Keywords
Chiari II malformation - craniocervical junction decompression - myelomeningocele
- spina bifida - syringomyelia
Introduction
Chiari malformation type II (CM-II) is the extrusion of the cerebellar tonsils and
vermis and the fourth ventricle through foramen magnum, resulting in the compression
of the medulla oblongata and the spinal cord. It is almost always present with spinal
myelomeningocele (MMC). Among other things, CM-II leads to a violation of the outflow
of cerebrospinal fluid (CSF) resulting in obstructive hydrocephalus. CM-II is the
most common Chiari malformation that presents itself during childhood and has an incidence
of 1/1000 births.[1]
A congenital malformation, Chiari syndrome, was first described by the German pathologist
Hans Chiari in 1890. Julius Arnold was studying the displacement of the tonsils from
the cerebellum and caudal brain into the foramen magnum at the same time. This anomaly
occurs with a frequency of 1 to 3:1000 newborns. Children born with MMC in 95% of
cases have a malformation of the posterior cranial fossa (CM-II) as an associated
pathology.[2]
Morphological manifestations of this pathology in the fetus can be detected during
an ultrasonography (USG) and predetermine further prognosis. Very often, the detection
of CM-II becomes the reason for termination of pregnancy.
The formation of the defect is based on a combination of pathological changes. The
spinal cord in its lower part with fixation to the posterior wall of the spinal canal
is unable to move cephalic during fetal growth. As a result, the medulla oblongata
and partly the cerebellum enter through a large opening into the lumen of the spinal
canal. With difficulty of normal CSF flow, hydrocephalus develops. At the same time,
the medulla oblongata is severely deformed, the cerebellum is compressed and delayed
in development. The process often progresses during the intrauterine and postnatal
periods. Depending on the type of hernia, there are three types of Chiari syndrome.[3] This study focuses on CM-II in the newborn and pediatric cases. This type of pathology
is characterized by a complex of brain deformities, an elongated shape of the dysplastic
(almond-shaped) cerebellum and brain stem, which are embedded (wedge-shaped) in the
large foramen. On the side of the lumbar spinal cord, there is a pathological development
in the form of spina bifida—meningocele or MMC. Pathology of the brain is accompanied
by dysgenesis of the corpus callosum, absence of a transparent septum, obstructive
hydrocephalus, polymicrogyria, porencephaly, schizencephaly, and fenestration of the
falx of the brain. Changes in the hindbrain in type II Arnold-Chiari malformation
include more pronounced elongation and caudal displacement of the structures of the
posterior cranial fossa into the spinal canal. In addition to these changes, changes
in the vault and base of the skull are often observed. The differential diagnosis
is with a CM-I (no MMC) and an isolated MMC without anomaly of the posterior cranial
fossa.[4]
The clinic is mainly associated with the compression mechanism of damage to the nervous
structures and impaired hemolytic dynamics. In this case, intracranial hypertension
and hydrocephalus develop. CM-II anomaly has clinical manifestations that become noticeable
from the first minutes of a child's life (spina bifida).[5] Children with this pathology are born with a hydrocephalic skull shape. Hydrocephalus
interferes with normal development, newborns suffer from respiratory, palpitation,
and swallowing disorders (bulbar disorders). Often the disease is accompanied by convulsive
seizures. Children develop nystagmus, apnea, stridor, paresis of the vocal cords,
dysphagia with regurgitation, and impaired tone in the limbs. The severity of neurological
symptoms primarily depends on the severity of CSF flow disorders, and not on the degree
of cerebellar tonsil ectopia.[6]
Although there is no clear algorithm for the treatment and surgical steps of CM-II,
most commonly accepted approach is primarily allowing for sufficient CSF drainage
by a craniovertebral junction (CVJ) decompression and addressing MMC.[2] CM-II presents itself in the newborn with more severe symptoms than type I. Paresis
of the vocal cords, impaired tone in the extremities, and apnea and dysphagia with
regurgitation are common clinical findings.[7]
Although clinical findings may be subtle, some life-threatening situations require
immediate intervention to prevent morbidity and mortality. The relevance of this study
is based on the demonstration of the key factors in the development of the problem
and the lack of proper research in this direction. Although this anomaly has already
been studied sufficiently, there is no single approach to address all the issues related
with CM-II, which necessitates the study of the presented anomaly. Despite the advances
in neonatal imaging, CM-II is usually diagnosed clinically; thus, a clear understanding
of the pathologies and the treatment approaches should be familiar to those who work
close with this entity. In this study, we report our 20-year experience with the surgical
management of 100 pediatric cases diagnosed and treated for CM-II along with hydrocephalus
and MMC.
