Relationships between executive functions and occupational performance of children with medulloblastoma

Abstract

Introduction

This study examines executive functions and occupational performances of children with medulloblastoma and children with typical development. The aim was to compare the executive function and occupational performance levels of children with medulloblastoma and children with typical development and to investigate the relationship between the executive function and occupational performance levels of children with medulloblastoma.

Method

Parents of 105 children (6–12 years) completed the Childhood Executive Function Inventory. A total of 105 children were administered the Canadian Occupational Performance Measurement to obtain information on occupational performance areas. Executive functions and occupational performance levels of children with medulloblastoma (n = 52) and typical development (n = 53) were compared. Correlation analysis was conducted between the executive functions and occupational performances of children with medulloblastoma.

Results

Executive function and occupational performance levels of children with medulloblastoma were lower than those with typical development. Significant relationships were found between the executive functions and occupational performances of children with medulloblastoma (p < 0.05, p < 0.001).

Conclusion

It is clear that the executive functions of children with medulloblastoma significantly affect their occupational performance level. Client-centered, occupation-oriented cognitive therapy interventions prepared according to occupational therapy theories and models might be useful to increase the occupational performance level of children with medulloblastoma.

Keywords

Medullablastoma cancer executive functions occupational performance activities of daily living occupational therapy

Introduction

Medulloblastoma (MB) is the most common malignant tumor in childhood. It accounts for about 20% of all childhood brain tumors and about 64% of embryonal tumors (Doussouki et al., 2019). Common types of treatment for MB include local radiotherapy, craniospinal radiotherapy, chemotherapy and surgical operation. These treatments cause serious neurocognitive deficits in children (Ribi et al., 2005). These neurocognitive deficits can be seen in the areas of intelligence, attention, processing speed, memory and executive function (Doussouki et al., 2019).

Executive functions (EF) require different cognitive processes, including initiation, planning, decision-making, cognitive flexibility, reasoning, and self-regulation for effective and appropriate behavior, and these functions shape various routine and non-routine activities of daily living (ADL). Reduced executive functions also inhibit the ability to execute tasks with multiple steps (Ribi et al., 2005). Neurological and neurocognitive deficits affect areas such as adaptation to social life, academic achievement and independence in daily life, and these deficits can continue from childhood into adulthood (LeBaron et al., 1988). Studies show that the executive function deficits of the survivors of childhood MB affect independent life in adulthood (Brinkman et al., 2012; Kieffer et al., 2019).

Studies show that the cumulative effects of disease and treatment factors inhibit brain development, and children with MB have deficits especially in the area of working memory (WM) (Knight et al., 2014; Palmer, et al., 2013). WM represents an important aspect of neurocognition and can be defined as a system with a limited capacity to temporarily hold information (Repovs and Baddeley, 2006). Memory is very important for recording new information and gaining new knowledge and skills. Therefore, it is directly associated with the academic achievement of children (Nesbitt et al., 2015). EF are not composed of just WM; they involve a wide range of processes. These processes include planning, inhibitor control, regulation, goal-setting and problem-solving. Although many problems have been identified in EF in children with medulloblastoma, an in-depth study of EF has not been conducted in this population (Law et al., 2017).

Individuals with problems in EF often struggle to organize daily activities in different settings. Lack of EF skills can lead to persistent cognitive, academic and social difficulties by limiting a child’s ability to successfully manage and complete daily activities and interact with the environment (Fogel et al., 2019). Although various studies have shown that children with MB experience deficiencies in EF, this deficiency has not been associated with ADL.

Children with MB experience reduced occupational performances due to tumor diagnosis, tumor treatments, hospitalizations and dropping out. In addition, the ability of these children to fully participate in the expected roles at home, at school and in social settings can be greatly affected (Ness and Gurney, 2007). The ability to perceive, plan, remember and execute personal care, productivity and leisure activities, as well as the routines, roles, tasks and sub-tasks required by these activities, are defined as occupational performance (Creek and Feaver, 1993).

The effects of illnesses and treatments on ADL are not adequately mentioned in the literature. In a study conducted by Smith et al. (1998), it was stated that the physical function and performance status of individuals should be examined carefully in children with brain tumors. We believe that developmental and cognitive research is needed to define interventions for children with childhood brain tumors to identify and adapt to both individual and social settings, including areas of self-care, productivity and leisure.

