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PEDIA AND OB ORAL REVALIDA NCMA 219 RLEHYDROCEPHALUSDEFINITION Hydrocephalus is a condition in which excess cerebrospinal fluid (CSF) builds up within the fluid- containing cavities or ventricles of the brain. The term hydrocephalus is derived from the Greek word’s "hydro" meaning water and "cephalu...

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PEDIA AND OB ORAL REVALIDA NCMA 219 RLE

HYDROCEPHALUS

DEFINITION

Hydrocephalus is a condition in which excess cerebrospinal fluid (CSF) builds up within the fluidcontaining cavities or ventricles of the brain. The term hydrocephalus is derived from the Greek word’s "hydro" meaning water and "cephalus"

meaning the head. Although it translates as "water on the brain," the word actually refers to the buildup of cerebrospinal fluid, a clear organic liquid that surrounds the brain and spinal cord. CSF is in constant circulation within the ventricles of the brain and serves many crucial functions: 1) it acts as a "shock absorber" for the brain and spinal cord; 2) it acts as a vehicle for delivering nutrients to the brain and removing waste from it; and 3) it flows between the cranium and spine to regulate changes in pressure. When CSF builds up around the brain, it can create harmful pressures on the tissues of the brain confined within the skull. The accumulation of CSF occurs due to either an increase in production of the fluid, a decrease in its rate of absorption or from a condition that blocks its normal flow through the ventricular system. Hydrocephalus can occur at any age, but is most common in infants and adults age 60 and older. According to the National Institute of Neurological Disorders and Stroke (NINDS), hydrocephalus is believed to affect approximately one to two in every 1,000 children born in the U.S. The majority of these cases are often diagnosed before birth, at the time of delivery or in early childhood.

PREDISPOSING FACTORS

Little is understood about the causes of hydrocephalus. Some cases of hydrocephalus are present at birth, while others develop in childhood or adulthood. Hydrocephalus can be inherited genetically, may be associated with developmental disorders, like spina bifida or encephalocele, or occur as a result of brain tumors, head injuries, hemorrhage or diseases such as meningitis. Based on onset, presence of structural defects or high vs. normal CSF pressures, hydrocephalus can be divided into categories. Acquired Hydrocephalus: This is the type of hydrocephalus that develops at birth or in

adulthood and is typically caused by injury or disease. Congenital Hydrocephalus: It is present at birth and may be caused by events that occur during fetal development or as a result of genetic abnormalities. Communicating Hydrocephalus: This type of hydrocephalus occurs when there is no obstruction to the flow of CSF within the ventricular system. The condition arises either due to inadequate absorption or due to an abnormal increase in the quantity of CSF produced. Non-communication (Obstructive) Hydrocephalus: It occurs when the flow of CSF is blocked along one of more of the passages connecting the ventricles, causing enlargement of the pathways upstream of the block and leading to an increase in pressure within the skull. Normal Pressure Hydrocephalus: It is a form of communicating hydrocephalus that can occur at any age, but is most common in the elderly. It is characterized by dilated ventricles with normal pressure within the spinal column. Hydrocephalus Ex-vacuo: It primarily affects adults and occurs when a degenerative disease, like Alzheimer’s disease, stroke or trauma, causes damage to the brain that may cause the brain tissue to shrink. The common risk factors of hydrocephalus include:      

Lack of pre-natal care. Multiparous gestation. Maternal diabetes. Maternal chronic hypertension. Maternal hypertension during gestation. Alcohol use during pregnancy.

