Neurologic deficits — The specific neurologic deficits depend upon the level of the lesion. In most affected patients, the entire spinal cord distal to the site of the lesion is nonfunctional. Motor and sensory deficits in the trunk and legs correspond to the segments that normally would have been innervated. The deficits usually are severe, resulting in complete paralysis and absence of sensation. The bladder and bowel are affected in nearly all patients, resulting in urinary and fecal incontinence.

Occasionally, the distal cord may retain some function, but the afferent pathways to the brain are disrupted. In this case, tendon reflexes or withdrawal to pain may be preserved, although voluntary control of movement and appreciation of pain are absent. A partially functioning segment of the spinal cord sometimes retains some central connections, resulting in voluntary control of isolated movements or the appreciation of sensation in part of the involved limbs. Aberrant connections in the involved spinal cord may result in unusual findings such as contraction of the contralateral limb when tendon reflexes are elicited.

Hydrocephalus — The majority of patients with myelomeningocele have hydrocephalus. The etiology is obstruction of fourth ventricular outflow or flow of CSF through the posterior fossa due to Chiari malformation or an associated aqueductal stenosis [23]. In one series of 156 children with myelomeningocele, 80 percent developed this disorder [24]. Hydrocephalus was due to aqueductal stenosis in 73 percent. Signs of hydrocephalus were present at birth in 15 percent of cases.

The likelihood of hydrocephalus depends upon the site of the lesion. Hydrocephalus is associated with approximately 90 percent of thoracolumbar, lumbar, and lumbosacral lesions, and approximately 60 percent of occipital, cervical, thoracic, or sacral lesions [22].

Ventricular dilatation is common at birth, often without increased head circumference or signs of increased intracranial pressure [25]. Hydrocephalus typically develops in the neonatal period after surgical repair of the back lesion. This is due to accumulation of excess CSF that previously was decompressed into the large sac or through a leaking myelomeningocele. Shunting is required in most patients.

Chiari malformation — The Chiari malformation is an anomaly of the hindbrain present in nearly all patients with thoracolumbar, lumbar, and lumbosacral myelomeningocele. It is the primary cause of the associated hydrocephalus. The major features of the anomaly are [22]:

Inferior displacement of the medulla and fourth ventricle into the upper cervical canal
Elongation and thinning of the upper medulla and lower pons and persistence of the embryonic flexure of these structures
Inferior displacement of the lower cerebellum through the foramen magnum in the upper cervical region
Bony defects of the foramen magnum, occiput, and upper cervical vertebrae
The malformation is classified into three types, according to the degree of caudal displacement. Type II, in which the fourth ventricle and lower medulla are displaced below the level of the foramen magnum, is the form that is usually associated with myelomeningocele.

Brain stem dysfunction due to the Chiari malformation occurs in some patients with myelomeningocele. This results in problems such as swallowing difficulties, vocal cord paresis causing stridor, and apneic episodes, and is associated with a high mortality rate [22]. Strabismus and facial weakness can also occur.

Other CNS anomalies — Other CNS anomalies often accompany myelomeningocele. In one report, neuropathologic examination was performed on 25 children with myelomeningocele, Chiari malformation, and hydrocephalus [26]. Cerebral cortical dysplasia occurred in 92 percent. The majority had neuronal heterotopias or polymicrogyria. Other abnormalities noted included cerebellar dysplasia (72 percent), hypoplasia or aplasia of cranial nerve nuclei (20 percent), fusion of the thalami (16 percent), agenesis of the corpus callosum (12 percent), and complete or partial agenesis of the olfactory tract and bulb (8 percent).

Scoliosis — Scoliosis occurs in most children with meningomyelocele who have lesions above L2 [22]. This complication is unusual when the lesion is below S1.

