Neuropsychological sequelae and quality of life following treatment of posterior fossa ependymomas in children

Predicting cerebellar mutism syndrome in children using lesion map combined with clinical features

OBJECTIVE

This study aimed to develop a predictive model for cerebellar mutism syndrome (CMS) in pediatric patients with posterior fossa tumors, integrating lesion-symptom mapping (LSM) data with clinical factors, and to assess the model's performance.

METHODS

A cohort of pediatric patients diagnosed with posterior fossa tumors and undergoing surgery at Beijing Children's Hospital from July 2013 to December 2023 was analyzed. Clinical variables gender, age at surgery, tumor characteristics, hydrocephalus, surgical route and pathology were collected. LSM was used to link tumor locations with CMS outcomes. Lasso regression and logistic regression were employed for feature selection and model construction, respectively. Model performance was assessed using area under the curve (AUC) and accuracy metrics.

RESULTS

The study included 197 patients in total, with CMS rates consistent across training, validation, and prospective groups. Significant associations were found between CMS and gender, tumor type, hydrocephalus, paraventricular edema, surgical route, and pathology. A predictive model combining voxel location data from LSM with clinical factors achieved high predictive performance (C-index: training 0.956, validation 0.933, prospective 0.892). Gender, pathology, and voxel location were identified as key predictors for CMS.

CONCLUSION

The study established an effective predictive model for CMS in pediatric posterior fossa tumor patients, leveraging LSM data and clinical factors. The model's accuracy and robustness suggest its potential utility in clinical practice for early CMS risk assessment and intervention planning.

Posterior fossa ependymoma in children: A long-term single-center experience

INTRODUCTION

Ependymomas in the posterior fossa have poor prognosis. This study reports a single-center pediatric series, focusing on the value of surgical resection.

MATERIAL AND METHODS

A single-center retrospective study included all patients operated on by the senior author (CM) for posterior fossa ependymoma from 2002 to 2018. Medical and surgical data were extracted from the hospital's medical database.

RESULTS

Thirty-four patients were included. Age ranged from 6 months to 18 years, with a median of 4.7 years. Fourteen patients underwent initial endoscopic third ventriculocisternostomy before the direct surgical resection. Surgical removal was complete in 27 patients. There were 32 surgeries for second-look, local recurrence or metastasis despite complementary chemotherapy and/or radiotherapy. Twenty patients were WHO grade 2 and 14 grade 3. Sixteen patients showed recurrence (47%). Overall survival was 61.8% at a mean 10.1 years' follow-up. Morbidities comprised facial nerve palsy, swallowing disorder, and transient cerebellar syndrome. Fifteen patients had normal schooling, 6 had special assistance; 4 patients reached university, 3 of whom experienced difficulties. Three patients had a job.

CONCLUSION

Posterior fossa ependymomas are aggressive tumors. Complete surgical removal is the most important prognostic factor, despite risk of sequelae. Complementary treatment is mandatory, but no targeted therapy has so far proved effective. It is important to continue the search for molecular markers in order to improve outcomes.

Posterior Fossa Tumours in the First Year of Life: A Two-Centre Retrospective Study

Posterior fossa tumours (PFTs) in infants are very rare, and information on these tumours is scarce in the literature. This retrospective study reports their pathological characteristics and describes surgical aspects and treatment outcomes. A two-centre cohort of infants with PFTs treated from 2007 to 2018 was retrospectively reviewed. Patient characteristics, clinical, and treatment data were reviewed. Survival curves for progression-free survival (PFS) and overall survival (OS) were generated. Thirty-three infants were retrieved. There were 11 low grade and 22 high-grade tumours. The most common presenting symptom was intracranial hypertension. Fifteen children out of thirty-three progressed. Five-year PFS was significantly lower in children with high-grade tumours (38.3%) than those with low-grade tumours (69.3%), p = 0.030. High-grade pathology was the only predictor of progression (HR 3.7, 95% CI 1.1–13.31), p = 0.045. Fourteen children with high-grade tumours died, with a 5-year OS of 55.25%. PFTs in children below one year of age still represent a unique challenge. Infants with high-grade tumours display the worst outcomes and the lowest survival, indicating that more effective strategies are needed.

Improved prediction of postoperative paediatric cerebellar mutism syndrome using an artificial neural network

Background

Postoperative paediatric cerebellar mutism syndrome (pCMS) is a common but severe complication which may arise following the resection of posterior fossa tumours in children. Two previous studies have aimed to preoperatively predict pCMS, with varying results. In this work, we examine the generalisation of these models and determine if pCMS can be predicted more accurately using an artificial neural network (ANN).

Methods

An overview of reviews was performed to identify risk factors for pCMS, and a retrospective dataset collected as per these defined risk factors from children undergoing resection of primary posterior fossa tumours. The ANN was trained on this dataset and its performance evaluated in comparison to logistic regression and other predictive indices via analysis of receiver operator characteristic curves. Area under the curve (AUC) and accuracy were calculated and compared using a Wilcoxon signed rank test, with p<0.05 considered statistically significant.

