Multimodal personalised executive function intervention (E-Fit) for school-aged children with complex congenital heart disease: protocol for a randomised controlled feasibility study

INTRODUCTION

Children with congenital heart disease (CHD) are at risk for executive functions (EF) impairments. To date, interventions have limited effects on EF in children and adolescents with complex CHD. Therefore, we developed a new multimodal and personalised EF intervention (E-Fit). This study aims to test the feasibility of this intervention called 'E-Fit' for children with complex CHD and EF impairments.

METHODS AND ANALYSIS

This is a single-centre, single-blinded, randomised controlled feasibility study exploring the E-Fit intervention. We aim to enrol 40 children with CHD aged 10-12 years who underwent infant cardiopulmonary bypass surgery and show clinically relevant EF impairments (T-score ≥60 on any Behaviour Rating Inventory for Executive Function questionnaire summary scale). The multimodal intervention was developed with focus groups and the Delphi method involving children and adolescents with CHD, their parents and teachers, and health professionals. The intervention is composed of three elements: computer-based EF training using CogniFit Inc 2022, performed three times a week at home; weekly EF remote strategy coaching and analogue games. The content of the computer and strategy training is personalised to the child's EF difficulties. The control group follows their daily routines as before and completes a diary about their everyday activities four times a week. Participants will be randomised in a 1:1 ratio. Feasibility is measured by the participants' and providers' ratings of the participants' adherence and exposure to the intervention, recruitment rates and the evaluation of the intended effects of the programme.

ETHICS AND DISSEMINATION

Local ethics committee approval was obtained for the study (BASEC-Nr: 2021-02413). Parents provide written informed consent. Key outputs from the trial will be disseminated through presentations at conferences, peer-reviewed publications and directly to participating families. Furthermore, these results will inform the decision whether to proceed to a randomised controlled trial to investigate effectiveness.

TRIAL REGISTRATION NUMBER

NCT05198583.

Counting on random number generation: Uncovering mild executive dysfunction in congenital heart disease

Congenital heart disease (CHD) is associated with various neurocognitive deficits, particularly targeting executive functions (EFs), of which random number generation (RNG) is one indicator. RNG has, however, never been investigated in CHD. We administered the Mental Dice Task (MDT) to 67 young adults with CHD and 55 healthy controls. This 1-minute-task requires the generation of numbers 1 to 6 in a random sequence. RNG performance was correlated with a global EF score. Participants underwent MRI to examine structural-volumetric correlates of RNG. Compared to controls, CHD patients showed increased backward counting, reflecting deficient inhibition of automatized behavior. They also lacked a small-number bias (higher frequency of small relative to large numbers). RNG performance was associated with global EF scores in both groups. In CHD patients, MRI revealed an inverse association of counting bias with most of the volumetric measurements and the amount of small numbers was positively associated with corpus callosum volume, suggesting callosal involvement in the "pseudoneglect in number space". In conclusion, we found an impaired RNG performance in CHD patients, which is associated with brain volumetric measures. RNG, reportedly resistant to learning effects, may be an ideal task for the longitudinal assessment of EFs in patients with CHD.

Brain volumes in adults with congenital heart disease correlate with executive function abilities

Congenital heart disease is the most common birth defect, and patients are at risk for neurodevelopmental impairment and brain abnormalities. Yet, little is known about the link between brain volumes and cognitive function in adults with congenital heart disease. Forty-four patients and 53 controls between 18 and 32 years underwent brain magnetic resonance imaging and cognitive testing, assessed with an intelligence quotient and executive function global score. Associations between brain volumes and cognitive function were calculated using linear models. Cognitive function in patients was within the normal range (intelligence quotient: 97.74 (10.76)). Total brain volume was significantly smaller in patients compared to controls (1067.26 (113.53) vs 1113.04 (97.88) cm³, P < 0.01), irrespective of cardiac factors (heart defect complexity, cyanosis, cardiopulmonary bypass: all P > 0.4). After adjusting for total brain volume, only corpus callosum volume remained significantly smaller (P = 0.03). Smaller total brain volume was associated with poorer overall executive functioning (P = 0.02) and inhibition (P < 0.01), in both patients and controls. The association between total brain volume and overall executive functioning was moderated by parental socioeconomic status (lower socioeconomic status was associated with a stronger association between brain volume and EF; interaction P = 0.03). In adults with congenital heart disease, despite normal intelligence quotient, brain volume alterations persist into adulthood and are related to executive functioning, in particular inhibitory control. Adults coming from low socioeconomic background and with altered brain volumes are especially vulnerable and should thus be followed-up during adulthood to ensure optimal social and educational support.

