1. Language Processing in Bilingual Versus Monolingual Pediatric Medulloblastoma Patients
Grace A. Mucci, Ph.D. 1,2; Tara DeLuco, MS1; Gabriella Santacruz, MA1;
Lara Tucci, MA1; Adrianne Alpern, Ph.D. 1;Jody Pathare, CNP1;
Tina Templeman, RN1; Cristian Gallagher MSW1; Violet Shen, MD1,2 1CHOC Children's Hospital University of California, Irvine
Introduction
Cognitive impairment is a significant comorbidity in children with posterior fossa brain tumors. 1 There are several known predictors of neurocognitive outcomes, including biological factors, developmental and cognitive reserve.2 Several studies have found that the functional brain organization of bilinguals and monolinguals have distinct and shared sites that support language.3.4 This retrospective study aims to examine the performance differences in language tasks between monolingual (N=9) and bilingual (N=11) children with medulloblastoma.  
Results
The models explained 68% to 95% of the variance in language outcomes. Bilingualism accounted for a significant amount of variance above and beyond other predictors for VC, WR, and EV, but not RV. The strongest predictors of VC were bilingualism, time since diagnosis, cerebellar mutism, and gender. A comparable pattern was found when predicting EV. The strongest predictors of WR were time since diagnosis, cerebellar mutism, and bilingualism. The best outcomes were for monolinguals girls without cerebellar mutism who were assessed shortly after the end of treatment (Table 2).
Methods
Retrospective chart review was conducted on 26 subjects diagnosed with medulloblastoma evaluated in the Pediatric Psychology Department at CHOC Children’s Hospital from 2011 through Six subjects were excluded from analysis due to not meeting initial inclusion criteria of intelligence >65. The remaining 20 subjects were included in the analysis (Table 1).
Hierarchical regression was performed to predict verbal comprehension (VC), word reading (WR), and expressive (EV) and receptive vocabulary (RV). Age at diagnosis, time since diagnosis, cerebellar mutism history, gender, and SES were predictors. SES was determined by examining the eligibility for California Children’s Services Insurance (CCS), and was used as a proxy variable. Bilingualism was entered in Step 2 to examine the variance explained by bilingualism above and beyond other predictors (ΔR2).
Table 2. Regression coefficients for separate models predicting VC, WR, EV, and RV. Each regression weight (β) shows the predictive value controlling for all other predictors. Darker cells represent stronger relationships.
Outcome variable
Standardized coefficient (β) VC WR EV RV
Time since diagnosis
-0.56 *
-0.60
***
-0.88 **
Cerebellar mutism
0.56
-0.43
0.50
0.42
n.s.
Gender (female)
0.43
-0.09
0.60
0.45
Age at diagnosis
0.31
0.17
Bilingualism (Step 2)
-0.58
-0.33
-0.86
-0.46
Model statistics
Bilingualism ΔR2
0.20
0.07
0.30
0.09
Final Model R2 (all predictors)
0.68
0.95
0.87
0.80
*p< **p< ***p<.001
Table 1. Descriptive statistics
Variable
M (SD) n
(%)
Age at diagnosis (years)
6.4 (5.1)
Time since diagnosis (years)
3.7 (2.5)
Cerebellar Mutism history 6
(30%)
Gender (female) 8
(40%)
Bilingual 11
(55%)
Spanish 7
(35%)
Vietnamese 3
(15%)
Arabic 1
(5%)
Conclusions
Results indicate that there are noteworthy differences between the neurocognitive outcomes of monolingual versus bilingual children with medulloblastoma. Interestingly, monolingual girls with no history of cerebellar mutism demonstrated more resiliency with regards to language functioning. Consistent with previous research, this study support that time since treatment remains a predictor of cognitive functioning.5 As the age of second language acquisition is an important mediator in the development of language, brain tumors during critical periods of neurodevelopment may impose a negative influence on a child’s language abilities. Specifically, bilingual patients demonstrated increased risk for difficulties with language processing, such as expressive vocabulary and verbal comprehension. Due to the small sample size of this study, further research is needed to better clarify the role that bilingualism plays in the neurocognitive outcome of pediatric medulloblastoma patients.
References
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2Dennis, M, Spiegler, B.J., Riva, D., & Macgregor, D. (2004). Neuropsychological outcome. In D.A. Walker et al. Brain and Spinal Tumors of Childhood, London: Arnold.
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