MANAGEMENT — Management of children with spina bifida should involve a multidisciplinary team with expertise in developmental pediatrics, neurosurgery, orthopedics, neurology, urology, and physical medicine and rehabilitation. Physical and occupational therapists, nutritionists, social workers, wound specialists, and psychologists are also helpful. This team of specialists works together to coordinate care and evaluate the patient's progress.

Delivery — If a prenatal diagnosis of myelomeningocele has been made, delivery should occur at a hospital with personnel experienced in the neonatal management of these infants [27]. Delivery before term may be indicated if rapidly increasing ventriculomegaly is observed and fetal lung maturity has been documented, otherwise, term delivery is preferable [27]. Sterile nonlatex gloves should be used during delivery to minimize the risk of latex sensitization [28].

Breech presenting fetuses are typically delivered by cesarean section. (See "Delivery of the fetus in breech presentation"). The optimal route of delivery of the vertex fetus is controversial, and no prospective randomized trials have been performed.

One study compared the outcome of 47 infants with a prenatal diagnosis of isolated myelomeningocele without severe hydrocephalus delivered by cesarean section before labor to a historic cohort of 113 infants with myelomeningocele diagnosed after delivery (35 delivered by cesarean section after a period of labor and 78 delivered vaginally) [29]. The level of paralysis at two years of age was approximately two segments lower in the group delivered by elective cesarean section without labor. However, it is possible that advances in neonatal care and prenatal diagnosis led to interventions in the delivery room that resulted in a better outcome in the study group. Several other retrospective studies, but not all [30], have not found a benefit of cesarean delivery, with or without labor, compared to vaginal birth [31-36].

Most centers deliver these infants by cesarean birth. Since data are inadequate to make a general recommendation about the optimal route of delivery, this decision should be individualized [27]. Future trials should address the effects of both route of delivery and labor on neuromuscular function.

Neonatal assessment — Immediately after birth, the lesion should be briefly assessed to note its location, size, and whether it is leaking CSF. Sterile non-latex gloves should be used. The defect should be covered with a sterile saline-soaked dressing. Large defects should also be covered by plastic wrap to prevent heat loss. In most cases, only the neurosurgeon should remove the dressing. The infant should be placed in a prone or lateral position to avoid pressure on the lesion.

The newborn should be evaluated thoroughly to detect associated abnormalities in order to make appropriate decisions regarding treatment [37]. The parents should be counseled regarding the infant's prognosis and participate in decisions regarding management [38].

The presence of the following should be noted:

Signs of hydrocephalus
Clubfeet
Flexion or extension contractures of hips, knees, and ankles
Kyphosis
Other abnormalities such as congenital heart disease; structural defects of the airway, gastrointestinal tract, ribs; developmental dysplasia of the hip; or ultrasound evidence of renal malformations such as hydronephrosis
Early complications such as CNS infection
A thorough neurologic examination should be performed. (See "Neurologic examination in children"). This should include:

Observation of spontaneous activity
Extent of muscle weakness and paralysis
Response to sensation
Deep tendon reflexes
Anocutaneous reflex (anal wink)
Surgical closure — The back lesion should be surgically closed within the first 24 to 48 hours after birth. This decreases the risk of CNS infection. Prophylaxis with broad spectrum antibiotics until the back is closed also reduces the risk of CNS infection. In a retrospective study of infants with back closure performed after 48 hours of age, ventriculitis occurred less with than without antibiotic prophylaxis (1 versus 19 percent) [39].

Hydrocephalus — Ventricular size should be evaluated soon after birth by ultrasound, CT, or MRI. Serial neuroimaging should be performed to identify the development of hydrocephalus. Progressive hydrocephalus should be treated by insertion of a ventriculoperitoneal shunt.

In some infants, simultaneous meningomyelocele repair and shunt placement may be appropriate. In a retrospective review, the frequency of CSF infection, shunt malfunction, and symptomatic Chiari malformation was similar with simultaneous and sequential repair and shunting [40]. The rate of wound leak was lower and hospital length of stay was shorter in the simultaneous group.