The aim of this study is to determine the relationship between EF and the occupational performance of children with MB, to investigate the effect of EF on individuals’ performance in ADL and to explore which areas of individuals’ performance are affected.

Our hypotheses are as follows:

H1: There is no difference between the EF of children with MB and EF of children with typical development (TD).

H2: There is no difference between the occupational performance and satisfaction level of children with MB and the occupational performance and satisfaction of children with TD.

H3: There is no relationship between the occupational performance and EF of children with MB, including WM, planning, regulation and inhibition skills.

Method

Participants

In total, 52 children with MB and 53 children with TD aged 6–12 years were included in the study. As inclusion criteria, children with MB should had started chemotherapy and should not have received a secondary diagnosis (autism spectrum disorder, attention deficit hyperactivity disorder (ADHD), mental retardation, etc.). The tumor should not have metastasized outside the central nervous system. Children with TD also should not had been diagnosed with autism, ADHD, mental retardation, etc. All individuals had to be cooperative. A written consent form was signed by both parents and children.

Instruments: participant characteristics

Demographic questionnaire

Two separate demographic questionnaires were prepared for children with MB and TD. Parents of children with MB completed the demographic questionnaire, which includes information about the child’s age, gender, number of hospitalizations, number of chemotherapy treatments received, surgical procedures, radiotherapy procedures, status of attending school and which class he/she is in. Parents of children with TD completed the demographic questionnaire, which includes information about the child’s age, gender and which class he/she is in.

Instruments: executive functioning assessment

Childhood Executive Functioning Inventory (CHEXI) (Thorell and Nyberg, 2008)

The information about the executive functions of children was collected using the CHEXI, which helps identify the executive function levels of children based on parental reports. The CHEXI was developed as a measurement focusing especially on executive functions and it can be used in children between the ages of 4 and 12 years (Thorell and Nyberg, 2008).

The CHEXI, which consists of 24 questions, is divided into four subgroups: WM (nine items), planning (four items), inhibition (six items) and regulation (five items). Questions are answered by parents or teachers. Each item is graded from 1 to 5 according to the degree of accuracy of the expression (1: definitely not true; 5: definitely true). The parent is asked to determine how appropriate the statement is to his/her child by marking the appropriate score. In the final scoring of the test, the WM and inhibition subgroups constitute the total score of “working memory” and the inhibition and regulation subgroups constitute the total score of “inhibition.” The higher the score obtained from the CHEXI, the weaker the executive functions of the child. Therefore, children with lower scores on the CHEXI have better executive function skills than those with higher scores (Thorell and Nyberg, 2008).

Instruments: occupational performance measure

The Canadian Occupational Performance Measure (COPM) (Law et al., 1990)

The COPM is a measure designed to help participants identify and evaluate occupational performance in the areas of self-care, productivity and leisure (Law et al., 2014).

This assessment scale uses a semi-structured interview to determine the problems faced by individuals in the field of occupational performance (Enemark et al., 2018). The individual is asked about their occupational performance problems and concerns about three areas: self-care, productivity and leisure activities. Up to three problems can be identified in each occupational area (personal care, productivity, leisure). The importance of problem areas is ranked between 1 and 10 (1: not important; 10: very important), and then the top five activities that are considered most important are graded according to performance and satisfaction levels. Performance and satisfaction scores are determined by the individual on a scale ranging from 1 to 10 points (Christiansen et al., 1999).

Data analyses

Statistical analyses were performed using SPSS software version 22. The variables were investigated using visual (histograms, probability plots) and analytical (Kolmogorov–Simirnov/Shapiro–Wilk test) methods to determine whether or not they are normally distributed. Descriptive analyses were presented using the median and interquartile range (IQR) for the non-normally distributed and ordinal variables. Since the ages, executive function points and occupational performance measurements were not normally distributed, nonparametric tests were conducted to compare these parameters. The Mann–Whitney U test was used to compare parameters between the groups. The correlation coefficients and their significance were calculated using Spearman’s test. A p-value of less than 0.05 was considered to show a statistically significant result.

Results

Participant characteristics

As a depicted in Table 1, the group with MB (n = 52) included 29 boys (55.8%) and 23 girls (44.2%), with a mean age of 8.6 years (standard deviation (SD)=1.9). The group with TD (n = 53) included 27 boys (50.9%) and 26 girls (49.1%), with a mean age of 8.3 years (SD=1.6).

