Wednesday, June 1, 2011

Spina bifida

Spina bifida or cystic myelomeningocele is the most complex and treatable abnormality of central nervous system. Brain and spinal malformations occur during embryological development. Neural tube defects ranging in severity shows a variety of clinical manifestations of recognition from birth until the accidental discovery of spina bifida occulta radiographic.Spina bifida is a defect of the vertebral arch variable spinal column which is incompletely formed or absent. The term comes from the Latin bifidus two parts. Although the condition also refers to myelomeningocele and myelodysplasia, spina bifida is the term generally accepted in the medical world.
Anomaly is a complex spinal condition that causes varying degrees of spinal deformity, spinal or myelodysplasia. It is classified as a developing neural tube defect in embryological life.Patients present a spectrum of deficits, but most important are functional impotence of the lower limbs, urinary and fecal incontinence, paralysis, loss of sensation and cognitive dysfunction.Because the nervous system exposure in spina bifida people with this disease do not survive in the era preantibiotica. Those who survived still had severe handicaps.
Spina bifida can be surgically closed after birth, but can not restore normal function of the affected spinal area. The main surgical procedures adopted in the case of spina bifida include the closure of the defect, reconstruction of vertebral deformity and lower extremity deformity correction. Intrauterine surgery for spina bifida has been tried. Safety and efficacy of this procedure is still under investigation. The incidence of spina bifida decreased by supplementation of folic acid before conception and after.There is no cure for this condition. To prevent nerve tissue damage and infection to close the defect. During surgery and spinal nerve roots are reintroduced into the column and covered with meninges.One may need to be continuous drainage of cerebrospinal fluid produced by the brain. Shunts drain into the abdomen.Most patients require regular evaluation by orthopedic specialists to check the bones and muscles, neurosurgeons to evaluate brain and spinal and urologists for the kidneys and bladder. Most patients require spinal rods, go-carts and wheelchairs to maximize mobility. The more the fault is taller so it is more severe paralysis.
PathogenesisNeural tube defects are the result of teratogenic processes that lead to lack of closure and abnormal differentiation in the embryonic neural tube during the first 4 weeks of gestation. Neural tube defects are anencephaly, the most common and myelomeningocele. Myelomeningocele result from lack of closure of neural tube caudal to the appearance of a bag or an open sore that contains spinal cord dysplasia, nerve roots, meninges, vertebral corpus and skin. Anatomical level of the lesion correlates with neurological deficits, sensory and motor of the patient.Types of myelomeningocele and other neural tube defects:Myelomeningocele Spina bifida is a cystic or neural tube defect that can occur anywhere along the spinal axis, but is found most often in the lumbar region. In this condition bifida column is a cystic formation. Myelomeningocele is a cystic formation of the dura and arachnoid which protrudes through the vertebral arch defect. A person with myelomeningocele may not show neurological sequelae. Myelomeningocele is the name of the faction-mielo ie spinal cord protrudes. The most severe form of spina bifida or cystic mielocelul mieloschizis is, variety in which the defect is covered by epithelium neural plate and neural plate extending beyond the surface.A child born with myelomeningocele may require surgery to release the lateral muscles of the spine and removal of skin to cover the defect.Spina bifida occulta:It represents a limited arc fault which does not involve protrusion of the spinal marrow or its membranes. They occur most often at lumbosacral junction. It is discovered incidentally in 10% of healthy population in radiography.Siringomeningocelul:It is another form of spina bifida. The Greek word syrinx meaning tube or plate is combined with menix Kele-tumor-membrane. The term describes a formation filled with fluid that communicates with the central spinal canal and is closed by a membrane with little medullary substance.Siringomielocelul:It is a type of spina bifida in which the protrusion of spinal membranes and lead to increased fluid in the central channel pushing medullary tissue bag walls meet fine. Hidrosiringomielia Siringomielia or cavities are present in the spinal cord as a result of cutting formations gliomatoase us.Diastematomielia:It comes from the Greek diastema and myelon-marrow-range.September 1 is accompanied by bone. Septum can cause a septal bone and irreversible neurological sequelae occur through different times of the spinal neural development.Myelodysplasia:It comes from the Greek word myelos-marrow combined with difficult and DYS-pals-application. It is an anomaly in the development of spinal bifida and spina description does not match because it assumes a normal marrow.Neurological Effects:Generally cause neurological destruction in neurogenic bladder and colon leading to incontinence. With neurogenic bladder infections cause hydronephrosis and renal failure. Neurological innervation is not symmetrical and normal for the two legs.Muscular imbalance is present that causes joint contractures and developmental problems such as hip dislocation and spinal deformities. Intelligence is normal if there hidrocefalus, although we can see a slightly defective coordination. Convulsive activity secondary neural tube defect can be described.
Causes and risk factors for spina bifidaHe proposed a genetic inheritance as the cause of spina bifida, coupled with environmental factors in the nutrition, including folic acid intake of mainly. Cytoplasmic factors, polygenic inheritance, chromosomal aberrations and external influences have all been suggested as possible causes. Prenatal vitamins, especially folic acid is indicated to diminish the appearance of the condition.
Neural tube defects occur between days 17 and 30 of gestation, when the mother knows she is pregnant and the fetus is the size of a grain of rice. This fetus has an open neural tube is marked by a high level of alpha-fetoprotein in amniotic fluid. Maximal concentrations of alpha-fetoprotein in weeks 13-15 of pregnancy diagnosis permit and ultrasound confirmation is possible in weeks 15-18. Encephalocele or leather covered mielocelele not detected by alpha-fetoprotein.
Some theories suggest that an increased amount of material in the neural ridge prevents closure of neural tube defect. Another hypothesis is that according to which u already closed tube rupture, increased permeability of the pit diamond leads to increased secretion and increased cerebrospinal fluid pressure tube luminal enlargement and splitting neural elements in the poorest areas.

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