Orthopedic problems — Orthopedic management should be directed at correcting deformities, maintaining posture, and promoting ambulation if possible, so that patients can function at their maximum capability. Factors that predict an increased likelihood of walking ability are motor level and sitting balance [41].

Orthopedic deformities result from congenital skeletal anomalies that often involve the feet, knees, hips, and spine; unbalanced muscle action around joints; and fractures, which often affect the legs of paraplegic patients. In a review from Spain of 393 infants with myelodysplasia, hip dislocation and feet deformities occurred in 24 and 50 percent, respectively [42]. Scoliosis also is common. Management techniques that often improve function include the use of casting and corrective appliances, surgical procedures on soft tissue and bone, and the use of orthoses.

Fractures — Fractures of the lower extremities occur in approximately 30 percent of patients with meningomyelocoele [43]. They may develop without known traumatic injury or may be related to vigorous physical therapy. Factors that increase the risk of fracture include the lack of protective sensation of the leg, osteopenia, nonambulation, foot arthrodesis (fusion of the joint), and higher level of paralysis [43,44].

A fracture should be strongly suspected when a patient with myelodysplasia presents with a red, warm, and swollen limb. These clinical signs are sometimes confused with cellulitis or osteomyelitis because some children with diaphyseal and metaphyseal fractures also have fever, elevated sedimentation rate, and leukocytosis [45], The diagnosis of fracture is confirmed with a radiograph of the limb.

Urinary tract complications — Nearly all patients with spina bifida have bladder dysfunction that can lead to deterioration of the upper urinary tract. The location of the spinal lesion or the neurologic examination do not predict the type of dysfunction. However, urinary continence with intermittent catheterization can be predicted by a positive anocutaneous reflex, which indicates a competent sphincter mechanism. In one report, continence was achieved in 26 of 29 patients (90 percent) with a positive reflex compared to 41 of 82 (50 percent) with a negative reflex [46]. Fewer patients with a positive reflex needed adjunctive surgery (7 versus 28 percent).

A baseline renal ultrasound and voiding cystourethrogram should be performed to identify patients at risk for upper tract deterioration. Function of the neurogenic bladder should be evaluated in affected newborns with a cystometrogram, which measures bladder capacity, compliance, voiding pressures, and the relationship between the detrusor and the urinary sphincter [47]. Vesicoureteral reflux may result from detrusor hyperreflexia or detrusor sphincter dyssynergy. In one report, urodynamic evaluation of 36 infants with myelodysplasia showed incoordination of the detrusor and external urethral sphincter, synergic activity of the sphincter, and no sphincter activity in 18, nine, and nine patients, respectively [48]. Infants with incoordination of the detrusor-external sphincter were at high risk for urinary tract deterioration. Of that group, 13 of 18 (72 percent) developed hydroureteronephrosis, compared to two of nine with synergy and one of nine with no sphincter activity.

Urologic function can deteriorate in affected children with normal urodynamic studies after surgical repair in the neonatal period [49]. Deterioration is due to spinal cord tethering, which is most likely to occur during the first six years of life. These children require close follow-up for the early detection and correction of tethered spinal cord (show figure 2).

Patients with vesicoureteral reflux should receive antibiotic prophylaxis, anticholinergic medication to lower detrusor filling and voiding pressures, and clean intermittent catheterization to prevent urinary tract deterioration [50,51]. The efficacy of this regimen was demonstrated in a sequential nonrandomized study that compared prophylactic (clean intermittent catheterization and oxybutynin) and expectant treatment in patients with these urodynamic findings [50]. During five years of follow-up, the upper urinary tract deteriorated less often in the treated group (8 versus 48 percent).

