On the changing epidemiology of hydrocephalus

Microcirculatory Impairment and Cerebral Injury in Hydrocephalus and the Effects of Cerebrospinal Fluid Diversion

BACKGROUND AND OBJECTIVES

Hydrocephalus is characterized by progressive enlargement of cerebral ventricles, resulting in impaired microvasculature and cerebral hypoperfusion. This study aimed to demonstrate the microvascular changes in hydrocephalic rats and the effects of cerebrospinal fluid (CSF) release on cerebral blood flow (CBF).

METHODS

On postnatal day 21 (P21), male Wistar rats were intracisternally injected with either a kaolin suspension or saline. On P47, Evan's ratio (ER) was measured using MRI. On P49, the arteriolar diameter and vascular density of the pia were quantified using a capillary video microscope. The CBF was measured using laser Doppler flowmetry. The expressions of NeuN and glial fibrillary acidic protein determined by immunochemical staining were correlated with the ER. The CBF and rotarod test performance were recorded before and after CSF release. The expressions of 4-hydroxynonenal (4-HNE) and c-caspase-3 were studied on P56.

RESULTS

Ventriculomegaly was induced to varying degrees, resulting in the stretching and abnormal narrowing of pial arterioles, which regressed with increasing ER. Quantitative analysis revealed significant decreases in the arteriolar diameter and vascular density in the hydrocephalic group compared with those in the control group. In addition, the CBF in the hydrocephalic group decreased to 30%-50% of that in the control group. In hydrocephalus, the neurons appear distorted, and the expression of 4-HNE and reactive astrogliosis increase in the cortex. After CSF was released, improvements in the CBF and rotarod test performance were inversely associated with the ER. In addition, the levels of 4-HNE and c-caspase-3 were further elevated.

CONCLUSION

Rapid ventricular dilatation is associated with severe microvascular distortion, vascular regression, cortical hypoperfusion, and cellular changes that impair the recovery of CBF and motor function after CSF release. Moreover, CSF release may induce reperfusion injury. This pathophysiology should be taken into account when treating hydrocephalus.

Impact of aquaporin-4 and CD11c + microglia in the development of ependymal cells in the aqueduct: inferences to hydrocephalus

AQP4 is expressed in the endfeet membranes of subpial and perivascular astrocytes and in the ependymal cells that line the ventricular system. The sporadic appearance of obstructive congenital hydrocephalus (OCHC) has been observed in the offspring of AQP4-/- mice (KO) due to stenosis of Silvio's aqueduct. Here, we explore whether the lack of AQP4 expression leads to abnormal development of ependymal cells in the aqueduct of mice. We compared periaqueductal samples from wild-type and KO mice. The microarray-based transcriptome analysis reflected a large number of genes with differential expression (809). Gene sets (GS) associated with ependymal development, ciliary function and the immune system were specially modified qPCR confirmed reduced expression in the KO mice genes: (i) coding for transcription factors for ependymal differentiation (Rfx4 and FoxJ1), (ii) involved in the constitution of the central apparatus of the axoneme (Spag16 and Hydin), (iii) associated with ciliary assembly (Cfap43, Cfap69 and Ccdc170), and (iv) involved in intercellular junction complexes of the ependyma (Cdhr4). By contrast, genes such as Spp1, Gpnmb, Itgax, and Cd68, associated with a Cd11c-positive microglial population, were overexpressed in the KO mice. Electron microscopy and Immunofluorescence of vimentin and γ-tubulin revealed a disorganized ependyma in the KO mice, with changes in the intercellular complex union, unevenly orientated cilia, and variations in the planar cell polarity of the apical membrane. These structural alterations translate into reduced cilia beat frequency, which might alter cerebrospinal fluid movement. The presence of CD11c + microglia cells in the periaqueductal zone of mice during the first postnatal week is a novel finding. In AQP4-/- mice, these cells remain present around the aqueduct for an extended period, showing peak expression at P11. We propose that these cells play an important role in the normal development of the ependyma and that their overexpression in KO mice is crucial to reduce ependyma abnormalities that could otherwise contribute to the development of obstructive hydrocephalus.

