myelomeningocele


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myelomeningocele

 [mi″ĕ-lo-mĕ-ning´go-sēl]
hernial protrusion of the spinal cord and its meninges through a defect in the vertebral arch (spina bifida); see also neural tube defect. Called also meningomyelocele.
Child with a large thoraco-lumbar myelomeningocele consisting of protruding spinal cord covered by meninges. From Mueller and Young, 2001.

me·nin·go·my·e·lo·cele

(mĕ-ning'gō-mī'ĕ-lō-sēl'),
Protrusion of the spinal cord and its membranes through a defect in the vertebral column.
[meningo- + G. myelos, marrow, + kēlē, tumor]

myelomeningocele

/my·elo·me·nin·go·cele/ (-mĕ-ning´go-sēl) hernial protrusion of the spinal cord and its meninges through a defect in the vertebral arch.

myelomeningocele

(mī′ə-lō-mə-nĭng′gə-sēl′)
n.
A severe form of spina bifida in which the meninges and spinal cord protrude through a defect in the vertebral column.

myelomeningocele

[mī′əlō′məning′gōsēl]
Etymology: Gk, myelos + menix, membrane, kele, hernia
a developmental defect of the central nervous system in which a hernial sac containing a portion of the spinal cord, its meninges, and cerebrospinal fluid protrudes through a congenital cleft in the vertebral column. The condition is caused primarily by failure of the neural tube to close during embryonic development, although in some instances it may result from the reopening of the tube as a result of an abnormal increase in cerebrospinal fluid pressure. Also called meningomyelocele, myelocele, myelocystocele, myelocystomeningocele. Compare meningocele. See also neural tube defect, spina bifida cystica.
observations The defect, which occurs in approximately 2 in every 1000 live births, is readily apparent and easily diagnosed at birth. Although the opening may be located at any point along the spinal column, the anomaly characteristically occurs in the lumbar, low thoracic, or sacral region and extends for three to six vertebral segments. The saclike structure may be covered with a thin layer of skin or with a fine membrane that can be easily ruptured, increasing the risk of meningeal infection. The severity of neurological dysfunction is directly related to the amount of neural tissue involved, which can be roughly estimated by the degree of the transillumination of the mass. Usually the condition is accompanied by varying degrees of paralysis of the lower extremities; by musculoskeletal defects such as clubfoot, flexion and joint deformities, or hip dysplasia; and by anal and bladder sphincter dysfunction, which can lead to serious genitourinary disorders. Hydrocephalus, frequently related to the Arnold-Chiari malformation, is the most common anomaly associated with myelomeningocele and occurs in approximately 90% of the cases in which the spinal lesion is located in the lumbosacral region. In most cases, hydrocephalus is apparent at birth, although it may appear shortly afterward. Supplementary diagnostic procedures include x-ray examination of the spine, skull, and chest to determine the extent of the vertebral defect and the presence of other malformations in other organ systems; a computed tomographic scan of the brain to establish the ventricular size and the presence of any structural congenital anomalies; and laboratory examinations, especially urine analysis, culture, blood urea nitrogen evaluation, and creatinine clearance determination. Amniocentesis is recommended for all pregnant women who have had a child with a neural tube defect.
interventions Immediate surgical repair is essential if the defect is leaking cerebrospinal fluid. However, surgical intervention may not be appropriate if neurological involvement is extreme, if the lesion is infected, or if associated problems, such as hydrocephalus, are severe. When surgical repair of the spinal defect is recommended, associated problems are managed by appropriate measures, including shunt procedures for correction of hydrocephalus; antibiotic therapy to reduce the incidence of meningitis, urinary tract infections, and pneumonia; casting, bracing, traction, and surgical techniques for correction of hip, knee, and foot deformities; and prevention and treatment of renal complications. Prognosis is determined by the severity of neurological involvement and the number of associated anomalies. With proper care and long-term maintenance most children can survive and do well. Early death is usually caused by central nervous system infection or by hydrocephalus, whereas mortality in later childhood is caused by urinary tract infection, renal failure, complications from shunt therapy, or pulmonary disease.
nursing considerations Immediate care centers on the prevention of local infection and trauma by carefully handling and positioning the infant, applying sterile moist dressings to the membranous sac, avoiding fecal contamination and breakdown of sensitive skin areas, and maintaining warmth, proper nutrition, and adequate hydration and electrolyte balance. Gentle range-of-motion exercises are carried out to prevent or minimize hip and lower extremity deformity. An important function of the nurse is to involve the parents in the care of the infant as soon as possible and to teach them the essential procedures for adequate home care, including how to observe for signs of complications. The nurse also helps the parents in long-term management by planning activities appropriate to the developmental age and physical limitations of the child and by providing information for teaching all family members about the condition.
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Myelomeningocele: protrusion of meninges and spinal cord through the skin
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Myelomeningocele: clinical presentation

