**5. Symptomatology**

*Spina Bifida and Craniosynostosis - New Perspectives and Clinical Applications*

**4. Etiology and pathophysiology**

regions with mandatory folic acid fortification [9].

metabolism and utilization of folate and folic acid.

**4.4 Decompensated diabetes mellitus**

**4.2 Positive family history of spina bifida**

**4.1 Folate deficiency**

**4.3 Medications**

**4.5 Obesity**

tube defect.

**4.6 Hyperthermia**

week [8]. Overall prevalence of spina bifida is lower in countries with mandatory folic acid fortification of grain products opposite to countries with voluntary or no

Detailed etiology of spina bifida is not known but it is assumed to result from a combination of more factors - genetic, nutritional and environmental risk factors. Genetic risk factor is a family history of neural tube defect. Most important nutritional factor is folate deficiency. Even though exact mechanisms leading to spina

Folate is a natural form of vitamin B9. Its synthetic form is folic acid. Folate is important for proper intrauterine development of fetus. Its deficiency is connested not only with spina bifida, but also with occurence of all neural tube defects. Spina bifida is significantly more common in countries without legislation regulating full-coverage folic acid fortification of the food supply and less common in world

Genetic factors seem to play important role in etiology of spina bifida. Couples with child born with spina bifida are at higher risk of having another child born with this defect. At higher risk of having child affected by spina bifida are also women who were born with neural tube defect and also higher frequency is in twins than in singletons. All this indicates a genetic contribution to etiology. But low frequency of families with multiple neural tube defects makes research more difficult [11].

Some drugs are under suspicion in contributing to higher risk of developmental

Women with decompensated or inadequatelly compensated glucose levels during

disorders of neural tube. Mostly anti-convulsants (anti-seisure mediacation), such as valproic acid, when taken during pregnancy. They probably interfere with

early stages of pregnancy are at higher risk of having child with spina bifida.

Spina bifida and all neural tube defects are more common in women with obesity. It is important to have adequate body mass index also prior to pregnancy.

Increased body temperature in early stages of pregnancy due to infection or using of sauna is believed to be potencially risky for having a child with neural

fortification [9, 10]. More affected are females and whites and Hispanics.

bifida are not clearly known, there are some of researchers interest [11].

**30**

Severity of symptoms depends on type of spina bifida ranging from no symptoms in spina bifida occulta to most severe in myelomenigocele. There are also interindividual differences. Spina bifida occulta is neurologically asymptomatic because there is no involvement of neurologickal structures.

#### **5.1 Skin lesions or visible sac**

Cutaneous lesions mostly in lumbar region could be associated with spina bifida or tethered spinal cord. Visible change of skin above the defect is usually an abnormal tuft of hair, dimple, subcutaneous lipoma or a birthmark [12]. Such skin lesion could also be a symptom of spinal cord abnormality that is covered by skin.

Sacral dimple is a common skin lesion and is found in 1,8 to 7,2% of newborns [13]. However, in most of newborns it is only a simple skin lesion without any effect on neurological functions. Possitive ultrasonography findings are usually filar cyst (24,8%), echogenic filum terminale (13,5%) and low-lying spinal cord (11,7%). Some literary sources consider filar cyst as a normal finding [14].

Simple solitaire sacral dimple in asymptomatic newborn with diameter less than 5 mm located no more than 25 mm above anal opening have extremely low risk of having spinal abnormality [15]. Considering this very low risk (approx. 0,34%), more recent guidelines state that sipmple solitaire non risky sacral dimples do not require additional imaging – only in case they are atypical, associated with other skin lesions or multiple. On the other hand around 86% of spinal dysraphisms are associated with overlying cutaneous lesion [16].

Open defect is mostly situated in the lumbar region and is characterized by opened spinal canal along more vertebras. At birth meninges, spinal nerves and spinal cord protrude above surrounding skin level forming a sac. This sac could be also covered by skin. These open defects are easily recognized whereas smaller or closed defects can present only by overlying cutaneous lesions [17].

#### **5.2 Paraparesis**

Degree of neurological impairment, walking disability and muscle weaknes depends on severity and extent of the defect, as well as on accuracy of prenatal or postnatal treatment. Neurological deficit varies from mild paraparesis to paraplegia. Myelomeningocele is the most common congenital anomaly causing physical disability [18].

According to level of defect there are various degrees of motor disability (**Table 2**). Patients with thoracic defect have flacid lower extremities, patients with high-lumbar defect usually can perform flexion in hip joint, in middle-lumbar defect also extension in knee, in low-lumbar defect is also foot dorsiflection present and sacral defect usually allows to perform also plantar flexion of foot [20].

Neurological deficit in patients with spina bifida is thought to be result of the primary insult - the congenital anomaly and the second - from direct exposure of spinal cord to amniotic fluid and intrauterine trauma [21].