Mortality and complications 1 year after treatment of hydrocephalus with endoscopic third ventriculostomy and ventriculoperitoneal shunt in children at Queen Elizabeth Central Hospital, Malawi

BACKGROUND

Over the past two decades, the management of hydrocephalus has witnessed the addition of endoscopic third ventriculostomy with or without choroid plexus cauterization (ETV ± CPC) to the traditional methods including ventriculoperitoneal shunt insertion (VPSI). We conducted this study to assess mortality and complications with surgical implications associated with the two procedures in children with hydrocephalus.

METHODS

We reviewed our operating theater registry to identify children below 17 years old who underwent hydrocephalus surgery for the first time in 2016. The patients were followed for up to 1 year from the date of the initial operation. Their vital status was confirmed by follow-up visits by a community nurse. Descriptive analyses were used to describe the characteristics of the patients and evaluate the study outcomes (i.e., mortality and complications).

RESULTS

One hundred fifty-three patients were eligible for the study; 56% were males and 73.2% had primary ETV ± CPC. Complete 1-year follow-up data was available for 79 patients, and 73.4% of these had ETV ± CPC. One-year success (event-free) rates for ETV and VPSI were similar at 67.4% and 66.7%, respectively. ETVs in infants under 6 months performed poorly; failing in half the infants, who were subsequently converted to VPS. Shunt sepsis was very high, 21.4% (95% CI 10.3-36.8). The majority of surgical complications (81.8%) occurred within 3 months of surgery.

CONCLUSION

ETV ± CPC and VPSI carry a similar frequency of mortality and complications in our setting, and therefore, both should be considered as a treatment option for patients with hydrocephalus. As VP shunt is still used for managing most of the patients, there is still a need to prioritize measures to reduce shunt infections.

Time to shunt failure in children with myelomeningocele: an analysis of the National Spina Bifida Patient Registry

OBJECTIVE

Hydrocephalus is common among children with myelomeningocele and is most frequently treated with a ventriculoperitoneal shunt (VPS). Although much is known about factors related to first shunt failure, relatively less data are available about shunt failures after the first one. The purpose of this study was to use a large data set to explore time from initial VPS placement to first shunt failure in children with myelomeningocele and to explore factors related to multiple shunt failures.

METHODS

Data were obtained from the National Spina Bifida Patient Registry. Children with myelomeningocele who were enrolled within the first 5 years of life and had all lifetime shunt operations recorded in the registry were included. Kaplan-Meier survival curves were constructed to evaluate time from initial shunt placement to first shunt failure. The total number of children who experienced at least 2 shunt failures was calculated. A proportional means model was performed to calculate adjusted hazard ratios (HRs) for shunt failure on the basis of sex, race/ethnicity, lesion level, and insurance status.

RESULTS

In total, 1691 children met the inclusion criteria. The median length of follow-up was 5.0 years. Fifty-five percent of patients (938 of 1691) experienced at least 1 shunt failure. The estimated median time from initial shunt placement to first failure was 2.34 years (95% confidence interval [CI] 1.91-3.08 years). Twenty-six percent of patients had at least 2 shunt failures, and 14% of patients had at least 3. Male children had higher likelihood of shunt revision (HR 1.25, 95% CI 1.09-1.44). Children of minority race/ethnicity had a lower likelihood of all shunt revisions (non-Hispanic Black children HR 0.74, 95% CI 0.55-0.98; Hispanic children HR 0.74, 95% CI 0.62-0.88; children of other ethnicities HR 0.80, 95% CI 0.62-1.03).

