Spinal dysraphism represents a generic term for abnormalities in the formation of the central nervous system. Specific dysraphisms discussed in this article are:
- Spina bifida occulta
- Spina bifida cystica
- Caudal regression syndrome
- Tethered cord
Primary neurulation of the spinal cord develops by closure of the spinal canal by day 27 of life. In patients with spina bifida occulta and cystica, failure to close completely results in posterior spinal abnormalities of varying clinical significance.
In patients with caudal regression syndrome, the lower portion of the spine fails to develop, resulting in a myriad of developmental outcomes.
Epidemiology including risk factors and primary prevention
Neural tube defects affect approximately 3000 pregnancies yearly in the United States. The incidence of affected pregnancies has decreased significantly since the introduction of folic acid fortified grains. The American Academy of Pediatrics recommends supplementation with folic acid 400 mcg/day for women of child-bearing age.
Despite the advances in understanding of etiology, disparities in the frequency of spinal dysraphisms remain between the population of Hispanic woman compared to non-Hispanic patients. Environmental and genetic factors influence the type and frequency of spinal dysraphism.
Spinal dysraphisms vary in their presentation and clinical description. A few of the more common dysraphisms are described below:
- Spina bifida occulta: a mild form of dysraphism in which the outer portion of the spinal cord is not closed. Most patients are diagnosed incidentally on radiograph.
- Spina bifida cystica: bony defect with herniation of spinal canal elements but without any neurologic herniation. Generally neurologic exam is normal.
- Caudal regression syndrome: absence of the sacrum and/or portions of the lumbar spine with motor and sensory abnormalities.
- Tethered cord: tethering of the spinal cord which stretches as a child grows to result in upper motor neuron signs, weakness, and bowel/bladder changes. Scoliosis and pain can also develop.
Disease progression including natural history, disease phases or stages, disease trajectory (clinical features and presentation over time)
With the exception of spina bifida occulta, patients with diagnosis of spinal dysraphism are generally followed from birth onward. Spina bifida occulta is rarely diagnosed and clinical exam remains normal through stages of life. In spina bifida cystica, patients may initially exhibit a normal exam and progress to having more issues if the spinal cord is tethered.
Patients with caudal regression syndrome who may initially have some ambulation may develop contractures as they develop, which may prompt more use of wheelchairs for long-distance mobility. Chronic wheelchair use may result in overuse injuries limiting function.
Continued monitoring for changes in symptoms and exams, coupled with a good transition to adult care providers, remains challenging due to the need for care coordination and adult provider education regarding this category of diagnosis.
Specific secondary or associated conditions and complications
In patients with spinal dysraphism, certain neurologic conditions can develop such as neurogenic bowel, neurogenic bladder, spasticity, weakness, altered sensation, scoliosis, and pain. Frequency of these issues is related to the underlying type of dysraphism present.
2. ESSENTIALS OF ASSESSMENT
Adequate prenatal history regarding maternal health, drug exposure, nutritional history, and prior family/birth history facilitates evaluation of potential problems that could have developed during embryonic formation.
Families provide valuable information regarding movement patterns, perceived level of sensation, function, and changes over time.
In patients with spinal dysraphism, exam can be completely normal, as in spina bifida occulta, to very involved, such as in patients with caudal regression syndrome or tethered cord.
The most important aspects of the exam are evaluation and documentation of the anatomic level of motor and sensory involvement and the level of functional impairment, if present. This helps with prognosis and serves as a reference if future issues arise. Sensory deficit should be observed as well as any signs/symptoms of neurogenic bowel or bladder issues.
Clinical functional assessment: mobility, self care, cognition/behavior/affective state
Utilization of physical and occupational therapy greatly influence the ability to objectively evaluate function in the clinical setting. Review of mobility, self-care and educational needs such as 504 or Individualized Educational Plans should be a routine part of a visit to assess functioning outside of the clinical setting.
Routine laboratory evaluation is not done in patients with spinal dysraphism; however, in pregnancy, mothers are generally checked for alpha-fetoprotein levels which are elevated in pregnancies with some forms of spinal dysraphism, namely spina bifida cystica.
Many times, routine prenatal ultrasound can detect spinal dysraphism before delivery; in some cases, magnetic resonance imaging can help to determine if there is protrusion of neural elements through a spinal opening.
Radiographic imaging may be important depending on the type of spinal dysraphism. Scoliosis can develop in different types of dysraphism, which may require serial monitoring with supine scoliosis images. In patients who are at risk for hip dysplasia, hip radiographs to evaluate for dysplasia or dislocation should be obtained. In children with tethered cord or caudal regression syndrome who can ambulate, radiographs can serve to help guide any intervention.
Supplemental assessment tools
In patients with suspected neurogenic bladder, a renal ultrasound, voiding cystourethrogram, and urodynamic assessment can help to evaluate the structure and physiology of the urologic system.
Additionally, in tethered cord, a magnetic resonance imaging scan can help to identify the area of the tethering.
Early prediction of outcomes
Prediction of better functional outcomes correlates with meeting earlier developmental milestones on time with peers. Patients with spinal bifida occulta rarely have issues; however, patients with caudal regression syndrome frequently have several areas of deficits including ambulation, which occurs due to underdevelopment of lower extremities with lesser range of motion. Patients with tethered cord progress well if early milestones are met; however, re-tethering in children who have had surgical intervention can limit progression to optimal outcomes. Variable levels of motor and sensory progression occur in tethered cord.