Materials and Methods
This retrospective analysis was carried out on 100 patients aged between 0 and 17
years operated on for CM-II associated with hydrocephalus and MMC at the Moscow Regional
Hospital. All patients underwent clinical, neuroimaging and laboratory studies. Magnetic
resonance imaging (MRI) of the brain and the spinal cord was the main method of neuroimaging
of CM-II malformation associated with hydrocephalus and MMC in children.
The examination of the patients included an assessment of the neurological status
and examination of the MRI data of the brain and spinal cord before and after the
operation ([Fig. 1]).
Fig. 1 (A) A 3-year-old boy with downward placement of cerebellar tonsils and brain stem. (B) Dramatic syringomyelia extending from C6 to lower thoracic levels in the same patients.
Concomitant scoliosis was also present. (C) A 5-year-old girl diagnosed for Chiari malformation type II with cervical syringomyelia
who underwent craniocervical junction decompression. (D) A 13-year-old boy with a severe herniation of cerebellar tonsils and brain stem.
The patient did not show any major symptoms in the first decade of his life. This
may have been due to a rather large foramen magnum and spinal canal at the C1-2 level.
Operations were performed by the neurosurgical department under general anesthesia.
After fixation with the Mayfield skull clamp in the prone position a linear midline
incision of the occipitocervical region was made. The muscles were dissected from
the midline. A wide suboccipital and C1 posterior arc decompression was performed.
Under the microscope, dura was opened linearly. There usually were a large number
of dense adhesions between the arachnoid and inner membrane of the dura mater. This
usually resulted in arachnoid fenestration. After a high flow of CSF, normal tonsil
pulsation was observed. The fascia was then used for expansive duraplasty.
The analysis of the results of surgical interventions was carried out on the basis
of protocols of operations and intraoperative observations. We analyzed the relationship
between the immediate and long-term results of operations with the volume of the operation
and preoperative parameters, including gender, age, clinical manifestations, and degree
of dystopia of the cerebellar tonsils, the presence, and prevalence of syringomyelia.
Results
A total of 100 patients were operated on for CM-II from March 2002 till May 2022 ([Table 1]). Patients underwent a comprehensive neurosurgical examination, which included general
somatic, clinical neurological, neuropsychological, examination by an otoneurologist
(35) and an ophthalmologist (24). When analyzing the history of 100 patients, pathological
conditions of the perinatal period (intrauterine hypoxia, rapid delivery) were detected
in 68 (68%) patients and birth trauma in 19 (19%) patients. Another 27 (27%) cases
had a history of repeated craniocerebral trauma in childhood and adolescence with
the site of application of the traumatic effect in the occipital region. Examination
of the entire length of the spinal cord was carried out in 77% of cases. According
to MRI data, the degree of herniation of the cerebellar tonsils below the McRae line
averaged 11.2 ± 5.1 mm. The average degree of tonsil dystopia in patients with syringomyelia
was 11.6 ± 4.6 mm and 10.8 ± 5.7 mm in patients without syringomyelia. It was found
that the degree of tonsil herniation did not correlate with the severity of clinical
manifestations and did not affect the development of syringomyelia or its prevalence
(p > 0.05). Being a retrospective study, exact timing of the operations was unable to
be obtained. Based on the available data, surgery was performed after diagnosis and
correct correlation of findings with symptoms ([Table 1]).
Table 1
Distribution of patients by sex and age
|
Age groups
|
Male
|
Female
|
Total
|
|
0–5 years
|
22
|
21
|
43
|
|
6–10 years
|
5
|
12
|
17
|
|
11–13 years
|
10
|
8
|
18
|
|
14–17 years
|
10
|
12
|
22
|
|
Total
|
47
|
53
|
100
|
Concomitant syringomyelia was observed in 60% of patients. Depending on the localization,
syringomyelia at the cervical level was detected in 30%, 40% in cervicothoracic, 10%
in thoracic, and holocord in 20%. The prevalence of syringomyelia over five vertebral
levels was 70%. The diameter of syringomyelia was determined in 60% of patients. Scoliotic
spinal deformity of more than 10 Cobb degrees at the time of hospitalization was diagnosed
in 45% of patients and was observed only in patients with concomitant syringomyelia.
