Introduction
Spina bifida cystica (myelomeningocele) is the most complex but treatable central nervous system abnormality. Recognized 4,000 years ago, it is visibly evident at birth.
Malformations of the brain and spinal cord can occur during embryologic development. Varying in severity, neural tube defects have a range of presentations, from stillbirth to incidental radiographic findings of spina bifida occulta (SBO). Treatment advances have allowed an increasing number of patients with neural tube defects to participate and be productive in mainstream society.
In this image of the lumbar region of a newborn with myelomeningocele, the skin is intact, and the placode-containing remnants of nervous tissue can be seen in the center of the lesion, which is filled with cerebrospinal fluid (CSF).
Axial T1-weighted MRI scan of a 15-year-old girl who was born with thoracic myelomeningocele, hydrocephalus, and Arnold-Chiari II syndrome. She was treated with a ventriculoperitoneal shunt. The ventricular system has a characteristic shape, with small frontal and large occipital horns, which are typical in patients with spina bifida. The shunt tube is shown in the right parietal region.
Neonate with a lumbar myelomeningocele with an L5 neurologic level. The diaphanous sac is filled with cerebrospinal fluid and contains fragile vessels in its membrane. The neural placode is plastered to the dorsal surface of the sac. The neural placode was circumnavigated and placed in the neural canal. A dural sleeve was fashioned so as to reconstruct the neural tube geometry.
Sagittal T1-weighted MRI image of a 7-year-old child after closure of a myelomeningocele. The spinal cord ends in the sacral region far below the normal level of T12-L1 and is tethered where the neural placode was attached to the skin defect during gestation.
The need for a team approach is recognized in contemporary treatment of spina bifida. Bringing together a number of medical and surgical specialists can help to spare parents the strain and exhaustion of coordinating with multiple doctors and can ensure availability of necessary services. The orthopedic surgeon assumes a significant role in coordinating the many treatment components that together allow patients to gain maximum function and, particularly, independence.
Participation in the care of patients with major, chronic physical disabilities requires commitment, coordination, and access to extensive clinical resources. Improved survival rates in patients with spina bifida can be expected with treatment; quality of life is at least partially dependent on the speed, efficiency, and comprehensiveness of that treatment from birth.
People with spina bifida may have physical challenges, but treatment rewards patients and, in turn, the overall population as these individuals become increasingly able to contribute to society.
Recent studies
Danzer et al did a retrospective chart review of 54 children who underwent fetal myelomeningocele (fMMC) closure, to determine lower extremity neuromotor function (LENF) and short-term ambulatory potential following fMMC closure. Thoracic lesions were present in 4 patients, lumbar lesions in 44, and sacral lesions in 6. At a median follow-up age of 66 months, 37 of 54 (69%) walked independently, 13 of 54 (24%) were assisted walkers, and 4 of 54 (7%) were wheelchair dependent. The strongest factors predicting a lower likelihood to walk independently were higher-level lesion and development of clubfoot deformity after fetal intervention. Despite improved ambulatory status, the majority of independent ambulators and all children requiring assistive devices had significant deficits in lower-extremity coordination.1
Folic acid
Bell and Oakley reported that current worldwide programs of folic fortification of wheat and maize flour have resulted in an annual worldwide decrease of about 6,600 folic acid-preventable spina bifida and anencephaly cases since 2006. They note that the pace of preventing these serious birth defects can be accelerated if more countries require fortification of both wheat and maize flour and if regulators set fortification levels high enough to increase a woman's daily average consumption of folic acid to 400 mcg.2,3
For excellent patient education resources, visit eMedicine's Brain and Nervous System Center and Kidneys and Urinary System Center. Also, see eMedicine's patient education articles Spina Bifida and Bladder Control Problems.
History of the Procedure
Because the spinal cord and, thus, the central nervous system are exposed in spina bifida, persons with this disease were not expected to survive in the preantibiotic era. Those who did survive had severe handicaps. Debate over whether surgical treatment should be offered or whether the disease should be allowed to take its natural course has been resolved in favor of treatment. The results of withheld treatment are well documented, with most patients dying within the first 6-12 months.