#### **Table 2.**

*Functional outcome according to level of spinal dysraphism [19].*

In a study with 50 years follow up of walking ability half of the patients with severe spina bifida was able to walk for 50 m butthis ability declined with age to 27% in the age of 50 years [22].

#### **5.3 Urinary dysfunction**

Nerve damage in neural tube defect leads to loss of sensation and bladder sphincter control. Very common is neurogenic bladder that leads to symptoms such as urinary retencion, overflow incontinence, urgency, frequency and nocturia. Possible complications are incontinence, repeated or chronic urinary infections, hydronephrosis and in later stages renal damage [23] that all leads to diminished quality of life [24].

#### **5.4 Bowel dysfunction**

Most of patients living with the diagnosis of spina bifida have some degree of bowel problems called neurogenic bowel dysfuntion. The lack of bowel movement results in obstipation and lack of anal sphincter control leads to intermitent or continual incontinence [23]. Bowel dysfunction leads to decreased life quality [19, 25].

#### **6. Complications**

Possible complication affect in some degree most of patients with open forms of spina bifida. The severity of complications depend on extent of defect and also on timing of treatment. Fetal surgery gives better prognosis.

#### **6.1 Hydrocephalus**

The majority of infants with open neural tube defects also has hydrocephalus [26]. Hydrocephalus is defined as an active distension of the ventricular system resulting

**33**

*Management of Pediatric Patients with Spina Bifida DOI: http://dx.doi.org/10.5772/intechopen.97237*

from inadequate passage of cerebrospinal fluid at some point from its production within ventricles to its absorption into the systemic circulation [27]. In infants it is a condition with ventricular enlargement that leads to rapid growth of head circumference and requires surgical intervention [28]. According to observations only 1 out of 6 infants with myelomenongocele has symptoms of raised intracranial pressure at birth and 1 out of 8 has head circumference above 98th percentille at birth [29]. Many infants develop ventriculomegally that leads to increase of head circumference after postnatal closure of open spina bifida. Slight ventricular enlargement with stable neurological status could be indication for conservative observation – radiological and clinical. Rapidly developed ventricullomegaly with worsening of neurological status and signs of intracranial hypertension requires quick neurosurgical intervention [26]. Surgical treatment possibilities are insertion of ventriculo-peritoneal shunt and endoscopic third ventriculostomy with cauterisation of choroid plexus. Minority of cases is indicated for conservative treatment – only those with relatively stable ventriculomegally [26]. Infants who underwent fetal surgical repair of myelome-

ningocele were less likely to require ventriculo-peritoneal shunting [30].

Presence of hydrocephalus in children with open spina bifida requires placement

Myelomeningocele as the most severe open defect is almost invariably associated

with this malformation. Chiari malformation type II is a group of disorders that includes herniation of fetal developing cerebellum upwards into the middle cranial fossa or downwards into cervical spinal canal. This malformation is often associated with other abnormalities such as: brainstem kinking, abnormal forth ventricle location and syringomyelia [30]. The research on animal models shows that chronic intrauterine leakage of cerebrospinal fluid can lead to Chiari II malformation [31]. It is common brain malformation in children with myelomeningocele. This malformation worsens the cerebrospinal fluid circulation leading to progression of hydrocephalus. Chiari malformation type II can present with rapidly present symptoms such as: breathing problems or apnoea, bradycardia, swallowing problems and other cranial nerves dysfunction when descending cerebellum presses on brainstem [26]. Under rare circumstances can lead to indication of decompression of craniocervical junction. Chiari malformation type II, its presence and severity can in huge extent determine the outcome of patients [26]. Chiari II malformation is significantly less severe in infants who underwent fetal surgery for myelomeningocele [30]. Improvement of this malformation and subsequent decrease in hydrocephalus in children with prenatal repair of myelomeningocele support the theory of relationship between continual intrauterine abnormal leakage of cerebrospinal fluid and subsequent development of Chiari II malformation and hydrocephalus

of ventriculo-peritoneal shunt in most of the cases. Proper function of shunt is inevitable. Unfortunately, shunt related complications are frequent – mainly shunt malfunction and infection. About 95% of patients who required shunt placement have to undergo at least one shunt revision [26]. Symptoms of shunt-related complications are: headache, irritability, confusion, somnolency, nausea, vomiting, feeding problems, fixed downward gaze, seizures. In case of shunt infections also symptoms like higher body temperature, redness along the shunt catheters, elevated

**6.2 Complications of ventriculo-peritoneal drainage**

and underline the importance of fetal surgery [26, 30].

blood parameters of infections.

