Language outcomes following risk-adapted treatments for tumors located within the posterior fossa

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.

Postoperative speech impairment and surgical approach to posterior fossa tumours in children: a prospective European multicentre cohort study

BACKGROUND

Brain tumours are the most common solid tumours in childhood. Half of these tumours occur in the posterior fossa, where surgical removal is complicated by the risk of cerebellar mutism syndrome, of which postoperative speech impairment (POSI) is a cardinal symptom, in up to 25% of patients. The surgical approach to midline tumours, mostly undertaken by transvermian or telovelar routes, has been proposed to influence the risk of POSI. We aimed to investigate the risk of developing POSI, the time course of its resolution, and its association with surgical approach and other clinical factors.

METHODS

In this observational prospective multicentre cohort study, we included children (aged <18 years) undergoing primary surgery for a posterior fossa tumour at 26 centres in nine European countries. Within 72 h of surgery, the operating neurosurgeon reported details on the tumour location, surgical approach used, duration of surgery, use of traction, and other predetermined factors, using a standardised surgical report form. At 2 weeks, 2 months, and 1 year after surgery, a follow-up questionnaire was filled out by a paediatrician or neurosurgeon, including neurological examination and assessment of speech. Speech was classified as mutism, reduced speech, or habitual speech. POSI was defined as either mutism or severely reduced speech. Ordinal logistic regression was used to analyse the risk of POSI.

FINDINGS

Between Aug 11, 2014, and Aug 24, 2020, we recruited 500 children. 426 (85%) patients underwent primary tumour surgery and had data available for further analysis. 192 (45%) patients were female, 234 (55%) patients were male, 81 (19%) patients were aged 0-2 years, 129 (30%) were aged 3-6 years, and 216 (51%) were aged 7-17 years. 0f 376 with known postoperative speech status, 112 (30%) developed POSI, 53 (14%) developed mutism (median 1 day [IQR 0-2]; range 0-10 days), and 59 (16%) developed reduced speech after surgery (0 days [0-1]; 0-4 days). Mutually adjusted analyses indicated that the independent risk factors for development of POSI were younger age (linear spline, p=0·0087), tumour location (four levels, p=0·0010), and tumour histology (five levels, p=0·0030); surgical approach (six levels) was not a significant risk factor (p=0·091). Tumour location outside the fourth ventricle and brainstem had a lower risk of POSI (with fourth ventricle as reference, odds ratio (OR) for cerebellar vermis 0·34 [95% CI 0·14-0·77] and OR for cerebellar hemispheres 0·23 [0·07-0·70]). Compared with pilocytic or pilomyxoid astrocytoma, a higher risk of POSI was seen for medulloblastoma (OR 2·85 [1·47-5·60]) and atypical teratoid rhabdoid tumour (10·30 [2·10-54·45]). We did not find an increased risk of POSI for transvermian surgical approach compared with telovelar (0·89 [0·46-1·73]). Probability of speech improvement from mutism reached 50% around 16 days after mutism onset.

INTERPRETATION

Our data suggest that a midline tumour location, younger age, and high-grade tumour histology all increase the risk of speech impairment after posterior fossa tumour surgery. We found no evidence to recommend a preference for telovelar over transvermian surgical approach in the management of posterior fossa tumours in children in relation to the risk of developing POSI.

FUNDING

The Danish Childhood Cancer Foundation, the Swedish Childhood Cancer Foundation, the UK Brain Tumour Charity, the Danish Cancer Society, Det Kgl Kjøbenhavnske Skydeselskab og Danske Broderskab, the Danish Capitol Regions Research Fund, Dagmar Marshall Foundation, Rigshospitalet's Research Fund, and Brainstrust.

Prospective longitudinal decline in cognitive-communication skills following treatment for childhood brain tumor

BACKGROUND

The effect of childhood brain tumor and its treatments on the developing brain are recognized to cause late-occurring structural and functional changes, inclusive of neurocognitive and communication disturbances.

AIMS

The aim of the present study was to investigate changes in function in the prospective cognitive-communication and language abilities of two children surviving childhood brain tumor (CBT) over a 12-month period post-treatment.

METHODS

The comprehensive language and cognitive-communication abilities of two cases (male aged 7;8-8;8, female aged 10;9-11;9) were assessed at two timepoints over a 12-month period: six months and 18 months following completion of CBT cancer treatment.

RESULTS

Findings revealed a sharp decline in problem solving abilities over a 12-month period in the early stages of recovery from CBT in both cases examined, despite no or mild-moderate deficits in cognitive-communication or language function at initial assessment. Pre-literacy skills were noted to deteriorate on one task for one child, despite intact abilities at first assessment.

CONCLUSIONS

The findings of progressive deterioration of cognitive-communication skills in both children treated for CBT highlights a clear need for ongoing surveillance and full comprehensive assessment across development. The critical need for ongoing management after discharge and implementation of early intervention throughout development is highlighted.

