What is spina bifida?
There spina bifida it's a serious one malformation of the spine, also called the rachis or vertebral column, existing since birth and originating during the first stage of pregnancy. It is a rare malformation (it affects about one newborn in every 8000), for which there are specific genetic risks or related to contaminated foods or toxic substances.
In children with spina bifida there is a defect in the formation of spine, which must be imagined as a bone canal containing the spinal cord, part of the central nervous system, from which originate the nerve roots embedded in the intravertebral space. In this disease the bone canal it does not close, because the vertebrae that compose it do not fuse completely, and the spinal cord containing the nervous tissue comes into contact with the surrounding tissues, causing a closure defect of the neural tube.
Through this defect you can have it herniation of the spinal cord or herniation of the dural sac, a component of the meninges, the membranes that surround the spinal cord, which are precisely the tough mother, L'arachnoid and the pious mother. The development of the spine and the spinal cord it contains usually begins at twenty-first day of pregnancy, therefore its correct formation is very sensitive to negative factors especially in the initial part of gestation.
The closure defect, also called vertebral cleft, usually it is located in the lower part of the vertebral column, at the lumbar or sacrum level, involving 2 or 3 vertebrae (we therefore speak, for example, of cleft of the posterior arch of s1 in case of sacral defect, cleft of L4- L5 in the case of the fourth or fifth lumbar vertebrae).
The more serious the disease is, the higher the defect is columnDefects higher up on the inside of the back will be more severe. Defects in a very low position, on the other hand, can be so slight that they go unnoticed and are only recognized later in the patient's growth.
In the most severe forms of spina bifida, we have the myelomeningocele or spina bifida open, that is, a hernia of the dural sac (part of the meninges, the membranes that surround the spinal cord) and of the spinal cord contained in it through the bone defect. We speak instead of meningocele when the medulla is in a normal position and only the meninges that contain it herniate through the defect of the vertebrae.
Finally in the spina bifida occulta the meninges and spinal cord are correctly positioned in the vertebral canal, but the vertebrae do not separate them from the subcutaneous tissue with which they come into contact. In children affected by spina bifida occulta, life expectancy may not be compromised, but as we will see later some disorders may appear.
What are the causes of spina bifida?
The causes of spina bifida, which can lead to abnormal fetal development, are various:
- Genetic predisposition, according to mechanisms not fully known, but clearly existing since spina bifida is often part of genetic syndromes such as Chiari malformation or Down syndrome.
- Shortage of vitamins, in particular thefolic acid
- Assumption of alcohol in pregnancy which can secondarily lead to folic acid deficiency.
- Assumption from the mother of some drugs, such as valproate or some other antiepileptics.
- Exposure to pesticides.
What are the main ones symptoms of spina bifida? In infants with myelomeningocele, the most severe forms, the innervation of the lower limbs and bladder may be missing, leading from the first days of life to paralysis of the limbs, lack of sensation and perceptions from the lower limbs ed incontinence of the bladder.
This type of malformation can cause the appearance of hydrocephalus, a serious condition characterized by increase of the intracranial pressure is convulsions, potentially lethal.
In less severe forms of the disease, the symptoms of spina bifida which appear more typically are related to sensory deficits, with lack of sensitivity ai lower limbs (anesthesia), lack of the proprioception, that is, the sense of positioning and orientation of the limbs in space.
The greatest risk associated with anesthesia is what some do trauma can go unnoticed, not generating pain. They may also be present motor disturbances with difficulty in march and in its learning. Bladder disorders are represented byinability of expel L'urine independently. This can lead to infections urinary (cystitis, pyelonephritis) or damage to the urinary tract related to fluid retention, up to kidney damage (renal failure).
As mentioned earlier some small patients have a spina bifida "occulta". It is a form not evident at birth, without any type of symptoms. Since the vertebrae are not complete, in these patients the meninges come into contact with the subcutaneous tissue.
They can form adhesions between subcutis and the spinal cord, which prevent it from rising normally upwards as the child grows. In fact, as a rule, the vertebral canal, made up of bone, stretches downwards, while the spinal cord inside it does not stretch and therefore rises upwards. In patients with spina bifida occulta this may not happen.
