Neuropsychological assessment of executive functions following pediatric traumatic brain injury

Network analysis of structural MRI predicts executive function in paediatric traumatic brain injury

INTRO

Paediatric traumatic brain injury (pTBI) is likely to result in cognitive impairment, specifically executive dysfunction. Evidence of the neuroanatomical correlates of this executive function (EF) impairment is derived from studies that treat morphometry of brain regions as distinct, independent features, rather than as a complex network of interrelationships. Morphometric similarity captures the meso-scale organisation of the cortex as the interrelatedness of multiple macro-architectural features and presents a novel tool with which to investigate the brain post pTBI.

METHODS

In a retrospective sample (83 pTBI patients, 33 controls), we estimate morphometric similarity from structural MRI by correlating morphometric features between cortical regions. We compared the meso-scale organisation of the cortex between groups then, using partial least squares regression, assessed the predictive validity of morphometric similarity in understanding later executive functioning, two years post-injury.

RESULTS

We found that patients and controls did not differ in terms of the overall magnitude of morphometric similarity. However, a pattern of ROI-level morphometric similarity was predictive of day-to-day EF difficulties reported by parents two years post-injury. This prediction was validated using a leave-one-out, and 20-fold cross-validation approach. Prediction was driven by regions of the prefrontal cortex, typically important for healthy maturation of EF skills in childhood. The meso-scale organisation of the cortex also produced more accurate predictions than any one morphometric feature (i.e. cortical thickness or folding index) alone.

CONCLUSION

We conclude that these methodologies show utility in predicting later executive functioning in this population.

Psychometric properties of the Behavior Rating Inventory of Executive Function, second edition (BRIEF2) self-report form in Iranian adolescents

BACKGROUND

This study investigated the psychometric properties of a Persian translation of the Behavior Rating Inventory of Executive Function, Second Edition (BRIEF2) Self-Report form.

METHOD

Participants were 589 typically developing adolescents (336 girls and 253 boys), ages 11-18 years old (M = 15.16; SD = 2.04), in Iran. They completed the Persian version of the BRIEF2 Self-Report form and Teenage Executive Functioning Inventory (TEXI). The Persian translated BRIEF2 psychometric properties were examined via internal consistency, test-retest reliability, convergent validity via associations with TEXI scores, and internal structure using structural equation modeling (SEM) to evaluate fit of the three-factor structure from the original English version BRIEF2.

RESULTS

Findings indicated the Persian version of BRIEF2 Self-Report form yielded scores with robust reliability, with internal consistency ranging from .87 to .93 and test-retest correlations ranging from .89 to .96, and adequate convergent validity, with correlations with the TEXI ranging from .48 to .79. SEM revealed that a three-factor solution was the best fitting model for the seven subscales of the Persian BRIEF2.

CONCLUSION

These findings support the clinical use of the Persian BRIEF2 in Iranian adolescents, including the interpretation of the BRIEF2 three-factor structure, as well as the multidimensional nature of executive functions.

Brain metabolites measured with magnetic resonance spectroscopy in pediatric concussion and orthopedic injury: An Advancing Concussion Assessment in Pediatrics (A-CAP) study

Millions of children sustain a concussion annually. Concussion disrupts cellular signaling and neural pathways within the brain but the resulting metabolic disruptions are not well characterized. Magnetic resonance spectroscopy (MRS) can examine key brain metabolites (e.g., N-acetyl Aspartate (tNAA), glutamate (Glx), creatine (tCr), choline (tCho), and myo-Inositol (mI)) to better understand these disruptions. In this study, we used MRS to examine differences in brain metabolites between children and adolescents with concussion versus orthopedic injury. Children and adolescents with concussion (n = 361) or orthopedic injury (OI) (n = 184) aged 8 to 17 years were recruited from five emergency departments across Canada. MRS data were collected from the left dorsolateral prefrontal cortex (L-DLPFC) using point resolved spectroscopy (PRESS) at 3 T at a mean of 12 days post-injury (median 10 days post-injury, range 2-33 days). Univariate analyses for each metabolite found no statistically significant metabolite differences between groups. Within each analysis, several covariates were statistically significant. Follow-up analyses designed to account for possible confounding factors including age, site, scanner, vendor, time since injury, and tissue type (and interactions as appropriate) did not find any metabolite group differences. In the largest sample of pediatric concussion studied with MRS to date, we found no metabolite differences between concussion and OI groups in the L-DLPFC. We suggest that at 2 weeks post-injury in a general pediatric concussion population, brain metabolites in the L-DLPFC are not specifically affected by brain injury.

The impact of intellectual disability and sport expertise on cognitive and executive functions

Our aim was to identify the suitability of three assessment tools (i.e., Flanker test, Updating Word Span, and Color Trails Test) for future inclusion in the classification process of elite Paralympic athletes with intellectual disability and to assess the strength of the relation between Executive function (EF) and intelligence. Cognitive and EF assessments were performed on 59 participants, divided into four groups according to their cognitive level (with versus without intellectual disability) and sport expertise (athlete versus novice). Inhibition and working memory update skills were implicated in people with intellectual disability. For set-shifting, a more nuanced picture was observed. Strong associations between EF and intelligence was found in people with intellectual disability. Working memory updating and set-shifting are relevant EF skills to assess in the context of elite sport; however, culture-free alternatives for the Updating Word Span test are needed, and alternatives to the Color Trails Test, less reliant on literacy skills are required.

Variability Across Caregiver and Performance-Based Measures of Executive Functioning in an Acute Pediatric Neurocritical Care Population

Youth admitted to the pediatric intensive care unit (PICU) for traumatic brain injury (TBI) commonly struggle with long-term residual effects in the domains of physical, cognitive, emotional, and psychosocial/family functioning. In the cognitive domain, executive functioning (EF) deficits are often observed. The Behavior Rating Inventory of Executive Functioning, Second Edition (BRIEF-2) is a parent/caregiver-completed measure that is regularly utilized to assess caregivers' perspectives of daily EF abilities. Using parent/caregiver-completed measures like the BRIEF-2 in isolation as outcome measures for capturing symptom presence and severity might be problematic given that caregiver ratings are vulnerable to influence from external factors. As such, this study aimed to investigate the association between the BRIEF-2 and performance-based measures of EF in youth during the acute recovery period post-PICU admission for TBI. A secondary aim was to explore associations among potential confounding factors, including family-level distress, injury severity, and the impact of pre-existing neurodevelopmental conditions. Participants included 65 youths, 8-19 years of age, admitted to the PICU for TBI, who survived hospital discharge and were referred for follow-up care. Non-significant correlations were found between BRIEF-2 outcomes and performance-based measures of EF. Measures of injury severity were strongly correlated with scores from performance-based EF measures, but not BRIEF-2. Parent/caregiver-reported measures of their own health-related quality of life were related to caregiver responses on the BRIEF-2. Results demonstrate the differences captured by performance-based versus caregiver-report measures of EF, and also highlight the importance of considering other morbidities related to PICU admission.