Correlation between Pre- and Post-Surgical Findings for Long-Term Neurocognitive and Behaviour Development Due to Posterior Fossa Pilocytic Astrocytomas: The Trend after 10 Years

Objective: The objective of the present study was to selectively evaluate the long-term impact of posterior fossa pilocytic astrocytomas, which are known to be among the most benign forms of paediatric brain tumours on neurocognitive and behavioural functions. Methods: Children that were operated on for a posterior fossa pilocytic astrocytoma in the Pediatric Neurosurgery Department of the Catholic University Medical School were selected according to the following criteria: (a) age > 5 years (in order to have a complete set of neurocognitive evaluations data), (b) ability to perform a complete set of tests before and after surgery, and (c) children that had a regular follow-up up to 10 years from the surgical treatment. Results: Forty-three percent of the children selected for the present study showed a borderline IQ before surgery, which is a result corresponding to those previously reported in the literature for children affected by posterior fossa pilocytic astrocytomas; praxis and visual perception were the selective functions that were more frequently affected. Language performance tests scores were below average in 40% of the cases but tended to improve in terms of expressive and receptive skills even at the 1-year follow-up; the improvements became significant at the 5-year and 10-year follow-ups. Conclusions: Recognising and measuring the short- and long-term effects of cerebellar tumours in children and their treatment are the first step towards improving their clinical course and quality of life. Early interventions should be offered to all of them, with specific attention bestowed on visual-spatial stimulation, speech and occupational therapies in order to act on praxic and visuo-perceptive skills, as well as on emotion and behaviour tracts of the neurocognitive profile, which more commonly tend to persist in the long term.

Communication and swallowing outcomes of children diagnosed with childhood brain tumor or leukemia: A systematic review

The purpose of this systematic review was to appraise and synthesize evidence on communication and swallowing outcomes associated with childhood brain tumor or leukemia (CBTL). A comprehensive database and grey literature search was conducted. Studies included: (a) peer-reviewed research published between 1998 and 2019, (b) English language, (c) children aged 0-16 years diagnosed with CBTL, and (d) used outcome measures focused on communication and/or swallowing. Quality assessment was completed and certainty of evidence rated using Grading of Recommendations Assessment, Development and Evaluation (GRADE). Fifty-seven studies met inclusion criteria: 46 examined communication, seven examined swallowing, and four considered both. Most studies were descriptive and prospective. Communication difficulties were frequently reported and apparent at one or more points from diagnosis to survivorship. Swallowing difficulties were frequently reported during oncology treatment. Despite quality assessment revealing methodological shortcomings, results have implications for clinical services and future research.

Cerebellar mutism syndrome

Cerebellar mutism most commonly, but not exclusively, develops in children after surgery for midline cerebellar or intraventricular tumors in the posterior fossa, typically medulloblastoma. Cerebellar mutism syndrome (CMS) comprises a complex set of neurologic and neurocognitive signs and symptoms, the cardinal and central component of which is an initially profound but usually reversible speech disorder. As such, CMS is currently recognized as an extreme form of the so-called cerebellar cognitive affective syndrome (Schmahmann syndrome). The putative cause of CMS is a substantial surgical injury to the proximal components of the bilateral efferent cerebellar pathways, disrupting cerebellar input to the supratentorial brain. The resultant cerebellocerebral diaschisis may lead to supratentorial cortical perfusion depression with frontal predominance. The speech disorder is, therefore, likely an apraxia. As our understanding of the mechanism and the clinical spectrum of CMS evolves, clinically useful preoperative risk stratification schemes, adjustments to surgical strategies and techniques, and possible early therapeutic-rehabilitative measures are being sought and developed to reduce the burden of this severe and particularly handicapping chronic morbidity on affected individuals and their families.

Cause and outcome of cerebellar mutism: evidence from a systematic review

PURPOSE

Cerebellar mutism is a serious neurosurgical complication after posterior fossa surgery, but the cause, incidence and outcome remain incompletely defined. The aim of this paper was to identify and review all reports of this phenomenon to better delineate and improve the evidence base.

METHODS

A systematic search and retrieval of databases was conducted using advanced search techniques. Review/outcomes criteria were developed, and study quality was determined.

RESULTS

The retrieval identified 2,281 papers of which 96 were relevant, identifying 650 children with cerebellar mutism. Causative factors, clinical features and outcomes were reported variably; papers focussed on multiple areas, the majority reporting incidence in single or series of case studies with little or no analysis further than description.

CONCLUSIONS

The complexity and variability of data reporting, likely contributing factors and outcomes make cerebellar mutism difficult to predict in incidence and the degree of impact that may ensue. A clear and accepted universal definition would help improve reporting, as would the application of agreed outcome measures. Clear and consistent reporting of surgical technique remains absent. Recommendations for practice are provided.