Malcolm Menelaus pioneered many advances in the treatment of patients with spina bifida and summarized them in his classic book The Orthopaedic Management of Spina Bifida Cystica.4
The many orthopedic procedures used in spina bifida treatment include the following:
- Closure of the defect over the spinal cord, without which survival is jeopardized
- Spinal deformity reconstruction, which may be particularly challenging because of posterior element deficiencies and can lead to instrumentation and fusion failures, infection from the neurogenic bladder, a closure scar, and ulcers from distal insensate skin
- Lower-extremity deformity correction, which is necessitated by muscle imbalance forces
Beyond closure, which is a neurosurgical procedure, shunting may be needed for hydrocephalus, including normal pressure hydrocephalus, and many urologic procedures may be required for the neurogenic bladder.
Customary techniques have been used for spinal deformity procedures, but anterior procedures now are being combined more frequently with the posterior approach to produce a satisfactory fusion. Lower-extremity procedures, particularly hip reduction, have been the most controversial. Opinions differ as to whether these aid in seating and ambulation. More recently, gait analysis has been used to analyze specific candidates who possess motor strength in the quadriceps in the range of "good plus" and who also have hip dysplasia or dislocation. Procedures distal to the hip often are similar to those for polio but generally are aimed at maintaining the ability to brace the limb in order to maximize accessibility and independence. Procedures below the hip are directed toward reducing deformity, releasing contractures, and balancing muscle forces from the variable neurologic lesions.
Problem
Spina bifida is a variable defect in which the vertebral arch of the spinal column is either incompletely formed or absent. The term bifida is from the Latin bifidus, or "left in 2 parts." Although the condition has also been referred to as myelodysplasia and myelomeningocele, spina bifida generally has been accepted as the preferred term, specifically by the American Academy of Orthopaedic Surgeons. Rachischisis posterior, the equivalent Greek term, is derived from rachis, meaning spine, and schisis, meaning division (spondyloschisis in Latin).
Spina bifida cystica
Spina bifida cystica (myelomeningocele), a neural tube defect, can occur anywhere along the spinal axis but most commonly is found in the lumbar region.
In spina bifida cystica, the spine is bifid and a cyst forms. A meningocele, a cystic swelling of the dura and arachnoid, protrudes through the spina bifida defect in the vertebral arch. A person with a meningocele may have no neurologic sequelae. A myelomeningocele, the name of which refers to the myelo, or spinal cord, also may occur, protruding through the defect. According to Menelaus, the myelomeningocele form of spina bifida cystica is the most significant and common type of spina bifida, accounting for 94% of cases. (SBO is not included in this figure.) The most severe form of spina bifida cystica is the myelocele, or myeloschisis, variety, in which the open neural plate is covered secondarily by epithelium and the neural plate has spread out onto the surface.
A child born with myelomeningocele requires specialty care and transfer to a center where neonatal surgery and closure can be performed. Surgery involves freeing lateral muscles and skin for coverage and attempting to form a closure of the neural elements with minimal scarring, because the late complication of a tethered cord has frequent and severe consequences. Further follow-up at a comprehensive, multidisciplinary clinic gives the patient access to a range of specialists, allowing the child to receive an extensive array of essential services without necessitating separate visits to multiple physicians.
Spina bifida occulta
SBO is a limited defect of the vertebral arch that does not involve protrusion of the cord or membrane. Most often occurring at the lumbosacral junction, SBO appears as an incidental radiographic finding in up to 10% of the healthy population.
Syringomeningocele
Syringomeningocele is another form of spina bifida. The Greek word syrinx, meaning tube or plate, is combined with meninx (membrane) and kele (tumor). The term thus describes a hollow center, with the spinal fluid connecting with the central canal of the cord enclosed by a membrane with very little cord substance.
