The Effect of Childhood Traumatic Brain Injury on Verbal Fluency Performance: A Systematic Review and Meta-Analysis

Traumatic brain injuries: a neuropsychological review

The best predictor of functional outcome in victims of traumatic brain injury (TBI) is a neuropsychological evaluation. An exponential growth of research into TBI has focused on diagnosis and treatment. Extant literature lacks a comprehensive neuropsychological review that is simultaneously scholarly and practical. In response, our group included, and went beyond a general overview of TBI's, which commonly include definition, types, severity, and pathophysiology. We incorporate reasons behind the use of particular neuroimaging techniques, as well as the most recent findings on common neuropsychological assessments conducted in TBI cases, and their relationship to outcome. In addition, we include tables outlining estimated recovery trajectories of different age groups, their risk factors and we encompass phenomenological studies, further covering the range of existing-promising tools for cognitive rehabilitation/remediation purposes. Finally, we highlight gaps in current research and directions that would be beneficial to pursue.

Norms, convergent validity, test-retest reliability, and practice effects for verbal fluency overall performance, clustering, and switching in Spanish-speaking children

OBJECTIVE

We conducted two empirical studies (in a cross-sectional and a longitudinal design) with the aim at establishing normative data (including norms for strategy use [i.e., clustering and switching strategies] and performance over time), and examining the convergent validity, the test-retest reliability (3-4 wks interval) and the changes in performance with practice (1 year interval) of the different verbal fluency (VF) quantitative and qualitative scores in Spanish-speaking children and adolescents.

METHOD

In S1 (n = 620 6- to 15-year-old Spanish-speaking children and adolescents), MANCOVA and Pearson's correlations were employed. In S2 (n = 148 6- to 12-year-old Spanish-speaking children), intraclass correlation coefficient (ICC), paired t-tests, and Confirmatory Factor Analysis (CFA) were used.

RESULTS

S1 results showed an age effect on all VF measures (quantitative and qualitative). The number of switches/clusters was more related to total word productivity and to executive functions (EF) than the mean cluster size. In S2, a significant increase in phonological VF performance was observed on number of switches and word productivity scores from baseline (Time 1) to repeat testing at Time 2. Practice effects were observed at Time 3 on all measures except for semantic and phonological mean cluster size. Test-retest reliability coefficients at Time 2 for number of clusters and switches, but not for mean cluster size, fell in the moderate range, ranging from ICCs .61 to ICCs .81. Test-retest reliability coefficients for total word productivity were higher (ICCs above .80) and stronger when testing as a unity with CFA methods (ϕ=.94, p < .001).

CONCLUSIONS

These data may be relevant for informing the neuropsychological assessment of spontaneous cognitive flexibility in children with typical development (TD) and those with developmental or acquired disorders.

Semantic fluency in 3-6 years old preschoolers: which executive functions?

Semantic Fluency (SF) increases with age, along with the lexicon and the strategies to access it. Among the cognitive processes involved in controlling lexical access, Executive Functions (EF) play an essential role. Nevertheless, which EF, namely inhibition, working memory, and cognitive flexibility, are specifically tapped by SF during preschool years, when these basic EF components are developing and differentiating, is still unknown. The study had a two-fold aim: 1. to analyze in preschoolers the role of EF basic components on SF; 2. to investigate if EF mediated the effect of age on SF. A total of 296 typically developing preschoolers (M age = 57.86; SD = 9.91; month range = 33-74) were assessed with an SF task and EF tasks measuring the main EF basic components. Results showed that during preschool, response inhibition, working memory, and cognitive flexibility were significant predictors of SF, explaining 27% of its variance. Moreover, the effect of age on the SF task performance correlated with the improvement of these EF components. This study supports the importance of considering cognitive control processes in 3-6 year-old preschoolers as they underline important competencies for the child's development, such as the ability to quickly access vocabulary.

Category Switching Test: A Brief Amyloid-β-Sensitive Assessment Tool for Mild Cognitive Impairment

The Category Switching Test (CaST) is a verbal fluency test with active semantic category switching. This study aimed to explore the association between CaST performance and brain amyloid-β (Aβ) burden in patients with mild cognitive impairment (MCI) and the neurofunctional mechanisms. A total of 112 participants with MCI underwent Florbetapir positron emission tomography, resting-state functional magnetic resonance imaging, and a neuropsychological test battery. The high Aβ burden group had worse CaST performance than the low-burden group. CaST score and left middle temporal gyrus fractional amplitude of low-frequency fluctuations (fALFF) related inversely to the global Florbetapir standardized uptake value rate. Functional connectivity between the left middle temporal gyrus and frontal lobe decreased widely and correlated with CaST score in the high Aβ burden group. Thus, CaST score and left middle temporal gyrus fALFF were valuable in discriminating high Aβ burden. CaST might be useful in screening for MCI with high Aβ burden.

Effects of Pediatric Traumatic Brain Injury on Verbal IQ: A Systematic Review and Meta-Analysis

OBJECTIVES

To examine the effects of pediatric traumatic brain injury (TBI) on verbal IQ by severity and over time.

