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== Introduction  ==
== Introduction  ==


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 word Bifidus, or "left in 2 parts." It is classified as a defect of the neural tube (i.e. the embryonic structure that develops into the spinal cord and brain). Neural tube defects have a range of presentations, from stillbirth to incidental radiographic findings of spina bifida occulta. The term myelodysplasia has been used as a synonym for Spina bifida.<ref name=":0">Lundy-Ekman L (2007). Neuroscience: Fundamentals for Rehabilitation. 3rd edition. St. Louis: Saunders, 2007</ref><ref name=":1">Spina Bifida: Background, Pathophysiology, Etiology [Internet]. Emedicine.medscape.com. 2019 [cited 2 March 2019]. Available from: <nowiki>http://emedicine.medscape.com/article/311113-overview</nowiki></ref>Lesions most commonly occur in the lumbar and sacral regions but can be found anywhere along the entire length of the spine.<ref name=":0" /> It is a treatable spinal cord malformation that occurs in varying degrees of severity.<ref name=":1" />
[[Spina Bifida|Spina bifida]] (or myelodysplasia) is a congenital condition where there is failure of the neural tubes to close during foetal development.<ref name=":5">Brea CM, Munakomi S. Spina Bifida. [Updated 2023 Feb 12]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK559265/?report=classic</ref> The neural tube is the embryonic structure that develops into the spinal cord and brain. Spina bifida ranges in terms of severity.<ref name=":0">Lundy-Ekman L (2007). Neuroscience: Fundamentals for Rehabilitation. 3rd edition. St. Louis: Saunders, 2007</ref><ref name=":1">Spina Bifida: Background, Pathophysiology, Etiology [Internet]. Emedicine.medscape.com. 2019 [cited 2 March 2019]. Available from: <nowiki>http://emedicine.medscape.com/article/311113-overview</nowiki></ref> Lesions most commonly occur in the lumbar regions but they can occur in all parts of the spine.<ref name=":0" />


== Types of Spina Bifida ==
=== Types of Spina Bifida ===
Spina Bifida Occulta: It can occur without neurologic defects.
Spina bifida is divided into spina bifida occulta and spina bifida aperta (see image below).<ref name=":5" />


Meningocele: A cystic swelling of the dura and arachnoid, protrudes through the spina bifida defect in the vertebral arch.
'''Spina bifida occulta'''<ref name=":5" />
* closed spinal dysraphism
* most mild form
* there is a hidden vertebral defect


Meningomyelocele: when cord tissue extends into the meningocele.


Myeloschisis: If the spinal cord is exposed on the surface of the back, the condition is called myeloschisis .<ref>4. Burke R, Liptak G. Providing a Primary Care Medical Home for Children and Youth With Spina Bifida. PEDIATRICS. 2011;128(6):e1645-e1657.</ref><br>
'''Spina bifida aperta'''<ref name=":5" />
* open spinal dysraphism
* examples of spina bifida aperta:
 
# meningocele: the meninges are involved<ref name=":6">Burke R, Liptak G. Providing a Primary Care Medical Home for Children and Youth With Spina Bifida. PEDIATRICS. 2011;128(6):e1645-e1657.</ref>
# meningomyelocele: the lesion involves parts of the spinal cord and the meninges within the sac<ref name=":6" />
# myeloschisis: the neural tissue is exposed to the environment, without a sac or meninges<ref>Chatterjee S, Dasgupta A. ''Myeloschisis'' . In: Alexiou, G, Prodromou N. (editors). Pediatric Neurosurgery for Clinicians. Springer: Cham, 2022.</ref><br>


[[File:Spina bifida image 1.jpg|center|thumb]]
[[File:Spina bifida image 1.jpg|center|thumb]]


== Embryology   ==
=== Embryology ===
 
Neural tube defects occur early in pregnancy, between day 17 and day 30 gestation. This defect disrupts the overlying tissues, thus preventing the vertebral arch from closing.<ref>Fletcher JM, Copeland K, Frederick JA (2005). Spinal lesion level in spina bifida: a source of neural and cognitive heterogeneity. Journal of Neurosurgery. 102(3 Suppl):268-79</ref> If the posterior vertebral arch and overlying tissues do not form normally, the spinal cord and meninges may then herniate out through the defect, resulting in meningomyelocele (MMC).
 