Syringomyelocele
Syringomyelocele is a type of spina bifida in which protrusion of the membranes and spinal cord lead to increased fluid in the central canal, attenuating the cord tissue against a thin-walled sac. Syringomyelia, or hydrosyringomyelia, is the presence of cavities in the spinal cord, which may occur as a result of the breakdown of gliomatous new formations.
Diastematomyelia
Diastematomyelia, from the Greek root diastema (interval) and myelon (marrow), is sometimes accompanied by a bony septum. This septum may cause a tethered cord and irreversible neurologic loss from differential growth of the spinal canal exceeding the earlier developing spinal cord, but a tethered cord also may exist without a bony septum.
Myelodysplasia
Myelodysplasia is from the Greek term myelos, meaning spinal cord, combined with dys, for difficult, and plasi, for molding. This is an abnormality in the development of the cord and, thus, is an inappropriate description for SBO, in which the cord is normal. As previously stated, however, it has nonetheless been used as a synonym for spina bifida.
Dysraphia
Dysraphia, from the Greek term raphia and its root, rhaphe, a seam, is a defective fusion of parts that normally unite. This term could be applied to the vertebral arch.
Arnold-Chiari deformity
Arnold-Chiari deformity is a malformation of the cerebellum, with elongation of the cerebellar tonsils. The cerebellum is drawn into the fourth ventricle. The condition also is characterized by smallness of the medulla and pons and by internal hydrocephalus. In fact, all patients with spina bifida cystica (failure to close caudally) have some form of Arnold-Chiari malformation (failure to close cranially).
Craniorachischisis
Craniorachischisis (total dysraphism) is a condition in which the brain and spinal cord are exposed. This often results in early spontaneous abortion, commonly associated with malformations of other organ systems. In anencephaly, brain tissue is exposed through a defect in the scalp and skull, but the spinal cord generally remains intact.
Frequency
The incidence of spina bifida has been estimated at 1-2 persons per 1000 population, with certain populations having a significantly greater incidence based on genetic predilection. Folate fortification of enriched grain products has been mandatory in the United States since 1998; research indicates that folate can reduce the incidence of neural tube defects by about 70% and can also decrease the severity of these defects when they occur.5,6,7,8
Siblings of patients with spina bifida have an increased incidence of neural tube defects. Consequently, following the birth of a child with spina bifida, amniocentesis is suggested during subsequent pregnancies to monitor fetoprotein (an indicator of failed spine closure and exposure of neural elements to the amniotic fluid). Intrauterine surgery for spina bifida has been performed, and early successes have promoted and justified further studies.1,9 A genetic defect has been identified in families with spina bifida.
The average worldwide incidence of spina bifida is 1 case per 1000 births, but marked geographic variations occur. The highest rates are found in parts of the British Isles, mainly Ireland and Wales, where 3-4 cases of myelomeningocele per 1000 population have been reported, along with more than 6 cases of anencephaly (both live births and stillbirths) per 1000 population. The reported overall incidence of myelomeningocele in the British Isles is 2-3.5 cases per 1000 births. In France, Norway, Hungary, Czechoslovakia, Yugoslavia, and Japan, a low prevalence is reported: 0.1-0.6 cases per 1000 live births. In the United States, a declining prevalence has been noted, with the incidence being higher on the East Coast than on the West Coast. The prevalence in African Americans (0.1-0.4 case per 1000 live births) is lower than that in white Americans (1 case per 1000 live births).10,11,12,13
Immigrants from Ireland have a higher prevalence of spina bifida than do nonimmigrants, suggesting a complex genetic relationship. A higher incidence in females than in males has been observed in anencephaly but not in myelomeningocele. An association has been reported with infertility and with antiepileptic drugs, particularly valproate and carbamazepine.14,15,16
Etiology
A multifactorial genetic inheritance has been proposed as the cause of spina bifida, coupled with environmental factors, of which nutrition, including folic acid intake, are key. Cytoplasmic factors, polygenic inheritance, chromosomal aberrations, and environmental influences (eg, teratogens) have all been considered as possible causes. Prenatal vitamins, especially folic acid, are recommended to discourage the condition's development. Current fortification programs are preventing about 22,000 cases, or 9% of the estimated folic acid-preventable spina bifida and anencephaly cases.2
Neural tube defects occur between the 17th and 30th day of gestation, at a time when the mother may not be aware that she is pregnant and the fetus is estimated to be about the size of a grain of rice.