For an anticholinergic agent, oxybutynin syrup (Ditropan, 1 mg/mL) is used in a dose of 0.1 mg/kg PO three times a day for infants <12 months of age, and 1, 2, 3, or 4 mg/kg per dose three times a day for children one, two, or three years of age, respectively. For children 5 years old, we use oxybutynin tablets (Ditropan, 5 mg PO three times a day), or the extended release preparation (Ditropan XL, beginning with 5 mg PO daily and titrated to effect, with maximum dose 20 mg daily). An alternative drug is tolterodine (Detrol) in a dose of 1 to 2 mg PO twice a day or the long-acting preparation (Detrol LA), 2 to 4 mg PO daily.

Several surgical procedures are used to manage neurogenic bladder in patients with meningomyelocele. Ureteral reimplantation is sometimes performed in patients with persistent reflux and upper tract deterioration or with recurrent urinary tract infections in spite of clean intermittent catheterization and prophylactic antibiotics [52]. A vesicostomy is performed for bladder drainage in infants with high bladder pressure who continue to worsen while receiving clean intermittent catheterization and anticholinergic medication [53]. Vesicostomy is usually used for temporary diversion, but is a long-term option in patients unlikely to achieve continence [53,54].

The most common surgical approach is augmentation of the bladder [55]. In this procedure, a detubularized segment of intestine (ileum, colon, or stomach) is added to the bladder to increase capacity and lower pressure. The procedure usually results in the achievement of urinary continence. Linear growth and bone density are comparable in children with myelomeningocele with or without the procedure, although serum bicarbonate levels are lower and chloride levels are higher in those who have ileal, but not gastric augmentation [56]. Other complications include bladder calculi, bladder rupture, and excessive mucus in the urine that may lead to catheter obstruction [52].

Patients who are unable to catheterize their own urethra may benefit from a continent catheterizable channel (such as a Mitrofanoff or Monti ileovesicostomy). The new channel is constructed from appendix or bowel with a stoma placed at the level of the umbilicus or on the lower abdomen [57,58]. This more accessible location reduces the time required for clean intermittent catheterization, especially in females with lesions at the thoracic level. The most common complication is stenosis of the stoma at the level of the skin which may require dilation or surgical revision.

A surgical technique to bypass the neurologic defect through the microanastomosis of the fifth lumbar ventral root to the third sacral ventral root has been described [59]. Among 20 children with myelomeningocele who had this procedure, 17 achieved satisfactory bladder control and continence within 8 to 12 months after the procedure. These results await confirmation by other centers.

Neurogenic bowel — The innervation for internal and external sphincter control is at the level of S2 to S5. Thus, patients with meningomyelocoele may experience varying degrees of fecal incontinence. As children become preschool or school aged, fecal incontinence leads to embarrassment and social isolation and should be avoided.

The goal of a neurogenic bowel continence program is to achieve timed elimination of stool through the use of oral laxatives, suppositories, and enemas [60]. These methods are used singly or in combination. Accomplishment of continence requires patience and motivation on the part of the family, physician, and nurse educator. A second goal is to avoid fecal impaction and the related liquid encopresis that occurs and is often mistaken by families as an episode of diarrhea. (See "Definition; clinical manifestations; and evaluation of encopresis").

].At the initiation of a bowel management program, bowel clean-out may be necessary. If the history of the patient reveals that there are several days without a bowel movement, or there is palpable stool on abdominal exam or rectal exam, then bowel clean out with a Fleet's enema should be initiated. The Pediatric Fleet's enema, which contains approximately 60 mL of solution should be used for children between 2 and 10 years of age. An abdominal radiograph should be ordered if confirmation of stool quantity is needed (eg, in an overweight patient). The assistance of a gastroenterologist may be needed if routine enemas do not produce acceptable results.