''Spina bifida occulta'' occurs if the vertebral arch fails to grow and fuse normally but the spinal cord and meninges are not disturbed.<ref name=":1" /><br>


Neural tube defects occur between the 17th and 30th days of gestation. This defect then disrupts all of the overlying tissues, preventing the vertebral arch from closing.<ref>Fletcher JM, Copeland K, Frederick JA (2005). Spinal lesion level in spina bifida: a source of neural and cognitive heterogeneity. Journal of Neurosurgery. 102(3 Suppl):268-79</ref>If the posterior vertebral arch and overlying tissues do not form normally, the normal spinal cord and meninges may then herniate out through the defect and cause a meningomyelocele (MMC). If the vertebral arch fails to grow and fuse normally and the spinal cord and meninges are not disturbed spina bifida occulta results.<ref name=":1" /><br>
=== Pathophysiology    ===
In MMC, the development of the cranial neural tube is affected. This causes various central nervous system changes, including [[Arnold Chiari Malformation|Chiari type II malformation]], which is a structural change in the cerebellum. Chiari type II malformation is associated with cerebellar hypoplasia and descent of the lower part of the brainstem into the upper cervical canal. This affects the movement and absorption of cerebrospinal fluid and results in [[hydrocephalus]] (please note that hydrochephalus affects >90% of infants with MMC).<ref name=":1" /> MMC can also cause spine malformations, hydronephrosis, cardiac defects, and gastrointestinal anomalies.<ref name=":1" />


== Pathophysiology ==
=== Epidemiology ===
MMC is associated with abnormal development of the cranial neural tube, which results in several characteristic CNS anomalies. The Chiari type II malformation is characterized by cerebellar hypoplasia and varying degrees of caudal displacement of the lower brainstem into the upper cervical canal through the foramen magnum. This deformity impedes the flow and absorption of cerebrospinal fluid (CSF) and causes hydrocephalus, which occurs in more than 90% of infants with MMC. Numerous other associated nervous system malformations include syringomyelia, diastematomyelia, and agenesis of the corpus callosum. Non-neurologic associations include spine malformations, hydronephrosis, cardiac defects, and gastrointestinal anomalies.<ref name=":1" />
The incidence of spina bifida worldwide 18.6 per 10,000.<ref>Hassan AE, Du YL, Lee SY, Wang A, Farmer DL. [https://www.mdpi.com/2221-3759/10/2/22 Spina Bifida: A Review of the Genetics, Pathophysiology and Emerging Cellular Therapies]. Journal of Developmental Biology. 2022 Jun 6;10(2):22.</ref> The most common open neural tube defect is myelomeningocele.<ref name=":2">Sahni M, Alsaleem M, Ohri A. Meningomyelocele. [Updated 2023 Feb 5]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK536959/</ref>


== Epidemiology ==
* There are within country differences between racial and ethnic groups<ref name=":7" />
There are variations in incidence between some racial populations. The incidence of MMC in America: 1.1 in 1000 births. The current incidence in America is about 0.6 per 1000, and there is good evidence that this has been steadily declining.<ref name=":2">5. Shin M, Besser L, Siffel C, Kucik J, Shaw G, Lu C et al. Prevalence of Spina Bifida Among Children and Adolescents in 10 Regions in the United States. PEDIATRICS. 2010;126(2):274-279.</ref> African-American cases are often a third of those found for white Americans, while those for Hispanic-Americans are two to three times greater<ref name=":1" />.1 case in 10,000 is reported in Finland and 5 in 1000 in Northern Ireland 5. There are at least 2000 cases/year in the US.<ref name=":2" />
** there are higher rates of spina bifida in Hispanic groups in the United States
** there is a lower prevalence in African-Americans
* The risk of myelomeningocele in females is 3-7 times higher than males
* There are higher rates of myelomeningocele in China, some parts of Africa, the Middle East, Thailand, India
** it has been noted that different guidelines on folate supplementation may have an impact on these variations in rates<ref name=":2" />


== Aetiology ==
== Aetiology ==
The risk of an adult with MMC having a child with a neural tube defect is 5% <ref name=":3">6. Canfield M, Ramadhani T, Shaw G, Carmichael S, Waller D, Mosley B et al. Anencephaly and spina bifida among Hispanics: maternal, sociodemographic, and acculturation factors in the National Birth Defects Prevention Study. Birth Defects Research Part A: Clinical and Molecular Teratology. 2009;85(7):637-646.</ref>. Several risk factors have been linked to neural tube defect, including;<ref>Copp AJ, Adzick NS, Chitty LS, Fletcher JM, Holmbeck GN, Shaw GM. Spina bifida. Nat Rev Dis Primers. 2015 Apr 30;1:15007.</ref>
Several risk factors have been linked to neural tube defect, including:<ref name=":7">Copp AJ, Adzick NS, Chitty LS, Fletcher JM, Holmbeck GN, Shaw GM. Spina bifida. Nat Rev Dis Primers. 2015 Apr 30;1:15007.</ref>