The fetal presence of an open neural tube defect is marked by an elevated alpha-fetoprotein level in the amniotic fluid. Peak concentrations of alpha-fetoprotein in the 13th to 15th weeks of pregnancy permit diagnosis, and ultrasound confirmation with amniocentesis generally is possible at 15-18 weeks. Encephaloceles or skin-covered myeloceles are unlikely to be detected by alpha-fetoprotein.
Following closure of the rostral neuropore, malformations of the central nervous system can arise (postneurulation) in association with neural tube defects. These include hydrocephalus, cephalocele, and the Arnold-Chiari malformations. Prenatal diagnosis and ultrasound confirmation allow for preparation and parental referral to appropriate care services. The pathogenesis of spina bifida has been suggested to involve a defect in neural tube closure or failure of the neural tube to close completely.
During prenatal development, neuroectoderm thickens into the neural plate, which then folds into a neural groove by the time somites appear. The groove deepens to become the neural tube, and dorsal fusion begins centrally, extending cephalad and caudally, with the cephalad pole fusing at the 25th day. The ventricle becomes permeable at the 6th to 8th week of gestation but apparently does not proceed normally in patients with myelomeningocele.
Some studies suggest that an increased amount of neural crest material in the defect prevents neural tube closure. Another hypothesis is that an already closed tube ruptures; increased permeability of the rhombic groove leads to greater cerebrospinal fluid (CSF) secretion and increased luminal pressure, with the tube then expanding and essentially splitting the neural element at its weakest areas (ie, the cephalic and caudal ends). Subsequent research by McLone and Knepper supports the latter hypothesis and details the implications of this defect on the entire central nervous system.17
Pathophysiology
Spina bifida cystica causes a problem when the meningeal cyst (meningocele) includes cord tissue extending into the cyst (in which case, it is a myelomeningocele). The condition is also of particular concern when the neural tube is completely open and the ependymal layer is exposed as a myelocele or myeloschisis. Meningocele alone may cause no neurologic problems if the cord is confined to the vertebral canal.
Myelomeningocele is the most common form of spina bifida, accounting for 94% of cases. SBO should be differentiated from spina bifida cystica. The term spina bifida does not refer to SBO. SBO may be seen in a very large number of healthy adults. Some contend that it could be found in up to one third of healthy adults if imaging studies were used to analyze the posterior vertebral arch.
Unprotected neural elements are at severe risk during delivery. (Intrauterine surgery, associated with cesarean delivery, has been proposed for cases of spina bifida, with some favorable results reported at selected centers.) The sequelae of the neural tube defect follow directly from this lack of protection, occurring mechanically or resulting from desiccation, scarring with closure, and/or a lack of vascular support or from other insults to the delicate neural elements.
The neurologic damage generally results in a neurogenic bowel and bladder, which leads to incontinence. With a lack of neural input, a contracted bladder causes hydronephrosis along with infections and renal failure, which may be the prime determinant of longevity in patients with spina bifida. As a pattern, neurologic innervation is not symmetrical between lower-limb flexors and extensors, as the corresponding levels are lower (caudal) for the extensors than for the flexors. Generally, muscular imbalance is present, which results in joint contractures and developmental problems, such as hip dislocation and spinal deformities. Normal intelligence can be expected with aggressive shunting for hydrocephalus, although a subtle defect in coordination may be associated with the cerebellar deficiency from the Arnold-Chiari malformation. Seizure activity secondary to the neural tube defect may be noted.