**6.3 Chiari malformation type II**

*Management of Pediatric Patients with Spina Bifida DOI: http://dx.doi.org/10.5772/intechopen.97237*

*Spina Bifida and Craniosynostosis - New Perspectives and Clinical Applications*

**Muscle function Ambulation**

Lack function of gluteus maximus and medius Retain quadriceps and medial hamstring function

*Functional outcome according to level of spinal dysraphism [19].*

**Sacral** Retain quadriceps and gluteus medius function

Low sacral Retain gastrocnemius function

Lack quadriceps function Children – ambulation with hip spanning orthosis

orthosis)

(hip-knee- ankle – foot orthosis or reciprocating gait

Adults – majority require wheelchair

Ambulate without braces or support

Require crutches for ambulation Most retain comunity ambulation as adults

In a study with 50 years follow up of walking ability half of the patients with severe spina bifida was able to walk for 50 m butthis ability declined with age to

High sacral Lack gastrocnemius function Ambulate with ankle-foot orthosis and no support

Nerve damage in neural tube defect leads to loss of sensation and bladder sphincter control. Very common is neurogenic bladder that leads to symptoms such as urinary retencion, overflow incontinence, urgency, frequency and nocturia. Possible complications are incontinence, repeated or chronic urinary infections, hydronephrosis and in later stages renal damage [23] that all leads to diminished

Most of patients living with the diagnosis of spina bifida have some degree of bowel problems called neurogenic bowel dysfuntion. The lack of bowel movement results in obstipation and lack of anal sphincter control leads to intermitent or continual incontinence [23]. Bowel dysfunction leads to decreased life

Possible complication affect in some degree most of patients with open forms of spina bifida. The severity of complications depend on extent of defect and also on

The majority of infants with open neural tube defects also has hydrocephalus [26]. Hydrocephalus is defined as an active distension of the ventricular system resulting

timing of treatment. Fetal surgery gives better prognosis.

27% in the age of 50 years [22].

**5.3 Urinary dysfunction**

**Level of lesion**

**Thoracic High Lumbar**

**Low lumbar**

**Table 2.**

quality of life [24].

quality [19, 25].

**6. Complications**

**6.1 Hydrocephalus**

**5.4 Bowel dysfunction**

**32**

from inadequate passage of cerebrospinal fluid at some point from its production within ventricles to its absorption into the systemic circulation [27]. In infants it is a condition with ventricular enlargement that leads to rapid growth of head circumference and requires surgical intervention [28]. According to observations only 1 out of 6 infants with myelomenongocele has symptoms of raised intracranial pressure at birth and 1 out of 8 has head circumference above 98th percentille at birth [29]. Many infants develop ventriculomegally that leads to increase of head circumference after postnatal closure of open spina bifida. Slight ventricular enlargement with stable neurological status could be indication for conservative observation – radiological and clinical. Rapidly developed ventricullomegaly with worsening of neurological status and signs of intracranial hypertension requires quick neurosurgical intervention [26].

Surgical treatment possibilities are insertion of ventriculo-peritoneal shunt and endoscopic third ventriculostomy with cauterisation of choroid plexus. Minority of cases is indicated for conservative treatment – only those with relatively stable ventriculomegally [26]. Infants who underwent fetal surgical repair of myelomeningocele were less likely to require ventriculo-peritoneal shunting [30].

### **6.2 Complications of ventriculo-peritoneal drainage**

Presence of hydrocephalus in children with open spina bifida requires placement of ventriculo-peritoneal shunt in most of the cases. Proper function of shunt is inevitable. Unfortunately, shunt related complications are frequent – mainly shunt malfunction and infection. About 95% of patients who required shunt placement have to undergo at least one shunt revision [26]. Symptoms of shunt-related complications are: headache, irritability, confusion, somnolency, nausea, vomiting, feeding problems, fixed downward gaze, seizures. In case of shunt infections also symptoms like higher body temperature, redness along the shunt catheters, elevated blood parameters of infections.

#### **6.3 Chiari malformation type II**

Myelomeningocele as the most severe open defect is almost invariably associated with this malformation. Chiari malformation type II is a group of disorders that includes herniation of fetal developing cerebellum upwards into the middle cranial fossa or downwards into cervical spinal canal. This malformation is often associated with other abnormalities such as: brainstem kinking, abnormal forth ventricle location and syringomyelia [30]. The research on animal models shows that chronic intrauterine leakage of cerebrospinal fluid can lead to Chiari II malformation [31]. It is common brain malformation in children with myelomeningocele. This malformation worsens the cerebrospinal fluid circulation leading to progression of hydrocephalus. Chiari malformation type II can present with rapidly present symptoms such as: breathing problems or apnoea, bradycardia, swallowing problems and other cranial nerves dysfunction when descending cerebellum presses on brainstem [26]. Under rare circumstances can lead to indication of decompression of craniocervical junction. Chiari malformation type II, its presence and severity can in huge extent determine the outcome of patients [26]. Chiari II malformation is significantly less severe in infants who underwent fetal surgery for myelomeningocele [30]. Improvement of this malformation and subsequent decrease in hydrocephalus in children with prenatal repair of myelomeningocele support the theory of relationship between continual intrauterine abnormal leakage of cerebrospinal fluid and subsequent development of Chiari II malformation and hydrocephalus and underline the importance of fetal surgery [26, 30].