More severe spinal deformity was observed in patients with widespread syringomyelia
(cervicothoracic and holocord, p = 0.04).
Clinical manifestations of CM-II associated with brain stem dysfunction and the lower
group of cranial nerves (CNs) are presented in [Table 2]. Severe obstructive hydrocephalus was more frequent in children aged between 0 and
5 years and 6 and 10 years (68%, 61%) compared with older age groups (27%, 23%).
Table 2
Clinical manifestations of patients associated with brain stem and cranial nerve dysfunction
|
Neurological syndrome, symptom
|
Number of patients
|
|
Reflex cough, choking
|
72
|
|
Syringomyelic syndrome
|
60
|
|
Pyramidal signs
|
58
|
|
Intermittent apnea
|
54
|
|
Neurogenic dysphagia
|
46
|
|
Behavioral syndromes
|
45
|
|
Nystagmus (especially downward)
|
37
|
|
Vegetovascular dystonia
|
36
|
|
Stridor
|
35
|
|
False Croup syndrome
|
35
|
|
Hypertension–hydrocephalic syndrome
|
28
|
|
Weak or no cry
|
27
|
|
Paraparesis of the upper limbs
|
25
|
|
Monoparesis of an upper limb
|
23
|
|
Cerebellar syndrome
|
23
|
|
Tetraparesis
|
22
|
|
Paresis of the facial muscles
|
21
|
|
Opisthotonus
|
21
|
|
Aspiration
|
11
|
Note: Patients showed a combination of symptoms therefore the total number does not
correspond to 100.
Patients with tethered cord syndrome presented with dermatological findings, lower
extremity neurological findings, spinal deformities, and pelvic floor dysfunction
findings. A special group consisted of newborns (n = 19), in whom manifestations of CM-II differed significantly from the older children.
The neonates were more likely to develop rapid neurological deterioration within hours.
The brain stem and cranial nerve dysfunctions were as follows: neurogenic dysphagia,
postfeeding cyanosis, nasal regurgitation, prolonged feeding time, salivary accumulation,
and decreased/absent gag reflex. Apnea due to impaired respiratory stimulation was
found in 12 newborns and 13 newborns had inspiratory stridor. Laryngoscope examination
revealed paralysis of the abductor and rarely adductor vocal cords. All newborns had
weakness in the upper limbs, downward nystagmus, a weak cry, and weakness of the facial
muscles.
Ventriculomegaly without periventricular edema and signs of CSF occlusion, according
to preoperative MRI, was observed in 15% of patients. In patients of the younger age
group (0–5 years), ventriculomegaly was observed statistically significantly more
often (p = 0.02), and syringomyelia was observed much less frequently (p = 0.04). The analysis of groups of patients with and without syringomyelia was carried
out ([Table 3]).
Table 3
Clinical symptoms of CM-II patients in accordance with syringomyelia
|
Clinical symptom
|
Syringomyelia absent
n (%)
|
Syringomyelia present
n (%)
|
Total (%)
|
|
Scoliosis
|
2 (5)
|
30 (40)
|
32 (32)
|
|
Bulbar disorders
|
7 (15)
|
9 (11)
|
16 (16)
|
|
Forced head position
|
–
|
8 (10)
|
8 (8)
|
|
Cephalic syndrome
|
30 (80)
|
40 (55)
|
70 (70)
|
|
Sensory deficits
|
2 (5)
|
18 (25)
|
20 (20)
|
|
Motor deficits
|
2 (5)
|
19 (27)
|
21 (21)
|
|
Dizziness
|
7 (15)
|
8 (10)
|
15 (15)
|
|
Cerebellar symptoms
|
9 (11)
|
25 (35)
|
34 (34)
|
|
Convergent strabismus
|
2 (5)
|
7 (15)
|
9 (9)
|
Abbreviation: CM-II, Chiari malformation type II.
Note: Patients showed a combination of symptoms therefore the total number does not
correspond to 100.
The clinical manifestations of the disease in different age groups were different.
In children of the younger age group, cerebellar symptoms and bulbar disorders were
more frequently observed (p = 0.03), and cephalic syndrome was noted much less frequently (p = 0.005). The clinical manifestations of the disease in patients with and without syringomyelia
were dominated by the cephalic syndrome. Headaches were more common in children in
the older age group (6–17 years; p = 0.01).
