Study protocol of a randomized controlled trial of home-based computerized executive function training for children with cerebral palsy

Background Cerebral palsy (CP) is frequently associated with specific cognitive impairments, such as executive dysfunction which are related to participation and quality of life (QOL). The proposed study will examine whether a computerized executive function (EF) training programme could provide superior benefits for executive functioning, participation, QOL and brain plasticity, as compared to usual care. Methods A single-blind randomized controlled trial (RCT) design will be performed. Thirty children with CP aged 8 to 12 years will participate in a home-based computerized multi-modal executive training programme (12 weeks, 5 days a week, 30 min a day training, total dose = 30 h). Thirty children with CP matched by age, sex, motor and intelligence quotient (IQ) will compose the waitlist group. Cognitive, behavioural, emotional, participation and QOL measures will be obtained at three time points: before, immediately after and 9 months after completing the training. Additionally, structural and functional (resting state) magnetic resonance images (MRI) will be obtained in a subsample of 15 children from each group. Outcomes between groups will be compared following standard principles for RCTs. Discussion The study will test whether the cognitive training programme exerts a positive effect not only on neuropsychological and daily functioning of children with CP but also on other measures such as participation and QOL. We will also use brain MRI to test brain functional and structural changes after the intervention. If this on-line and home-based training programme proves effective, it could be a cost-effective intervention with short- and long-term effects on EF, participation or QOL in CP. Trial registration ClinicalTrials.gov: NCT04025749. Registered 19 July 2019. Retrospectively registered.


INTELLIGENCE Raven's Coloured Progressive Matrices
This test consists of 36 items, grouped into three sets of 12 items of increasing difficulty within each set. Each item contains a pattern problem with one part removed. The participant has to choose which of the six alternatives completes the pattern (7). It has been proved that this test gives comprehensive information on cognitive performance in CP, comprising not only visual but also verbal functions (8).

OTHER MEASURES Strengths and Difficulties Questionnaire
This questionnaire is used to assess parents' perceptions of pro-social and difficult behaviours in their child. Five sub-scales are considered: frequency of emotional symptoms; conduct problems; inattention/hyperactivity; peer problems; and prosocial behaviour (9).

Autism Spectrum Screening Questionaire
It is a screening questionnaire used to identify autism spectrum symptoms in high-functioning children and adolescents (10).

Pain Scale
It is a scale to assess the intensity of pain in children with CP. Firstly, parents were asked if the child had experienced any pain anytime and during the last month. Secondly, participants responded the two questions on pain about intensity and frequency during the last month using the Child Health Questionnaire as in the Study of Participation of Children with CP living in Europe (SPARCLE) (11).

Parental Stress Scale
It is a self-report scale that measures changes in parental stress levels for careers who have accessed targeted support, such as family support, parenting courses and one to one parenting support (12). Beach Center Family Quality of Life Scale This questionnaire assesses families' perceptions of their satisfaction with different aspects of family quality of life. It contains five subscales: family interaction, parenting, emotional wellbeing, physical/material wellbeing and disability-related support (13).
Additional file. Neuropsychological tests and parental questionnaires at T0, T1 and T2 assessments.

NEURO-PSYCHO-SOCIAL MEASURES INSTRUMENT BRIEF DESCRIPTION RELIABILITY Inhibition and Working memory
Spatial Span subtest (WNS) It comprises two series: the forward condition, in which the examiner points out some cubes and the examinee must indicate the same cubes in the same order; and backward, in which the examinee must indicate the cubes in the reverse order. In both conditions, the length of the sequences is gradually increased.
The reliability of the subtest is 0.73 (14).

Digit Span subtest (WISC-V)
It comprises two series: the forward condition, in which the person who perform the assessment read a sequence of numbers and the examinee must recall the numbers in the same order; and the backward condition, in which the examinee must recall the numbers in reverse order.
The reliability of the cognitive competence index (CCI), composed of the subtest of digits, is 0.92 (15).

Conner's Continuous Performance Test -II
In this task respondents are required to press whenever any letter except the target letter 'X' appears on the computer screen.

Auditory Attention and Response Set (NEPSY-II)
The task consists in listening a series of words and when a target word is listened the examinee must touch the correspondent circle associated. The reliability of this subindex is 0.87 (17).

Cognitive flexibility Five Digit Test
It is considered as an alternative for the Stroop Test. FDT is a multilingual non-reading test to assess cognitive flexibility and inhibition. It minimizes the effects of education and social class and allows the testing of some severe clinical cases.

Word Generation (NEPSY-II)
This subindex is aimed to evaluate the acquisition and recuperation of language, recuperation of the vocabulary, spelling ability, starting, working memory, speed of processing, attention, sustained effort and verbal productivity through a task based on generate words that belong to a certain semantic category or with a specific initial letter.
This subindex has a reliability of 0.79 (17).

Tower (D-KEFS)
The Tower Test is a modification similar to earlier Tower test, that is, Tower of Hanoi. The D-KEFS version's usefulness in comparison to these other version is not documented, but D-KEFS version will prove more child-friendly that these other tower tasks remains to be seen (Sue Baron, 2004).
The reliability for the population between 8 to 19 years is 0.51; in population with CP is 0.74 (19).

Theory of mind (NEPSY-II)
This subtest evaluates social perception through assessing the ability to understand mental functions such as believes intention, hoax, emotion, imagination and pretending. The tasks consist in a series of questions about images in which the subject must understand the other person point of view.

Affect recognition (NEPSY-II)
This subindex evaluates the ability of recognise emotions through pictures of kids' faces.

Memory Memory for Designs (NEPSY-II)
This subindex evaluates the ability of learn and remember visual information of children.

Word Selective Reminding (TOMAL)
This subindex evaluates the ability of learn and remember verbal information of children.
The reliability of this test is 0.96 (20).

Visuospatial processing
Arrows (NEPSY-II) This subindex consists in judging the orientation of a line. Several arrows are disposed around a dot and the examinee has to say which lines are addressed towards the dot. The reliability of this test is 0.74-0.88 (17).

Benton's Facial Recognition test
Subjects are presented with a target face above six test faces, and they are asked to indicate which of the six images match the target face.
Part-whole correlation coefficients between the short and long forms of the test ranged from 0.884 to 0.940 (21). Parental Questionnaires Behavior Rating Inventory of Executive Function, Second Edition BRIEF is a parent-rated questionnaire designed to assess the behavioural manifestations of executive functions in everyday life. It consists of eight subscales which combine to form the Behavioural Regulation Index and the Metacognition and Global index.
The reliability is on the 0.90 (22).
Cerebral Palsy Quality of Life CP QOL refers to an individual's perception of their wellbeing across various domains of life. The topics are: social wellbeing and acceptance; feelings about functioning; participation and physical health; emotional wellbeing and self-esteem; access to services; pain and impact of disability and family health (22).

Participation and Environment Measure for Children and Youth
It is used to examine the frequency and level of participation in home, school and community settings (23). The measure also addresses whether the surrounding environment makes it easier or harder to participate.