Spina bifida (cleft spine)
Last updated date: 07-May-2023
Originally Written in English
Spina Bifida (Cleft Spine)
Spina bifida is a congenital abnormality caused by inadequate neural tube development. It's a term that's often used to refer to any degree of neural tube closure. Spina bifida occulta and spina bifida aperta are two types of spina bifida. Closed spinal dysraphism, or spina bifida occulta, is the least severe form of neural tube defect (NTD), involving a hidden vertebral defect and limited neural involvement. Meningocele and myelomeningocele are examples of spina bifida aperta, or open spinal dysraphism, which is a condition in which neural tissues interface with the external environment. Because of the degree of neuralization, these circumstances cause a wide range of neurological symptoms. Because spina bifida is frequently linked with a variety of other developmental problems, a multidisciplinary medical approach is critical for survival and excellent results.
Since its discovery, the prevalence and incidence of NTDs have fluctuated but overall have decreased as a result of various interventional initiatives and increasing fetal screening. Between 1999 and 2007, the overall prevalence of spina bifida in the United States was 3.1 per 10,000 live births. According to research, roughly 1,350 healthy babies born each year might have had NTDs if folic acid fortification had not been implemented into routine prenatal care. NTD appears to affect a large percentage of Hispanic women's pregnancies. Hispanics had a prevalence of 3.8/10,000 live births worldwide, compared to 2.7/10,000 for non-Hispanic Black or African Americans and 3.1/10,000 for non-Hispanic Whites. The degree of the abnormality, as well as family medical history, geographical area, and severity of the disease, all raise the likelihood of recurrence. It has been observed that after one affected pregnancy or maternal history of the abnormality, there is a higher risk of recurrence of roughly 4-8 percent, and the risk grows with an increasing number of affected offspring.
Spina Bifida Causes
The inadequate closure of the posterior spinal components causes these spinal dysraphisms, which normally occur between 18 and 30 days of fetal development. Primary and secondary neuralization are the two stages of the neuralization process. The closing of the neural tube that forms the brain and spinal cord is referred to as primary neuralization. Secondary neuralization is the process of the neural tube's caudal structures creating the sacrum and coccygeal part. These caudal structures appear about day 26 of pregnancy, and their closure failure causes variable degrees of spinal dysraphisms.
Environmental and genetic variables are thought to play a role in neural tube development defects. Folate deficiency is the most frequent environmental cause, with the majority of cases classified as "folic acid-sensitive." Dietary folate fortification programs have been established all over the world, and they have reduced the prevalence of anencephaly and spina bifida by 28%. Other risk factors in the environment include maternal obesity, diabetes, and teratogens like valproic acid. Valproic acid has the strongest link to the development of NTDs, with a tenfold increase in the risk. Some genetic variables, such as chromosomal abnormalities and genetic polymorphism, have also been linked to inadequate neuralization. Polymorphisms in the gene encoding the MTHFR enzyme, which is essential for folate metabolism, have been identified as a possible genetic risk factor. While most NTDs are isolated abnormalities, some are linked to chromosomal disorders, the most common of which are Trisomy 13 and 18.
Spina Bifida Symptoms and Signs
To enhance outcomes, patients with NTDs should be identified during prenatal screening and at-risk females should be advised before conception. However, in some locations, particularly marginalized communities and those from low socioeconomic backgrounds, effective screening may not be available, and diseases may show at birth or in infancy. Serum AFP levels are tested for NTD at 16-18 weeks as part of standard prenatal screening. Ultrasound with a sensitivity of 89-90 percent can be used for follow-up. Patients can appear with a wide range of symptoms and diseases due to the wide variety of neuralization. The presence of an open or closed spinal dysraphism can be determined physically by visualizing the lower sections of the spine. There is no visible deformity in spina bifida occulta, however, a hairy patch of skin or a dimple can sometimes be detected where the predicted spinal defect resides. Meningocele is a condition in which the posterior components of the spine are damaged, resulting in the extrusion of meninges and cerebrospinal fluid (CSF) without the involvement of the neural elements. Meninges, CSF, and functioning neural components such as nerve or spinal cord contents are all extruded in myelomeningocele. Because nerve tissue is implicated in myelomeningocele, it usually results in additional functional impairment in the future. Spasticity, discomfort, motor dysfunction, neurogenic bowel and/or bladder, cognitive problems, convulsions, and even endocrine abnormalities such as precocious puberty are all possible symptoms. Because neural tissue can protrude outside the defect and be damaged, neurological impairment is more likely in open dysraphisms such as meningocele and myelomeningocele. Patients with NTDs are more likely to have latex allergies, which affect 10% of patients. A comprehensive gestational, birth, and family history should be collected once any of these signs or symptoms are noticed in order to understand the possible contributions and to direct family counseling.
