-like structure called the neural tube that once developed, forms the nervous system. Sometimes, the neural tube does not close completely, causing anatomical abnormalities. This condition is called spina bifida.1
Types of spina bifida
There are various forms of spina bifida depending on the defect in the closure of the spinal cord.
- Occulta: mild form involving a small gap in closure usually without any symptoms
- Meningocele: the spinal cord develops normally but there is a small gap in the layer surrounding the spinal cord causing the cerebrospinal fluid to leak out and cause a small fluid-filled swelling
- Meningomyocele: this is a severe version of a meningocele. The gap in the layers of the spinal cord is bigger, causing the spinal cord and nerve roots to protrude through the layers into the fluid-filled sac. This causes damage to the delicate structures of the nervous system, resulting in severe neurological symptoms. These can include problems in movement, abnormal sensations, numbness, and in severe cases, paralysis
While these are the more commonly diagnosed subtypes, TSD represents a rare diagnosis with milder symptoms. TSD may not be apparent on physical examination or imaging scans at the first instance.2
What is Transitional Spinal Dysraphism (TSD)?
Transitional spinal dysraphism is a disorder resulting in anatomical abnormalities of the vertebrae, covering of the spinal cord, and skin abnormalities. It is often asymptomatic and may not be diagnosed easily through physical examination or imaging studies. The syndrome can manifest as spinal cord abnormalities and stiffness in the vertebrae later in life.2
Clinical presentation of TSD
Common signs and symptoms include:2,3
- Skin changes: these can include discolouration, tufts of hair, skin dimples or masses under the skin, or dark patches in the area of the spine (your back). These can be present at birth or can develop over time
- Movement: being clumsy very often while walking or toe-walking
- Sensory disturbances: numbness or tingling in the legs
- Weakness or in severe cases, paralysis in the legs
- Bowel or bladder dysfunction2,3
Causes and risk factors
It is essential to note that TSD does not have any specific cause. Research shows some possible causes of the condition which are outlined below:3
- Genetic predisposition: while there is no inheritance pattern observed for this condition, certain genetic variations are identified that can be tested during pregnancy
- Folic acid deficiency: it is essential to have your prenatal vitamins that include folic acid during your pregnancy. If your family has a history of having neural tube disorders, you may be instructed to begin folic acid supplements during the time you intend to conceive as well
- Maternal factors: obesity, diabetes and certain medications can increase the risk of TSD
- Family history: while there is no genetic predisposition of note, some genetic variations in the family do increase the risk of developing the disease
Diagnosis
A comprehensive medical history along with a thorough physical examination is the first step in understanding the cause of the symptoms. An MRI will be done next to visualise the spinal cord and vertebrae, identifying any abnormalities. Sometimes an electromyography can be done to understand the electrical activity of the nerves and muscle function.2,3
Management and treatment options
The management plan is based on the severity of the anatomical abnormality and the symptoms present.
- Surgical management: surgery may be required when the spinal cord is affected
- Physical therapy is effective for muscle weakness, walking issues, and bladder training
- Medications such as painkillers and muscle relaxants address symptoms of pain and cramping. Bladder dysfunction can be treated with medication as well
- Long-term monitoring is essential to keep track of the progression of symptoms and the defect in the vertebrae4
Prognosis
The success of treatment depends on various factors such as:
- Severity of the spinal cord abnormality
- Success of the surgery
- Presence of complications
- Adherence to physical therapy
- Severity of symptoms on presentation4
FAQs
What are the risk factors for developing transitional spinal dysraphism (TSD)?
Risk factors for TSD include genetic predisposition, maternal folate deficiency, maternal obesity, and certain medications or environmental exposures during pregnancy.3
Can transitional spinal dysraphism (TSD) be prevented?