### **6.4 Tethered spinal cord**

Tethered spinal cord is a neurological disorder that is caused by abnormal attachment of the spinal cord to surrounding structures. In case of patients with myelomeningocele spinal cord is mostly attached to scar from previous operation [32]. Symptoms are caused by increased tension and stretch-induces dysfunction of the caudal spinal cord and conus and include motor and sensitive dysfunction, gait abnormalities, symptoms of cauda equina syndrome and urological symptoms [12, 32].

Filum terminale lipoma can cause cord tethering, lipoma is the most common cause of thick filum terminale. That is why detection of abnormal thickening of filum terminale is important. Initial detection is usually performed by ultrasonography [2] followed by MR imaging [12]. Tethered cord syndrome must be suspected when conus medullaris is placed dorsaly in the spinal canal and terminates below the superior aspect of L3 vertebral body. Also thickened filum terminale can be present. MR imaging is indicated in ultrasonography evidence of tethered cord or in case of doubts [3].

Although some patients with anatomic cord tethering do not develop symptoms, most of the patients are symptomatic and do not naturally improve without surgical untethering. Neurosurgical intervention is the treatment of choice, though with varying results [33]. Timing of the surgery is also important – early intervention after symptom development is necessary for recovery or at least improval of neurological functions. Early surgical intervention as a prevention of further neurological damage requires early diagnostics [12].

#### **6.5 Meningitis**

Infants with open neural tube defects can experience meningitis – inflammation of brain and spinal cord surrounding meninges. Meningitis could develop as a consequence of open defect, as a complication of surgical procedures as well as a complication of shunting procedures. In case of bacterial meningitis there is a need for massive antibiotic therapy.

#### **6.6 Urological complications**

Most of the patients with severe spinal dysraphism suffer from neuropathic bladder impairment [24]. As the nerve damage causes urological complication by means of neurgenic bladder, this situation also brings specific possible complications. Usual problem is urinary retention that could lead to overflow incontinence, renal damage and urinary tract infections, that could be repeated or chronic and often requires antibiotic treatment.

It is necessary to maintain proper urine derivation with no residual urine left. These patients require long time follow up by urologist. Urological complications and renal disease as a consequence is very common cause of higher morbidity mainly in older children and adults with open spinal defect. Severe bladder mortality is most frequently present in patients with huge spinal defects without covering membrane. This verifies the theory of increased damage of nerve roots from direct exposure to amniotic fluid [34].

#### **6.7 Gastrointestinal complications**

One of the most common problems of patient with spina bifida in adulthood is neuropathic bowel dysfunction with constipation and incontinence, but these patients also often suffer from dysphagia – mainly patients with brain stem compression.

**35**

*Management of Pediatric Patients with Spina Bifida DOI: http://dx.doi.org/10.5772/intechopen.97237*

later to peptic ulcer disease [34, 35].

complications [34].

(club foot) [37].

**6.10 Latex allergy**

**6.9 Orthopedic complications**

quadriceps and hamstring muscles [11].

**6.8 Bronchopulmonal complications**

Brain and spinal cord nerves modulate activity of enteric nervous system. Patients with severe and highly located forms of open spina bifida and resulting Chiari II malformation have impaired function of nerves leading to dysfunction of gastrointestinal tract mobility. Gastrointestinal problem that these patients suffer from is diminished bowel movements causing obstipation or opposite also diarrhea.

Patients often suffer from anal incontinence from mild to severe degree [19]. Patients with large and high located myelomeningocele often suffer from dysphagia. Development of dysphagia in children with myelomeningocele is caused by cervicomedulary kinking and brainstem compression due to crowding in the posterior fossa in Chiari II malformation. Dysphagia leads to swallowing difficulties, feeding difficulties, failure to thrive, bronchopulmonary complications and

Children with large and high located myelomeningocele display also other complications such as Chiari II malformation that often leads to dysfagia. Severe dysphagia causes swallowing and feeding problems that might cause complications as aspiration pneumonia, pulmonary disease, reactive airway disease, bronchiectasis, stridor or apnoea [35]. Although almost all children with open spina bifida live into adulthood, patient suffering with brainstem dysfunction leading to such bronchopulmonary complications are at higher risk of fatal

Children with thoracic and thoracolumbar levels of defect might in some cases also have impaired function of the accessory respiratory muscles. They also often have scoliosis that could lead to reduced forced vital capacity of the lungs [36].