CONCLUSIONS

Among the children with myelomeningocele, the estimated median time to shunt failure was 2.34 years. Forty-five percent of children never had shunt failure. The observed higher likelihood of shunt revisions among males and lower likelihood among children of minority race/ethnicity illustrate a possible disparity in hydrocephalus care that warrants additional study. Overall, these results provide important information that can be used to counsel parents of children with myelomeningocele about the expected course of shunted hydrocephalus.

Full-mouth Rehabilitation of a Ventriculoperitoneal Shunt-treated Hydrocephalic Pediatric Patient: A Case Report

Hydrocephalus is characterized by accumulation of cerebrospinal fluid in the lateral ventricles of the brain, which results in progressive ventricular dilatation and an increased intracranial pressure. A ventriculoperitoneal shunt (VPS) is the most common treatment for hydrocephalus. Delayed development, behavioral disturbance, chronological changes in the eruption of their teeth, changes in the occlusion, greater accumulation of plaque, and increased caries prevalence are some of the clinical manifestations in these patients, which are encountered by a pediatric dentist. Behavioral disturbance in these patients makes sedation or general anesthesia the most feasible behavior management technique. During dental treatment of shunt-treated patients, care should be taken to avoid applying excessive force on the catheter. A referral to a neurosurgeon is recommended for patients with shunts undergoing invasive dental procedures for assessment of the need for prophylactic antibiotics. The present case report discusses full-mouth rehabilitation of a pediatric patient under general anesthesia who presented with severe early childhood caries and a medical history of ventriculoperitoneal shunt-treated hydrocephalus.

How to cite this article: Poonia A, Chengappa MMD, Mitra R, et al. Full-mouth Rehabilitation of a Ventriculoperitoneal Shunt-treated Hydrocephalic Pediatric Patient: A Case Report. Int J Clin Pediatr Dent 2020;13(1):103–106.

Current Management Strategies of Hydrocephalus in the Child With Open Spina Bifida

Symptomatic hydrocephalus is a common condition associated with myelomeningocele (open spina bifida). Traditionally, hydrocephalus was treated with insertion of a ventriculo-peritoneal (VP) shunt. This has been the standard of treatment since the introduction of the Holter shunt valve for the VP shunt in the late 1950s. Now there are other treatments that offer alternatives to VP shunt diversion for hydrocephalus. This article is a review of hydrocephalus associated with myelomeningocele and its treatment options. Treatment in the form of a VP shunt, endoscopic third ventriculostomy (ETV), and conservative management are discussed.

Cerebrospinal fluid circulation and hydrocephalus

Hydrocephalus (HC) is classically defined as dynamic imbalance between the production and absorption of cerebrospinal fluid (CSF) leading to enlarged ventricles. Potential causative factors include various brain disorders like tumors causing obstruction of CSF flow within the ventricular system or the subarachnoid space. Classification of HC is based on the site of CSF flow obstruction guiding optimal treatment, with endoscopic third ventriculostomy in intraventricular obstruction and CSF shunt in communicating HC. Another clinically relevant classification is acute and chronic; the most frequent chronic form is idiopathic normal-pressure hydrocephalus (iNPH). The reported incidence of HC varies according to the study population and classification used. The incidence of congenital HC is approximately 0.4-0.6/1,000 newborns and the annual incidence of iNPH varies from 0.5/100,000 to 5.5/100,000. Radiologically, ventricular dilatation may be nonspecific, and differentiation of iNPH from other neurodegenerative diseases may be ambiguous. There are no known specific microscopic findings of HC but a systematic neuropathologic examination is needed to detect comorbid diseases and possible etiologic factors of HC. Depending on the etiology of HC, there are several nonspecific signs potentially to be seen.

