SGD B.8 / LT Day 12 [NEUROSCIENCE] Congenital Disorder | Surgical Aspect

Scenario

(Study guide page 72)

1. What is your assessment for this patient?

Assessment: Patient is a baby (female, 6 months), weakness of four limbs since birth. Has a big lump on lumbal area. Her mother has measles on one month. The patient is suspected neural tube defect (NTB) spina bifida aperta type meningomyelocele.

Need further investigation and diagnostic procedure to support the diagnosis (make appropriate assessment) like ultrasonography, MRI, urodynamic, amniocentesis and neurologic examination. But, in this case we can make the diagnosis just on anamnesis and physical examination (written in the case). Meningomyelocele is usually apparent in specific sign: lump in lumbosacral area, paresis/plegi on limbs, incontinense, decrease of tonus and reflex.

2. What is your diagnosis?

The baby is suffered neural tube defect: spina bifida aperta type meningomyelocele (myelomeningocele).

It is established from the clinical apparent (weakness of all limbs, big lump on lumbal area).

3. What is your plan in managing this patient?

Surgery to repair the defect (myelomeningocele repair is surgery to repair birth defects of the spine and spinal membranes) is usually recommended at an early age. Before surgery, the infant must be handled carefully to reduce damage to the exposed spinal cord. This may include special care and positioning, protective devices, and changes in the methods of handling, feeding, and bathing.

Antibiotics may be used to treat or prevent infections such as meningitis or urinary tract infections.

Most children will require lifelong treatment for problems that result from damage to the spinal cord and spinal nerves. This includes:

Latex precaution Gentle downward pressure over the bladder may help drain the bladder. In severe cases, drainage tubes

(catheters) may be needed. Bowel training programs and a high fiber diet may improve bowel function.

Orthopedic or physical therapy may be needed to treat musculoskeletal symptoms.

Urologic consultation is essential.

Neurological losses are treated according to the type and severity of function loss.

Follow-up examinations generally continue throughout the child's life. These are done to check the child's developmental level and to treat any intellectual, neurological, or physical problems.

Visiting nurses, social services, support groups, and local agencies can provide emotional support and assist with the care of a child with a myelomeningocele who has significant problems or limitations.

Neuroscience and Neurological Disorder| Medical Faculty – Udayana University 2012 SGD B.8

SGD B.8 / LT Day 12 [NEUROSCIENCE] Congenital Disorder | Surgical Aspect

Learning Task

1. General features of normal neurodevelopment

Neurulation is the formation of the neural tube from the ectoderm of the embryo. It follows gastrulation in all vertebrates.

During gastrulation cells migrate to the interior of embryo, forming three germ layers— the endoderm (the deepest layer), mesoderm and ectoderm (the surface layer)—from which all tissues and organs will arise. In a simplified way, it can be said that the ectoderm gives rise to skin and nervous system, the endoderm to the guts and the mesoderm to the rest of the organs.

After gastrulation the notochord—a flexible, rod-shaped body that runs along the back of the embryo—has been formed from the mesoderm. During the third week of gestation the notochord sends signals to the overlying ectoderm, inducing it to become neuroectoderm. This results in a strip of neuronal stem cells that runs along the back of the fetus. This strip is called the neural plate, and is the origin of the entire nervous system. The neural plate folds outwards to form the neural groove. Beginning in the future neck region, the neural folds of this groove close to create the neural tube (this form of neurulation is called primary neuralation). The anterior (front) part of the neural tube is called the basal plate; the posterior (rear) part is called the alar plate. The hollow interior is called the neural canal. By the end of the fourth week of gestation, the open ends of the neural tube (the neuropores) close off

The spinal cord forms from the lower part of the neural tube. The wall of the neural tube consists of neuroepithelial cells, which differentiate into neuroblasts, forming the mantle layer (the gray matter). Nerve fibers emerge from these neuroblasts to form the marginal layer (the white matter).

The ventral part of the mantle layer (the basal plates) forms the motor areas of the spinal cord, whilst the dorsal part (the alar plates) forms the sensory areas. Between the basal and alar plates is an intermediate layer that contains neurons of the autonomic nervous system

Late in the fourth week, the superior part of the neural tube flexes at the level of the future midbrain—the mesencephalon. Above the mesencephalon is the prosencephalon (future forebrain) and beneath it is the rhombencephalon (future hindbrain). The optical vesicle (which will eventually become the optic nerve, retina and iris) forms at the basal plate of the prosencephalon.

2. Etiology neural tube defect

Chromosomal abnormalities (trisomy 13, 18, 21) also have been associated with NTDs. Environmental factors (decrease of folic acid) have been implicated in the pathogenesis of NTDs. NTDs

Neuroscience and Neurological Disorder| Medical Faculty – Udayana University 2012 SGD B.8

SGD B.8 / LT Day 12 [NEUROSCIENCE] Congenital Disorder | Surgical Aspect

3. Pathogenesis of neural tube defect

Maternal folic acid deficiency is an environmental factor strongly associated with neural tube defects. Serum from women with pregnancy complicated by a neural tube defect may contain autoantibodies that bind folate receptors and block the cellular uptake of folate.

4. Possible treatment of the symptom

Took appropriate folic acid supplements before and during pregnancy, NTDs could be reduced by close to 75 percent. The symptom is variety, according to the severity of neural tube defects.

5. Prognosis of the disease

The prognosis for neural tube defects varies significantly from one case to the next. Whether a child will do well or not and whether a fetus will survive to become a child depends on the type of defect that occurs and how severe it is. There are many types of neural tube defect, prognosis factors, and other elements to consider. In general, the prognosis is relatively grim for most patients. Those who survive to birth and live more than a few days will likely face serious motor skill issues and physical development issues. All in all, the actual prognosis will vary from one condition to the next.

Prognosis for Severe Neural Tube Defects

Anencephaly, Iniencephaly, and Hydranencephaly are the most dangerous of the neural tube defects that you will find. These are very severe malformations that occur early on and the fetus will rarely make it to birth. In the event that birth occurs, most will be stillborn. The infants who are alive at birth will generally only live for a matter of hours with these conditions. As such, treatment is focused more on lowering the mother’s risk and supportive or symptomatic treatment at the time of birth, if necessary.

In the case of these defects, the mother’s life can also be jeopardized. Some professionals will discuss voluntary termination at this point because of the poor prognosis and the risk involved with the mother’s life.

Prognosis for Mild and Moderate Neural Tube Defects

Conditions that are milder like Spina Bifida, Chiari Malformation, and other neural tube defects that aren’t severe will have a much better prognosis. In some cases, children can live for years without incident, and even have a rich, full life. Some impaired motor skills and developmental disabilities will result from the defect, but this should not cause serious issues in daily life. Infants who develop these conditions typically live to birth and well beyond, and can have successful treatment of their condition so that they can live a full life. Of course, it varies from one condition to the next, but these defects have a much lower risk of death than the severe defects listed above.

Neuroscience and Neurological Disorder| Medical Faculty – Udayana University 2012 SGD B.8