Results

204 children were included, of whom 80 developed pCMS. The performance of the ANN (AUC 0.949; accuracy 90.9%) exceeded that of logistic regression (p<0.05) and both external models (p<0.001).

Conclusion

Using an ANN, we show improved prediction of pCMS in comparison to previous models and conventional methods.

Neuropsychological Profile in Children with Posterior Fossa Tumors with or Without Postoperative Cerebellar Mutism Syndrome (CMS)

Cerebellar mutism syndrome (CMS) is a common surgical sequela in children following posterior fossa tumor (PFT) resection. Here, we analyze the neuropsychological features associated with PFT in children, focusing particularly on the differential profiles associated with the presence or absence of CMS after surgery. We further examine the effect of post-resection treatments, tumor type, and presence/absence of hydrocephalus on surgical outcome. Thirty-six patients diagnosed with PFT (19 with and 17 without CMS) and 34 age- and gender-matched healthy controls (HCs) were recruited. A comprehensive neuropsychological evaluation was conducted in all patients postoperatively and in HCs, including an assessment of general cognitive ability, motor skills, perception, language, memory, attention, executive functions, and academic competence. CMS was found to be a clinical marker of lower neuropsychological profile scores across all cognitive domains except auditory-verbal processing and visual memory tasks. PFT patients not presenting CMS exhibited milder impairment in intellectual functioning, motor tasks, reasoning, language, verbal learning and recall, attention, cognitive executive functions, and academic competence. High-grade tumors were associated with slower processing speed and verbal delayed recall as well as alterations in selective and sustained attention. Hydrocephalus was detrimental to motor functioning and nonverbal reasoning. Patients who had undergone surgery, chemotherapy, and radiotherapy presented impaired processing speed, verbal learning, and reading. In addition to the deleterious effects of PFT, post-resection PFT treatments have a negative cognitive impact. These undesired consequences and the associated tumor-related damage can be assessed using standardized, long-term neuropsychological evaluation when planning rehabilitation.

Establishing reproducible predictors of cerebellar mutism syndrome based on pre-operative imaging

PURPOSE

To establish some explicit, feasible, and reproducible predictors for CMS.

MATERIALS AND METHODS

This study was a retrospective case study. Data were obtained from 82 patients with medulloblastoma at a single center, Beijing Tiantan Hospital. Based on medical records, we created two independent samples: the CMS group comprising 23 patients and the non-CMS group comprising 23 patients. Pre-operative imaging was studied by performing quantitative assessments of specific indicators.

RESULTS

The CMS group showed greater differences in pre-operative imaging data with the non-CMS group. The A_axi/d_axi ratio in pre-operative MR imaging captured in the axial plane was used to quantify the compression of the cerebellum and brainstem, and significant differences were observed between the CMS group and non-CMS group (p = 0.0002). In the sagittal plane, D_sag*d_sag was used to quantify the area of the tumor that invaded the brainstem, and significant differences were observed between the two groups (p = 0.0003). In the coronal plane, A_cor/d_cor was used to quantify the compression of the upper functional brain region, and significant differences were noted between the two groups (p = 0.0219). Additionally, Evans' index was introduced to quantify the degree of hydrocephalus. The CMS group tended to show an increased Evans' index (p = 0.0027).

CONCLUSION

Based on pre-operative imaging data, some reproducible predictors, such as A_axi/d_axi, D_sag*d_sag, A_cor/d_cor, and Evans' index, were established.

Postoperative posterior fossa syndrome: unraveling the etiology and underlying pathophysiology by using magnetic resonance imaging

BACKGROUND

Posterior fossa syndrome (PFS) is a severe, postoperative complication occurring in about 25 % of pediatric patients undergoing surgery for midline tumors in the posterior fossa. In recent years, MRI-based research elucidated the cause of PFS and shed new light on its putative pathophysiology. This review highlights the major advances arising from research of this topic.

RESULTS

Postsurgical damage patterns in patients after posterior fossa surgery show that PFS results from bilateral surgical damage to the proximal efferent cerebellar pathways (pECPs). Surgical pECP disruption has other MRI-detectable effects that are more remote. Patients with PFS tend to develop global supratentorial cortical hypoperfusion, likely representing reversed, cerebello-cerebral diaschisis. Because this hypoperfusion is most prominent in frontal regions, cerebellar mutism may indicate a dominantly frontal lobe dysfunction, hence a peculiar form of speech apraxia. Injury to the pECP also leads to contralateral inferior olivary nucleus degeneration. When bilateral hypertrophic olivary degeneration (HOD) is observed after posterior fossa surgery, affected patients have clinical PFS. Therefore, it is suggested that bilateral HOD may be a sensitive and, in appropriate clinical settings, reliable a posteriori surrogate imaging indicator of bilateral disruption of the pECPs and consequently of PFS. Having such a "validation tool" presents new opportunities to develop better definitions for the phenotypes within the clinical spectrum of PFS.