Epidemiology of adult-onset hydrocephalus: institutional experience with 2001 patients

OBJECTIVE Adult-onset hydrocephalus is not commonly discussed in the literature, especially regarding its demographic distribution. In contrast to pediatric hydrocephalus, which is related to a primary CSF pathway defect, its development in adults is often secondary to other pathologies. In this study, the authors investigated the epidemiology of adult-onset hydrocephalus as it pertains to different etiologies and in reference to age, sex, and race distributions. METHODS The authors retrospectively reviewed the clinical notes of 2001 patients with adult-onset hydrocephalus who presented to Louisiana State University Health Sciences Center within a 25-year span. Significant differences between the groups were analyzed by a chi-square test; p < 0.05 was considered significant. RESULTS The overall mean (± SEM) incidence of adult hydrocephalus in this population was 77 ± 30 per year, with a significant increase in incidence in the past decade (55 ± 3 [1990-2003] vs 102 ± 6 [2004-2015]; p < 0.0001). Hydrocephalus in a majority of the patients had a vascular etiology (45.5%) or was a result of a tumor (30.2%). The incidence of hydrocephalus in different age groups varied according to various pathologies. The incidence was significantly higher in males with normal-pressure hydrocephalus (p = 0.03) or head injury (p = 0.01) and higher in females with pseudotumor cerebri (p < 0.0001). In addition, the overall incidence of hydrocephalus was significantly higher in Caucasian patients (p = 0.0002) than in those of any other race. CONCLUSIONS Knowledge of the demographic variations in adult-onset hydrocephalus is helpful in achieving better risk stratification and better managing the disease in patients. For general applicability, these results should be validated in a large-scale meta-analysis based on a national population database.

Hydrocephalus compacted cortex and hippocampus and altered their output neurons in association with spatial learning and memory deficits in rats

Hydrocephalus is a common neurological disorder in children characterized by abnormal dilation of cerebral ventricles as a result of the impairment of cerebrospinal fluid flow or absorption. Clinical presentation of hydrocephalus varies with chronicity and often shows cognitive dysfunction. Here we used a kaolin-induction method in rats and studied the effects of hydrocephalus on cerebral cortex and hippocampus, the two regions highly related to cognition. Hydrocephalus impaired rats' performance in Morris water maze task. Serial three-dimensional reconstruction from sections of the whole brain freshly froze in situ with skull shows that the volumes of both structures were reduced. Morphologically, pyramidal neurons of the somatosensory cortex and hippocampus appear to be distorted. Intracellular dye injection and subsequent three-dimensional reconstruction and analyses revealed that the dendritic arbors of layer III and V cortical pyramid neurons were reduced. The total dendritic length of CA1, but not CA3, pyramidal neurons was also reduced. Dendritic spine densities on both cortical and hippocampal pyramidal neurons were decreased, consistent with our concomitant findings that the expressions of both synaptophysin and postsynaptic density protein 95 were reduced. These cortical and hippocampal changes suggest reductions of excitatory connectivity, which could underlie the learning and memory deficits in hydrocephalus.

Two Hundred Thirty-Six Children With Developmental Hydrocephalus: Causes and Clinical Consequences

Few systematic assessments of developmental forms of hydrocephalus exist. We reviewed magnetic resonance images (MRIs) and clinical records of patients with infancy-onset hydrocephalus. Among 411 infants, 236 had hydrocephalus with no recognizable extrinsic cause. These children were assigned to 1 of 5 subtypes and compared on the basis of clinical characteristics and developmental and surgical outcomes. At an average age of 5.3 years, 72% of children were walking independently and 87% could eat by mouth; in addition, 18% had epilepsy. Distinct patterns of associated malformations and syndromes were observed within each subtype. On average, children with aqueductal obstruction, cysts, and encephaloceles had worse clinical outcomes than those with other forms of developmental hydrocephalus. Overall, 53% of surgically treated patients experienced at least 1 shunt failure, but hydrocephalus associated with posterior fossa crowding required fewer shunt revisions. We conclude that each subtype of developmental hydrocephalus is associated with distinct clinical characteristics, syndromology, and outcomes, suggesting differences in underlying mechanisms.

Shunt malfunction mimicking a cystic tumour

Shunt malfunction represents one of the most common problem to deal with in the daily neurosurgical practice. Among the variety of possible presentations, the cyst-like dilatation of the brain around the proximal catheter is one of the most rare and misleading type. The case of a boy with a 'tumour-like' proximal shunt malfunction is described and the pertinent literature is analysed.