Table 1.

Participant characteristics in each group.

		MB (n = 52)		TD (n = 53)
	M (SD)	Range	M (SD)	Range	Z	P-value
Age (years)	8.6 (1.9)	6–12	8.3(1.6)	6–12	–0.6	0.55
		Frequency (%)		Frequency (%)
Gender
Boys		29 (55.8)		27 (50.9)
Girls		23 (44.2)		26 (49.1)
Going to school
Yes		14 (26.9)		53 (100)
No		38 (73.1)		–
Radiotherapy
Yes		27 (51.9)		–
No		25 (48.1)		–
Surgery
Yes		39 (75)		–
No		13 (25)		–

MB: group with medulloblastoma; TD: group with typical development; M: mean; SD: standard deviation.

Determining and comparing the executive function situations of groups using the CHEXI

The mean CHEXI score in children with MB was 63.7 (SD=15.8) and in children with TD was 38 (SD=6.1). The executive functions of the children with MB, including working memory, planning, regulation and inhibition (total), were found to be significantly weaker compared to children with TD (p <0.001) (Figure 1).

Figure 1.

Comparison of CHEXI and COPM scores of children with MB and children with TD.

Determining and comparing the occupational performance situations of groups using the COPM

According to the COPM, activities in the self-care area revealed that individuals have primarily low self-evaluated performance: 38 children with MB had low performance in sleeping; 31 had low performance in bathing and 26 had low performance in tooth brushing. The children with TD did not state any activity in this area. In the area of productivity, 43 children with MB stated that they had low performance for going to school, whereas children with TD did not state any low performance regarding this activity. Seven children with MB and 34 children with TD stated that they had low performance for doing homework. In the area of leisure activities, 49 children with MB and 29 children with TD stated that they had low performance for spending time with their peers (Figure 2).

Figure 2.

Activities in which groups have restricted participation.

The mean score of occupational performance in children with MB was 4.8 (SD = 1.1) and in children with TD was 7.9 (SD = 1). The occupational performance and occupational satisfaction of the children with MB were found to be significantly weaker compared to children with TD (p < 0.001) (Figure 1).

Relationship between executive functions and occupational performance of children with medulloblastoma

The relationship between the performance scores of the participants in activities in which they were experiencing restriction and the evaluations of the families about the executive functions of the children were examined. CHEXI scores are formed by using the parents’ answers to the questions about the executive functions of children; a higher score indicates weaker executive functions. Therefore, the relationship between CHEXI and COPM was found to be negative. A negative correlation was found between occupational performance and satisfaction, and working memory, planning, inhibition (total) and regulation areas in children with MB (p <0.05) (Table 2).

Table 2.

Correlations between CHEXI and COPM scores.

	COPM
	OP		OS
	r	p	r	P
CHEXI
WM (Sub1)	−0.38	0.005**	−0.31	0.02*
Planning (Sub2)	−0.42	0.002**	−0.28	0.04*
WM tot. (Sub1 + 2)	−0.44	0.001**	−0.36	0.009**
Regulation (Sub3)	−0.49	0.0002***	−0.41	0.003**
Inhibition (Sub4)	−0.36	0.008**	−0.23	0.1
Inhibition tot. (Sub3 + 4)	−0.48	0.0003***	−0.41	0.003**
Total	−0.49	0.0002***	−0.40	0.003**

COPM: Canadian Occupational Performance Measurement; OP: occupational performance; OS: occupational satisfaction; CHEXI: Childhood Executive Functioning Inventory; WM: working memory; tot.: total; Sub: subtest.

*p<0.05; **p<0.01; ***p<0.001.

Discussion and implications

In this study, it was determined that EF, including WM, planning, inhibition and regulation areas, were weaker in children with MB than typically developing children. Self-perceptions of children with MB aimed at occupational performance were weaker than in typically developing children, and the satisfaction level of children with MB for occupational performance was also lower than typically developing children.

However, the unique contribution of this study is that a powerful relationship was found between EF and occupational performances of children with MB. In other words, the weakening of executive functions of children with MB significantly affects their performance in ADL. This result is an extremely important factor that occupational therapists should consider in rehabilitation programs.