Orthopedics deal in patients with spina bifida with congenital and acquired deformities. Because of weak muscles of spine and lower extremities, these patients with open spinal defects can present with variety of orthopedic problems. Most frequently occuring problems are: scoliosis, kyphosis, muscle contractions, bone and joints deformities, hip dislocation, abnormal growth and talipes

Scoliosis is present in almost all children with severe and highly located myelomeningocele. Children born without covering membrane of the defect tend to have neuromuscular imbalance and spinal cord tethering which are conditions leading to scoliosis. Severe paraparesis leading to full-time use of wheelchair also enables occurrence of scoliosis [34]. Scoliosis also leads to pelvic obliquity with subsequent changes in sitting balance and contributes to unequal pressure during sitting. This factor together with lack of sensitivity leads to skin breakdowns [36]. One of the most important factors for maintaining ambulation in adulthood is strength of

Many patients with open spinal defects are at higher risk of latex allergy. This means allergic reaction to natural rubber and latex products. Symptoms could be mild – such as rush, sneezing, itching, conjunctivitis and rhinitis, as well as very severe condition – anaphylaxis, that is potentially life threatening situation. This is a potential reason for using latex-free gloves at labor and also at giving care to these patients. Latex allergy could also lead to perioperative complications [11].

*Management of Pediatric Patients with Spina Bifida DOI: http://dx.doi.org/10.5772/intechopen.97237*

*Spina Bifida and Craniosynostosis - New Perspectives and Clinical Applications*

Tethered spinal cord is a neurological disorder that is caused by abnormal attachment of the spinal cord to surrounding structures. In case of patients with myelomeningocele spinal cord is mostly attached to scar from previous operation [32]. Symptoms are caused by increased tension and stretch-induces dysfunction of the caudal spinal cord and conus and include motor and sensitive dysfunction, gait abnormalities, symptoms of cauda equina syndrome and

Filum terminale lipoma can cause cord tethering, lipoma is the most common cause of thick filum terminale. That is why detection of abnormal thickening of filum terminale is important. Initial detection is usually performed by ultrasonography [2] followed by MR imaging [12]. Tethered cord syndrome must be suspected when conus medullaris is placed dorsaly in the spinal canal and terminates below the superior aspect of L3 vertebral body. Also thickened filum terminale can be present. MR imaging is indicated in ultrasonography evidence of tethered cord or in case of doubts [3]. Although some patients with anatomic cord tethering do not develop symptoms, most of the patients are symptomatic and do not naturally improve without surgical untethering. Neurosurgical intervention is the treatment of choice, though with varying results [33]. Timing of the surgery is also important – early intervention after symptom development is necessary for recovery or at least improval of neurological functions. Early surgical intervention as a prevention of further neurological

Infants with open neural tube defects can experience meningitis – inflammation of brain and spinal cord surrounding meninges. Meningitis could develop as a consequence of open defect, as a complication of surgical procedures as well as a complication of shunting procedures. In case of bacterial meningitis there is a need

Most of the patients with severe spinal dysraphism suffer from neuropathic bladder impairment [24]. As the nerve damage causes urological complication by means of neurgenic bladder, this situation also brings specific possible complications. Usual problem is urinary retention that could lead to overflow incontinence, renal damage and urinary tract infections, that could be repeated or chronic and

It is necessary to maintain proper urine derivation with no residual urine left. These patients require long time follow up by urologist. Urological complications and renal disease as a consequence is very common cause of higher morbidity mainly in older children and adults with open spinal defect. Severe bladder mortality is most frequently present in patients with huge spinal defects without covering membrane. This verifies the theory of increased damage of nerve roots from direct

One of the most common problems of patient with spina bifida in adulthood is neuropathic bowel dysfunction with constipation and incontinence, but these patients also often suffer from dysphagia – mainly patients with brain stem compression.

**6.4 Tethered spinal cord**

urological symptoms [12, 32].

damage requires early diagnostics [12].

for massive antibiotic therapy.

**6.6 Urological complications**

often requires antibiotic treatment.

exposure to amniotic fluid [34].

**6.7 Gastrointestinal complications**

**6.5 Meningitis**

**34**

Brain and spinal cord nerves modulate activity of enteric nervous system. Patients with severe and highly located forms of open spina bifida and resulting Chiari II malformation have impaired function of nerves leading to dysfunction of gastrointestinal tract mobility. Gastrointestinal problem that these patients suffer from is diminished bowel movements causing obstipation or opposite also diarrhea. Patients often suffer from anal incontinence from mild to severe degree [19].

Patients with large and high located myelomeningocele often suffer from dysphagia. Development of dysphagia in children with myelomeningocele is caused by cervicomedulary kinking and brainstem compression due to crowding in the posterior fossa in Chiari II malformation. Dysphagia leads to swallowing difficulties, feeding difficulties, failure to thrive, bronchopulmonary complications and later to peptic ulcer disease [34, 35].

#### **6.8 Bronchopulmonal complications**

Children with large and high located myelomeningocele display also other complications such as Chiari II malformation that often leads to dysfagia. Severe dysphagia causes swallowing and feeding problems that might cause complications as aspiration pneumonia, pulmonary disease, reactive airway disease, bronchiectasis, stridor or apnoea [35]. Although almost all children with open spina bifida live into adulthood, patient suffering with brainstem dysfunction leading to such bronchopulmonary complications are at higher risk of fatal complications [34].