* Chromosomal and genetic conditions: parents or siblings with neural tube defect, trisomies 13 and 18, HARD syndrome (Hydrocephalus, agyria and retinal dysplasia) etc.
# Chromosomal and genetic conditions:
** Maternal environmental factors and exposure: alcohol use, caffeine intake, smoking, air pollution, disinfectant byproducts in drinking water, exposure to organic solvents, pesticides, nitrate-related compounds, polycyclic aromatic hydrocarbons, fumonisins, EM field, maternal fever or hyperthermia ( especially in the first trimester) from febrile illness or external sources like sauna, hot tub.<ref name=":1" />
#* parents or siblings with neural tube defect increases the risk
** Maternal medical conditions: Women with low RBC cell folate levels during early pregnancy have up to a 6 times greater risk of having a child with a neural tube defect, elevated glycemic index, and gestational diabetes mellitus infections, obesity, and stress, maternal diarrhoea.<ref name=":3" />
#* trisomies 13 and 18
** Maternal nutritional deficiencies, folate, methionine, zinc, vitamin C, vitamin B12, and choline.
#* HARD syndrome ([[Hydrocephalus]], agyria and retinal dysplasia)
** Maternal medications: Intrauterine exposure to antiepileptic drugs, particularly valproate and carbamazepine, and to drugs used to induce ovulation, various folic acid antagonists.
# Maternal environmental factors and exposure:
#* alcohol use
#* caffeine intake
#* smoking, air pollution
#* disinfectant by-products found in drinking water
#* exposure to organic solvents, pesticides, nitrate-related compounds, polycyclic aromatic hydrocarbons, fumonisins
#* maternal fever or hyperthermia (especially in the first trimester) from febrile illness or external sources like a sauna, or hot tub<ref name=":1" />
# Maternal medical conditions:
#* women with low red blood cell folate levels during early pregnancy have up to a 6 times greater risk of having a child with a neural tube defect
#* elevated glycemic index, and gestational diabetes mellitus
#* infections
#* obesity
#* stress
#* maternal diarrhoea<ref name=":3">Canfield M, Ramadhani T, Shaw G, Carmichael S, Waller D, Mosley B et al. Anencephaly and spina bifida among Hispanics: maternal, sociodemographic, and acculturation factors in the National Birth Defects Prevention Study. Birth Defects Research Part A: Clinical and Molecular Teratology. 2009;85(7):637-646.</ref>
# Maternal nutritional deficiencies:
#* folate
#* methionine
#* zinc
#* vitamin C
#* vitamin B12
#* choline
# Maternal medications:
#* intrauterine exposure to antiepileptic drugs, particularly valproate and carbamazepine
#* drugs used to induce ovulation
#* various folic acid antagonists


== Diagnostic Procedures ==
=== Diagnostic Procedures ===


The diagnosis in a newborn is usually obvious because of the visible bulge in the back which consists of protruding membrane-covered sac containing meninges, cerebrospinal fluid (CSF) and nerve tissue seen through a vertebral column defect. The clinical features of meningomyelocele depend on the:
Diagnosis of MMC in a ''newborn'' is usually obvious because there is a visible bulge in the back, which consists of the protruding membrane-covered sac containing meninges, cerebrospinal fluid and nerve tissue. The clinical features of MMC depend on the:


* Level of involvement
* level of involvement
* The presence of hydrocephalus
* presence of hydrocephalus
* Associated brain abnormalities
* associated brain abnormalities


In addition, the measurement of maternal serum α-fetoprotein (MSAFP) levels is a common screening test. If the level is elevated, indicating that any portion of the fetus is not covered by skin, this screening test is then followed by detailed ultrasonography. Ultrasound scans will diagnose 92% of neural tube defects. Mothers with elevated MSAFP levels and a normal-appearing ultrasound scan may be evaluated by amniocentesis for the presence of elevated acetylcholinesterase levels in the amniotic fluid.<ref name=":1" /><br>  
Testing options in the ''foetus'' include:<ref name=":1" /><ref name=":8">National Institute of Neurological Disorders and Stroke. Spina Bifida. Available from: https://www.ninds.nih.gov/health-information/disorders/spina-bifida (last accessed 15 May 2023).</ref>


== Outcome Measures  ==
* maternal serum α-fetoprotein (MSAFP) screening test
** abnormally elevated levels can suggest (but not confirm) the baby has spina bifida / a neural tube defect
* detailed ultrasonography (diagnosis is usually more accurate in the second trimester<ref name=":8" />)
** ultrasound scans will diagnose 92% of neural tube defects


The [[Outcome Measures|Functional independence measure]] (FIM) is the most widely accepted functional measure. FIM consists of 18 scales scored from 1 to 7; higher numbers mean greater ability. Others include the Child Health Questionnaire (CHQ), [[Outcome Measures|Barthel Index (BI)]]. 
* mothers with elevated MSAFP levels and a normal-appearing ultrasound scan may be evaluated by amniocentesis for the presence of elevated acetylcholinesterase levels in the amniotic fluid<ref name=":1" />