PATHOPHSYIOLOGY

CSF is chiefly produced by the choroid plexus, which is located within the lateral, third, and fourth ventricles. It travels through the ventricular system from the lateral ventricle to the third ventricle via the foramen of Monro, from third to the fourth ventricle via the cerebral aqueduct or aqueduct of Sylvius. It leaves the fourth ventricle through two lateral foramina of Luschka and median foramen of Magendie to enter basal cisterns, and part of it continues to flow around the spinal cord and in the central canal of the spinal cord. The main sites of CSF absorption are arachnoid granulations that projects into dural venous sinuses, especially superior sagittal sinus. CSF is absorbed into the venous sinuses and enters systemic circulation. The average CSF volume is approximately 150 ml, and the daily production is about 500ml. This means that the total CSF volume is replaced three times per 24hours. CFS flows slowly from sites of production to the sites of absorption according to the “bulk flow” model. Any physical or functional obstruction within the ventricular system, subarachnoid space, or venous sinuses can be a reason for developing hydrocephalus. An obstructive lesion or gliosis can block CSF flow within the ventricular system. Inflammation or scarring of subarachnoid space or elevated venous pressure within the venous sinuses can impair CSF absorption into the systemic circulation. According to the Monro-Kellie doctrine, the total volume of the brain, CSF, and blood within the skull is constant. An increase in one compartment must accompany a decrease in volume in another compartment; otherwise, the pressure within the head will be increased, as happens in hydrocephalus. Increased ICP results in trans ependymal extravasation of CSF into the brain tissue causing brain damage and pressure-induced atrophy

LAB AND DX

Laboratory Studies No specific blood tests are recommended in the workup for hydrocephalus. Genetic testing and counseling might be recommended when X-linked hydrocephalus is suspected. Neurological Exam The type of neurological exam will depend on a person's age. The neurologist might ask questions and conduct relatively simple tests in the office to judge muscle condition, movement, well-being and how well the senses are functioning. Brain Imaging Imaging tests that can help diagnose hydrocephalus and identify underlying causes of the symptoms include: 

Ultrasound. This test is often used for an initial assessment for infants because it's a relatively simple, lowrisk procedure. The ultrasound device is placed over the soft spot (fontanel) on the top of a baby's head. Ultrasound might also detect hydrocephalus before birth during routine prenatal examinations.

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MRI. This test uses radio waves and a magnetic field to produce detailed images of the brain. This test is painless, but it is noisy and requires lying still. MRI scans can show enlarged ventricles caused by excess cerebrospinal fluid. They can also be used to identify causes of hydrocephalus or other conditions contributing to the symptoms.

Children might need mild sedation for some MRI scans. However, some hospitals use a fast version of MRI that generally doesn’t require sedation. 

CT scan. This specialized X-ray technology produces cross-sectional views of the brain. Scanning is painless and quick. But this test also requires lying still, so a child usually receives a mild sedative. CT scanning produces less detailed images than MRI does and causes exposure to a small amount of radiation. CT scans for hydrocephalus are usually used only for emergency exams.

MEDICAL MGT

Treatment Options Although many causes of hydrocephalus exist, the number of treatments is limited. All successful, long-term treatments are surgical. There is little use for medication in hydrocephalus. In some acquired cases, as with tumors and infections, resolving the underlying condition will resolve the hydrocephalus, but most patients still require surgical intervention.6 There are generally two approaches to treating hydrocephalus. The most common treatment is the placement of a shunt.3 In use since the 1950s, this approach is considered the best treatment option in most cases. The other procedure, endoscopic third ventriculostomy (ETV), involves the surgical creation of an opening in the floor of the third ventricle to enable the passage of CSF.6,9 Shunt Placement: As noted above, the standard treatment for hydrocephalus is shunt placement.

Shunts are usually placed in the lateral ventricle and can have one of three different drainage points. The most common drainage site is the peritoneum, which is connected to the shunt with subcutaneous tubing. This is known as a ventriculoperitoneal shunt. Two other types of shunts, ventriculopleural and ventriculoatrial, terminate in the pleural space and the internal jugular vein, respectively. The last type, the lumboperitoneal shunt, is placed in the lumbar intradural space.3 Shunt systems include a valve that controls the rate of drainage. The valve may have to be accessed surgically, or it may be placed so that adjustments can be made without further surgery ETV: As mentioned previously, ETV is an alternative treatment for hydrocephalus. It is indicated in patients with an obstruction that prevents CSF from draining between the third ventricle and the cortical subarachnoid spaces. In this procedure, the floor of the third ventricle is punctured, allowing CSF to flow into the cortical subarachnoid space. TV is currently approved in the treatment of obstructive hydrocephalus and in patients who have had multiple shunt failures and replacements. TV also has been shown to be effective for treating NPH. The procedure is difficult and requires that the third ventricle floor and the surrounding structures have dimensions appropriate for successful completion of the procedure. Imaging must be performed before surgery to determine that the anatomy of these structures is appropriate. Lumbar Puncture: A short-term option for the treatment of hydrocephalus is to perform periodic lumbar punctures. This is a temporary approach to reduce the amount of CSF until a long-term treatment can be performed. Lumbar puncture may be used to treat communicating hydrocephalus, although it is sufficient only for patients who are still able to absorb some CSF. In some cases, a drain may be placed so that continuous lumbar tapping is not necessary; however, there is a relatively high rate of infection