Presentation
Patients who are born with a sac containing neural elements of the spine require neurosurgical closure of the defect in the neonatal period. They should be referred to an interdisciplinary clinic that includes the services of an orthopedic surgeon.
Although SBO is common and almost always without consequence, some developmental abnormalities may occur—such as a spinal cord lipoma or a fibrous cord—that can cause subtle or rare neurologic signs.
A fibrous cord may extend from an interdural component of one of these developmental abnormalities to the skin, producing a dimple, an area of pigmentation, or a hairy patch at the base of the spine; such symptoms can be noted on physical examination. Patients with a fibrous cord may have problems with micturition, or they may have subtle neurologic signs, such as a foot deformity (most commonly, a cavus foot). A prompt and thorough investigation is mandatory for any progressive neurologic signs. When a lipoma is present, there may be a lipomeningocele, a lipomyelomeningocele, or a lipomyelocele. These may be associated with areas of fluid in the cord, which may be a syringomyelia.
From a neurologic standpoint, the Arnold-Chiari II malformation may be accompanied by temporary stridor and/or apnea, but these problems rarely are severe. A varying degree of interference with cerebellar function seems to occur, particularly with balance and coordination, which has a significant influence on ambulation, the results of physical therapy, and overall orthopedic care. Failure to control a seizure disorder, recurrence of hydrocephalus, or even low pressure hydrocephalus can cause subtle coordination defects and interruption of some cognitive functions.
The tethered cord may be signaled by foot deformities that previously braced easily, new onset of hip dislocation, or worsening of a spinal deformity, particularly scoliosis. Progressive neurologic defects in growing children may suggest a lack of extensibility of the spine or suggest that the spine is tethered and low lying in the lumbar canal, with the potential for progressive, irreversible neurologic damage that requires surgical release.
Height and weight should be assessed for patients with spina bifida. Excessive weight impedes maximal independence and ambulation. Height may be impaired significantly because of an associated growth hormone deficiency. Growth spurts require close monitoring for any deformities, from scoliosis to deformities of the lower extremities.
Indications
Patients with spina bifida have variable neurologic deficits that characteristically cause deformity as a result of muscle imbalance forces. Unopposed muscle pull can cause spinal deformity, progressive lower-extremity contractures, hip dislocations, and, less commonly, dislocations in other joints.
The assessment of the patient with spina bifida needs to focus on function (ie, accessibility, gait, independence), and treatment should be directed at addressing any deformity that interferes with the patient's potential. When serial follow-up examinations demonstrate worsening function associated with progression of a deformity, surgery should be considered to correct the deformity in combination with release of the deformity and rebalancing of muscle forces around the involved joint as necessary.
Relevant Anatomy
Pertinent anatomy includes neural innervation, particularly of the lower extremities. Examination of neurologic deficit helps determine the functional level at which the spina bifida cystica lesion has interrupted function. The myelomeningocele lesion is unique; its effects are significantly different from those of poliomyelitis, in which anterior horn cells are injured; thus, with a myelomeningocele, motor function is deficient, but sensation is preserved. The symptoms are also unlike those of cerebral palsy, in which spasticity is common. This is because the spina bifida lesion is generally flaccid, although in some cases a myelomeningocele may be associated with a measure of spasticity.
At birth, 2 main types of neurologic involvement can be recognized. Type I, which is considered typical, is present in one third of patients in the neonatal period. A certain segmental level is involved, with resulting flaccid paralysis, loss of sensation, and loss of reflexes. Type II is present in two thirds of patients and is characterized by the interruption of long track signs, with preservation of pure reflex activity, although it may be grossly exaggerated in isolated distal segments. This can present as 3 subtypes, as follows:
- Cord function is intact to a certain level, below which a gap is manifested by flaccid paralysis, loss of sensation, and loss of reflexes. More distally, isolated cord function is evident from exaggerated reflex activity.