== Management / Interventions   ==
=== Management / Interventions ===
Generally, infants with MMC have surgery to close the spinal cord defect soon after birth.<ref name=":1" /><ref name=":8" /> Additional surgeries may be required to manage other issues in the feet, hips, or spine. Individuals with hydrocephalus will also require a shunt to be placed (and subsequent surgeries for the shunt). Surgery may also be required to help prevent issues such as weakness and bladder / bowel dysfunction. Catheterisation may be necessary to help preserve bladder function.<ref name=":1" /><ref name=":8" />


Generally, surgery follows within the first few days of life to close the spinal cord defect.<ref name=":1" /> It is also important to prevent infection and additional trauma to the exposed tissues. Additional surgeries may be required to manage other problems in the feet, hips, or spine. Individuals with hydrocephalus will also require subsequent surgeries due to the shunt needing to be replaced. Due to the bowel and bladder problems that are often caused by the neural tube defect, catheterization may be necessary.  
'''Management of Myelomeningocele Study (MOMS)''':<ref name=":9">Farmer DL, Thom EA, Brock JW 3rd, Burrows PK, Johnson MP, Howell LJ, et al. [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7737375/ The Management of Myelomeningocele Study: full cohort 30-month pediatric outcomes]. Am J Obstet Gynecol. 2018 Feb;218(2):256.e1-256.e13.</ref> The MOMS trial was a multicentre clinical trial sponsored by the National Institutes of Health in the United States. It began in 2002 and was designed to determine the best treatment for MMC - it compared foetal surgery and surgical repair after birth. It was found that prenatal surgery:<ref name=":10">University of California San Francisco. Spina Bifida MOMS Trial. Available from: https://fetus.ucsf.edu/spina-bifida-moms-trial/ (last accessed 13 May 2023). </ref><ref name=":9" />


The Management of Myelomeningocele Study (MOMS).<ref>7. McLone D, Knepper P. The Cause of Chiari II Malformation: A Unified Theory. Pediatric Neurosurgery. 1989;15(1):1-12.</ref>The MOMS trial is an NIH-sponsored multicenter clinical trial that began in 2002 to evaluate what was the best treatment for myelomeningocele — fetal surgery or surgical repair after birth.
* reduces midbrain herniation
* decreases the need to shunt cerebrospinal fluid from the brain
* had a positive impact on mental development / motor function
* improved the likelihood that a child would be able to walk unaided


The clinical trial results showed prenatal surgery significantly reduced the need to divert, or shunt, fluid away from the brain; improved mental development and motor function; and increased the likelihood that a child will walk unassisted. The MOMS trial has proved that some of the factors causing problems like Chiari II malformation and hydrocephalus are in fact those that develop during the second half of pregnancy. Closing the fetus’s back early may allow some nerve function to be restored in pregnancy, and actually, reverse the development of this serious condition.
The MOMS trial, therefore, supports the use of foetal surgery as an effective option for MMC.<ref name=":9" /> It found that some of the factors associated with Chiari type II malformation and hydrocephalus develop during the second half of pregnancy. Therefore, early surgery may enable some restoration of nerve function in pregnancy and potentially reverse the development of MMC.<ref name=":10" />


== Physiotherapy Management ==
== Rehabilitation  ==
A multidisciplinary approach towards managing patients with MMC is essential for successful outcomes. The patient should be assessed as soon after birth as possible. At different stages, the focus of physiotherapy will change with the changing needs of the patient. Regular review is essential to meet up with patient needs. Parents and caregivers should be involved in patient care.
A multidisciplinary approach is essential for successful outcomes in individuals with MMC. An individual should be assessed as soon after birth as possible. The focus of rehabilitation will change with the changing needs of the patient. Regular review is essential ensure rehabilitation continues to meet the patient's needs. Parents / caregivers should be involved in patient care.
* CLINICAL PRESENTATION - The following can be observed in the case of MMC.<ref name=":1" />Flaccid or spastic paralysis of the lower limbs, Urinary and or faecal incontinence, Hydrocephalus, Poor trunk control, Musculoskeletal complications, Scoliosis, Hip dysplasia, Hip dislocation, Hip/knee contracture, Clubfoot, Muscle Atrophy


* PHYSICAL ASSESSMENT- The following may be observed during the physical assessment.
=== Clinical Presentation ===
** Open wound
Possible signs include:<ref name=":1" />
** Deformities
** Skin abnormalities
** Sensation
** Muscle tone
** Muscle Strength
** Range of Motion
** Contractures
** Dislocation
** Developmental Milestones


* PLAN OF CARE
* flaccid or spastic paralysis of the lower limbs
** Prevent/correct deformity 
* urinary and / or faecal incontinence
** Maintain/improve physiological properties of joints and muscles 
* hydrocephalus
** Monitor normal motor development 
* poor trunk control
** Educate parent(s), caregivers 
* musculoskeletal complications
** Encourage and maximise independent mobility 
* scoliosis
** Encourage participation in regular physical activity.


