Tethered Cord in Children
Introduction to Tethered Cord Syndrome in Children
Tethered cord syndrome (TCS) is a neurological disorder characterized by an abnormal attachment of the spinal cord to surrounding tissues, limiting its normal movement within the spinal canal. This condition most commonly occurs in children but can also affect adults. In a normal spine, the conus medullaris (the tapered, lower end of the spinal cord) typically ends at the level of the L1-L2 vertebrae in adults and L3 in newborns. In TCS, the spinal cord is anchored at a level lower than normal, usually below L2, causing tension on the cord as the child grows.
The incidence of tethered cord syndrome is estimated to be 0.05 to 0.25 per 1,000 live births, with a higher prevalence in patients with spinal dysraphism. Early recognition and treatment of this condition are crucial to prevent irreversible neurological deficits.
Etiology of Tethered Cord Syndrome
Tethered cord syndrome can be congenital or acquired. The main causes include:
- Spinal dysraphism: This includes conditions such as:
- Myelomeningocele
- Lipomyelomeningocele
- Diastematomyelia (split cord malformation)
- Dermal sinus tracts
- Tight filum terminale: An abnormally thickened or fatty filum terminale can restrict cord movement.
- Postoperative adhesions: Following surgery for spinal dysraphism or other spinal procedures.
- Spinal cord tumors: Intramedullary tumors or lipomas can cause cord tethering.
- Trauma: Scar tissue formation after spinal cord injury can lead to tethering.
Genetic factors may play a role in some cases, particularly those associated with syndromic conditions like VACTERL association or Currarino syndrome.
Clinical Presentation of Tethered Cord Syndrome
The clinical presentation of tethered cord syndrome can vary widely, from asymptomatic to severe neurological deficits. Symptoms often progress with age and growth. Common signs and symptoms include:
- Cutaneous manifestations:
- Hairy patch or dimple in the lower back
- Subcutaneous lipoma
- Hemangioma or port-wine stain
- Dermal sinus tract
- Neurological symptoms:
- Lower extremity weakness or paralysis
- Sensory deficits in the legs or perineal area
- Gait abnormalities
- Foot deformities (e.g., pes cavus, clubfoot)
- Scoliosis or other spinal deformities
- Urological symptoms:
- Urinary incontinence or retention
- Recurrent urinary tract infections
- Neurogenic bladder
- Pain:
- Back pain, often worsening with flexion
- Leg pain or radiculopathy
- Gastrointestinal symptoms:
- Constipation
- Fecal incontinence
It's important to note that symptoms can be subtle in young children and may become more apparent as they grow older and engage in more physical activities.
Diagnosis of Tethered Cord Syndrome
Diagnosing tethered cord syndrome involves a combination of clinical evaluation and imaging studies:
- Clinical examination:
- Thorough neurological assessment
- Evaluation of cutaneous stigmata
- Assessment of gait and spinal curvature
- Urological evaluation, including urodynamic studies
- Imaging studies:
- Magnetic Resonance Imaging (MRI): The gold standard for diagnosis. It can visualize:
- Position of the conus medullaris
- Thickness of the filum terminale
- Associated spinal cord abnormalities
- Presence of lipomas or other lesions
- Plain radiographs: May show spinal dysraphism or vertebral anomalies
- Computed Tomography (CT): Can provide detailed bony anatomy, useful in complex cases
- Ultrasound: Useful in infants with open fontanelles for initial screening
- Magnetic Resonance Imaging (MRI): The gold standard for diagnosis. It can visualize:
- Urodynamic studies: To assess bladder function and detect early neurogenic bladder
- Electrophysiological studies: Such as somatosensory evoked potentials (SSEPs) and electromyography (EMG), may be used to assess neurological function
The diagnosis of tethered cord syndrome is primarily based on radiological findings, particularly the position of the conus medullaris below the L1-L2 level. However, it's important to correlate imaging findings with clinical symptoms, as some individuals with a low-lying conus may be asymptomatic.
Treatment of Tethered Cord Syndrome
The primary treatment for symptomatic tethered cord syndrome is surgical untethering. The goals of treatment are to prevent further neurological deterioration and, if possible, improve existing symptoms.
- Surgical untethering:
- Involves releasing the spinal cord from abnormal attachments
- May include resection of lipomas, division of the filum terminale, or removal of scar tissue
- Microsurgical techniques are used to minimize trauma to the spinal cord
- Intraoperative neurophysiological monitoring is often employed to reduce the risk of neurological injury
- Timing of surgery:
- Generally recommended when symptoms are present or progressing
- Prophylactic surgery may be considered in asymptomatic patients with significant radiological findings, though this remains controversial
- Postoperative care:
- Close monitoring for cerebrospinal fluid (CSF) leak
- Early mobilization as tolerated
- Physical therapy and rehabilitation
- Non-surgical management:
- Regular neurological and urological follow-up for asymptomatic patients
- Management of neurogenic bladder and bowel dysfunction
- Physical therapy for gait abnormalities and muscle weakness
- Pain management as needed
- Complications and considerations:
- Risk of retethering, particularly in cases of complex spinal dysraphism
- Potential for CSF leak or pseudomeningocele formation
- Transient worsening of neurological symptoms postoperatively
The decision to perform surgery should be made on a case-by-case basis, considering the patient's age, symptoms, radiological findings, and potential risks and benefits of the procedure. Close long-term follow-up is essential for all patients with tethered cord syndrome, regardless of whether they undergo surgical intervention.