Children with thoracic and thoracolumbar levels of defect might in some cases also have impaired function of the accessory respiratory muscles. They also often have scoliosis that could lead to reduced forced vital capacity of the lungs [36].

#### **6.9 Orthopedic complications**

Orthopedics deal in patients with spina bifida with congenital and acquired deformities. Because of weak muscles of spine and lower extremities, these patients with open spinal defects can present with variety of orthopedic problems. Most frequently occuring problems are: scoliosis, kyphosis, muscle contractions, bone and joints deformities, hip dislocation, abnormal growth and talipes (club foot) [37].

Scoliosis is present in almost all children with severe and highly located myelomeningocele. Children born without covering membrane of the defect tend to have neuromuscular imbalance and spinal cord tethering which are conditions leading to scoliosis. Severe paraparesis leading to full-time use of wheelchair also enables occurrence of scoliosis [34]. Scoliosis also leads to pelvic obliquity with subsequent changes in sitting balance and contributes to unequal pressure during sitting. This factor together with lack of sensitivity leads to skin breakdowns [36]. One of the most important factors for maintaining ambulation in adulthood is strength of quadriceps and hamstring muscles [11].

#### **6.10 Latex allergy**

Many patients with open spinal defects are at higher risk of latex allergy. This means allergic reaction to natural rubber and latex products. Symptoms could be mild – such as rush, sneezing, itching, conjunctivitis and rhinitis, as well as very severe condition – anaphylaxis, that is potentially life threatening situation. This is a potential reason for using latex-free gloves at labor and also at giving care to these patients. Latex allergy could also lead to perioperative complications [11].


*4.2. Strengths and Weaknesses*

The results must be viewed in the context of some limitations. First, compared with the AN and BN groups, the BED group was small (*n* = 15), which could have minimized the power of the study. Second, the cognitive distortions that usually affect ED patients, notably AN patients, could have skewed the way they answered the questionnaires. Some items, such as "I continued to eat certain foods even though I was no longer hungry", "I spend a lot of time feeling sluggish or fatigued from overeating", "I felt so bad about overeating that I didn't do other important things", *or* "I didn't do well at work or school because I was eating too much", could have been coded as positive by the patients because of difficulties in recognizing sensations of hunger or satiety and because of particular beliefs about eating. However, as previously stated, the YFAS does not measure objective overeating but a particular relationship with food and eating; thus AN patients could satisfy the criteria for FA even if it is quite difficult to determine whether this tendency stems from starvation or a natural affinity for eating. Other limitations include the cross-sectional design of the study and the definition of the FA concept in itself, which is still a debated topic (i.e., does the YFAS truly measure what it is designed to measure?).

These limits are compensated by the strengths of the study. First, we want to emphasize the sample size. Two hundred and one patients were recruited, and such a large number allowed for a good representativeness of patients seeking treatment for ED. Moreover, ED diagnoses were established by structured clinical interviews and were based on DSM criteria. All patients were assessed at the beginning of the care in our specialized department. Finally, to the best of our knowledge, only a few studies have evaluated FA in AN [20,21], and we provided original results.


*2.5. Machine Learning Algorithm of Modeling FSV*

The random forest (RF) is a machine learning algorithm that uses multiple decision tree classifiers for classification and prediction. In recent years, studies on RF algorithms have rapidly developed accompanied by large numbers of applied research carried out in many fields. The RF algorithm is an efficient bagging-based integrated learning algorithm, and numerous prior studies have shown that the RF algorithm performs well in regression prediction [35–38]. Therefore, this study chooses the RF algorithm for modeling and analysis. The RF algorithm operates by utilizing the bootstrap method, that involves randomly sampling from the original population to create multiple samples. These samples are then used to generate a set of decision trees (ntree). The RF algorithm achieves higher accuracy and robustness by increasing the number of decision trees. At each splitting node, the RF algorithm randomly selects a subset of predictors (mtry) to build each tree. Additionally, there is no need to prune each tree. The RF algorithm employs the "out-ofbag" (OOB) error procedure to independently build each tree based on the training data. This procedure allows for the calculation of variable importance (VI) and OOB error for each tree grown by the RF algorithm. An estimation of the OOB error can be obtained using the following formula:

$$\text{COB}\_{\text{error}} = \frac{1}{n} \sum\_{i=1}^{n} (y\_i - \hat{y}\_i)^2 \tag{2}$$

where *yi* is the measured FSV, *y*ˆ*i* is the predicted FSV, and *n* is the total number of OOB samples.

In this study, three RF-based models composed of bands and vegetation indices (VIs) to estimate FSV, namely the bands-based model (BBM), VIs-based model (VBM), and bands + VIs-based model (BVBM) have been used.


