Language outcomes in children who underwent surgery for the removal of a posterior fossa tumor: A systematic review

BACKGROUND

Children who underwent posterior fossa tumor removal may have spoken or written language impairments. The present systematic review synthesized the literature regarding the language outcomes in this population. Benefits of this work were the identification of shortcomings in the literature and a starting point toward formulating guidelines for postoperative language assessment.

METHODS

A systematic literature search was conducted, identifying studies with patients who had posterior fossa surgery before 18 years of age. Included studies were narratively synthesized to understand language outcomes by language function (e.g., phonology, morphosyntax) at a group and individual level. Furthermore, the influence of several mediators (e.g., postoperative cerebellar mutism syndrome (pCMS), tumor type) was investigated. A critical evaluation of the language assessment tools was conducted.

RESULTS

The narrative synthesis of 66 studies showed that a broad spectrum of language impairments has been described, characterized by a large interindividual heterogeneity. Patients younger at diagnosis, receiving treatment for a high-grade tumor and/or radiotherapy and diagnosed with pCMS seemed more prone to impairment. Several gaps in language assessment remain, such as a baseline preoperative assessment and the assessment of pragmatics and morphosyntax. Further, there were important methodological differences in existing studies which complicated our ability to accurately guide clinical practice.

CONCLUSION

Children who had posterior fossa surgery seem to be at risk for postoperative language impairment. These results stress the need for language follow-up in posterior fossa tumor survivors.

The tilts, twists, and turns of torticollis

PURPOSE OF REVIEW

The purpose of this review is to outline the most recent understanding of torticollis in the pediatric population.

RECENT FINDINGS

It is important to diagnose the underlying condition of torticollis early in childhood, as some conditions that cause torticollis may result in major developmental delays in early motor milestones. Recent studies have highlighted that many of the rarer causes of torticollis are often misdiagnosed as congenital muscular torticollis, suggesting that physicians should pay close attention to the results of clinical and radiographic examinations when patients present with torticollis.

SUMMARY

Congenital muscular torticollis is the most common cause of torticollis. Other, less common causes of torticollis include vertebral abnormalities, ocular torticollis, gastrointestinal disorders, soft tissue infections of the neck, posterior fossa tumors, and benign paroxysmal torticollis. Although rare, these differential diagnoses should be considered during a clinical work-up for a patient who presents with torticollis.

Machine Learning in the Classification of Pediatric Posterior Fossa Tumors: A Systematic Review

Background: Posterior fossa tumors (PFTs) are a morbid group of central nervous system tumors that most often present in childhood. While early diagnosis is critical to drive appropriate treatment, definitive diagnosis is currently only achievable through invasive tissue collection and histopathological analyses. Machine learning has been investigated as an alternative means of diagnosis. In this systematic review and meta-analysis, we evaluated the primary literature to identify all machine learning algorithms developed to classify and diagnose pediatric PFTs using imaging or molecular data. Methods: Of the 433 primary papers identified in PubMed, EMBASE, and Web of Science, 25 ultimately met the inclusion criteria. The included papers were extracted for algorithm architecture, study parameters, performance, strengths, and limitations. Results: The algorithms exhibited variable performance based on sample size, classifier(s) used, and individual tumor types being investigated. Ependymoma, medulloblastoma, and pilocytic astrocytoma were the most studied tumors with algorithm accuracies ranging from 37.5% to 94.5%. A minority of studies compared the developed algorithm to a trained neuroradiologist, with three imaging-based algorithms yielding superior performance. Common algorithm and study limitations included small sample sizes, uneven representation of individual tumor types, inconsistent performance reporting, and a lack of application in the clinical environment. Conclusions: Artificial intelligence has the potential to improve the speed and accuracy of diagnosis in this field if the right algorithm is applied to the right scenario. Work is needed to standardize outcome reporting and facilitate additional trials to allow for clinical uptake.

Radiomics and radiogenomics in pediatric neuro-oncology: A review

The current era of advanced computing has allowed for the development and implementation of the field of radiomics. In pediatric neuro-oncology, radiomics has been applied in determination of tumor histology, identification of disseminated disease, prognostication, and molecular classification of tumors (ie, radiogenomics). The field also comes with many challenges, such as limitations in study sample sizes, class imbalance, generalizability of the methods, and data harmonization across imaging centers. The aim of this review paper is twofold: first, to summarize existing literature in radiomics of pediatric neuro-oncology; second, to distill the themes and challenges of the field and discuss future directions in both a clinical and technical context.