- The gap in cord function is narrow, virtually amounting to a transection. (This condition occurs especially in newborns.) There is no movement of the lower limb when the infant is crying, but there is a wealth of purely reflexive activity, including flexor withdrawal, which can be elicited by direct stimulation.
- If transection of the long track is incomplete, the child will have spastic paraplegia with preservation of some voluntary movement and sensation. In up to 5% of patients, a hemimyelomeningocele is present, in which one leg is affected with a type I or II lesion and the other may basically be unaffected.
After recognizing the complexity of the actual neurologic deficit, it is clinically useful—because the function and treatment of patients with spina bifida follow broad guidelines—to categorize these patients into general groups. Generally, neurologic levels are grouped as thoracic, upper lumbar (L1, L2, L3), lower lumbar (L4, L5), and sacral.
Independent ambulation generally is a function of having an intact quadriceps muscle with good-plus or excellent-plus strength levels. Patients who do not have adequate quadriceps function may require bilateral Lofstrand crutches or may be restricted primarily to a wheelchair. In such cases, reduction of hip dislocation typically has not been advised because the effect on a person who cannot ambulate is not as consequential as it would be upon a person who can (although some hip dislocations may have a significant impact on a patient's ability to sit properly). Functional ambulation generally is described according to the following levels, developed by Hoffer and colleagues18 :
- Community ambulator - Indoors or outdoors, crutches with or without braces
- Household ambulator - Only indoors, crutches with or without braces
- Nonfunctional ambulator - Wheelchair, crutches, and braces, in therapy
- Nonambulator - Wheelchair bound
Contraindications
Because neurologic impairment is associated with most functional problems, any corrective surgery would presuppose a stable neurologic status. In the patient with spina bifida, a tethered cord may represent a changing neurologic situation that would contraindicate any surgical procedures.
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References
Danzer E, Gerdes M, Bebbington MW, Sutton LN, Melchionni J, Adzick NS, et al. Lower extremity neuromotor function and short-term ambulatory potential following in utero myelomeningocele surgery. Fetal Diagn Ther. Jan 28 2009;25(1):47-53. [Medline].
Bell KN, Oakley GP Jr. Update on prevention of folic acid-preventable spina bifida and anencephaly. Birth Defects Res A Clin Mol Teratol. Jan 2009;85(1):102-7. [Medline].
Oakley GP Jr. The scientific basis for eliminating folic acid-preventable spina bifida: a modern miracle from epidemiology. Ann Epidemiol. Apr 2009;19(4):226-30. [Medline].
Menelaus MB. The Orthopaedic Management of Spina Bifida Cystica. 2nd ed. New York, NY: Churchill Livingston;1980.
Holmes LB. Does taking vitamins at the time of conception prevent neural tube defects?. JAMA. Dec 2 1988;260(21):3181. [Medline].
Milunsky A, Jick H, Jick SS, et al. Multivitamin/folic acid supplementation in early pregnancy reduces the prevalence of neural tube defects. JAMA. Nov 24 1989;262(20):2847-52. [Medline].
Mulinare J, Cordero JF, Erickson JD, et al. Periconceptional use of multivitamins and the occurrence of neural tube defects. JAMA. Dec 2 1988;260(21):3141-5. [Medline].
Cotter AM, Daly SF. Neural tube defects: is a decreasing prevalence associated with a decrease in severity?. Eur J Obstet Gynecol Reprod Biol. Apr 1 2005;119(2):161-3. [Medline].
Fichter MA, Dornseifer U, Henke J, Schneider KT, Kovacs L, Biemer E, et al. Fetal spina bifida repair--current trends and prospects of intrauterine neurosurgery. Fetal Diagn Ther. 2008;23(4):271-86. [Medline].
Cotton P. Finding neural tube 'zippers' may let geneticists tailor prevention of defects. JAMA. Oct 13 1993;270(14):1663-4. [Medline].
Lemire RJ. Neural tube defects. JAMA. Jan 22-29 1988;259(4):558-62. [Medline].