In patients with concomitant syringomyelia, symptoms of myelopathy were observed in
40% of patients and more often (29%) manifested as progressive scoliosis. In other
cases (31%), motor, sensory disorders, a combination of motor and sensory disorders,
sympathetic disorders (Horner's syndrome), and radicular pain were observed.
Severe ataxia and moderate bulbar symptoms were observed in children under 7 years
of age statistically more often (p < 0.05). The main complaints from parents were increased fatigue, memory loss, capriciousness,
and frequent irritability of children. The first symptoms of the disease were cluster
headache (87%), coordination disorders (78%), and oculomotor disorders (24%). The
early psychomotor development of the patients did not stray from the average age limits;
most of the children were adaptive and attended school. An in-depth diagnosis of emotional
and behavioral patterns was carried out ([Table 4]).
Table 4
The emotional and behavioral symptoms before surgery
|
Emotional–behavioral disorders
|
0–5 years[a]
|
6–10 years[a]
|
11–13 years[a]
|
14–17 years[a]
|
Overall
|
|
Emotional lability
|
26
|
8
|
4
|
9
|
47%
|
|
Conduct violations
|
6
|
1
|
1
|
2
|
10%
|
|
Neuroticization
|
22
|
8
|
1
|
20
|
51%
|
|
Psychopathological symptoms
|
7
|
0
|
0
|
1
|
8%
|
|
Obsessive-compulsive traits
|
19
|
6
|
4
|
7
|
36%
|
a Values are given in number of patients.
According to the scales for diagnosing the emotional–behavioral sphere, 46% of children
had emotional instability and 41% had a high level of neuropsychic stress (irritability,
high anxiety, an abundance of fears, autonomic dysfunction, decreased appetite). Attention
was drawn to the frequency and severity of obsessive–compulsive behavioral traits.
In young children, persistent onychophagia and chronic lip biting were frequently
observed (44%). Almost one-third of the patients in the 11 to 17 years of age group
had compulsive-obsessive features in the form of obsessive rituals, vague fears, and
early awakenings with a feeling of severe anxiety. At the same time, parents noted
the occurrence of these features some time before the onset of the first symptoms
of the disease. Moderate behavioral disorders were observed more often in patients
under 7 years of age (13%). Cases of pathopsychological symptoms (nightmares, aggressiveness)
were noted in the younger group (16%). In addition, a 16-year-old patient had a psychotic
disorder in the form of delusions of persecution and visual hallucinations.
Progressive scoliosis was observed only in patients with syringomyelia. Although the
literature describes cases of scoliosis in patients without syringomyelia due to the
presence of increased cerebrospinal pressure in the central canal, in the present
study, the severity of scoliotic deformity correlated with the prevalence of syringomyelia
(p = 0.03).
In the postoperative period, clinical improvement was noted in 80% of patients, stabilization
in 15%, and regression of syringomyelia was noted in 5% of cases. Complete or partial
regression of the cephalic syndrome after surgery was observed in 63% of patients
(p = 0.003), symptoms of trunk lesions and cranial nerves in 15%, cerebellar symptoms
in 13%, and symptoms of myelopathy in 9%.
Satisfactory results were significantly more often observed in patients of the older
age group (p = 0.02). Patients with unsatisfactory results at the time of treatment were significantly
younger (p = 0.02). In this group, cerebellar symptoms were more often detected (p = 0.02). After the operation, 26 patients developed cerebellar mutism syndrome, 22
patients developed cerebellar cognitive-affective syndrome without loss of speech,
and 52 children had no complex symptoms.
When comparing preoperative clinical and neuropsychological parameters in the selected
groups, there were no significant differences in the groups in terms of gender and
age. However, there was a trend toward the greatest vulnerability of children aged
between 0 and 5 years to the occurrence of neuropsychological syndromes.
When evaluating the individual results of surgical treatment of CM-II associated with
hydrocephalus and MMC in children, their relationship with the method of posterior
decompression of the CVJ was well established. Our results were significantly better
in patients who underwent duraplasty (p = 0.01), and worse in the group of patients with extradural decompression (EDD; p = 0.03).