Infantile hydrocephalus: a review of epidemiology, classification and causes

Hydrocephalus is a common but complex condition caused by physical or functional obstruction of CSF flow that leads to progressive ventricular dilatation. Though hydrocephalus was recently estimated to affect 1.1 in 1000 infants, there have been few systematic assessments of the causes of hydrocephalus in this age group, which makes it a challenging condition to approach as a scientist or as a clinician. Here, we review contemporary literature on the epidemiology, classification and pathogenesis of infantile hydrocephalus. We describe the major environmental and genetic causes of hydrocephalus, with the goal of providing a framework to assess infants with hydrocephalus and guide future research.

Congenital hydrocephalus in the northeast of Brazil: epidemiological aspects, prenatal diagnosis, and treatment

PURPOSE

Congenital hydrocephalus (CH) has higher proportions in developing countries such as Brazil, reaching rates of 3.16:1,000 newborns. Early diagnosis is essential and can be done during the second trimester of pregnancy, highlighting the importance of regular prenatal care. Our objective is to describe the epidemiological profile of children with CH in the state of Bahia.

METHODS

Consecutive medical records of patients with CH, aged less than 2 years and operated at a pediatric reference hospital between September 2009 and September 2012, were reviewed.

RESULTS

One hundred twenty-one children underwent ventricular peritoneal shunt (VP shunt) due to CH. As for prenatal care, 38% of pregnant women did it regularly. Males predominated with 56% of cases with a median age of 3 months, and 68% were from the countryside area. The most frequent clinical manifestations were bulging fontanelle (37%) and increased head circumference (30%). There were 13 (11%) reports of complications associated with VP shunts. There were nine deaths (7%), and respiratory complications were the main cause.

CONCLUSIONS

Public health measures are the key to increase mothers' knowledge about the importance of regular prenatal monitoring. There was a predominance of male children, with a median age of 3 months, with the majority coming from the countryside.

Myelomeningocele: the management of the associated hydrocephalus

BACKGROUND

The pathogenesis of the hydrocephalus associated with myelomeningocele (MMC) has been the subject of an extensive number of studies. The contemporary reduction of the incidence of the Chiari II malformation and of the associated active hydrocephalus after closure of the spinal defect in utero is in line with previous studies suggesting a prominent role of the posterior cranial fossa abnormalities, where even the increased venous pressure might be at least mostly a consequence of the constriction of the posterior cranial fossa structures. Pure absorptive abnormalities however coexist, the main ones documented to be abnormal cisternal spaces and peculiar cerebrospinal fluid chemical features.

MATERIALS AND METHODS

We reviewed the pertinent literature concerning the pathogenesis and management of the hydrocephalus associated to MMC. We also reviewed our personal experience in managing the hydrocephalus in such patients through an endoscopic third ventriculostomy.

RESULTS AND CONCLUSIONS

The literature review demonstrated an overall reduction in more recent series of children with MMC needing to be treated for the associated hydrocephalus postnatally, questioning the role of the prenatal care of the disease in this context. Less severe conditions and a more conservative neurosurgical attitude have certainly contributed to the reduction of the reported active postnatal hydrocephalus rate. Long-term cognitive evaluation of the children with MMC that we managed with an endoscopic third ventriculocisternostomy (ETV) as primary as well as secondary procedure did not demonstrate significant differences in the outcome compared with non-complicated extrathecally shunted children, favouring ETV as a valuable option in this subset of patients.

Time trends and age-related etiologies of pediatric hydrocephalus: results of a groupwise analysis in a clinical cohort

OBJECTIVE

The current study aimed at evaluating experience with pediatric hydrocephalus and reviewing time trends and age-related differences in etiology, management, and outcomes of pediatric hydrocephalus at a tertiary care center in a south Asian country.