with this approach compared with serial lumbar punctures. Lumbar puncture may be used in neonates, who have an extremely low surgical success rate with ETV Noninvasive Treatments: At present, there are no significant noninvasive treatment alternatives. Some studies have shown that acetazolamide or furosemide may be acceptable for CSF fluid reduction, but these medications currently are used only on a temporary basis. Both drugs act to reduce the production of CSF by the choroid plexus. As with lumbar puncture, these agents are typically used in low-birthweight infants who will have a low success rate with shunt placement or ETV. There is no evidence that either of these medications increases survival rates, and a Cochrane review concluded that therapy with acetazolamide or furosemide is neither effective nor safe for treating posthemorrhagic ventricular dilatation in infants.  Acetazolamide (2-acetylamino-1,3,4thiadiazole-5-sulfonamide) is a sulphonamide derivative with a potent inhibitory effect on carbonic anhydrase, used in the treatment of cardiac edema, glaucoma, urinary alkalinization, metabolic alkalosis, and acute mountain sickness  Furosemide selectively inhibits sodium reabsorption in the nephron at the loop of Henle, which is a potent loop diuretic used to treat high blood pressure, congestive heart failure, and swelling due to excess body water and also used in hyperkalemia and acute renal failure. Studies have shown that furosemide reduces the production of cerebrospinal fluid by inhibiting the transport of Cl− to the cerebrospinal fluid. In the medical treatment of hydrocephaly, the usual dose of furosemide is 1 mg/kg/day divided into two doses/day  Isosorbide (1,4:3,6-dianhydro-d-glucitol) is an osmotic agent developed for the treatment of glaucoma. It has also been

shown to reduce the intracranial pressure. The single oral dose of isosorbide significantly reduces intraventricular pressure. Multiple studies showed the usual dose of isosorbide, which is 2–3 g/kg/day given at intervals of 6–12 h. NURSING MGT

Nursing Management Managing a child with hydrocephalus warrants skill and compassion for nurses and all the members of the healthcare team. Nursing Assessment  Accurate information is essential in the assessment of the child with hydrocephalus.  Head circumference. Measurement of the newborn‘s head is essential.  Neurologic and vital signs. Obtaining accurate vital and neurologic signs is necessary before and after surgery.  Check the fontanelles. If the fontanelles are not closed, carefully observe them for any signs of bulging.  Monitor increase in intracranial pressure. Observe, report, and document all signs of IICP.  History taking. If the child has returned for revision of an existing shunt, obtain a complete history before surgery from the family caregiver to provide a baseline of the child’s behavior. Nursing interventions for the newborn with hydrocephalus include: 

Preventing injury. At least every 2 to 4 hours, monitor the newborn’s level of consciousness; check the pupils for equality and reaction; monitor the neurologic status, and observe for a shrill cry, lethargy, or irritability; measure and record the head

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circumference daily, and keep suction and oxygen equipment convenient at the bedside. Promoting skin integrity. After a shunting procedure, keep the newborn’s head turned away from the operative site until the physician allows a change in position; reposition the newborn at least every 2 hours, as permitted; inspect the dressings over the shunt site immediately after the surgery, every hour for the first 3 to 4 hours, and then at least every 4 hours. Preventing infection. Closely observe for and promptly report any signs of infection; perform wound care thoroughly as ordered, and administer antibiotics as prescribed. Promoting growth and development. The newborn needs social interaction and needs to be talked to, played with, and given the opportunity for activity; and provide toys appropriate for his mental and physical capacity. Reducing family anxiety. Explain to the family the condition and the anatomy of the surgical procedure in terms they can understand; encourage them to express their anxieties and ask questions; and give accurate, nontechnical answers that are easy to understand. Providing family teaching. Demonstrate care of the shunt to the family caregivers and have them perform a return demonstration; provide them with a list of signs and symptoms that should be reported, and discuss appropriate growth and development expectations for the child, and stress realistic goals.