3.1.2. Apparent Digestibility

Feed supplementation with ZnGly decreased the apparent total tract digestibility (ATTD) of Zn (*p* = 0.01), but the apparent digestibility of Zn in the duodenum, jejunum, and ileum did not differ between the dietary treatments (Table 2). Intake of both PF diets increased the total apparent digestibility of Zn (*p* < 0.01) compared to the ZnGly treatments as well as DM digestibility in piglets. The highest value DM digestibility was recorded in the PF + ZnGly treatment compared to the C and ZnGly treatments (Table 5).

Intake of the PF diets increased the total apparent digestibility of Cu (*p* < 0.01), but Cu digestibility did not change in the small intestine. Interaction between Zn and fibre sources affected Cu digestibility in the duodenum (*p* < 0.05), with decreased Cu digestibility in the PF treatment compared to the PF + ZnGly treatment (*p* < 0.05).

On the other hand, PF supplementation significantly reduced Fe digestibility from the ileum as well as decreased the ATTD of Fe (*p* < 0.001), while the apparent digestibility of Fe was not changed in the other small intestine segments.

ZnGly in the diet increased duodenal apparent digestibility of Mn (*p* < 0.05). However, the Zn source affected the apparent duodenal digestibility of Mn, Mn absorption did not differ between the dietary treatments in the jejunum and ileum. The effects of both dietary sources and source interaction were observed on ATTD of Mn, whereby negative values in the parameter were found, with the lowest values in the PF + Gly treatment.

No changes in pH were found in any small intestinal segments in our in vivo experiment (Table 5).

**Table 2.** Apparent digestibility of Zn, Cu, Fe and Mn in the small intestine and total tract of piglets fed diets supplemented with zinc and fibre from different sources.

1 C—cellulose, PF—potato fibre, ZnGly—zinc chelate with glycine. a–b Means within a row with different superscript letters are significantly different (*p* < 0.05) as a result of a Tukey's means comparison (*n* = 6). A,B Means within lines with different superscript letters are significantly different (*p* < 0.05) using by Fisher's LSD post hoc test.

## *3.2. Experiment in situ*

#### In Situ Soluble TEs

Interaction between Zn and fibre sources affected soluble Zn concentration in digesta of each small intestinal segment (Table 3). Zn solubility in the duodenum and jejunum were not affected by any dietary sources, but the effect of both dietary sources on the soluble concentration of Zn in the ileum was observed. Due to dietary source interaction, significant decreased in situ Zn solubility was observed in the duodenum (*p* < 0.01), but soluble Zn concentration increased in the jejunum (*p* < 0.05) in the PF + Gly treatment compared to the ZnGly and PF treatments. Increased Zn soluble content was observed in the ileal digesta of piglets fed the PF diet in comparison to the other dietary treatments (*p* = 0.001).

Supplementation with PF decreased in situ soluble content of Cu in the jejunum without any significant differences between the treatments.

Zn source affected soluble Fe concentration in the jejunal digesta with significantly decreased soluble content of Fe in the ZnGly treatment to the control treatment (C). Fe solubility in the ileum was affected by both dietary sources (*p* < 0.0001). The highest value was observed in the PF treatment, while the lowest in vitro solubility of Fe was observed in the ZnGly treatment compared to others.

In situ solubility of Mn was affected by both dietary sources in the jejunum and ileum. ZnGly in the diets decreased soluble Mn in the duodenum and ileum, but ZnGly increased Mn solubility in the jejunum. Feed supplementation with PF reduced the soluble content of Mn in the jejunum, on the contrary, increased in vitro solubility of Mn was observed in the ileal digesta in the PF treatment (*p* < 0.01). However, the interaction between both dietary sources affected soluble Mn concentration in the ileal digesta.

**Table 3.** In situ soluble content of Zn, Cu, Fe and Mn from intestinal digesta after dietary treatments with Zn and fibre from different sources.

1 C—cellulose, PF—potato fibre, ZnGly—zinc chelate with glycine. a–c Means within a row with different superscript letters are significantly different (*p* < 0.05) as a result of a Tukey's means comparison (*n* = 6). A–C Means within lines with different superscript letters are significantly different (*p* < 0.05) using by Fisher's LSD post hoc test.

#### *3.3. Experiment In Vitro*

#### 3.3.1. In Vitro Solubility of Zn Sources

The effects of pH on Zn solubility from both Zn sources in different buffers simulating pH in gastric and small intestine digestion were estimated in vitro (Figure 1). The in vitro solubility of Zn from ZnSO4 and ZnGly was affected by pH (*p* < 0.0001) and Zn source (*p* = 0.003), with the lowest Zn solubility at pH 6.8 simulating digestion in the lower part of the small intestine (Tukey's post hoc multiple comparisons test with individual variance computed for pair-wise comparisons in Supplementary materials, Figure S1, Table S1). The solubility of ZnSO4 was found to be significantly higher than Zn solubility from ZnGly (two-way ANOVA with the main effect only, *p* < 0.001, Figure 1).

