Actuality: Intracranial hypertension (IH) is a rare syndrome in children, which may be associated with headache (in older children). In younger children the clinical symptoms of intracranial hypertension are obscured due to age particularities. One of the causes of IH in children are brain and cerebellar tumors. Th e purpose of the study was determined by the retrospective analysis of IH signs in children who were confi rmed to have brain tumors. Methodology of the study: Th e study included 27 children aged 0-16 (girls – 11, boys – 16) who were diagnosed with brain tumors. Th e diagnosis was confi rmed by imaging examinations (2014-2018). Th e research criteria were the age of the child, as well as the early symptoms of brain tumors. Results: In younger children (up to 3 years): sleep disturbances, behavior disturbances (lachrymosity) and vomiting were among the fi rst symptoms of brain tumors, and in older children (3 years and older) headaches, nausea and vomiting. Th e most aff ected age – 10 and 14 years, followed by those between 5-9 years, then the children of 0 to 4 years. Conclusions: Children are at an increased risk of developing brain tumors. One of the cardinal syndromes of brain tumors in children is IH, accompanied by headaches, vomiting, nausea, vision changes, behavioral disorders, convulsions, etc. In older children, IH syndrome has non-specifi c manifestations, so any changes suggestive of a brain tumor require further examination. Ophthalmoscopy, a basic exam for identifying IH in young children, is oftentimes not suggestive. Suspicion of a cerebral tumor requires the examination of a child of any age through cerebral imaging. Key words: intracranial hypertension, brain tumors, child
ACTUALITY Intracranial hypertension (IH) is a rare syndrome in children, which may be associated with headache (in older children). In young children the clinical symptoms of IH are obscured due to age particularities. In general, IH is a major pediatric emergency and can lead to significant morbidity. In order to reduce morbidity coefficients, it is important to address appropriate patient behavior, including: elucidation of IH etiology, confirmation of early diagnosis and effective management. Among the objectives established in the child’s examination we quote the following: headache monitoring, neurological and ophthalmic examination, cerebral imaging and lumbar puncture. IH management should be coordinated with the neurologist, ophthalmologist or neuro-ophthalmologist. IH syndrome in children
may be primary (idiopathic IH), or may appear as an expression of an identifiable secondary cause. One of the causes of IH in children is cerebral and cerebellar tumors. In the Republic of Moldova the incidence of cerebral tumors in children is 1.74 – 1.9 / 100.000 and cerebellar tumors – 1.54 / 100.000. The data from specialized literature suggests that in over 50% of children diagnosed with brain tumors, the signs of IH are absent, at the beginning of the disease. In addition, IH syndrome in children with cerebral tumors is installed gradually. The most important signs of IH are: headache, visual disturbances, nausea, vomiting, further evolving towards loss of consciousness. The purpose of the study was determined by the retrospective analysis of IH signs in children who were confirmed to have cerebral tumors.
METHODOLOGY OF THE STUDY
The study included 27 children aged 0-16 (girls – 11, boys – 16) who were diagnosed with brain tumors. The diagnosis was confirmed by imaging examinations (2014-2018). The research criteria were the age of the child, as well as the early symptoms of brain tumors.
In younger children (up to 3 years): sleep disturbances, behavior disturbances (lachrymosity) and vomiting were among the first symptoms of brain tumors, and in older children (3 years and older) headaches, nausea and vomiting. Clinical manifestations were displayed in the following order (figure1):
In children with hemisphere and cerebellar vermis tumors, these symptoms were associated with other types of clinical manifestations (Figure 2).
In brain stem tumors – signs of dysfunction of the cranial nerves, and in cerebral hemispheres – convulsions, motor and sensory disorders. The most affected age – 10 and 14 years, followed by those between 5-9 years, then children aged 0-4. Through their histological affiliation, brain tumors were divided into several groups: medulloblastoma – 40%, anaplastic astrocytoma – 25%, glioblastoma –
10%, anaplastic ependymoma – 7%, other tumors – 18%. DISCUSSIONS Intracranial hypertension (IH) is a rare syndrome in children, which may be associated with headache (in older children) . In young children, the clinical symptoms of IH are obscured due to age particularities. Intracranial hypertension can cause pronounced morbidity because it is rarely encountered and practitioners can easily overlook it. To reduce the morbidity rate, early diagnosis is important and also the correct therapeutic approach of the patient, which includes: the elucidation of the etiology of IH, the confirmation of the early diagnosis and the effective management. Among the objectives proposed in the examination of the child we mention the following: headache monitoring, neurological, ophthalmological examination, examination by brain imaging and lumbar puncture.