The Multidimensional Aspects of Sleep Spindles and Their Relationship to Word-Pair Memory Consolidation

STUDY OBJECTIVES

Several studies proposed a link between sleep spindles and sleep dependent memory consolidation in declarative learning tasks. In addition to these state-like aspects of sleep spindles, they have also trait-like characteristics, i.e., were related to general cognitive performance, an important distinction that has often been neglected in correlative studies. Furthermore, from the multitude of different sleep spindle measures, often just one specific aspect was analyzed. Thus, we aimed at taking multidimensional aspects of sleep spindles into account when exploring their relationship to word-pair memory consolidation.

DESIGN

Each subject underwent 2 study nights with all-night high-density electroencephalographic (EEG) recordings. Sleep spindles were automatically detected in all EEG channels. Subjects were trained and tested on a word-pair learning task in the evening, and retested in the morning to assess sleep related memory consolidation (overnight retention). Trait-like aspects refer to the mean of both nights and state-like aspects were calculated as the difference between night 1 and night 2.

SETTING

Sleep laboratory.

PARTICIPANTS

Twenty healthy male subjects (age: 23.3 ± 2.1 y).

MEASUREMENTS AND RESULTS

Overnight retention was negatively correlated with trait-like aspects of fast sleep spindle density and positively with slow spindle density on a global level. In contrast, state-like aspects were observed for integrated slow spindle activity, which was positively related to the differences in overnight retention in specific regions.

CONCLUSION

Our results demonstrate the importance of a multidimensional approach when investigating the relationship between sleep spindles and memory consolidation and thereby provide a more complete picture explaining divergent findings in the literature.

Sleep spindles are related to schizotypal personality traits and thalamic glutamine/glutamate in healthy subjects

BACKGROUND

Schizophrenia is a severe mental disorder affecting approximately 1% of the worldwide population. Yet, schizophrenia-like experiences (schizotypy) are very common in the healthy population, indicating a continuum between normal mental functioning and the psychosis found in schizophrenic patients. A continuum between schizotypy and schizophrenia would be supported if they share the same neurobiological origin. Two such neurobiological markers of schizophrenia are: (1) a reduction of sleep spindles (12-15 Hz oscillations during nonrapid eye movement sleep), likely reflecting deficits in thalamo-cortical circuits and (2) increased glutamine and glutamate (Glx) levels in the thalamus. Thus, this study aimed to investigate whether sleep spindles and Glx levels are related to schizotypal personality traits in healthy subjects.

METHODS

Twenty young male subjects underwent 2 all-night sleep electroencephalography recordings (128 electrodes). Sleep spindles were detected automatically. After those 2 nights, thalamic Glx levels were measured by magnetic resonance spectroscopy. Subjects completed a magical ideation scale to assess schizotypy.

RESULTS

Sleep spindle density was negatively correlated with magical ideation (r = -.64, P < .01) and thalamic Glx levels (r = -.70, P < .005). No correlation was found between Glx levels in the thalamus and magical ideation (r = .12, P > .1).

CONCLUSIONS

The common relationship of sleep spindle density with schizotypy and thalamic Glx levels indicates a neurobiological overlap between nonclinical schizotypy and schizophrenia. Thus, sleep spindle density and magical ideation may reflect the anatomy and efficiency of the thalamo-cortical system that shows pronounced impairment in patients with schizophrenia.

Molecular basis for the coupling ion selectivity of F1F0 ATP synthases: probing the liganding groups for Na+ and Li+ in the c subunit of the ATP synthase from Propionigenium modestum

The conserved glutamate residue at position 65 of the Propionigenium modestum c subunit is directly involved in binding and translocation of Na+ across the membrane. The site-specific introduction of the cQ32I and cS66A substitutions in the putative vicinity to cE65 inhibited growth of the single-site mutants on succinate minimal agar, indicating that both amino acid residues are important for proper function of the oxidative phosphorylation system. This growth inhibition was abolished, however, if the cF84L/cL87V double mutation was additionally present in the P. modestum c subunit. The newly constructed Escherichia coli strain MPC848732I, harboring the cQ32I/cF84L/cL87V triple mutation, revealed a change in the coupling ion specificity from Na+ to H+. ATP hydrolysis by this enzyme was therefore not activated by NaCl, and ATP-driven H+ transport was not affected by this alkali salt. Both activities were influenced, however, by LiCl. These data demonstrate the loss of the Na+ binding site and retention of Li+ and H+ binding sites within this mutant ATPase. In the E. coli strain MPC848766A (cS66A/cF84L/cL87V), the specificity of the ATPase was further restricted to H+ as the exclusive coupling ion. Therefore, neither Na+ nor Li+ stimulated the ATPase activity, and no ATP-driven Li+ transport was observed. The ATPase of the E. coli mutant MPC32N (cQ32N) was activated by NaCl and LiCl. The mutant ATPase exhibited a 5-fold higher Km for NaCl but no change in the Km for LiCl in comparison to that of the parent strain. These results demonstrate that the binding of Na+ to the c subunit of P. modestum requires liganding groups provided by Q32, E65, and S66. For the coordination of Li+, two liganding partners, E65 and S66, are sufficient, and H+ translocation was mediated by E65 alone.