Spina Bifida Diagnosis
As previously said, women should be screened on a regular basis to detect NTD early and aid in therapeutic strategy and counseling. Serum AFP is used for initial screening, however, in cases of high suspicion, amniocentesis might be used for confirmation. Due to the risk of amniocentesis and the accuracy of ultrasound, the latter has become the gold standard for in-utero identification. A number of ultrasonography signals have been found as being diagnostically reliable. NTD has been linked to a short biparietal diameter. The lemon and banana signs, on the other hand, are the most frequently cited signs. The overlap of the frontal bones caused by a posterior movement of intracranial contents is known as the lemon sign. Due to its downward displacement, the banana sign is that of a bent cerebellum, which frequently leads to Arnold-Chiari II malformation at birth. Ventriculomegaly can be visible on ultrasonography even if there is no hydrocephalus. Further down the spine, ultrasound can help to recognize the damaged vertebral segments and provide prognostic information concerning bowel, bladder, gait, and other issues. In 62 percent of patients, the functional status after birth corresponds to the level of injury indicated by prenatal ultrasound. In 90% of cases, magnetic resonance imaging (MRI) can be employed after delivery for prognostication within one to two spinal levels.
Spina Bifida Treatment
Prevention is the most effective treatment for NTDs like spina bifida. To avoid NTDs, women of reproductive age should supplement their diet with folate. To help reduce cases, the United States began mandating the fortification of grains with folic acid. Those who are trying to conceive should take 0.4mg of folic acid daily before conception, while women with a history of NTD or a previous impacted pregnancy should take 4mg. The majority of patients with occult spina bifida do not require surgery to fix the problem. Surgical therapies, on the other hand, may be able to help minimize the neurologic consequences of open NTDs. An intrauterine correction can be attempted in a small number of patients to avoid future difficulties. To be eligible for this dangerous procedure, the fetus must have a T1-Sacrum lesion, Arnold Chiari malformation, and be between the ages of 18 and 25 weeks. These treatments greatly reduced the requirement for future ventriculoperitoneal shunt insertion, demonstrated proper cerebellum repositioning, and improved leg function and mobility. Intrauterine correction, on the other hand, carries a major risk, including an increased chance of preterm and serious maternal problems.
There are many implications and sequela that must be watched and controlled during the newborn stage. To avoid major neurologic decline and to reduce the danger of infection or injury to any exposed defect, it is preferable to close the defect within 3 days. After the defect is closed, patients may require a ventriculoperitoneal shunt to treat hydrocephalus. Arnold Chiari malformations are prevalent and frequently require surgery; however, when patients are symptomatic, this operation poses a high risk of death. Because numerous organ systems might be damaged, long-term therapy necessitates an interdisciplinary approach. The disease is commonly manifested by the neurogenic bowel and bladder. Detrusor-sphincter dyssynergia is a common symptom of neurogenic bladder, and if not treated properly, it can progress to renal failure. Patients should have biannual renal ultrasounds for surveillance, and long-term care may necessitate intermittent catheterization. Patients may also have neurogenic bowel, which is caused by a lack of sensation and sphincter control. For adequate control, patients may have to learn a consistent bowel program that includes stool softeners, motility medications, and digital stimulation.
NTDs can cause a wide range of motor symptoms in children, including weakness, flaccidity, rigidity, and contractures. Patients with severe contractures that interfere with walking, hygiene, or posture may benefit from tendon lengthening operations. Foot abnormalities such as equinovarus, calcaneus, and rocker bottom deformities are frequent in NTDs. With considerable spasticity and/or contractures, splinting, passive stretching, and serial cast can aid.
Spina Bifida Complications
Patients may experience a variety of problems, some of which have already been mentioned. Acute renal failure/urosepsis is the most prevalent consequence, which is caused by ureteral reflux induced by a neurogenic bladder. It is critical to begin active therapy and monitoring of urologic dysfunction. For urinary management, many patients will require intermittent catheterization. Scoliosis is another prevalent consequence, affecting approximately 35% of patients, followed by chronic pain and epilepsy. Patients with tethered cords or hydromyelia may experience an abrupt loss in neurologic function, spasticity, or discomfort. NTD is linked to an increased risk of fracture, which is likely due to osteopenia, contractures, diminished sensation, and immobility.
Spina Bifida Prognosis
Given the tremendous advancements in spina bifida therapy, there are few current longitudinal studies on spina bifida and long-term results, making it difficult to prognosticate for patients. In most research, data from patients with both open and closed dysraphisms is merged. Overall, the prognosis is mostly determined by the existence of hydrocephalus, the severity of the lesion, and the degree of the Chiari malformation. According to a recent study, overall survival up to the age of one year was around 73 percent. 66 percent of those with hydrocephalus and 88 percent of those without survived past the age of one, respectively. As patients with hydrocephalus get older, their survival rates drop significantly, to around 52% by the age of 20. Convulsions, pulmonary emboli, hydrocephalus, and acute renal failure/sepsis are the leading causes of death in children over the age of five. NTDs, on the other hand, are associated with severe morbidity if patients are not well handled. Urinary tract infections are the most prevalent consequence of NTDs related to neurogenic bladder, affecting roughly half of all patients and leading to renal failure in 7% of cases. In newborns with NTDs, the degree of Chiari malformation is a substantial risk factor for death, and it can cause sleep apnea, vocal cord paralysis, and bradycardia. Patients frequently worry about functional results, particularly the prognosis for ambulation. Only 8% of participants in the Management of Myelomeningocele Study (MOMS) required a wheelchair for ambulation. The remaining 3% can ambulate with the aid of assistive equipment, and roughly 30% are completely self-sufficient.