**Figure 1.** In vitro solubility of Zn from both Zn sources (ZnSO4, ZnGly) subjected to different buffers simulating gastric digestion in 0.2 M Gly-HCl at pH 2.0, or simulating small intestinal digestion in 0.2 M sodium acetate buffer at pH 4.8 and 6.8; Asterisks represent *p-* value classification (\* *p* < 0.05, \*\* *p* < 0.01, \*\*\*\* *p* < 0.0001).

Data were analyzed using two-way ANOVA, followed by the post hoc Tukey's multiple comparisons test, which included the main effect only (pH and Zn source).

#### 3.3.2. In Vitro Simulated Solubility of TEs

In vitro soluble or bioaccessible concentrations of TEs in the experimental diets in each digestion phase are shown in Table 4. Zn, Mn, and Cu were almost totally dissolved in the gastric digestive juice but rapidly decreased solubility of Zn, Mn, and Fe was found in the small intestine phase (SIP). The in vitro solubility of Zn, Fe, and Mn in each experimental diet was observed to be lower in the SIP than in the gastric and large intestinal phases (two-way ANOVA with main effect only, *p* < 0.001); however, Cu solubility did not differ between the simulated digestion phases.

**Table 4.** In vitro solubility of Zn, Cu, Fe, and Mn from the dietary treatments subjected to three-step in vitro simulated digestion assay.

1C—cellulose, PF—potato fibre, ZnGly—zinc chelate with glycine. ab Means within a row with different superscript letters are significantly different (*p* < 0.05) as a result of a Tukey's means comparison (*n* = 9). A–C Means within lines with different superscript letters are significantly different (*p* < 0.05) using Fisher's LSD post hoc test.

The in vitro solubility of Zn did not differ between the dietary treatments in each phase of simulated digestion. Intake of PF diets decreased soluble Cu in the gastric phase (GP) and affected solubility of Fe in the large intestinal phase (LIP).

The Zn source influenced in vitro solubility of Cu in LIP, soluble Fe in GP and LIP, and Mn solubility in gastric digestion phases. Supplementation with organic ZnGly increased in vitro solubility of Cu in LIP (*p* < 0.05) and soluble Mn in GP (*p* < 0.001). Zn source also affected the solubility of Fe in GP and LIP; however, the interaction between Zn and fibre sources was observed in both of these digestion phases. Decreased in vitro solubility of Fe in GIP was observed in the ZnGly treatment, while the highest soluble Fe concentration in LIP was observed in the control treatment compared to other treatments.

#### 3.3.3. In Vitro Dry Matter Digestibility and pH

Although feed supplementation with PF increased in vivo DM digestibility in piglets, in vitro dry matter digestibility (IVDMD) was not influenced by the dietary treatments (Table 5).

**Table 5.** Effects of dietary treatments with added Zn and fibre from different sources on pH and dry matter digestibility subjected to in vivo and in vitro digestion assay.

1 C—cellulose, PF—potato fibre, ZnGly—zinc chelate with glycine. a–c Means within a row with different superscript letters are significantly different (*p* < 0.05) as a result of a Tukey's means comparison, means represent 6 replicates in vivo, 9 replicates in vitro (DM digestibility) or 3 replicates in vitro (pH). A–B Means within lines with different superscript letters are significantly different (*p* < 0.05) using Fisher's LSD post hoc test.

Different effects of Zn and fibre sources on pH values were determined: PF affected pH in the in vitro simulated GP (*p* < 0.01) and Zn source in the SIP (*p* < 0.05). The diets containing PF increased pH in the gastric phase, while ZnGly in the diets slightly decreased pH in the SIP (Table 5). Interaction between both dietary sources affected pH in LIP with increased pH in the Gly and PF treatments.


**6.2 Antibiotics**

The WHO recommends mass distribution of antibiotics in communities where follicular trachoma is >10% in children [12]. In 1940, sulfonamide was the first antibiotic to be used at a large scale to treat trachoma. Over the ensuing decades, several other antibiotics were evaluated with little success until in 1990 when tetracycline became the drug of choice.

In more recent decades, azithromycin has been adopted as the drug of choice by many trachoma control programs because of its many advantages over tetracycline ointment [51]. For example, azithromycin is a single-dose regime and treatment can be directly observed to improve compliance significantly.

The WHO has developed guidelines for determining how community treatment of trachoma based solely on the prevalence of trachoma follicles in children aged 1–9 (**Figure 2**) [52]. It is recommended that trachoma control programs use either 6 weeks' regimen of tetracycline eye ointment instilled into the lower conjunctival sacs two times a day or a single dose of azithromycin (20 mg/kg up to 1 g) [53, 54]. The duration of treatment remains a subject of debate and further research. The WHO recommends three annual rounds of mass treatment endemic communities after which a reassessment of active disease will determine whether another round of treatment will be needed or discontinued [55].