Recent years have seen advances in childhood brain tumour management, with the consequence that survival rates have dramatically increased (Royal Children's Hospital (Brisbane, 2000). Consequently, there is renewed need to examine factors impacting quality of life in this population, including the immediate and long-term impact on language ability. Although some preliminary research has been conducted in children with posterior fossa tumour, limited information exists relating to the long-term effects on language in children treated for brain tumour, including supratentorial, brainstem, and posterior tumour. In light of the limited existing literature and recent emergent theories implicating the cerebellum and brainstem in language function, the present study investigated the general and high-level language and phonological awareness abilities of twenty-four children treated for brain tumour.
Twenty-four children treated for brain tumour (fourteen males and ten females), ranging in age fi-om three years nine months to fourteen years eleven months, participated in the study. Six children with brainstem tumour, six children with supratentorial tumour, and twelve children with posterior fossa tumour were respectively compared with groups of age- and gender-matched peers. The general language abilities of each group was examined using an assessment battery consisting of a comprehensive measure of both receptive and expressive language (Clinical Evaluation of Language Fundamentals -Third Edition / Clinical Evaluation of Language Fundaments - Preschool), a standardized test of receptive vocabulary (Peabody Picture Vocabulary Test - Third Edition), and a confrontation naming assessment (Hundred Pictures Naming Test). An assessment battery incorporating both high-level language and phonological awareness was also administered to each group, and included the Test of Problem Solving, the Test of Word Knowledge, the Test of Language Competence - Expanded, and the Queensland University Inventory of Literacy (QUIL). In addition to statistical analysis of each group, an individual comparison of each child's performance to the normative data was conducted to determine individual level of language competency.
Results revealed that a group of six children treated for brainstem tumour were not significantly different to a group of individually matched peers on measures of general language, high-level language, and phonological awareness. At an individual level, however, one case treated with a combination of radiotherapy and chemotherapy for brainstem glioma demonstrated evidence of subtle high-level lexical disturbances, while an additional case exhibited reduced performance on one isolated area of phonological awareness. The impact of an increase in treatment combinations and young age at treatment is highlighted in the discussion of this case data. The group findings, however, indicated functionally adequate language abilities in the majority of the children post treatment for brainstem tumour.
A second study of six children treated for supratentorial tumour demonstrated a pattern of reduced expressive language skills when compared to a group of individually matched peers. At an individual level, however, only two of the six children examined demonstrated evidence of language deficits. One child treated with surgery for a large left parietal tumour exhibited difficulties in expressive language and syntax, whereas the second child who had been treated with surgery for an optic nerve glioma demonstrated reduced receptive semantic abilities. The two cases with identified general language deficits were also noted to be the only children of five to demonstrate disturbances in high-level language, despite overall group findings of reduced problem solving and receptive semantics. Individual deficits were noted either primarily in expressive language or across all areas of high-level language, respectively. Specific deficits in phonological awareness, however, were noted in four out of five children with supratentorial tumour. The findings again demonstrated variability within the group and factors which may have contributed to these features are discussed.
An examination of a group of twelve children with posterior fossa demonstrated significantly reduced performance on general measures of both receptive and expressive language abilities (including receptive vocabulary) compared to a group of individually matched peers. At an individual level, only three children demonstrated evidence of language deficits. Reduced performance was noted to be primarily in the areas of expressive language and syntax. While few factors were considered uniquely different in the remaining nine cases without identified language difficulties, the impact of a fourth ventricular location and increased intracranial pressure on language function, as well as young age at treatment, were discussed. A group including ten of the twelve children with posterior fossa was also administered assessments of high-level language and phonological awareness. At a group level, children treated for posterior fossa exhibited poor performance compared to their individually matched peers across all areas of high-level language examined. On a case-by-case basis, six of the twelve cases examined exhibited evidence of high-level language deficit. While three demonstrated global high-level language impairments, specific deficits were noted in three additional cases in the areas of problem solving, and expressive semantic and lexical knowledge. Phonological awareness difficulties were noted in five of the ten children treated for posterior fossa tumour. The importance of investigating high-level language in children treated for posterior fossa tumour regardless of intact or impaired general language is highlighted.
A prospective examination of two cases either treated with chemotherapy for brainstem tumour, or radiotherapy for posterior fossa tumour, respectively, revealed specific declines in function in the area of problem solving, as well visual rhyme in one of the two children over a twelve month period. The structural and functional impact of radiotherapy and chemotherapy in children is highlighted, as is the need for long-term monitoring of all language skills over several years, given the potential for long-term difficulties to occur several years following treatment.
Findings of this study provide significant direction for both clinicians and researchers in understanding the needs of children treated for brain tumour. Results are discussed in the context of factors contributing to language disturbances, including direct involvement of a tumour in the language centres of the brain including recently recognised areas of the cerebellum and involvement of the brainstem, tumour type, increases in intracranial pressure, treatment effects such as the impact of radiotherapy and chemotherapy, and age at diagnosis/treatment. Despite various contributing factors being highlighted, clear patterns of treatment and non-treatment effects were limited in this extremely variable population. The importance of monitoring high-level language and phonological awareness in populations of children with and without identified general language deficits was also highlighted. Further research is needed to determine the impact of effects such as the direct impact of tumour location, radiotherapy, chemotherapy, on the long-term language and literacy function of these children.