Facing CAR T Cell Challenges on the Deadliest Paediatric Brain Tumours

Central nervous system (CNS) tumours comprise 25% of the paediatric cancer diagnoses and are the leading cause of cancer-related death in children. Current treatments for paediatric CNS tumours are far from optimal and fail for those that relapsed or are refractory to treatment. Besides, long-term sequelae in the developing brain make it mandatory to find new innovative approaches. Chimeric antigen receptor T cell (CAR T) therapy has increased survival in patients with B-cell malignancies, but the intrinsic biological characteristics of CNS tumours hamper their success. The location, heterogeneous antigen expression, limited infiltration of T cells into the tumour, the selective trafficking provided by the blood-brain barrier, and the immunosuppressive tumour microenvironment have emerged as the main hurdles that need to be overcome for the success of CAR T cell therapy. In this review, we will focus mainly on the characteristics of the deadliest high-grade CNS paediatric tumours (medulloblastoma, ependymoma, and high-grade gliomas) and the potential of CAR T cell therapy to increase survival and patients' quality of life.

Risk factors for surgical site infection in pediatric posterior fossa tumors

PURPOSE

Posterior fossa tumors are the most frequent pediatric solid tumor. Its main treatment is a surgical resection. Being a frequent procedure does not mean that it is exempt from complications, such as surgical site infections (SSI). The main objective of this paper is to study the risk factors associated with SSI following a resection of posterior fossa tumors in a purely pediatric population.

METHODS

A retrospective case-control study including all posterior fossa tumor surgeries performed at our hospital between January 2014 and December 2019 was conducted. All patients with a diagnosis of a postoperative SSI have been included as cases, and those who had surgery and no infectious complications have been considered as controls.

RESULTS

When analyzing risk factors, we have found that patients with ventriculoperitoneal shunt (VPS) (p = 0.03) or external ventricular drainage (EVD) (p = 0.005) placement had a greater chance of presenting a postoperative surgical site infection. Prolonged operative time (p < 0.001) and cerebrospinal fluid (CSF) leak through the wound (p = 0.002) also caused an increase in the risk of SSI in the postoperative period. A higher hemoglobin value (p = 0.002) would seem to be a preventive factor.

CONCLUSIONS

Some strategies that could help to reduce the risk of infections are managing hydrocephalus preferably with endoscopic third ventriculostomy, minimizing the needed operative time to perform the procedure, obtaining an adequate serum hemoglobin level, and avoiding CSF leak through the wound.

Cerebellar Mutism Syndrome: An Overview of the Pathophysiology in Relation to the Cerebrocerebellar Anatomy, Risk Factors, Potential Treatments, and Outcomes

Cerebellar mutism syndrome (CMS) is one the most disabling postoperative neurological complications after posterior fossa surgery in children. CMS is characterized by a transient mutism with a typical onset demonstrated within 2 days postoperatively accompanied by associated ataxia, hypotonia, and irritability. Several hypotheses for the anatomical basis of pathophysiology and risk factors have been suggested. However, a definitive theory and treatment protocols have not yet been determined. Animal histological and electrophysiological studies and more recent human imaging studies have demonstrated the existence of a compartmentalized representation of cerebellar function, the understanding of which might provide more information on the pathophysiology. Damage to the dentatothalamocortical pathway and cerebrocerebellar diaschisis have been described as the anatomical substrate to the CMS. The risk factors, which include tumor type, brainstem invasion, tumor localization, tumor size, and vermal splitting technique, have not yet been clearly elucidated. The efficacy of potential pharmacological and speech therapies has been studied in small trials. Long-term motor speech deficits and associated cognitive and behavioral disturbances have now been found to be common among CMS survivors, affecting their development and requiring rehabilitation, leading to significant financial effects on the healthcare system and distress to the family. The aim of the present review was to outline the cerebellar anatomy and function and its connections in relationship to the pathophysiology and to refine the risk factors and treatment strategies for CMS.

Surgical management of posterior fossa medulloblastoma in children: The Lyon experience

INTRODUCTION

Modern approach for the treatment of posterior fossa medulloblastomas remains a challenge for pediatric neurosurgeons and pediatric oncologists and requires a multidisciplinary approach to optimize survival and clinical results.

MATERIAL AND METHODS

We report the surgical principles of the treatment of posterior fossa medulloblastomas in children and how to avoid technical mistakes especially in very young patients. We also report our experience in a series of 64 patients operated from a medulloblastoma between 2000 and 2018 in Lyon.