Evaluation of school and social environment is paramount to allow for socialization and learning similar to peers without impairments. Accessibility can be a factor in patients with caudal regression syndrome, especially if they are primarily wheelchair users for mobility.
Social role and social support system
Urologic issues may significantly impact social interactions. Patients with poor bowel and bladder control tend to have worse self-esteem. Parents and caregivers provide the initial support for children with spinal dysraphisms; however, peers impact decision making especially from early adolescence and onward.
The primary aim of each healthcare professional remains to impact children with spinal defects in a manner that allows them to progress through their developmental milestones at an age-appropriate level. Physical, social, cognitive, and psychological outcomes are equally important. Parents may consider adoption or termination of the pregnancy given a prenatal diagnosis. Appropriate guidance regarding accurate functional and cognitive outcomes aids in parental decision-making.
3. REHABILITATION MANAGEMENT AND TREATMENTS
Available or current treatment guidelines
Little, if any, rehabilitation needs are found for both spina bifida occulta and cystic in patients with normal exam findings; however, other spinal dysraphisms have varied levels of rehabilitation needs. In tethered cord, management of neurogenic bowel/bladder programs, tone and ambulation help improve social integration and school performance. Neuropsychological testing may benefit cognitive development if needed.
In caudal regression syndrome, the risk of cognitive deficits are minimal and rehabilitation providers should seek to facilitate mobility to allow experiential learning. Prevention of contractures allows for longer independent mobility and education about wound prevention improves overall health.
By using equipment, therapies, medications, and bracing, the functional level of patients with spinal dysraphisms can be improved.
At different disease stages
Children from birth to the first six months of life generally have no increased difficulties with meeting expected age-appropriate milestones.
From 6 months to 1 year of age, children with caudal regression syndrome may not be as able to sit or ambulate independently. In children with spina bifida cystica, ambulation can be achieved although it may be slightly delayed. Children with tethered cord have variable level of function depending on the area and degree of tethering.
In the young childhood time period as children grow, children with caudal regression may choose to use wheelchairs primarily for mobility even if they maintain ambulation ability due to energy conservation and biomechanics. Patients with tethered cord who undergo surgery may have a change in their ambulation ability as their spasticity changes. Children with spina bifida occulta or cystica may never have any difficulty with development milestones.
The role of the rehabilitation physician as the child ages is to facilitate achievement and maintenance of the most function possible depending on the age of the child. Progression through the natural developmental stages influences treatment and guides therapies, bracing, and other interventions.
Coordination of care
Team-based approaches with a multidisciplinary clinic involving rehabilitation medicine, orthopedics, neurosurgery, urology, physical therapy, occupational therapy, nutrition, social work and nursing allow for improvement of care coordination.
In early adolescence, discussions regarding transitions of care should begin to encourage more independence and ownership by the patient of health-related problems before moving to an adult provider.
Patient & family education
Families who have children with spinal dysraphisms should have education regarding expectations related to motor function, risks of decreased sensation, possibilities of bowel or bladder dysfunction. Families are responsible for this care at early ages, but this responsibility falls on the patient as they age. Counseling regarding potential for any orthopedic and neurosurgical problems helps educate family about potential warning signs such as skin ulcers, abnormal orthopedic growth, bowel/bladder changes, or neurologic complications.
Measurement of Treatment Outcomes including those that are impairment-based, activity participation-based and environmentally-based
Although there is no commonly used treatment outcome measure for the spinal dysraphisms listed in this article, the primary goal is to approximate age-appropriate development across affected domains of function. Because some children with spinal dysraphisms never present during the childhood period, treatments are not always necessary. In patients with Caudal Regression or tethered cord, continued maximizing of mobility into adulthood, social integration, and cognitive development are the main targeted outcomes.
Translation into Practice: practice “pearls”/performance improvement in practice (PIPs)/changes in clinical practice behaviors and skills
4. CUTTING EDGE/EMERGING AND UNIQUE CONCEPTS AND PRACTICE
5. GAPS IN THE EVIDENCE-BASED KNOWLEDGE
Agrawal A, Sampley S. Spinal dysraphism: A challenge continued to be faced by neurosurgeons in developing countries. Asian J Neurosurg 2014;9:68-71.
DeLaRosa M; Kondamudi V; Kondamudi N; Juratli S. Tethered cord syndrome with abnormal gait. J Am Board Fam Med. 2003;16(4):345-348
Pico, E; Wilson P; Hass R. Spina Bifida. In: Alexander M and Matthews D, Eds. Pediatric Rehabilitation: Principles and Practices. 4th Ed. New York, NY: Demos Medical; 2010: 199-230.
Rekate H. Spina Bifida. 1st ed. Boca Raton, FL: CRC Press; 1991.
Santiago Medina L; Crone K: Kuntz K. Newborns with suspected occult spinal dysraphisms: a cost-effective analysis of diagnostic strategies. Pediatrics. 2001; 108(6). E101.
Matthew McLaughlin, MD
Nothing to Disclose