* MEANS OF TREATMENT
* hip dysplasia
** Serial casting (CTEV) 
* hip dislocation
** Passive mobilization, graded exercises and stretches.
* hip / knee contracture
** Tactile stimulation
* clubfoot
** Balance & Trunk control exercises
* muscle atrophy
** Positioning
** Orthosis & Assistive devices
** Parent education: Parents should be educated about the child’s condition, progress, and prognosis and involved in treatment planning and home programmes.<ref>8. McDonnell G, McCann J. Issues of medical management in adults with spina bifida. Child's Nervous System. 2000;16(4):222-227.</ref> Serial casting for CTEV.<br>


== Complications  ==
=== Physical Assessment ===
During the physical assessment, assess for:
* open wound
* deformities
* skin abnormalities
* sensation
* changes in muscle tone
* changes in muscle strength
* changes in range of motion
* contractures
* dislocation
* developmental milestones


=== Common Complications of MMC Include the Following.<ref name=":1" /> ===
=== Plan of care ===
* Reproductive organs impairment
The plan of care will include:
* Neurogenic Bladder: The vast majority of children with MMC have a neurogenic bladder.
* preventing / correcting deformity
* Only 5.0% to 7.5% of the MMC population have a normal urologic function.
* maintaining / improving physiological properties of joints and muscles
* Neurogenic Bowel: Traditional bowel continence is present in approximately 10% of children with MMC.
* monitoring normal motor development
* Musculoskeletal complications.
* educating parent(s), caregivers
* Psychosocial issues: Vulnerable child syndrome.
* encouraing and maximising independent mobility
* Pressure sores
* encouraging participation in regular physical activity
* Learning disabilities


=== Neurosurgical Complications ===
=== Means of Treatment ===
* Wound infection rates range from 7% to 12% <ref name=":1" />
Treatments might include:
* Hydrocephalus; visual impairment
* serial casting
* Ventriculitis: low subsequent IQ
* passive mobilisation, graded exercises and stretches
* Shunt failure
* tactile stimulation
** 5% - 32% of infants with MMC will present with signs of Chiari compression, making it the most common cause of death in patients with MMC
* balance and trunk control exercises
* Chiari compression can occur at any time, presentation in the first year of life is associated with up to 50% mortality.<ref name=":4">Campbell, SK, Linden, DW, Palisano RJ (2000). Physical Therapy for Children (2nd Edition). Philadelphia, PA: W.B. Saunders.</ref>
* positioning
* Chronic headaches are the most frequently reported symptom.<ref name=":4" />
* orthotics and assistive devices
* Obesity - Obesity is prevalent in children with MMC. The higher the level of the lesion along the spine the higher her percentage of body fat.<ref name=":1" />In children with L1–L3 lesions, the effect of increasing obesity is a critical factor in the loss of ambulation<ref name=":1" />Typically, children with MMC reach their peak ambulatory abilities around the age of 10 years. They then experience a slow decline in function over the next 10 years. The children who ambulate more have a lower percentage of body fat. <ref name=":1" /><br>
* parent / caregivers education: parents or caregivers should be educated about the child’s condition, progress, and prognosis and be involved in treatment planning and home programmes<ref>McDonnell G, McCann J. Issues of medical management in adults with spina bifida. Child's Nervous System. 2000;16(4):222-227.</ref> <br>


== Conclusion    ==
== General Complications ==
Complications of MMC include the following:<ref name=":1" />
* reproductive organs impairment
* only 5.0% to 7.5% of the MMC population have a normal urologic function
* neurogenic bowel: approximately 10% of children with MMC have bowel continence
* musculoskeletal complications
* psychosocial issues: vulnerable child syndrome
* pressure sores
* learning disabilities


About 90% of babies born with Spina Bifida now live to be adults, about 80% have normal intelligence and about 75% play sports and do other fun activities. Most do well in school, and many play sports.<ref name=":1" />
=== Neurosurgical Complications ===
 