Once the bowel clean out has been accomplished, the patient may be placed on a regular program of a daily oral agent. Alternative regimens include:

Senokot: 0.5 to 1 tsp (2.5 to 5 mL) PO at bedtime in children 2 to 6 years of age and 1 to 2 tsp (5 to 10 mL) at bedtime in older children
Perdiem (100 percent psyllium): 1 to 2 tsp (5 to 10 mL) PO each day with 8 ounces (240 mL) of fluid per dose)
Lactulose (10 g/15 mL): 0.5 to 1 tsp (2.5 to 5.0 mL) PO each day
In addition, to the oral agent, a glycerin or bisacodyl suppository (10 mg) should be administered once per day 15 to 20 minutes after a meal to take advantage of the gastrocolic reflex. This is followed by placing the young child on the toilet and making sure his or her feet are well supported.

Some patients require daily evacuation of stool with the use of the visi-flow enema, which requires 20cc/kg of saline. This enema system comes with a water regulator so that the parent or the patient can control the speed of the water (or turn it off altogether for a rest) if he or she experiences abdominal cramping. Completing the enema takes usually 20 to 30 minutes. School-aged patients appreciate having the opportunity to have a nightly enema and avoid school accidents the following day.

If conservative medical management fails, then a surgical option is the antegrade continence enema [61-65].In this procedure, the appendix and cecum (or ileum if the appendix is not available) are used to create a catheterizable stoma. The patient is able to clean out the colon from the proximal end of the large intestine while sitting on the toilet, reducing the risk of fecal soiling and constipation. Fecal continence is achieved with this technique in approximately 85 percent of patients with spina bifida [65].

Skin integrity — Disruption of skin integrity is an important cause of morbidity in children with myelomeningocoele and often leads to hospitalization [66,67]. Decubiti often develop on the sacrum, buttocks, back, and feet. Other lesions include burns, abrasions, and ammoniacal dermatitis. Affected children are especially susceptible to burns because their lower extremities lack sensation and may not detect an elevated temperature. They should not be placed under running water without supervision because they may not detect exposure to very hot water. Similarly, they should avoid leaving hot food on the lap for a prolonged period which may lead to burns of the anterior thighs.

Patients with high level lesions may develop pressure decubiti with subcutaneous tissue necrosis. Patients with defects at the thoracic level are at risk for skin breakdown over the perineum and gibbus (bony angulation of collapsed vertebrae). The skin breakdown over the perineum is due to asymmetrical weight bearing and fecal and urinary incontinence. A commonly affected area is the ischial tuberosities, which should be inspected closely.

Ulceration over bony prominences and beneath orthotic devices can become very deep and involve muscle and/or bone. A chronic ulcer that does not improve with medical management should be evaluated for evidence of osteomyelitis. An abnormal radiograph or bone scan or an elevated sedimentation rate or C-reactive protein level may help distinguish an infected ulcer requiring long-term antibiotic therapy from a chronic ulcer that might benefit from consultation with a wound care specialist or plastic surgeon [68].

Neuropathic foot ulceration is common in patients who have low lumbar or sacral myelomeningocele. In one report, patients most likely to develop ulcers had foot rigidity, nonplantigrade position, and had undergone surgical arthrodesis [69

Factors contributing to skin breakdown include excessive pressure associated with limited mobility and overweight, infection, trauma, poor circulation, lack of sensation. and fecal and urinary incontinence. Prevention and management include [70,71]:

Careful inspection of the skin
Proper skin cleansing
Avoidance of occlusive clothing
Elimination of movements that cause friction
Proper fitting orthosis and wheelchairs
Symmetric weight bearing
Frequent weight shifts
Exposure of the affected skin to air
Prompt medical attention to an affected area
Protective skin lotions and ointments may reduce pain and erythema associated with perineal skin breakdown in incontinent patients. Although no studies are available in children, these preparations have been shown to be effective in incontinent elderly patients [72].

Latex allergy — Many children with myelomeningocele have allergic reactions to latex, ranging in severity from contact urticaria to anaphylactic shock [73]. In one review of 60 children with myelomeningocele, 48 percent were sensitized and 15 percent were allergic to latex [74]. In another review of 71 patients who were followed for 20 to 25 years, 33 percent were allergic to latex and 9 percent had experienced a life-threatening reaction [28]. The mechanism for development of allergy is thought to be repeated exposures to latex rubber during multiple surgical procedures, as well as daily bladder catheterization and bowel management, although there may be factors unique to the underlying condition [75]. Products containing latex should be avoided [76].