Velie EM, Shaw GM, Malcoe LH, et al. Understanding the increased risk of neural tube defect-affected pregnancies among Mexico-born women in California: immigration and anthropometric factors. Paediatr Perinat Epidemiol. May 2006;20(3):219-30. [Medline].
Williams LJ, Rasmussen SA, Flores A, et al. Decline in the prevalence of spina bifida and anencephaly by race/ethnicity: 1995-2002. Pediatrics. Sep 2005;116(3):580-6. [Medline].
Wu YW, Croen LA, Henning L, et al. Potential association between infertility and spinal neural tube defects in offspring. Birth Defects Res A Clin Mol Teratol. Oct 2006;76(10):718-22. [Medline].
Canfield MA, Ramadhani TA, Shaw GM, Carmichael SL, Waller DK, Mosley BS, et al. Anencephaly and spina bifida among Hispanics: maternal, sociodemographic, and acculturation factors in the National Birth Defects Prevention Study. Birth Defects Res A Clin Mol Teratol. Jul 2009;85(7):637-46. [Medline].
Canfield MA, Marengo L, Ramadhani TA, Suarez L, Brender JD, Scheuerle A. The prevalence and predictors of anencephaly and spina bifida in Texas. Paediatr Perinat Epidemiol. Jan 2009;23(1):41-50. [Medline].
McLone DG, Knepper PA. The cause of Chiari II malformations: a unified theory. Pediatr Neurosci. 1989;15:1-12.
Hoffer MM, Feiwell E, Perry R, et al. Functional ambulation in patients with myelomeningocele. J Bone Joint Surg Am. Jan 1973;55(1):137-48. [Medline].
Mercado E, Alman B, Wright JG. Does spinal fusion influence quality of life in neuromuscular scoliosis. Spine. sep/2007;32:s120.
Bruner JP, Tulipan N, Reed G, et al. Intrauterine repair of spina bifida: preoperative predictors of shunt-dependent hydrocephalus. Am J Obstet Gynecol. May 2004;190(5):1305-12. [Medline].
Park TS, Cail WS, Maggio WM, et al. Progressive spasticity and scoliosis in children with myelomeningocele. Radiological investigation and surgical treatment. J Neurosurg. Mar 1985;62(3):367-75. [Medline].
Shurtleff DB, Goiney R, Gordon LH, et al. Myelodysplasia: the natural history of kyphosis and scoliosis. A preliminary report. Dev Med Child Neurol Suppl. 1976;126-33. [Medline].
Sharrard WJ. Posterior iliopsoas transplantation in the treatment of paralytic dislocation of the hip. J Bone Joint Surg Br. Aug 1964;46:426-44. [Medline].
Tarcan T, Onol FF, Ilker Y, et al. Does surgical release of secondary spinal cord tethering improve the prognosis of neurogenic bladder in children with myelomeningocele?. J Urol. Oct 2006;176(4 Pt 1):1601-6; discussion 1606. [Medline].
Eichholzer M, Tonz O, Zimmermann R. Folic acid: a public-health challenge. Lancet. Apr 22 2006;367(9519):1352-61. [Medline].
Robbins JM, Tilford JM, Bird TM, et al. Hospitalizations of newborns with folate-sensitive birth defects before and after fortification of foods with folic acid. Pediatrics. Sep 2006;118(3):906-15. [Medline].
De Wals P, Tairou F, Van Allen MI, Uh SH, Lowry RB, Sibbald B, et al. Reduction in neural-tube defects after folic acid fortification in Canada. N Engl J Med. Jul 12 2007;357(2):135-42. [Medline].
De Wals P, Tairou F, Van Allen MI, Lowry RB, Evans JA, Van den Hof MC, et al. Spina bifida before and after folic acid fortification in Canada. Birth Defects Res A Clin Mol Teratol. Sep 2008;82(9):622-6. [Medline].
Balagura S. Late neurological dysfunction in adult lumbosacral lipoma with tethered cord. Neurosurgery. Nov 1984;15(5):724-6. [Medline].