RESULTS

All patients had a craniospinal MRI. Eighty-one percent of the patients (n=50) had strictly midline tumor while 19% (n=14) had lateralized one. Eleven percent (n=7) had metastasis at diagnosis on the initial MRI. Forty-one percent (n=29) had an emergency ETV to treat hydrocephaly and the intracranial hypertension. All patient underwent a direct approach and a complete removal was achieved in 78% (n=58) of the cases on the postoperative MRI realized within 48h postsurgery. Histological findings revealed classical medulloblastoma in 73% (n=46), desmoplastic medulloblastoma in 17% (n=11) and anaplastic/large cell medulloblastoma in 10% (n=7). Patients were classified as low risk in 7 cases, standard risk in 30 cases and high risk in 27 cases. Ninety-six percent (n=61) of the patient received radiotherapy. Seventy-six percent (n=48) received pre-irradiation or adjuvant chemotherapy. At last follow-up in December 2018, 65% (n=41) of the patient were in complete remission, 12% (n=8) were in relapse and 27% (n=15) had died from their disease. The overall survival at five , ten and fifteen years for all the series was of 76%, 73% and 65.7% respectively.

CONCLUSIONS

Medulloblastomas remain a chimiosensible and radiosensible disease and the complete surgical removal represents a favorable prognostic factor. The extension of surgery has also to be weighted in consideration of the new biomolecular and genetic knowledge that have to be integrated by surgeons to improve quality of life of patients.

Paediatric posterior fossa tumour resection rates in a small volume centre: the past decade's experience

BACKGROUND

Paediatric brain tumour resection rates have been shown to correlate with outcome and, it is argued, are linked to operator volume and caseload. The British paediatric neurosurgery community has previously debated centralisation of paediatric neuro-oncology. At the 2018 British Paediatric Neurosurgery Group (BPNG) meeting, a commitment was made to prospectively collect tumour resection data at each Neurosurgical Unit (NSU). Here we review our prospectively-collected 10-year database of the three commonest paediatric posterior fossa tumours - astrocytomas, medulloblastomas and ependymomas.

MATERIALS AND METHODS

Our primary outcome was extent of resection (EOR) on post-operative MRI scans reviewed by neuro-radiologists. Secondary outcomes comprised neurosurgical morbidity including infection, need for cerebrospinal fluid (CSF) diversion and the occurrence of posterior fossa syndrome (PFS).

RESULTS

55 children had 62 operations, where our complete resection rates for pilocytic astrocytomas, medulloblastomas and ependymomas were 77%, 79% and 63%, respectively. Both our primary and secondary outcomes were in keeping with the published literature and we discuss here some of the factors which may contribute towards favourable outcomes in a small volume centre.

CONCLUSION

Our results suggest that small volume centres can expect equivalent results to larger volume NSUs with regards to paediatric brain tumour surgery. Continuing efforts nationally for data collection on resection rates and operative outcomes is a key step towards optimising management in these children.

The Satisfactory Surgical Outcome of Posterior Fossa Brain Tumors in Children at Civil Hospital, Karachi

Introduction:

Posterior fossa brain tumor is the most devastating forms of human illness, primarily because of the limited space within the posterior fossa, the potential involvement of vital brain stem nuclei, and the mass effect causes obstructive hydrocephalus. Posterior fossa tumors are more common in children than adults.

The Objective of the Study:

To find out the satisfactory surgical outcome of posterior fossa brain tumors in children at Civil hospital, Karachi.

Materials and Methods and Duration of Study Setting:

This prospective observational, case series study was conducted from February 2015 to February 2105 in the Department of neurosurgery, Dow University of Health Sciences, Civil Hospital, Karachi, Karachi. Postoperative patients with the diagnosis of posterior fossa tumor were enrolled in the study. Detailed history, physical examination, anthropometrics, and biochemical measurements were recorded. Magnetic resonance imaging was done to determine the satisfactory surgical outcome. Patients were followed up at the third postoperative month to determine the satisfactory surgical outcome.

Results:

Seventy-one patients fulfilling the inclusion criteria, the mean ± standard deviation age of the study population was 6.63 ± 3.181 years. 29 (40.8%) were <7 years of age and 42 (59.2%) were of age 7 years and above. 50 (70.4%) were males and 21 (29.6%) were females. 49 (69%) patients presented with vomiting. 34 (47.9%) presented with seizures. (40.8%) had papilledema. (25.4%) presented with hemiparesis. 8 (11.3%) had meningismus. On analysis of the frequency of outcome variables (80.3%) achieved the satisfactory surgical outcome.