METHODS

We conducted a retrospective cohort study based on case note review of pediatric patients (age, 1 month to 15 years) with hydrocephalus managed at Aga Khan University Hospital Karachi, over an 18-year period (1988-2005). For analysis, the study period was divided into two epochs (period A, 1988-1996; period B, 1997-2005) and study population was divided into two age groups (0-12 months and 1-15 years).

RESULTS

A total of 338 cases of pediatric hydrocephalus were identified. Most common etiology of pediatric hydrocephalus was meningitis (38.1%), followed by congenital hydrocephalus (20.4%) and brain tumors (8.3%). Shunt infection and blockage were seen in 38 (11.2%) and 54 (16.0%) children, respectively; 67 (19.8%) required shunt revision. Highest rates of shunt failure were seen in bacterial meningitis (35.3%) and aqueductal stenosis (29.2%). Neurological and/or cognitive deficits were observed more frequently in children under 1 year of age (P = 0.029). Duration of hospital stay in period A was significantly higher than in period B (P < 0.001). Mortality occurred in 38 (11.2%); it did not differ between two epochs and age groups (P = 0.059 and P = 0.865, respectively). Highest mortality was associated with intraventricular hemorrhage (23.1%) and brain tumors (21.4%).

CONCLUSION

Despite recent advancements, hydrocephalus is still associated with high rate of shunt failure and mortality. Factors associated with poor outcome include younger age group and etiology of hydrocephalus.

Evaluation of the ShuntCheck Noninvasive Thermal Technique for Shunt Flow Detection in Hydrocephalic Patients

BACKGROUND:

ShuntCheck (Neuro Diagnostic Devices, Inc., Trevose, Pennsylvania) is a new device designed to detect cerebrospinal fluid (CSF) flow in a shunt by sensing skin temperature downstream from a region of CSF cooled by an ice cube.

OBJECTIVE:

To understand its accuracy and utility, we evaluated the use of this device during routine office visits as well as during workup for suspected shunt malfunction.

METHODS:

One hundred shunted patients were tested, including 48 evaluated during possible shunt malfunction, of whom 24 went on to surgical exploration. Digitally recorded data were blindly analyzed and compared with surgical findings and clinical follow-up.

RESULTS:

Findings in the 20 malfunctioning shunts with unambiguous flow or absence of flow at surgery were strongly correlated with ShuntCheck results (sensitivity and specificity to flow of 80% and 100%, respectively, P = .0007, Fisher's exact test, measure of agreement κ = 0.8). However, the thermal determination did not distinguish patients in the suspected malfunction group who received surgery from those who were discharged without surgery (P = .248 by Fisher's exact test, κ = 0.20). Half of the patients seen in routine office visits did not have detectable flow, although none required shunt revision on clinical grounds. Intermittent flow was specifically demonstrated in one subject who had multiple flow determinations.

CONCLUSION:

Operative findings show that the technique is sensitive and specific for detecting flow, but failure to detect flow does not statistically predict the need for surgery. A better understanding of the normal dynamics of flow in individual patients, which this device may yield, will be necessary before the true clinical utility of non-invasive flow measurement can be assessed.

Characteristics of individuals with hydrocephalus and their dental care needs

Hydrocephalus is considered a congenital disease affecting the central nervous system, and is characterized by accumulation of cerebrospinal fluid in the lateral ventricles of the brain causing progressive ventricular dilatation. This review paper reports on the oral characteristics of persons with hydrocephalus and discusses their dental care needs. It has been reported that patients with hydrocephalus can present chronological changes in the eruption of their teeth, changes in the occlusion, greater accumulation of plaque, and have a higher caries prevalence. Regular dental visits are needed to control caries as well as to educate the caretakers about oral hygiene for children with hydrocephalus. In addition, the dental practitioner should be careful not to put pressure on the ventricular-peritoneal drainage tube during dental treatment. Special devices are available to support the patient's head if they have macrocephally.