The management of the child with IH should be coordinated with the neurologist, ophthalmologist or neuro-ophthalmologist . Intracranial pressure (IP) is the pressure in the intracranial space relative to the atmospheric pressure. IP is rarely constant and is normally subjected to substantial individual variations and physiological fluctuations, for example, posture change, strain and cough [1,2]. Also the intracranial pressure increases under the influence of different pathological mechanisms, causing IH.
The first description in literature of intracranial hypertension in 1897 belongs to Quincke, in a patient with severe meningitis. From this first publication, a myriad of terms have emerged that refer to IH: toxic hydrocephalus, otogenic hydrocephalus, cerebral pseudotumor, benign intracranial hypertension, idiopathic intracranial hypertension, pseudotumoral cerebral syndrome. Today the most commonly used terms are: pseudotumor cerebri and idiopathic intracranial hypertension. But the term cerebral pseudotumor becomes confusing when the cause of IH is established, which is why the term primary (PIH) and secondary (SIH) is preferred. The diagnosis of PIH is established when no causative agent has been established for IH and replaces the term idiopathic intracranial hypertension, pseudotumor cerebral syndrome. Risk factors for PIH are considered: female gender, postpubertal status, obesity, polycystic ovary syndrome, but these factors do not have a direct influence on IH . The term SIH refers to cases when IH results directly from other causes. The most common cause of SIH is sinus thrombosis , constitutes 11% of the etiology of SIH and can be caused by numerous pathologies, including brain tumors. Because cerebrospinal fluid is absorbed into the venous circulation, the increase in venous pressure results in decreased reabsorption, which causes increased intracranial pressure . Older studies have shown that intracranial pressure depends on the age of the child. Children up to 8 years of age have cerebrospinal fluid pressure at lumbar puncture (LP) equal to or less than 18 cmH2O, and for children over 8 years cerebrospinal fluid pressure at LP equal to or less than 25 cmH2O and is similar to adults [4, 6]. Intracranial pressure in children is traditionally divided into the prepubertal and pubertal age categories. Those who have entered or have completed puberty have the same risk factors as adults. Studies have shown a distribution of IH close to 1: 1 of female and male in prepubertal patients, compared to the 4: 1 ratio observed in adults . In 2 separate studies, obesity has not been shown to increase the risk of IH in prepubertal patients. Examination of pediatric patients in a large Intracranial Hypertension Registry (joint project of the Intracranial Hypertension Research Foundation and the Casey Eye Institute at Oregon Health & Science University; USA), found significantly higher Body Mass Index (BMI) (30.7 kg/m2 vs. 21.6 kg/m2) in postpubertal patients with IH compared to their prepubertal patients . The modified Dandy criteria that correspond to IH in adults have been reviewed and adapted to pediatric patients and to cases where papillary edema is missing by Friedman et al. . These criteria stipulate that patients have:
1. Signs and symptoms of IH (headache, nausea, vomiting, transient visual disorders, or papillary edema)
2. Focal neurologic signs, except for the bilateral or paresis of the abducens nerve
3. Cerebrospinal fluid pressure at lumbar puncture over 25 cm H2O, with a normal composition,
4. Normal or reduced size of the ventricles at brain tumors, presently at the MRI – method of selection. Lee et al. performed a separate analysis of patients diagnosed with IH in demyelinating pathologies
and found an average cerebrospinal fluid pressure at the lumbar puncture of 21.5 cm H2O, which is higher than the total population average – 20.3 cm H2O . Morgan-Followell and Aylward evaluated cohorts of patients with demyelinating conditions and IH to highlight the correlation between age and gender of patients, but found no statistically significant differences in cerebrospinal fluid pressure at lumbar puncture between the two groups . This suggests that demyelinating pathologies have high cerebrospinal fluid pressure and that including them in a normative population may falsely raise the media. Patients often have cerebrospinal fluid (CSF) pressure at the lumbar puncture well above any cut off point, and to avoid inaccurate assessment of morbidity by omitting cases, the authors prefer to use the older criteria.
Secondary IH syndrome in children may occur as an expression of an identifiable secondary cause. One of the causes of IH in children is brain and cerebellar tumors . Intracranial hypertension syndrome in brain tumors gradually settles . High intracranial hypertension manifests through headaches, vision disorders, nausea, vomiting and ultimately, loss of consciousness . Brain tumors in children are predominantly primary. The conditionality and the genetic predisposition for the development of tumors in children are confirmed, about two thirds of the tumors in children have a disontogenetic origin, being determined by the tissue defects in the organ in which the tumor develops . Cerebellar tumors constitute 59% of the structure of posterior fossa tumors in children . Among the most common cerebellar tumors in children are solid neoplasms. The most common histological entities are: pilocytic astrocytoma, medulloblastoma, ependymoma; rarer are atypical rhabdoid / teratoid tumors [17, 18].