While not all cases of TSD can be prevented, measures such as maternal folic acid supplementation, avoidance of teratogenic substances, and maintaining a healthy lifestyle before and during pregnancy can help reduce the risk of neural tube defects, including TSD.3
How is transitional spinal dysraphism (TSD) diagnosed prenatally?
Prenatal diagnosis of TSD may be achieved through maternal serum alpha-fetoprotein (MSAFP) screening, foetal ultrasonography, or prenatal magnetic resonance imaging (MRI) to detect structural abnormalities of the spinal cord and surrounding structures.2
What are the treatment options for transitional spinal dysraphism (TSD)?
Treatment options for TSD may include surgical intervention to release tethering of the spinal cord, address associated anomalies, and alleviate compression of neural structures. Non-surgical management strategies such as physical therapy, monitoring, and symptomatic treatment may also be employed.4
What are the potential complications of transitional spinal dysraphism (TSD)?
Complications associated with TSD may include neurological deterioration, orthopaedic abnormalities, bladder and bowel dysfunction, and psychosocial challenges. Regular monitoring and follow-up care are essential to detect and address these complications promptly.2
What is the long-term outlook for individuals with transitional spinal dysraphism (TSD)?
The long-term outlook for individuals with TSD varies depending on factors such as the severity of spinal cord abnormalities, the success of treatment, and the presence of associated complications. With appropriate management and support, many individuals with TSD can lead fulfilling and independent lives.4
Are there any support services available for individuals and families affected by transitional spinal dysraphism (TSD)?
Yes, there are various support services available for individuals and families affected by TSD, including patient advocacy groups, multidisciplinary healthcare teams, rehabilitation services, educational resources, and psychosocial support networks. These resources can provide valuable information, emotional support, and practical assistance for navigating the challenges of living with TSD.
Summary
- Transitional spinal dysraphism is a complex congenital condition involving abnormalities in the spinal cord and vertebrae
- This rare subtype of spina bifida can be asymptomatic and be hard to diagnose via imaging studies, however, it can present in imaging studies such as an MRI
- Sometimes the disease is symptomatic, presenting with mild symptoms such as weakness, gait abnormalities, or lower back pain and cramping to severe symptoms such as paralysis in the lower limbs and bladder and bowel dysfunction
- A team of healthcare providers diagnose the condition by first taking a comprehensive medical history, clinical examination, and then MRI and EMGs
- Treatment includes symptomatic management with medications and physical therapy and surgery in severe cases
- Some preventative measures are folic acid supplementation before and during pregnancy, healthy lifestyle choices, and prenatal screening
- TSD is a manageable condition with a holistic treatment plan encompassing physiotherapy, psychosocial, and educational support
References
- Pang D, Dias MS, Ahab-Barmada M. Split cord malformation: Part I: A unified theory of embryogenesis for double spinal cord malformations. Neurosurgery [Internet]. 1992 Sep 1;31(3):451-80. Available from: http://journals.lww.com/00006123-199209000-00010.
- Venkataramana NK. Spinal dysraphism. Journal of pediatric neurosciences [Internet]. 2011 Oct 1;6(Suppl 1):S31-40. Available from: https://journals.lww.com/10.4103/1817-1745.85707.
- Davis MC, Hopson BD, Blount JP, Carroll R, Wilson TS, Powell DK, McLain AB, Rocque BG. Predictors of permanent disability among adults with spinal dysraphism. Journal of Neurosurgery: Spine [Internet]. 2017 Aug 1;27(2):169-77. Available from: https://thejns.org/view/journals/j-neurosurg-spine/27/2/article-p169.xml.
- Vetrano IG, Barbotti A, Erbetta A, Mariani S, Bova SM, Colombo L, Caretti V, Marinoni F, Vestri E, Selvaggio GG, Valentini LG. Multidisciplinary management of children with occult spinal dysraphism: A comprehensive journey from birth to adulthood. Children [Internet]. 2022 Oct 12;9(10):1546. Available from: https://www.mdpi.com/2227-9067/9/10/1546.