Conclusions:

There has been no major study to determine satisfactory surgical outcome in postoperative patients with posterior fossa brain tumor in our population. The study was to provide local data in our population and compare it to the international data. This may help in proper patient management. Majority of the patients had satisfactory surgical outcome. The absence of papilledema, hemiparesis, and meningismus had more chances of satisfactory surgical outcome.

Medulloblastoma: Distinctive Histo-Molecular Correlation with Clinical Profile, Radiologic Characteristics, and Surgical Outcome

OBJECTIVE

Medulloblastoma (MB) is a heterogenous tumor, and the prognosis is influenced by various clinical, histological, and molecular factors. The aim of the study is to determine the clinical profile and radiologic characteristics among the histo-molecular subgroups, the predictors of surgical outcome, and the pattern of relapse in pediatric and adult MB.

METHOD

An analysis of 118 patients of MB who underwent surgical treatment at National Institute of Mental Health and Neurosciences, India, over a 7-year period (2005-2011) is presented. The clinical profile, radiologic characteristics, surgical nuances, and survival patterns are discussed. The relevant statistical analysis was done using SPSS software, version 22.0.

RESULTS

The mean age of the cohort was 12 years (12.3 ± 8.7). The primary manifestation was raised intracranial tension headache in 53 patients (44.9%), which was the predominant symptom in large cell/anaplastic (LCA)- and WNT-activated subgroups. The median preoperative Karnofsky performance score was 60 (60.6 ± 12.9). Vermian and hemispheric location of tumor was most commonly observed in non-WNT/non-SHH (groups 3 and 4; 91.7%) and SHH-activated (42.9%) subgroups, respectively. Ninety-two patients (78%) underwent preoperative ventriculoperitoneal shunts (VPS) for obstructive hydrocephalus (HCP) and 14 patients (11.8%) underwent VPS in the postoperative period. The median overall survival (OS) for the whole group was 82.1 ± 5.7 months and the median recurrence-free survival was 51.0 ± 4.8 months. While radiotherapy had a significant influence on OS, progression-free survival was influenced by radiotherapy as well as chemotherapy in both pediatric and adult cohort. Desmoplastic/nodular subtype and WNT-activated subgroup had the best prognosis; LCA and non-WNT/non-SHH had the worst prognosis.

CONCLUSIONS

Majority of the patients were pediatric in the study. Age, hemispheric location of tumor, extent of resection, and adjuvant treatment status were the important clinical prognostic factors for survival. Surgery for MB is formidable, and VPS can be considered in persistent symptomatic and progressive HCP. Our study on pediatric and adult MB validates the prognostic significance of various clinical, radiologic, and histo-molecular parameters of MB.

Ewing sarcoma of the posterior fossa in an adolescent girl

Medulloblastoma, astrocytoma, and ependymoma represent the most common infratentorial tumors in childhood, while Ewing sarcomas in that localization are extremely rare. A large left infratentorial space-occupying lesion was diagnosed in a 12-year-old girl with signs of increased intracranial pressure. Following total tumor resection, histological and molecular examination revealed Ewing sarcoma with rearranged EWSR-1 gene. The patient achieved complete remission following adjuvant chemotherapy and radiotherapy according to Euro-EWING 2008 treatment protocol. Intracranial Ewing sarcoma, although rare, should be an important differential diagnosis of intracranial tumors in childhood which requires aggressive multimodal treatment.

External drainage with an Ommaya reservoir for perioperative hydrocephalus in children with posterior fossa tumors

PURPOSE

This study aims to evaluate an external drainage using an Ommaya reservoir for relieving perioperative hydrocephalus and reducing postoperative complications in children with posterior fossa tumors.

METHODS

We retrospectively analyzed the data from 48 children with posterior fossa tumors who underwent tumor resection between May 2006 and June 2012. An Ommaya reservoir was placed in the right lateral ventricle forehead for continuous perioperative drainage of cerebrospinal fluid (CSF).

RESULTS

Tumors were successfully removed from all patients. Intracranial infection occurred in nine patients and was controlled by antibiotic treatment. Preoperative obstruction and obstructive hydrocephalus were relieved, and the need for a shunt or endoscopic third ventriculostomy was avoided. One patient who underwent a second surgical procedure had intracranial infection, hydrocephalus, and occipital pseudomeningocele. After continuous drainage and anti-infective treatment, hydrocephalus and intracranial infection were effectively controlled.