The problem with this is that traction can be generated on the spinal cord with growth, which leads to the appearance of disturbances of the bladder and of lower limbs, feet and legs first, with ache widespread. The clinical picture can worsen over time.
In patients with spina bifida occulta, a tuft of hairs (call "beard of faun"), a sacro-lumbar cyst (above the anus or just above the buttocks), a sacral dimple or at the level of coccyx. These anomalies may be the result of the fusion of the nervous tissue with the subcutis.
If there is evidence of one of these characteristics in your child, it will be useful to contact the pediatrician to clarify whether it is a simple imperfection or if further investigations are necessary to exclude the presence of spina bifida occulta.
In adulthood, people with spina bifida can develop cancer of the caudal portion of the spine, or a cystic accumulation of fluid myelocystomeningocele which can connect, via a fistula, to the skin.
Spina bifida can often be accompanied by other orthopedic problems, such as scoliosis, myogenic stiff neck or pes cavus. In patients with spina bifida, the correction of these other diseases is often resistant to treatment, because it is associated with a neurological problem.
There diagnosis of spina bifida it can be more or less difficult depending on the case. In severe cases, with evident myelomeningocele, the diagnosis may already be known before birth, thanks to thefetal screening ultrasound, combined with blood tests such as alpha-fetoprotein assay.
This first screening it is usually done around the twelfth week of pregnancy. The diagnosis can also be made later, with themorphological ultrasound performed around the twentieth-twenty-third week of gestation. back bifida In these cases, we speak of prenatal diagnosis of spina bifida.
In the less severe, rarer forms of spina bifida occulta, diagnosis by ultrasound and blood tests is not possible, since the defect is undetectable. A suspected it may be present in case of known risk factors when the newborn presents typical lesions such as lipomas, angiomas or patches of hair in the lumbosacral area.
The defect in question is evident only at the magnetic resonance of the column, which allows to obtain images of spina bifida. The problem can be diagnosed later in growth with the appearance of bladder disorders, leg disorders, or sometimes when an MRI is done for other reasons.
It is important to differentiate the spina bifida from the syndrome of Currarino, presenting with a partial sacral formation defect, with presacral mass and an anorectal malformation. Unlike spina bifida in Currarino's syndrome, the vertebral anomaly is anterior and not posterior.
There isn't one care that allows you to heal from spina bifida. In the most severe cases of manifest spina bifida, with extensive deficits in the lower limbs, appropriate intervention can be made rehabilitation to help the patient's mobilization and autonomy. The presence of bladder disorders may make it necessary to perform catheterisms bladder which can be performed by the people who are next to the patient, after appropriate teaching, or by the patient himself.
In a child with spina bifida occulta, after diagnosis it is good to intervene as soon as possible with the surgery medullary disengagement. The operation is aimed at removing the connections between the subcutaneous tissue and the spinal cord avoiding the appearance of disorders. It is a complex preventive intervention, to be carried out possibly in the first years of life, before the appearance of symptoms. In patients who are already symptomatic, surgery is able to stop the progression of the picture, preventing it from worsening.
Between consequences of the spina bifida, the patient must undergo follow-up visits to follow the growth and possible development of disorders that may signal a relapse of the disease. It is important to check thestatural growth of patients, especially during puberty, when boys are at their peak.
Since this is a complex problem, checks are often carried out by multidisciplinary teams made up of various specialists, in order to better manage the disease. Relapses after surgery are not frequent today thanks to the introduction of more and more modern tools for treatment, however if there are they may require surgery again. Once the growth is complete, adult spina bifida is a stable problem.
For the prevention of spina bifida, an intervention of great and proven efficacy in the prevention of this pathology is the administration of folic acid, a vitamin of group B, to pregnant women, from the earliest stages of gestation. It is also useful to avoid the consumption of alcohol, contact with toxic substances or pesticides, and the intake of certain medications such as valproate.
Sources: Spina Bifida, Andrew J. Copp, N. Scott Adzick, Lyn S. Chitty, Jack M. Fletcher, Grayson N. Holmbeck, and Gary M. Shaw
Tags: Children Vertebral column Neurosurgery Neurology