In this study, children’s executive functions were evaluated based on their family’s reports. Parental assessments are important for exploring the capacities of children in real-life situations that cannot be assessed using performance-based measures applied in a structured clinical setting (Knight et al., 2014). The results of parent reports showed that the executive functions of children with MB were weaker than those of typically developing children. The weakness of all evaluated executive function skills indicates that children with MB should be included in rehabilitation programs during cancer diagnosis, treatment and post-treatment.

WM is a system that protects and manages information temporarily during the planning and execution of many cognitive tasks, and an active WM is required for all occupational performance areas, from the completion of dressing without reminder to the ability to do their homework independently (Kulkarni and Moningi, 2015; Nouchi and Kawashima, 2014). In this study, most families’ “true” or “definitely true” answers to statements such as “Has difficulty remembering what he/she is doing, in the middle of an activity” and “When asked to do several things, he/she only remembers the first or last” may express the influence of WM on children with MB. Various studies in the literature also show that the WM of children with MB is weaker than typically developing children (Palmer, 2008).

In this study, the inhibition and regulation skills of children with MB were found to be significantly weaker than in typically developing children. Inhibition and regulation skills ensure that appropriate behaviors can be demonstrated in a newly encountered situation or in an unusual occupation (Duckworth et al., 2016). Since children with MB who are affected in these areas cannot adequately regulate how they can react in different situations, they may show less willingness to participate in social activities, which may lead to social isolation in children (Noll et al., 1999). Although inhibition and regulation skills are very important in routine and non-routine activities, there are not enough studies in the literature regarding these skills in children with medulloblastoma.

According to the results of this study, children with MB experience restricted self-care, productive and leisure activities. These children are restricted in activities such as sleeping, bathing and brushing teeth. Self-care plays an important role in the development of independence in childhood (Mohammadi et al., 2017), so it can be considered that self-care may form the basis of occupational performance difficulties in children with MB.

The majority of children with MB do not attend school and as a result of this the area of productive activity is disrupted. Failure to attend school and children being away from their academic environments and peers bring about a decrease in quality of life and psychosocial problems. Going back to school demonstrates that the child’s life is returning to normal, and that families can provide children with opportunities to maintain and manage their daily activities, and to learn and socialize (Bruce et al., 2008). For this reason, we think that children with MB should be provided with activities to help them prepare for a return to school, and practice including preparation for and adaptation to school activities should be an important constituent of rehabilitation.

Children with MB also stated that they experienced restriction in leisure activities such as spending time with their peers, playing/going to games and traveling. It is clear that the occupational balance of children with MB who have restricted occupational performance is affected. Occupational therapists believe that occupational balance is necessary for a person’s health and wellbeing, and that the balance of activity should be determined according to individuals’ involvement in self-care, productivity and leisure activities (Hammell, 2009)

Because the children with MB reported restrictions in all areas of occupational performance, it is not surprising that occupational performance and satisfaction levels of children with MB were found to be significantly lower than children with TD, and these results are consistent with studies in the literature. When comparing children with brain tumors to their healthy siblings, Ness et al. (2005) found that the performance of ADL of children with brain tumors was significantly lower than that of healthy siblings. While the children with brain tumors who participated in this study stated that they had restricted self-care activities, and their daily routines such as attendance were interrupted, their healthy siblings did not report any problems in these areas. Mohammadi et al. (2017) found that children with brain tumors had significantly lower levels of perceived performance in ADL than healthy children. In addition, the intensity of participation, enjoyment of daily activities and satisfaction were found to be low in children with brain tumors compared to healthy children. Occupational therapists can help resolve such problems and provide interventions for children with MB to improve their performance and satisfaction in everyday life by providing social welfare and engaging them in activities.

In this study, WM, planning, regulation and inhibition skills, and the occupational performance and satisfaction of children with medulloblastoma were found to be correlated. It is reported in the literature that children with medulloblastoma are affected by impaired executive functions, especially in WM, and their ADL are interrupted. Yağcı-Küpeli et al. (2012) found that there is a significant relationship between the executive functions of children with medulloblastoma and their physical activity levels, social participation levels and academic life continuity. Netson et al. (2016) found significant relationships between the executive functions of children with brain tumors and their ability to make friends, attend school and have good physical and emotional wellbeing. In these studies, quality of life questionnaires were used to examine the relationship between children’s daily life and executive functions. Occupational therapists believe that for health and wellbeing there must be a balance in the areas of self-care, productive time and leisure time (Hammell, 2009). Therefore, we think that using evaluations that can analyze occupational performance areas in detail may be more beneficial for rehabilitation goals. In this sense, COPM, which helps to assess children’s perceptions of their own performance, can be a guide for creating person-centered interventions.