PROGNOSIS — The prognosis for patients with myelomeningocele depends upon decisions regarding their care, the level of the lesion, and the presence and severity of neurologic deficits, hydrocephalus, and other central nervous system anomalies, as illustrated below.

With aggressive treatment, the majority (approximately 85 percent) of patients survive the neonatal period [77,78]. In one review of 212 patients, 72 percent of survivors were ambulatory and 79 percent were considered to have normal cognitive development [77]. In another series of 200 patients, 74 percent were at least partially ambulatory and 87 percent had urinary continence [78]. There was a small, but statistically significant improvement in the first year survival rate of infants with spina bifida in the United States after the introduction of mandatory folic acid fortification of the grain supply (from 90.3 to 92.1 percent) [79]. (See "Prevention of neural tube defects", section on Relationship between folate and NTDS).

In children with myelomeningocele and hydrocephalus, high spinal cord lesions (T12 and above) are associated with more severe anomalous brain development. More severe anomalous brain development is associated with poor neurobehavioral outcomes on measures of intelligence, academic skills, and adaptive behavior [80].

The long-term outcome of myelomeningocele was outlined in a review of 118 children with myelomeningocele who were treated nonselectively [81]. Among the 71 patients who were available for follow-up at 20 to 25 years, the following findings were noted:

The overall mortality was 24 percent and continued to increase into young adulthood
86 percent of patients had undergone cerebrospinal fluid (CSF) diversion and 95 percent had undergone at least one shunt revision
32 percent had undergone release of tethered cord, after which 97 percent had improvement or stabilization in their preoperative symptoms
43 percent had undergone spinal fusion for scoliosis
23 percent had had at least one seizure
85 percent were attending or had graduated from high-school and/or college
Long-term survival may be related to the need for CSF diversion. In one review of 904 patients with myelomeningocele seen in a multidisciplinary clinic over 43 years, survival into adolescence was similar for patients with and without CSF diversion [28]. However, for patients alive at 16 years, survival after age 34 years was decreased for those with shunted hydrocephalus compared to those without a shunt.

FETAL SURGERY — In animals with a surgically created spinal defect, intrauterine closure of the exposed spinal cord tissue prevents secondary neurologic injury [82]. In one study in humans, intrauterine repair was performed at 24 to 30 weeks gestation in 29 patients with isolated fetal myelomeningocele [83]. The following results were reported:

Compared to matched controls, fewer infants in the treatment group required shunt placement for hydrocephalus at six months of age (59 versus 91 percent)
Compared to controls, the median age at shunt placement was later
(50 versus 5 days of age)

The incidence of hindbrain herniation was reduced (38 versus 95 percent).
The treatment group had a higher incidence of oligohydramnios (48 versus 4 percent) and preterm contractions (50 versus 9 percent) than the control group
The treatment group had lower mean gestational age (33.2 versus 37) and birth weight (2171 versus 3075 g) than the control group
In a subsequent report, the same group described 116 infants who had undergone intrauterine repair of spina bifida and had postnatal follow-up of at least 12 months [84]; 54 percent required the placement of a ventricluloperitoneal shunt by one year of age. Shunt placement was less likely to be necessary among fetuses who had a ventricular size of <14 mm at the time of surgery, who had surgery at 25 weeks gestation, and had defects located at or below L4 (all fetuses with defects at or above L1 required shunts).

In other reports, intrauterine repair did not improve lower extremity function [85] or affect the progression of ventriculomegaly [86]. This approach is not recommended until data on long-term follow-up and the results of an ongoing randomized trial are available [87].

PREVENTION — The prevention of neural tube defects is discussed separately. (See "Prevention of neural tube defects").

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