In republic of Moldova, the incidence of brain tumors in children is 1.74 – 1.9 / 100,000, and the incidence of cerebellar tumors in children is 1.54 / 100,000 . In the differential diagnosis in the examination of children with symptoms of intracranial hypertension such as: headache, more pronounced at night or in the morning; vomiting, apathy; ataxia; nistagmul; visual disturbances; stiff neck; seizures, must be considered brain tumors .
Typical neuroimaging changes, establishment of normal cerebrospinal fluid pressure during lumbar puncture in children (up to 25 cm H2O) and criteria that differentiate intracranial hypertension without papillary edema from intracranial hypertension with papillary edema have helped to understand this disorder. IH is present in brain tumors in children. Particularities of Intracranial Hypertension in Intracerebral Tumors:
1. Low malignancy brain disorders: focal neurological syndrome dominates.
2. Highly malignant brain gliomas: intracranial hypertension syndrome occurs by compression of neighboring structures or circulatory pathways of the cerebrospinal fluid and intracranial pressure increases through tumor development.
3. Brain metastases are accompanied by major cerebral edema and IH is common.
4. Benign intracranial tumors develop slowly, IH is delayed by blocking the circulation of the cerebrospinal fluid. Cerebral and brainstem tumors often have a late and acute clinical onset [20, 21]. The cerebellum is the most common localization of tumors in CNS in children. Children are often hospitalized with acute IH symptoms, requiring urgent neurosurgical interventions. Low-grade gliomas are benign and more frequent, have a slow growth, and surgical resection is curative and sufficient. Embryonic tumors, most commonly presented with medulloblastoma, are very aggressive and treatment includes intensive post-surgical radiation and chemotherapy . Headache is a common symptom in brain tumors in children in 30-40% cases, and its aggravation indicates a change in the oncological situation and is frequently determined by cerebral edema or tumor recurrence . IP increase is characteristic of the terminal phase in patients with highly differentiated gliomas, 36–62% of patients have headache in the last week of life, consciousness disorders are present in 85–94% [24, 25, 26, 27, 28]. In over 50% of children with brain tumors the signs of intracerebral hypertension were absent [29, 30, 31, 32]. The most common symptoms and diagnostic signs of intracranial hypertension were established [29, 33]:
– for intracranial tumors – headache (33%), nausea and vomiting (32%), gait and coordination disorders (27%), papillary edema (13%);
– for intracranial tumors in children under 4 years
– macrocephaly (41%), nausea and vomiting (30%), irritability (24%), lethargy (21%);
– for posterior fossa tumors – nausea and vomiting (75%), headache (67%), gait and coordination disorders (60%), papillary edema (34%);
– for central brain tumors – headache (49%), abnormal movements of the eyeballs (21%), strabismus (21%), nausea and vomiting (19%);
– for brainstem tumors – walking and coordination disorders (78%), cranial nerve palsy (52%), pyramidal signs (33%), headache (23%), strabismus (19%).
In children with cerebellar tumors, at the onset focal neurologic signs appear: walking and coordination disorders, vertigo, muscular hypotonia, weakness in extremities, later cerebellar ataxia becomes pronounced, children are no longer able to walk, abasia, nystagmus. The normally developing child begins to lose the skills already acquired. When the cerebellar tumor compresses the liquor pathways, hydrocephalus appears [34, 35]. Management of hydrocephalus associated with posterior fossa tumors is always a difficult problem. There is no single management strategy . About 70-94% of patients with posterior fossa tumors at the time of addressing show hydrocephalus . Persistent and / or progressive hydrocephalus occurs in 10-62% of cases, despite efficient primary tumor decompression . There are two treatment methods for hydrocephalus: ventriculo-peritoneal shunt (VPS) and Endoscopic third ventriculostomy (EVT). ) .