There are specific neurosurgical complications that should be considered:
A cross-sectional study (August 2020) by a multidisciplinary team describing health issues and living conditions in a cohort of adults living with Spina bifida suggest the presence of a higher prevalence of urinary and faecal incontinence, pain, and overweight in adults with Spina Bifida. Persons with the condition greater than 46 years had less complicated medical conditions, better physical and cognitive functions, and higher education, independent living, and participation in society, whereas individuals < 46 years had more secondary conditions such as hydrocephalus, Chiari II malformation, tethered cord symptoms, and latex allergy<ref>Bendt M, Gabrielsson H, Riedel D, Hagman G, Hultling C, Franzén E, Eriksson M, Seiger Å. [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7428499/ Adults with spina bifida: A cross‐sectional study of health issues and living conditions.] Brain and Behavior. 2020 Aug;10(8):e01736.</ref>.  
* wound infection rates range from 7% to 12%<ref name=":1" />
* hydrocephalus
* visual impairment
* ventriculitis
* shunt failure
* Chiari compression
** 5-32% of infants with MMC present with signs of Chiari compression
** it is the most common cause of death in patients with MMC
** Chiari compression can occur at any time, but if it occurs in the first year of life it is associated with a mortality rate of up to 50%<ref name=":4">Campbell, SK, Linden, DW, Palisano RJ (2000). Physical Therapy for Children (2nd Edition). Philadelphia, PA: W.B. Saunders.</ref>
* chronic headaches (the most frequently reported symptom)<ref name=":4" />
* obesity
** common in children with MMC
** the higher the lesion, the higher the percentage of body fat<ref name=":1" />
** in children with L1–L3 lesions, increasing obesity is associated with decreased ability to ambulate<ref name=":1" />
*** children with MMC tend to reach peak ambulation at around 10 years
*** this is followed by a gradual decrease in function over the following 10 years
*** children who ambulate more have been found to have a lower percentage of body fat<ref name=":1" /><br>
== References  ==
== References  ==


<references />
<references />
[[Category:Spina Bifida]]
[[Category:Paediatrics]]
[[Category:Paediatrics]]
[[Category:Paediatrics - Conditions]]
[[Category:Paediatrics - Conditions]]
[[Category:Non Communicable Diseases]]
[[Category:Non Communicable Diseases]]
[[Category:Course Pages]]

Latest revision as of 12:12, 13 May 2023

Original Editor - Ayobami Ayodele Top Contributors - Jayati Mehta, Jess Bell, Vidya Acharya, Olajumoke Ogunleye, Kim Jackson, Rishika Babburu, Rucha Gadgil, Robin Tacchetti, Naomi O'Reilly, Meaghan Rieke and Ayobami Ayodele

 

Introduction[edit | edit source]

Spina bifida (or myelodysplasia) is a congenital condition where there is failure of the neural tubes to close during foetal development.[1] The neural tube is the embryonic structure that develops into the spinal cord and brain. Spina bifida ranges in terms of severity.[2][3] Lesions most commonly occur in the lumbar regions but they can occur in all parts of the spine.[2]

Types of Spina Bifida[edit | edit source]

Spina bifida is divided into spina bifida occulta and spina bifida aperta (see image below).[1]

Spina bifida occulta[1]

  • closed spinal dysraphism
  • most mild form
  • there is a hidden vertebral defect


Spina bifida aperta[1]

  • open spinal dysraphism
  • examples of spina bifida aperta:
  1. meningocele: the meninges are involved[4]
  2. meningomyelocele: the lesion involves parts of the spinal cord and the meninges within the sac[4]
  3. myeloschisis: the neural tissue is exposed to the environment, without a sac or meninges[5]
Spina bifida image 1.jpg

Embryology[edit | edit source]

Neural tube defects occur early in pregnancy, between day 17 and day 30 gestation. This defect disrupts the overlying tissues, thus preventing the vertebral arch from closing.[6] If the posterior vertebral arch and overlying tissues do not form normally, the spinal cord and meninges may then herniate out through the defect, resulting in meningomyelocele (MMC).

Spina bifida occulta occurs if the vertebral arch fails to grow and fuse normally but the spinal cord and meninges are not disturbed.[3]

Pathophysiology[edit | edit source]

In MMC, the development of the cranial neural tube is affected. This causes various central nervous system changes, including Chiari type II malformation, which is a structural change in the cerebellum. Chiari type II malformation is associated with cerebellar hypoplasia and descent of the lower part of the brainstem into the upper cervical canal. This affects the movement and absorption of cerebrospinal fluid and results in hydrocephalus (please note that hydrochephalus affects >90% of infants with MMC).[3] MMC can also cause spine malformations, hydronephrosis, cardiac defects, and gastrointestinal anomalies.[3]

Epidemiology[edit | edit source]

The incidence of spina bifida worldwide 18.6 per 10,000.[7] The most common open neural tube defect is myelomeningocele.[8]

  • There are within country differences between racial and ethnic groups[9]
    • there are higher rates of spina bifida in Hispanic groups in the United States
    • there is a lower prevalence in African-Americans
  • The risk of myelomeningocele in females is 3-7 times higher than males
  • There are higher rates of myelomeningocele in China, some parts of Africa, the Middle East, Thailand, India
    • it has been noted that different guidelines on folate supplementation may have an impact on these variations in rates[8]

Aetiology[edit | edit source]

Several risk factors have been linked to neural tube defect, including:[9]