Birmingham PK, Dsida RM, Grayhack JJ, et al. Do latex precautions in children with myelodysplasia reduce intraoperative allergic reactions?. J Pediatr Orthop. Nov-Dec 1996;16(6):799-802. [Medline].
CDC. Spina bifida incidence at birth—United States, 1983-1990. MMWR Morb Mortal Wkly Rep. Jul 10 1992;41(27):497-500. [Medline].
Czeizel A. Neural tube defects. JAMA. Jun 24 1988;259(24):3562. [Medline].
Foster MR. Acquired hip dislocation in myelomeningocele associated with a tethered cord. Eastern Orthopaedic Association, October 16, 1992, Puerto Rico. Ortho Trans. 1993;17(1):143.
Gardner RJ, Alexander C, Veale AM. Spina bifida occulta in the parents of offspring with neural tube defects. J Genet Hum. Dec 1974;22(4):389-95. [Medline].
Green NS. Folic acid supplementation and prevention of birth defects. J Nutr. Aug 2002;132(8 Suppl):2356S-2360S. [Medline].
Gunther KP, Nelitz M, Parsch K, et al. Allergic reactions to latex in myelodysplasia: a review of the literature. J Pediatr Orthop B. Jun 2000;9(3):180-4. [Medline].
Hall PV, Campbell RL, Kalsbeck JE. Meningomyelocele and progressive hydromyelia. Progressive paresis in myelodysplasia. J Neurosurg. Oct 1975;43(4):457-63. [Medline].
Kinsman SL, Levey E, Ruffing V, et al. Beyond multidisciplinary care: a new conceptual model for spina bifida services. Eur J Pediatr Surg. Dec 2000;10 Suppl 1:35-8. [Medline].
Lorber J. Results of treatment of myelomeningocele. An analysis of 524 unselected cases, with special reference to possible selection for treatment. Dev Med Child Neurol. Jun 1971;13(3):279-303. [Medline].
Lorber J. Selective treatment of myelomeningocele: to treat or not to treat?. Pediatrics. Mar 1974;53(3):307-8. [Medline].
Rosenberg IH. Folic acid and neural-tube defects--time for action?. N Engl J Med. Dec 24 1992;327(26):1875-7. [Medline].
Shurtleff DB. Myelodysplasia: management and treatment. Curr Probl Pediatr. Jan 1980;10(3):1-98. [Medline].
Shurtleff DB, Hayden PW, Loeser JD, et al. Myelodysplasia: decision for death or disability. N Engl J Med. Nov 7 1974;291(19):1005-11. [Medline].
Further Reading
Related eMedicine topics
Management of Spina Bifida, Hydrocephalus and Shunts
Hydrocephalus
Normal Pressure Hydrocephalus
Syringohydromyelia
Clinical guidelines
Folic acid for the prevention of neural tube defects: U.S. Preventive Services Task Force recommendation statement. United States Preventive Services Task Force - Independent Expert Panel. 1996 (revised 2009). 6 pages. NGC:007233
Neural tube defects. American College of Obstetricians and Gynecologists - Medical Specialty Society. 2001 (revised 2003 Jul). 11 pages. NGC:003131
Management of neurogenic bladder in children. In: Guidelines on paediatric urology. European Association of Urology - Medical Specialty Society
European Society for Paediatric Urology - Medical Specialty Society. 2008 Mar. 10 pages. [NGC Update Pending] NGC:006508
Clinical trials
Psychosocial Adjustment of Adolescents With Spina Bifida
Study of Genetic Risk Factors for Spina Bifida and Anencephaly
Genetics of Spina Bifida and Anencephaly
Keywords
spina bifida, spina bifida cystica, spina bifida occulta, SBO, myelomeningocele, myelodysplasia, syringomeningocele, rachischisis posterior, syringomyelocele, diastematomyelia, dysraphia, Arnold-Chiari deformity, craniorachischisis, spondyloschisis