HOME CARE TEACHING

 Give your child pain medicines as your healthcare provider directs.  Feed your child his or her regular diet.  Wash your child’s incision each day with mild soap. Rinse the incision with water and gently pat it dry.  Don’t allow your child to soak in water (in the bathtub or swimming pool) until the incision is completely healed.  Allow your child to resume normal activities gradually after returning home.  Be aware that if your child needs an MRI, the newer shunts are MRI compatible. Check with your healthcare provider to be sure. SPINA BIFIDA

DEFINITION

Spina bifida is a condition that affects the spine and is usually apparent at birth. It is a type of neural tube defect (NTD). Spina bifida can happen anywhere along the spine if the neural tube does not close all the way. When the neural tube doesn’t close all the way, the backbone that protects the spinal cord doesn’t form and close as it should. This often results in damage to the spinal cord and nerves. Spina bifida might cause physical and intellectual disabilities that range from mild to severe. The severity depends on: The size and

location of the opening in the spine. Whether part of the spinal cord and nerves are affected.

another baby with the same defect. That risk increases if two previous children have been affected by the condition. In addition, women who were born with a neural tube defect have a greater chance of giving birth to a child with spina bifida than someone who doesn't have a neural tube defect. However, most babies with spina bifida are born to parents with no known family history of the condition.

Classification Spina bifida can be classified into three: 

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Spina bifida occulta. A bony defect that occurs without soft tissue involvement is called spina bifida occulta. Spina bifida with meningocele. When part of the spinal meninges protrudes through the bony defect and forms a cystic sac, the condition is termed spina bifida with meningocele. Spina bifida with myelomeningocele. In spina bifida with myelomeningocele, there is a protrusion of the spinal cord and the meninges, with nerve roots embedded in the wall of the cyst.

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Some medications. For example, antiseizure medications, such as valproic acid seem to cause neural tube defects when taken during pregnancy. This might happen because they interfere with the body's ability to use folate and folic acid.

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Diabetes. Women with diabetes who don't have well-controlled blood sugar have a higher risk of having a baby with spina bifida.

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Obesity. Pre-pregnancy obesity is associated with an increased risk of neural tube birth defects, including spina bifida.

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Increased body temperature. Some evidence suggests that increased body temperature (hyperthermia) in the early weeks of pregnancy may increase the risk of spina bifida. Increases in core body temperature, due to fever or use of a sauna or hot tub, have been associated with a slightly increased risk of spina bifida.

PREDISPOSING FACTORS

Spina bifida is more common among white people and Hispanics, and females are affected more often than males. Although doctors and researchers don't know for sure why spina bifida occurs, they have identified some risk factors: 

Folate deficiency. Folate, the natural form of vitamin B-9, is important to the development of a healthy baby. The synthetic form, found in supplements and fortified foods, is called folic acid. A folate deficiency increases the risk of spina bifida and other neural tube defects.

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Family history of neural tube defects. Couples who've had one child with a neural tube defect have a slightly higher chance of having

PATHOPHYSIOLOGY

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Neural tube defects are the result of a teratogenic process that causes failed closure and abnormal differentiation of the embryonic neural tube.

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During prenatal development, neuroectoderm thickens into the neural plate which folds into a neural groove by the time somites appear. The groove deepens to become the neural tube, and dorsal fusion begins centrally, extending cephalad and caudally, with the cephalad pole fusing at the 25th day. The ventricle becomes permeable at the 6th to 8th week of gestation but this does not proceed normally in patients with spina bifida.

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LAB AND DX

Assessment and laboratory findings of a patient with spina bifida may reveal the following: 

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AFP levels. Elevated maternal alpha fetoprotein levels in the maternal seruma nd the amniotic fluid indicates the probability of CNS abnormalities. Ultrasonography. Ultrasonographic examination of the fetus may show an incomplete neural tube. Clinical examination. Diagnosis of spina bifida is made from clinical observation and examination. Other imaging studies. Additional evaluation of the defect may include magnetic resonance imaging (MRI), computed tomography (CT), and myelography.

Surgery...