  1. Chromosomal and genetic conditions:
    • parents or siblings with neural tube defect increases the risk
    • trisomies 13 and 18
    • HARD syndrome (Hydrocephalus, agyria and retinal dysplasia)
  2. Maternal environmental factors and exposure:
    • alcohol use
    • caffeine intake
    • smoking, air pollution
    • disinfectant by-products found in drinking water
    • exposure to organic solvents, pesticides, nitrate-related compounds, polycyclic aromatic hydrocarbons, fumonisins
    • maternal fever or hyperthermia (especially in the first trimester) from febrile illness or external sources like a sauna, or hot tub[3]
  3. Maternal medical conditions:
    • women with low red blood cell folate levels during early pregnancy have up to a 6 times greater risk of having a child with a neural tube defect
    • elevated glycemic index, and gestational diabetes mellitus
    • infections
    • obesity
    • stress
    • maternal diarrhoea[10]
  4. Maternal nutritional deficiencies:
    • folate
    • methionine
    • zinc
    • vitamin C
    • vitamin B12
    • choline
  5. Maternal medications:
    • intrauterine exposure to antiepileptic drugs, particularly valproate and carbamazepine
    • drugs used to induce ovulation
    • various folic acid antagonists

Diagnostic Procedures[edit | edit source]

Diagnosis of MMC in a newborn is usually obvious because there is a visible bulge in the back, which consists of the protruding membrane-covered sac containing meninges, cerebrospinal fluid and nerve tissue. The clinical features of MMC depend on the:

  • level of involvement
  • presence of hydrocephalus
  • associated brain abnormalities

Testing options in the foetus include:[3][11]

  • maternal serum α-fetoprotein (MSAFP) screening test
    • abnormally elevated levels can suggest (but not confirm) the baby has spina bifida / a neural tube defect
  • detailed ultrasonography (diagnosis is usually more accurate in the second trimester[11])
    • ultrasound scans will diagnose 92% of neural tube defects
  • mothers with elevated MSAFP levels and a normal-appearing ultrasound scan may be evaluated by amniocentesis for the presence of elevated acetylcholinesterase levels in the amniotic fluid[3]

Management / Interventions[edit | edit source]

Generally, infants with MMC have surgery to close the spinal cord defect soon after birth.[3][11] Additional surgeries may be required to manage other issues in the feet, hips, or spine. Individuals with hydrocephalus will also require a shunt to be placed (and subsequent surgeries for the shunt). Surgery may also be required to help prevent issues such as weakness and bladder / bowel dysfunction. Catheterisation may be necessary to help preserve bladder function.[3][11]

Management of Myelomeningocele Study (MOMS):[12] The MOMS trial was a multicentre clinical trial sponsored by the National Institutes of Health in the United States. It began in 2002 and was designed to determine the best treatment for MMC - it compared foetal surgery and surgical repair after birth. It was found that prenatal surgery:[13][12]

  • reduces midbrain herniation
  • decreases the need to shunt cerebrospinal fluid from the brain
  • had a positive impact on mental development / motor function
  • improved the likelihood that a child would be able to walk unaided

The MOMS trial, therefore, supports the use of foetal surgery as an effective option for MMC.[12] It found that some of the factors associated with Chiari type II malformation and hydrocephalus develop during the second half of pregnancy. Therefore, early surgery may enable some restoration of nerve function in pregnancy and potentially reverse the development of MMC.[13]

Rehabilitation[edit | edit source]

A multidisciplinary approach is essential for successful outcomes in individuals with MMC. An individual should be assessed as soon after birth as possible. The focus of rehabilitation will change with the changing needs of the patient. Regular review is essential ensure rehabilitation continues to meet the patient's needs. Parents / caregivers should be involved in patient care.

Clinical Presentation[edit | edit source]

Possible signs include:[3]

  • flaccid or spastic paralysis of the lower limbs
  • urinary and / or faecal incontinence
  • hydrocephalus
  • poor trunk control
  • musculoskeletal complications
  • scoliosis
  • hip dysplasia
  • hip dislocation
  • hip / knee contracture
  • clubfoot
  • muscle atrophy

Physical Assessment[edit | edit source]

During the physical assessment, assess for:

  • open wound
  • deformities
  • skin abnormalities
  • sensation
  • changes in muscle tone
  • changes in muscle strength
  • changes in range of motion
  • contractures
  • dislocation
  • developmental milestones

Plan of care[edit | edit source]

The plan of care will include:

  • preventing / correcting deformity
  • maintaining / improving physiological properties of joints and muscles
  • monitoring normal motor development
  • educating parent(s), caregivers
  • encouraing and maximising independent mobility
  • encouraging participation in regular physical activity

Means of Treatment[edit | edit source]

Treatments might include:

  • serial casting
  • passive mobilisation, graded exercises and stretches
  • tactile stimulation
  • balance and trunk control exercises
  • positioning
  • orthotics and assistive devices
  • parent / caregivers education: parents or caregivers should be educated about the child’s condition, progress, and prognosis and be involved in treatment planning and home programmes[14]