CONCLUSIONS

Anatomical and functional MRI techniques are suitable and valuable tools with which to detect structural changes and pathophysiological processes in the development and evolution of PFS and may be key, integral components of future clinical research endeavors.

Emotional and behavioral functioning after conformal radiation therapy for pediatric ependymoma

PURPOSE

The standard of care for pediatric patients with ependymoma involves postoperative radiation therapy. Prior research suggests that conformal radiation therapy (CRT) is associated with relative sparing of cognitive and academic functioning, but little is known about the effect of CRT on emotional and behavioral functioning.

METHODS AND MATERIALS

A total of 113 patients with pediatric ependymoma underwent CRT using photons as part of their enrollment on an institutional trial. Patients completed annual evaluations of neurocognitive functioning during the first 5 years after CRT. Emotional and behavioral functioning was assessed via the Child Behavior Checklist.

RESULTS

Before CRT, emotional and behavioral functioning were commensurate with those of the normative population and within normal limits. After 5 years, means remained within normal limits but were significantly below the normative mean. Linear mixed models revealed a significant increase in attention problems over time. These problems were associated with age at diagnosis/CRT, tumor location, and extent of resection. A higher-than-expected incidence of school problems was present at all assessment points after baseline.

CONCLUSIONS

The use of photon CRT for ependymoma is associated with relatively stable emotional and behavioral functioning during the first 5 years after treatment. The exception is an increase in attention problems. Results suggest that intervening earlier in the survivorship period-during the first year posttreatment-may be beneficial.

Long-term sequelae after acquired pediatric hemorrhagic cerebellar lesions

PURPOSE

The aim of the present study was to assess cognitive, affective, and motor long-term sequelae after acquired focal pediatric cerebellar lesions.

METHODS

Eight patients with a history of isolated acquired hemorrhagic cerebellar lesions before the age of 13 participated in this study. All participants underwent a neurologic examination, including the Zurich Neuromotor Assessment (ZNA) and the International Cooperative Ataxia Rating Scale (ICARS). Cognitive functions have been evaluated with a general cognitive assessment and an extensive neuropsychological battery. Furthermore, patients and parents filled in questionnaires about quality of life and possible behavioral or emotional problems.

RESULTS

The results revealed that all patients exhibited motor problems (ZNA). Most participants had further restricted oculomotor movements (ICARS). Age at injury and the full scale IQ were significantly positively correlated (Pearson correlation 0.779; p = 0.023). Conversely, no overall neuropsychological profile could be identified except for marginally reduced reaction times and susceptibility to interference. In addition, borderline results in semantic and phonemic word fluency tasks were apparent. A dysexecutive syndrome was diagnosed in one patient. However, verbal performance and reading abilities were non-pathologic in all participants. The patients reported having a good quality of life without major physical restrictions.

CONCLUSIONS

Emotional disturbances and the presence of a mild cerebellar cognitive affective syndrome (as frequently described in adult patients) could only be confirmed in adolescents with vermis lesions. Nevertheless, in laboratory conditions, neuropsychological impairments were present in all patients. Heterogeneity of age at injury and exact lesion site may have led to interpersonal differences in neuropsychological outcome.

Neurocognitive outcome 12 months following cerebellar mutism syndrome in pediatric patients with medulloblastoma

The aim is to prospectively assess early neurocognitive outcome of children who developed cerebellar mutism syndrome (CMS) following surgical resection of a posterior fossa embryonal tumor, compared with carefully matched control patients. Children who were enrolled on an ongoing IRB-approved protocol for treatment of embryonal tumors, were diagnosed with postoperative CMS, and had completed prospectively planned neuropsychological evaluation at 12 months postdiagnosis were considered eligible. The cognitive outcomes of these patients were examined in comparison to patients without CMS from the same treatment protocol and matched with regard to primary diagnosis, age at diagnosis, and risk/corresponding treatment (n = 22 pairs). Seventeen were also matched according to gender, and 14 were also matched according to race. High-risk patients received 36-39.6 Gy CSI and 3D conformal boost to the primary site to 55.8-59.4 Gy. Average-risk patients received 23.4 Gy CSI and 3D conformal boost to the primary site to 55.8 Gy. Significant group differences were found on multiple cognitive outcomes. While the matched control patients exhibited performance in the average range, patients who developed CMS postsurgery were found to have significantly lower performance in processing speed, attention, working memory, executive processes, cognitive efficiency, reading, spelling, and math. Patients treated for medulloblastoma who experience postoperative CMS show an increased risk for neurocognitive impairment, evident as early as 12 months following diagnosis. This study highlights the need for careful follow-up with neuropsychological evaluation and for obtaining critical support for patients and their families.