In patients without syringomyelia, clinical results were statistically significantly
better with extra-arachnoid duraplasty (EAD; p = 0.04). Intra-arachnoid dissection and duraplasty (IAD) (with or without shunting)
were accompanied by a higher frequency of positive MRI dynamics (p = 0.0003). After shunting, regression of syringomyelia (partial or complete) was observed
in all cases (p = 0.02). Children of the younger age group more often had an unsatisfactory result
in the postoperative period (p = 0.02). Postoperative complications without syringomyelia were more often observed
in patients of the younger age group (p = 0.04). The reoperation rate was 13.6%. When analyzing the methods of posterior decompression
of the CVJ, it was found that EDD was associated with a greater need for repeated
operations (p = 0.008).
Discussion
Depending on the quality of pregnancy monitoring and the volume of medical research,
CM can be diagnosed even in the womb or sometime after birth. A number of authors
believe that the cause of the pathology is the small size of the posterior cranial
fossa, and other authors are inclined to believe that the anomaly develops against
the background of an increased size of the brain. The development of type 2 malformation
may be accompanied by other dysplasias of the nervous system. The difficulty of diagnosing
this disease at an early age is because the clinical picture may not immediately warrant
a suspicion. With the development of the disease, the brain stem is affected and may
cause a compression of cranial nerve nuclei. This threatens normal vision and hearing,
the processes of swallowing, and coordinated movement.[8]
McRae line is clinically useful in measuring the level of cerebellar herniation; however,
this itself is not a major prognostic factor. The degree of herniation should not
be overestimated for the progression of the disease or syrinx cavity as evidenced
by previous studies[9] and this study. There was no statistically significant relationship between the
severity of symptoms and syringomyelia with level of cerebellar herniation. However,
the presence of syringomyelia was found to be well correlated with the incidence of
spinal deformity. The syrinx diameter is suggestive of deformity and scoliosis.[10] This should be taken into consideration as 60% of the patients presented with syringomyelia.
On the other hand, the direct relationship between level of tonsillar herniation without
syringomyelia to spinal deformity needs further evaluation.
The relationship between hydrocephalus and CM-II is well established. Earlier it was
thought that the increased intracranial pressure by hydrocephalus caused the tonsillar
herniation. However, it was later proven that the herniation itself plugged the foramen
magnum causing a disturbance in the flow of CSF.[11] Younger children in this series had more severe hydrocephalus requiring urgent intervention.
This may be because more severe hydrocephalus presenting with debilitating neurological
findings is diagnosed at a younger age and treated earlier. This was observed in newborns
as well. Newborns diagnosed with CM-II had a more rapid neurological deterioration,
which further emphasized the importance of fetal diagnosis.
Our cases hide a wide range of neurological manifestations due to CM-II. Frequent
choking, syringomyelic syndrome, pyramidal signs, intermittent apnea, and neurogenic
dysphagia were the most commonly encountered findings. This is not unusual of CM-II
as the tonsillar herniation causes a compression of the brain stem leading to numerous
clinical findings. Although these findings are suggestive and expected for CM-II,
almost half of the patients had various emotional and behavioral findings. Although
psychiatric evaluation of patients with CM-I has been discussed within the literature,[12] evaluation of nonmotor behaviors caused by cerebellar dysfunction in patients with
CM-II is lacking. Although cerebellar pathologies are well known for coordination
and movement deficits, its relationship with cognitive impairment, language disorder,
executive function impairment, visuospatial deficits, regressive personality, emotional
lability, and dramatic mood swings are still being investigated.[13] It is important for families and physicians to recognize the co-existence of psychological
disorders that may be caused by the disease itself or developmental disturbance due
to prolonged hospitalization and treatment. The early detection of cerebellar cognitive
and emotional pathologies would result in an earlier therapeutic intervention and
restore normal emotional and cognitive functioning.
According to the results of our study, in patients with a syrinx cavity diameter of
more than 6 mm, a 70% improvement in the patients with myelopathic symptoms and an
80% improvement in the group of patients without myelopathic symptoms were observed.
Based on the results obtained, we formulated criteria for the effectiveness of surgical
treatment of CM-II in children:
-
Dynamics of clinical symptoms of the disease after surgery (for patients without syringomyelia).
-
Dynamics of neuroimaging data according to the results of control MRI: the appearance
of subarachnoid liquor spaces in the area of the craniovertebral junction, the large
occipital cistern; reduction in the length (on sagittal slices) and diameter (on axial
slices) of syringomyelia (in patients with concomitant syringomyelia).