The most appropriate time to resolve hydrocephalus remains to be determined. Treating hydrocephalus before the tumor removal intervention is associated with easier opening of the dural sac, more favorable operating conditions, reduction of postoperative liquorrhea and risk of developing pseudomeningocele . However, there is a risk of possible complications related to this primary deviation of the cerebrospinal fluid: risk of tumor bleeding and brain herniation. In cases where cerebrospinal fluid diversion follows primary surgery, the overall success rate of Endoscopic third ventriculostomy or ventriculo-peritoneal shunt is approximately 70%. . The risk of postoperative increase of intracranial pressure with the development of hydrocephalus in posterior cerebral fossa tumors is 27%, and Dr. SainteRose et al. demonstrated that it can be reduced to 6%, if the Endoscopic third ventriculostomy is used in the first stage of the intervention . CPPRH score (Canadian Preoperative Prediction Rule for Hydrocephalus) allows to calculate the risk of of development of hydrocephalus 6 months postoperatively, a negative prognosis have children under 2 years of age, cerebral metastases, moderate / severe hydrocephalus, papillary edema, preoperative estimated diagnosis of medulloblastoma, ependymoma, exophytic dorsal glioma (table I, II).
Hydrocephaly is associated with the gradual destruction of the periventricular white matter leading to a disconnection syndrome. Under immature brain conditions, hydrocephalus also interferes with developmental processes, including cell genesis and myelination . Progressive ventricular dilation, where shunt therapy with Endoscopic third ventriculostomy (EVT) or ventriculo-peritoneal shunt (VPS) is probably required, may be used to temporarily protect the brain prior to shunt. None of the non-surgical therapy has been shown to be effective in resolving hydrocephalus, despite multiple studies conducted over the past five decades . Posterior reversible encephalopathy syndrome (PRES) is a clinical-neuro-radiological entity that involves the posterior cerebral fossa, including the occipital and parietal lobes .The syndrome is characterized by headaches, altered mental status, seizures and vision disorders. Although the pathogenesis remains unclear, the cause of this syndrome may be endothelial dysfunction. In most cases, PRES is resolved spontaneously, and patients have both clinical and radiological improvement. In severe forms, PRES can even cause death, as a result of acute bleeding or massive edema of the posterior fossa causing obstructive hydrocephalus or compression of the brainstem. Early identification, active and appropriate treatment is very important. Studies have shown that prognostic value in cerebellar tumors has: tumor localization, histological classification, degree of tumor resection, and the age of the child does not influence the outcome , [45, 46].
Previously it was assumed that one of the causes of Posterior Fossa Syndrome is local postoperative cerebral edema that is maximal at two hours, but persists for three days postoperatively with the development of IH. Posterior Fossa Syndrome or its subtypes, “Cerebellar” mutism with Subsequent Dysarthria (MSD) occurs quite frequently in children after posterior fossa interventions, occurs in approximately 13% – 29% of cases. The etiology of Posterior Fossa Syndrome is largely unknown. C. Catsman-Berrevoet et al analyzing 42 cases of MSD reached the conclusion that it is installed after the removal of the medulloblastomas with a diameter of over 5 cm .
Previous studies have suggested that it may be related to transient disturbances in the cerebellum-thalamocortical pathways. The specific changes associated with Posterior Fossa Syndrome revealed in Technetium-99m-99mHMPAO SPECT brain perfusion models in previous studies could not be confirmed in a recent prospective study [48, 49]. Also, no causal link between PFS and hydrocephalus has been established. In patients with PFS there were no characteristic changes in pre- or postoperative MRI, except for lesions in the cerebellum. In contrast, at Technetium-99mHMPAO-SPECT scan in all children with Posterior Fossa Syndrome, a bilateral basal fronto-temporo-occipital cerebral hypoperfusion was observed, with a relatively less marked perfusion decrease in the fronto-parietal convexal cortex, but in children who did not develop Posterior Fossa Syndrome cerebral hypoperfusion was not registered. With PFS resolution, cerebral hypoperfusion also decreased. Hydrocephaly was not associated with PFS. . IN CONCLUSION Children have an increased risk of developing brain tumors, and about 59% are located in the cerebellum. Due to age particularities, symptoms of intracranial hypertension in children are rarely manifested, although hydrocephalus is associated with 57% of posterior fossa tumors. Intracranial pressure depends on the child’s age and is traditionally divided
into the prepubertal and pubertal age category. One of the cardinal syndromes of cerebral tumors in children is intracranial hypertension, accompanied by headaches, vomiting, nausea, visual changes, behavioral disorders, seizures, etc. In young children, IH syndrome has nonspecific manifestations, so any changes that suggest a brain injury require further examination. Ophthalmoscopy, the basic examination for intracranial hypertension identification in young children, is often not suggestive. Suspecting a cerebral volume expanding process requires examination of the child of any age by brain imaging (CT and / or MRI). Because the prognosis is directly proportional to the rate of early detection, we always have to consider central nervous system tumors in the differential diagnosis in children with headaches, vomiting, lethargy, ataxia, visual changes, seizures, torticollis, nystagmus, etc. Early detection of central nervous system tumors ensures healing in 70% of cases.
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