CONCLUSIONS

Using an Ommaya reservoir for perioperative external ventricular CSF drainage enabled tumors to be wholly and safely removed. Restoring CSF circulation provided an effective means of controlling and preventing hydrocephalus secondary to posterior fossa tumors in children.

Classification of single-voxel 1H spectra of childhood cerebellar tumors using LCModel and whole tissue representations

In this study, mean tumor spectra are used as the basis functions in LCModel to create a direct classification tool for short echo time (1)H magnetic resonance spectroscopy of pediatric brain tumors. LCModel is a widely used analysis tool designed to fit a linear combination of individual metabolite spectra to in vivo spectra. Here, we have used LCModel to fit mean spectra and corresponding variability components of childhood cerebellar tumors, as calculated using principal component analysis, and assessed for classification accuracy. Classification was performed according to the highest estimated tumor proportion. This method was tested in a leave-one-out analysis discriminating between pediatric brain tumor spectra of medulloblastoma vs. pilocytic astrocytoma and medulloblastoma vs. pilocytic astrocytoma vs. ependymoma. Additionally, the effect of accepting different Cramér-Rao Lower Bound cut-off criteria on classification accuracy and estimated tissue proportions was investigated. The best classification results differentiating medulloblastoma vs. pilocytic astrocytoma and medulloblastoma vs. pilocytic astrocytoma vs. ependymoma were 100 and 87.7%, respectively. These results are comparable to a specialized pattern recognition analysis of this data set and give easy to interpret results in the form of estimated tissue proportions. The method requires minimal user input and is easily transferable across sites and to other magnetic resonance spectroscopy classification problems.

Executive dysfunction in pediatric posterior fossa tumor survivors: a systematic literature review of neurocognitive deficits and interventions

Improved medical therapies have increased survivorship rates for children with posterior fossa tumors; resultantly, morbidities associated with survivorship, such as executive function deficits, have become increasingly important to identify and address. Executive dysfunction can impact academic achievement as well as functional outcomes. We summarize studies describing executive functioning deficits in pediatric posterior fossa tumor survivors who received cranial radiation therapy and intervention studies that have targeted executive functioning deficits. Previous theoretical models describing the etiology of these deficits are reviewed, and a new, more comprehensive model is proposed. Future research should move toward incorporating neuroimaging, longitudinal designs, and multiple informants.

Medulloblastoma in childhood-King Edward Memorial hospital surgical experience and review: Comparative analysis of the case series of 365 patients

AIM

Medulloblastoma is one of the most common posterior fossa tumors in childhood. The treatment-related side effects as well as predictive outcome still remain as a major challenge. The improved understanding of the disease and advances in molecular biology is changing the treatment paradigms from Chang's staging system to molecular risk stratification. However, surgery still remains as an important mainstay of therapy and is formidable. The role of radical surgery has always been a crucial factor in the outcome of these patients, the best survival being reported in patients who had total excision of the tumor and with no metastasis.

PATIENT AND METHODS

An analysis of 365 patients (age<18 years) of medulloblastoma who underwent treatment at the Seth G.S. Medical College and King Edward VII Memorial hospital (KEM), Mumbai over a 25- year period (1985-2000 and 2001-2010) is presented. The clinical profile, radiological features, pathology and surgical nuances are discussed.

RESULTS

The most common age group affected was between 3 and 12 years. 75.3% presented with headaches, vomiting and 63.2% with papilledema. Sitting position was used in majority of cases. A total of 8 patients underwent shunting; all of them were in the postoperative period (5.19%). 92.2% (142 cases) had classical medulloblastoma, 5.1% (8 cases) had desmoplastic variant, 1.9% (3 cases) had anaplastic changes and 0.6% (1 case) had glial differentiation. The 5-year and 10-year progression free survival rate was 73 and 41% for average risk disease while for high risk disease rate it was 34%. The mortality rate was 2%. The quality of life was enhanced in patients who survived 5-10 years after treatment.

CONCLUSION

Surgery for medulloblastoma is formidable. The option of sitting position for medulloblastoma surgery is still viable. A vigilant neuroanesthesiologist and a safe surgery are necessary to achieve a good postoperative result. Radiological characteristics are helpful adjuncts for determining effective surgical strategy. Permanent CSF drainage can be avoided in majority of patients and can be definitively considered in progressive symptomatic hydrocephalus. A safe maximal resection and a good Karnofsky score are paramount to ensure compliance with adjuvant therapy and contribute to an overall survival advantage.