Treatment focuses on decompression of the tonsillars concomitantly brain stem and
restoration of a normal CSF flow. Surgery still remains the most effective method
in achieving these goals and alleviating symptoms. Patients in this study benefited
greatly from CVJ decompression. However, it should be noted that patients who underwent
EDD had a higher rate of reoperation. Extra-arachnoid duraplasty and IAD resulted
in clinically better results that were statistically significant. Bony decompression
alone does not allow for sufficient decompression in the subdural area as the overlying
dura is usually thicker and fibrotic. Thus, opening of the dura with a widening duraplasty
and fenestration of arachnoid for CSF diversion should be strongly considered.
In the presence of concomitant diseases, there are indications for surgical intervention
even in the early years of life. When deciding on the appointment of an operation,
the presence or absence of anomalies of the bony structures, the presence or absence
of hydrocephalus, and the condition of the hernial sac are taken into account. Identification
of these pathologies is a must for diagnosis and surgical intervention.
To reduce the risks and prevent anomalies, prenatal diagnostic tools are vital. Prenatal
diagnosis should be carried out in a timely manner using USG at 18 to 20 weeks of
gestation focusing on the posterior fossa. At the end of the first trimester, USG
allows for the identification of the hemispheres and large cisterns and more significantly
in this case, changes in the shape and size of the cerebellum. Intrauterine cerebellar
pathologies are almost always indicative of some type of CM. In 70 to 85% of cases,
CM is accompanied by hydrocephalus or spinal hernia. Therefore, the detection of signs
of pathology in the fetus should be the basis for excluding defects in the development
of the spine.[14] USG is able to diagnose intracranial pathologies as well. A “banana”-shaped cerebellum
(obliterated cisterna magna) with the frontal bones indented as in a “lemon” shape
is almost always indicative for CM-II along with spina bifida. This should be supported
by a study of the spine and the ventricles as well before drawing a conclusion. Ventricle
shapes may be dynamic and change as the disease progresses. USG should be performed
both in the horizontal and sagittal plane but may be difficult due to obesity or patient
incompliance. In suspected cases, MRI may be employed starting from the 20th week
of pregnancy.[15]
Based on the analysis of clinical and neuroimaging data of patients, the following
indications for surgical treatment in children with CM-II associated with hydrocephalus
and MMC were formulated:
-
“Classic” pain in the craniovertebral region, aggravated or provoked by Valsalva maneuver
(with straining),
-
Persistent headaches with the ineffectiveness of conservative treatment,
-
Neurological symptoms of the level of the cervicomedullary junction,
-
The presence of syringomyelia and symptoms of myelopathy,
-
The progression of syringomyelia,
-
Syringomyelia at the cervical level and symptoms of the disease; widespread syringomyelia
at the cervicothoracic level or throughout the spinal cord with a diameter of more
than 6 mm (more than half the diameter of the spinal cord) in the absence of symptoms
of the disease.
The presence of widespread syringomyelia with a diameter of more than 6 mm (more than
half the diameter of the spinal cord) in combination with symptoms of myelopathy worsens
the outcome of the disease.
Conclusion
If CM-II is asymptomatic, then no specific treatment is prescribed. If the patient
develops simple pain in the occiput and neck not aggravated by Valsalva maneuver,
then pain relievers are prescribed. If a patient has neurological disorders, surgical
intervention is indicated. The operation is also performed if the pain syndrome cannot
be overcome within the framework of conservative therapy. Indications for surgical
treatment are disorders of the cranial nerves and disorders of the sensitivity of
the extremities and paresis.
CM-II associated with hydrocephalus and MMC in children is a severe pathology of the
central nervous system. Despite the fact that the disease is infrequent, it is this
type of disease that develops in newborns during pregnancy and in the first years
of life. The only definite treatment is surgery. For the purpose of timely detection
of diagnostics, it is recommended to conduct ultrasound with scanning of the brain
and examination of the spine in several planes, as well as conduct MRI. The comparative
analysis of the results of surgical treatment of CM-II, associated with hydrocephalus
and MMC in children, carried out in the study, the revealed features of the clinical
and neuroimaging picture of the disease, made it possible to clarify the definition
criteria and indications for surgical treatment and to optimize the choice of the
posterior decompression volume to improve the immediate and long-term results of treatment.
In order to prevent and correct neuropsychological complications, further retrospective
clinical and neuropsychological studies are needed in pediatric patients with CM-II
associated with hydrocephalus and MMC.