meningomyelocele

Protrusion of the spinal meninges and cord through a defect of the vertebral column, usually at the distal end; when accompanied by a bone defect, it is termed spina bifida.

Epidemiology
1:5000 births.

Other findings
Often accompanied by midline defects—e.g., of the anus, heart and trachea (tracheo-oesophageal fistulas).

myelomeningocele

Neonatology A common birth defect characterized by nonclosure of the vertebral and spinal canal, resulting in protrusion of spinal cord and covering meninges from the dorsal surface; spina bifida is a more generic term which includes any defect characterized by incomplete spinal closure; myelomeningocele accounts for ±75% of all spina bifida, affecting ±1/800 infants; most of the rest are spina bifida occulta–the vertebral arches don't close, the spinal cord and meninges are simply covered by skin, and meningoceles–in which the meninges protrude through the vertebral defect while the spinal cord remains in place Etiology Unknown; folic acid deficiency may play a part in neural tube defects; it has a familial tendency, possibly triggered by a viral infection or environmental factors–eg, radiation; protrusion of cord and meninges damages the spinal cord and nerve roots, compromising function at or below the defect; most defects are lower lumbar or sacral, as these regions are the last to close in the early embryo Clinical Partial or complete paralysis, loss of sensation, bladder or bowel control; the exposed cord is at risk for infection. See Hydrocephalus, Hip dislocation, Spina bifida, Syringomyelia.

me·nin·go·my·e·lo·cele

(mĕ-ning'gō-mī'ĕ-lō-sēl)
Protrusion of the meninges and spinal cord through a defect in the vertebral column.
Synonym(s): myelocystomeningocele, myelomeningocele.
[meningo- + G. myelos, marrow, + kēlē, tumor]

myelomeningocele

See MENINGOMYELOCELE.

myelomeningocele

hernial protrusion of the spinal cord and its meninges through a defect in the vertebral column.
References in periodicals archive ?
Preservation of renal function in children with myelomeningocele managed with basic newborn evauation and close follow-up.
McLone of Children's Memorial Hospital in Chicago says his mice with genetic myelomeningocele do not show any destruction of nervous tissue, adding that he is unaware of the evidence Heffez cites of such nerve damage in humans.
If the patient does not develop hydrocephalus in the first week or two after closure of the myelomeningocele, measurement of head circumference on an outpatient basis, and plotting these values on standard charts, is continued.
Regardless of the time, label, or circumstances involved, chronic sorrow has emerged as an important variable to consider in parents of children with myelomeningocele, the most common form of NTD (Burke, 1989).
Early Management and Decisionmaking for Myelomeningocele," Pediatrics 72 (1983), 450-58.
Early cystometrograms can predict the response to intravesical instillation of oxybutynin chloride in myelomeningocele patients.
Each fetus had a myelomeningocele located between the T1 and S1 vertebrae, evidence of hindbrain herniation, and a gestational age of 19.
Electrophoresis of AF acetylcholinesterase is a specific and sensitive method for diagnosis of myelomeningocele (1, 2).
In a 1999 study of children with myelomeningocele, a neural tube defect, Grogan and Ekvall found that the abdominal and triceps skin folds best measured a child's fatness.
Chiari II malformation is almost exclusively associated with myelomeningocele and hydrocephalus.
The primary goal of the orthopaedic management of myelomeningocele is mobility.