Prognosis of Tethered Cord Syndrome
The prognosis for children with tethered cord syndrome varies depending on several factors, including the severity of the tethering, age at diagnosis, presence of associated anomalies, and timing of intervention.
- Outcomes after surgical untethering:
- Pain improvement: 50-100% of patients
- Motor function improvement: 30-50% of patients
- Urological function improvement: 20-70% of patients
- Stabilization of symptoms: Majority of patients
- Factors influencing prognosis:
- Early diagnosis and intervention generally lead to better outcomes
- Preoperative duration of symptoms affects the degree of recovery
- Complex spinal dysraphism may have a higher risk of retethering and poorer outcomes
- Long-term considerations:
- Risk of retethering: 5-50%, depending on the underlying pathology
- Need for ongoing monitoring and potential repeat surgeries
- Progression of scoliosis or other spinal deformities
- Long-term management of neurogenic bladder and bowel dysfunction
- Quality of life:
- Many patients achieve good functional outcomes and quality of life with appropriate management
- Psychosocial support and multidisciplinary care are important for optimal outcomes
It's important to counsel patients and families about the chronic nature of tethered cord syndrome and the need for long-term follow-up. While surgical untethering can significantly improve or stabilize symptoms, some neurological deficits may be permanent, especially if diagnosis and treatment are delayed.
Tethered Cord in Children
- What is the primary defining characteristic of a tethered cord?
Answer: Abnormal attachment of the spinal cord to surrounding tissues, restricting its movement - Which of the following is NOT a common cause of tethered cord syndrome?
Answer: Cervical spinal stenosis - At what level of the spine does the conus medullaris typically end in a normal child?
Answer: L1-L2 vertebral level - Which of the following is a common cutaneous marker associated with tethered cord syndrome?
Answer: Dimple above the gluteal cleft - What imaging modality is considered the gold standard for diagnosing tethered cord syndrome?
Answer: Magnetic Resonance Imaging (MRI) - Which of the following is NOT a typical clinical manifestation of tethered cord syndrome in children?
Answer: Macrocephaly - What is the most common type of spinal dysraphism associated with tethered cord syndrome?
Answer: Spina bifida occulta - Which of the following neurological deficits is commonly seen in children with tethered cord syndrome?
Answer: Lower extremity weakness - What is the term for the fibrous band that can cause tethering of the spinal cord?
Answer: Filum terminale - Which of the following is NOT a typical urological symptom associated with tethered cord syndrome?
Answer: Polyuria - What is the primary goal of surgical intervention in tethered cord syndrome?
Answer: To release the spinal cord from abnormal attachments - Which of the following conditions is often associated with tethered cord syndrome?
Answer: Lipomyelomeningocele - What is the term for the abnormal connection between the skin and spinal cord that can cause tethering?
Answer: Dermal sinus tract - Which of the following is a common orthopedic manifestation of tethered cord syndrome?
Answer: Foot deformities - What is the approximate incidence of tethered cord syndrome in the general population?
Answer: 0.1 - 0.2 per 1000 live births - Which of the following is NOT a typical indication for surgical intervention in tethered cord syndrome?
Answer: Asymptomatic incidental finding on MRI - What is the term for the condition where the spinal cord is abnormally attached to a benign fatty mass?
Answer: Lipomyelomeningocele - Which of the following is a common pain characteristic associated with tethered cord syndrome?
Answer: Pain exacerbated by flexion of the spine - What is the term for the regression of neurological function often seen in untreated tethered cord syndrome?
Answer: Neurological deterioration - Which of the following is NOT a typical finding on MRI in tethered cord syndrome?
Answer: Hydrocephalus - What is the term for the abnormal persistence of embryonic tissue connecting the spinal cord to the overlying skin?
Answer: Dermal sinus tract - Which of the following is a common gait abnormality associated with tethered cord syndrome?
Answer: Toe walking - What is the most common location for a tethered cord?
Answer: Lumbosacral region - Which of the following is NOT a typical complication of untreated tethered cord syndrome?
Answer: Increased intracranial pressure - What is the term for the abnormal collection of fat within the spinal canal that can cause cord tethering?
Answer: Intradural lipoma - Which of the following is a common urodynamic finding in children with tethered cord syndrome?
Answer: Detrusor-sphincter dyssynergia - What is the approximate age range when symptoms of tethered cord syndrome typically first appear?
Answer: 3-10 years old - Which of the following surgical techniques is commonly used to treat tethered cord syndrome?
Answer: Microsurgical untethering - What is the term for the reappearance of symptoms after initial surgical treatment of tethered cord?
Answer: Retethering - Which of the following is NOT a typical postoperative complication of tethered cord release surgery?
Answer: Hydrocephalus