General Complications[edit | edit source]

Complications of MMC include the following:[3]

  • reproductive organs impairment
  • only 5.0% to 7.5% of the MMC population have a normal urologic function
  • neurogenic bowel: approximately 10% of children with MMC have bowel continence
  • musculoskeletal complications
  • psychosocial issues: vulnerable child syndrome
  • pressure sores
  • learning disabilities

Neurosurgical Complications[edit | edit source]

There are specific neurosurgical complications that should be considered:

  • wound infection rates range from 7% to 12%[3]
  • hydrocephalus
  • visual impairment
  • ventriculitis
  • shunt failure
  • Chiari compression
    • 5-32% of infants with MMC present with signs of Chiari compression
    • it is the most common cause of death in patients with MMC
    • Chiari compression can occur at any time, but if it occurs in the first year of life it is associated with a mortality rate of up to 50%[15]
  • chronic headaches (the most frequently reported symptom)[15]
  • obesity
    • common in children with MMC
    • the higher the lesion, the higher the percentage of body fat[3]
    • in children with L1–L3 lesions, increasing obesity is associated with decreased ability to ambulate[3]
      • children with MMC tend to reach peak ambulation at around 10 years
      • this is followed by a gradual decrease in function over the following 10 years
      • children who ambulate more have been found to have a lower percentage of body fat[3]

References[edit | edit source]

  1. ↑ 1.0 1.1 1.2 1.3 Brea CM, Munakomi S. Spina Bifida. [Updated 2023 Feb 12]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK559265/?report=classic
  2. ↑ 2.0 2.1 Lundy-Ekman L (2007). Neuroscience: Fundamentals for Rehabilitation. 3rd edition. St. Louis: Saunders, 2007
  3. ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 3.13 3.14 Spina Bifida: Background, Pathophysiology, Etiology [Internet]. Emedicine.medscape.com. 2019 [cited 2 March 2019]. Available from: http://emedicine.medscape.com/article/311113-overview
  4. ↑ 4.0 4.1 Burke R, Liptak G. Providing a Primary Care Medical Home for Children and Youth With Spina Bifida. PEDIATRICS. 2011;128(6):e1645-e1657.
  5. ↑ Chatterjee S, Dasgupta A. Myeloschisis . In: Alexiou, G, Prodromou N. (editors). Pediatric Neurosurgery for Clinicians. Springer: Cham, 2022.
  6. ↑ Fletcher JM, Copeland K, Frederick JA (2005). Spinal lesion level in spina bifida: a source of neural and cognitive heterogeneity. Journal of Neurosurgery. 102(3 Suppl):268-79
  7. ↑ Hassan AE, Du YL, Lee SY, Wang A, Farmer DL. Spina Bifida: A Review of the Genetics, Pathophysiology and Emerging Cellular Therapies. Journal of Developmental Biology. 2022 Jun 6;10(2):22.
  8. ↑ 8.0 8.1 Sahni M, Alsaleem M, Ohri A. Meningomyelocele. [Updated 2023 Feb 5]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK536959/
  9. ↑ 9.0 9.1 Copp AJ, Adzick NS, Chitty LS, Fletcher JM, Holmbeck GN, Shaw GM. Spina bifida. Nat Rev Dis Primers. 2015 Apr 30;1:15007.
  10. ↑ Canfield M, Ramadhani T, Shaw G, Carmichael S, Waller D, Mosley B et al. Anencephaly and spina bifida among Hispanics: maternal, sociodemographic, and acculturation factors in the National Birth Defects Prevention Study. Birth Defects Research Part A: Clinical and Molecular Teratology. 2009;85(7):637-646.
  11. ↑ 11.0 11.1 11.2 11.3 National Institute of Neurological Disorders and Stroke. Spina Bifida. Available from: https://www.ninds.nih.gov/health-information/disorders/spina-bifida (last accessed 15 May 2023).
  12. ↑ 12.0 12.1 12.2 Farmer DL, Thom EA, Brock JW 3rd, Burrows PK, Johnson MP, Howell LJ, et al. The Management of Myelomeningocele Study: full cohort 30-month pediatric outcomes. Am J Obstet Gynecol. 2018 Feb;218(2):256.e1-256.e13.
  13. ↑ 13.0 13.1 University of California San Francisco. Spina Bifida MOMS Trial. Available from: https://fetus.ucsf.edu/spina-bifida-moms-trial/ (last accessed 13 May 2023).
  14. ↑ McDonnell G, McCann J. Issues of medical management in adults with spina bifida. Child's Nervous System. 2000;16(4):222-227.
  15. ↑ 15.0 15.1 Campbell, SK, Linden, DW, Palisano RJ (2000). Physical Therapy for Children (2nd Edition). Philadelphia, PA: W.B. Saunders.
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