This study is a comprehensive study evaluating all occupational performance areas by examining performance and satisfaction levels in self-care, productive and leisure activities in relation to EF. Considering the effects of EF on ADL, it is important to know the relationship between EF and occupational performance level in all performance areas, especially when planning occupational therapy interventions.

Limitations and future directions

Despite the meaningful results, this study had some limitations. In this study, the information about executive functions was considered only from the parents’ point of view, and the information about occupational performance was considered only from the children’s point of view. Future studies may be examined from both parents’ and children’s perspectives for both areas and may consider the gap between these two perspectives. When examining the factors that affect performance and satisfaction in ADL, we recommend that future researchers choose a more holistic perspective by considering factors such as social cognition, relationships with the social environment, and physical and emotional state along with EF. Since there are different treatment options and combinations in the treatment of children with MB, we think that the executive functions and occupational performance levels of children may be affected to different degrees. We believe that more homogeneous groups should be researched in collaboration with doctors in order to achieve generalizable results according to treatment options.

Implications for occupational therapy

Children with MB are exposed to treatment and treatment combinations such as chemotherapy, radiotherapy and surgical interventions after diagnosis of tumor. During these treatments, hospitalizations, dropping out and side effects of the treatments may affect the EF of children with MB and cause a decrease in their performance in ADL.

At the clinical level, the results of the study show that cognitive and occupation-based occupational therapy interventions to strengthen executive functions can help improve the daily functioning of community settings for children with MB and increase their occupational performance and satisfaction levels. We think that the cognitive support of children during the diagnosis and treatment of medulloblastoma will facilitate the adaptation of children to social life after the planning and implementation of person-centered, cognitive-based occupational therapy programs prepared considering the performance and capacity of the children. Such interventions can be performed through top-down, occupation-based intervention approaches to therapy. These approaches can include the cognitive orientation to daily occupational performance approach, the Cog-Fun model of intervention and functional individualized therapy for children with executive deficits (Fogel et al., 2019), and deal with different environmental factors, such as hospital, home and school, that enable or inhibit functioning and, therefore, can meet these children’s needs. When preparing individualized intervention plans, it is important for occupational therapists to adapt the activities to the functional status of the children with MB and to consider the environment in which the child is living, in order to improve the perceived performance and satisfaction level of the children.

Various factors such as diagnostic process, treatments, hospitalizations, weakening of peer relationships and dropping out may cause not only cognitive but also sensory, physical and psychosocial influences in children with MB, and these effects may cause limitations in children’s occupational performance. Therefore, when evaluating the occupational performances of children with MB, we think that the cognitive, sensory, physical and psychosocial aspects of the children should be considered holistically.

Key findings

Children with medulloblastoma are a vulnerable group in society in terms of executive functions including working memory, planning, inhibition and regulation.

Children with medulloblastoma experience limitations in all areas of self-care, productivity and leisure, and as a result the occupational performance and satisfaction levels of children decrease.

The lack of executive functions of children with medulloblastoma is strongly associated with poor performance and low satisfaction in their activities of daily living.

What the study has added

This study contributes to occupational therapists’ theoretical and clinical knowledge about executive functions and the occupational profiles of children with medulloblastoma, and the need to refer to them as an integral part of the treatment goals. In addition, this study shows that these two areas should be evaluated as an inseparable whole.

Footnotes

Acknowledgments

The authors would like to thank Assoc. Prof. Ahmet Demir, who helped with data collection, and all the families and children who participated in this study.

Research ethics

Ethics Committee approval was obtained for the study from Hacettepe University Non-Invasive Clinical Investigation Ethics Committee (approval number 18/655-18), dated 13 July 2018.

Consent

All respondents and their parents signed written informed consent forms for participation.

Declaration of conflicting interests

The authors declare no potential conflicts of interest with respect to the research, authorship and/or publication of this article.

Funding

This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors.

Contributorship

Both authors contributed to the development of the study methodology, data collection and analysis. Both authors participated in writing, reviewing and editing the manuscript, and approved the final version.

ORCID iD

Meral Huri

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