Improving functional results and quality of life requires early rehabilitative intervention. Early mobilization and stretching can assist patients to retain a range of motion for future gait, hygiene, and daily living activities (ADLs). Most patients experience symptoms from both upper and lower motor neurons, as well as varying motor function, necessitating specific treatment regimens. Orthotics are often required for joint stabilization, deformity prevention, gait improvement, and overall enhanced function. Assistive aids, such as crutches, walkers, or wheelchairs, will be required for support. ADLs may necessitate the use of assistive technology in some cases. Physical and occupational therapy should be done on a long-term basis for patients. Dysphagia, slurred speech, vocal cord dysfunction, and cognitive training may all necessitate speech therapy. In the early phases of adolescence, neuropsychology would be useful in assisting with the adjustment to issues as they arise. Despite the potential of serious problems, just 6% of people suffer depression, according to a study.
To avoid NTDs, women of childbearing age should be advised to take folic acid supplements. Women who are considering pregnancy should take 0.4 mg daily, while those who have a family history of NTD or have had a previous child with the disease should take 4 mg daily.
Close family members require the most knowledge in the early phases of the conditions in order to equip them to be effective advocates for the patient during childhood. Patients should be given increased autonomy as their cognitive development progresses. It's critical that patients and their caregivers feel like they're part of the medical team.
Families must be instructed during their child's therapy so that they can care for their children efficiently as they grow older. Patient mobilization, effective use of orthotics and assistive equipment, and optimal body mechanics are all important issues. They must also be taught how to recognize the signs and symptoms of dangerous diseases such as UTIs, hydrocephalus, and seizures.
Children should be included in the decision-making discussion if they are old enough to understand their situation and requirements, and they should be educated on self-care. Patients with occult spina bifida may have few comorbidities, while those with open dysraphisms may require more frequent monitoring. It's possible that patients will need to be taught how to self-catheterize or manage their own bowel regimen.
As patients get older, many will express concerns about ambulation. As previously stated, the majority of patients will achieve effective ambulation, with only 8% requiring wheelchair-level ambulation.
To promote patient involvement in their healthcare and achieve better outcomes, psychosocial dimensions of the patient's health must also be addressed. Cognitive-behavioral therapy in a high-intensity rehabilitation program improved self-care, cognition and mood, and independence, according to a randomized controlled experiment.
The best outcomes for patients with spina bifida are achieved by a mixed medical and psychological approach. The spectrum of conditions can be addressed comprehensively by a team approach comprising multiple doctors and therapy providers. As a version of the commonly referred medical home model, Dicianno proposes the specialized medical home as the optimum management option for spina bifida patients. The primary care physician operates as a central point for all accumulated medical data and as the referring physician, coordinating the team dynamic amongst specialists in the medical home model. However, because most of the comorbidities being handled arise from the underlying ailment, it has been recommended that the specialized physician operates as the medical home in certain situations.
This team-based medical treatment should continue throughout adulthood, but many patients encounter obstacles to a seamless transition of care. The involvement of parents, caregivers, transitioning members, and both pediatricians and physicians in the transition is critical. Early planning is essential for a smoother transition and should be handled early on. Because patients frequently spend several years of their lives with a single physician group, the transition to adult treatment can be difficult for patients, caregivers, and providers. To ensure that the patient is ready to move out of pediatric care, the timing of the transfer should take into account not only the patient's age but also their intellectual capability. This transfer will necessitate close collaboration between the pediatrician, the new specialist provider, and any other team members who may be needed.
To help manage the disease and its consequences, this team-based approach includes clinicians, physiotherapists, occupational therapists, speech and language therapists, and neuropsychologists. Kahn et al. found that high-intensity, multidisciplinary rehabilitation with included cognitive behavioral therapy considerably enhanced cognitive function, mood, independence, and bowel/bladder dysfunction in a randomized controlled experiment.
Finally, despite the fact that spina bifida is the most frequent birth abnormality affecting the central nervous system and is typically defined as the most complex birth condition compatible with survival, there is no cure. Individuals can be affected by a wide range of things, which vary depending on the severity of the disease. This condition has therapies, but none that can cure or even avoid it. Scientists are continuously looking into potential causes and cures.