METHODS

A systematic review and subsequent meta-analysis of verbal IQ by TBI severity were conducted using a random effects model. Subgroup analysis included two epochs of time (e.g., <12 months postinjury and ≥12 months postinjury).

RESULTS

Nineteen articles met inclusion criteria after an extensive literature search in MEDLINE, PsycInfo, Embase, and CINAHL. Meta-analysis revealed negative effects of injury across severities for verbal IQ and at both time epochs except for mild TBI < 12 months postinjury. Statistical heterogeneity (i.e., between-study variability) stemmed from studies with inconsistent classification of mild TBI, small sample sizes, and in studies of mixed TBI severities, although not significant. Risk of bias on estimated effects was generally low (k = 15) except for studies with confounding bias (e.g., lack of group matching by socio-demographics; k = 2) and measurement bias (e.g., outdated measure at time of original study, translated measure; k = 2).

CONCLUSIONS

Children with TBI demonstrate long-term impairment in verbal IQ, regardless of severity. Future studies are encouraged to include scores from subtests within verbal IQ (e.g., vocabulary, similarities, comprehension) in addition to functional language measures (e.g., narrative discourse, reading comprehension, verbal reasoning) to elucidate higher-level language difficulties experienced in this population.

Parent Interventions Improve Behavior After Pediatric Traumatic Brain Injury: A Systematic Review and Meta-analysis

OBJECTIVE

To examine child behavior change scores from randomized controlled trials (RCTs) of parent interventions for pediatric traumatic brain injury (TBI).

METHODS

MEDLINE, EMBASE, PsycINFO, and CINAHL were searched to identify studies that examined parent interventions for pediatric TBI. Inclusion criteria included (i) a parent intervention for children with TBI; (ii) an RCT study design; (iii) statistical data for child behavior outcome(s); and (iv) studies that were published in English.

RESULTS

Seven studies met inclusion criteria. All interventions reported improved child behavior after pediatric TBI; however, child and parent factors contributed to behavior change scores in some interventions. Factors found to contribute to the level of benefit included age of child, baseline behavior levels, sociodemographics (eg, parent income, parent education), and parent mental health.

CONCLUSION

Improved child behavior outcomes resulting from parent interventions for pediatric TBI are well supported by the evidence in the peer-reviewed literature. Clinicians are encouraged to consider child and parent factors as they relate to child behavior outcomes.

Quantitative Meta-analyses of Cognitive Abilities in Children With Pediatric-onset Multiple Sclerosis

Pediatric-onset multiple sclerosis (POMS), is the manifestation of multiple sclerosis in individuals before 18 years of age. About a third of children with POMS show some form of lower cognitive performance. The purpose of this study is to examine using quantitative meta-analyses the effect size of altered performance between children with and without POMS on overall intelligence quotient (IQ), information processing speed, and language functions. We searched the literature for studies that reported scores on cognitive tests administered to children with and without POMS. Studies were systematically reviewed using PRISMA guidelines. We analyzed data from 14 studies that examined 1283 children with and without POMS when cognitive categories consisted of five or more studies. Effect sizes, publication bias and potential confounds were considered. Significant cognitive differences are revealed for all categories with the strongest effect observed for overall IQ. A moderate effect is observed for information processing speed, and small effects for verbal fluency and verbal memory. Cognitive abilities present differently in children with POMS and a better understanding of this manifestation will inform intervention and remediation tools that can improve clinical and educational practice for the benefit of children with POMS.

Cognitive Differences between Men and Women with HIV: A Systematic Review and Meta-Analysis

OBJECTIVE

Although many studies report that women with HIV (WWH) are more vulnerable to cognitive impairment than men with HIV (MWH), this trend is not described consistently in the literature. In this systematic review and meta-analysis, we investigated whether the weight of evidence supports the existence of a significant sex difference in cognitive functioning among people with HIV and, if so, whether specific domains are affected.

METHOD

A systematic literature search retrieved 4,062 unique articles published between January 2000 and June 2019. Eligibility criteria were that studies directly compared adult WWH and MWH using a neuropsychological test battery. After extensive screening, we included 11 studies in the systematic review (N = 3,333) and 6 in the meta-analysis (N = 2,852).

RESULTS

Six studies included in the systematic review found WWH performed significantly more poorly on measures of cognitive performance than MWH; the other five found no sex differences. Meta-analytic results indicated that WWH performed significantly more poorly than MWH in three cognitive domains (psychomotor coordination, visuospatial learning, and memory), but magnitudes of effect sizes were small (d = -.16, -.43, and - .30, respectively). Analyses detected no sex differences in global cognitive functioning and in the other cognitive domains.

CONCLUSIONS

Sex differences in cognitive performance are small, and sociodemographic and psychiatric characteristics of WWH and MWH differ between studies. Cognitive differences between WWH and MWH may be explained by sex-based variation in these characteristics, the impact of which seems to outweigh that of HIV-related clinical variables (e.g., CD4 count and viral load).