Cognitive Outcome After Complicated Mild Traumatic Brain Injury: A Literature Review and Meta-Analysis

Exploring the link among injury severity, white matter connectivity and psychosocial outcomes in pediatric TBI: a probabilistic tractography approach

AIM

We examined associations among injury severity, white matter structural connectivity within functionally defined brain networks and psychosocial/adaptive outcomes in children with traumatic brain injury (TBI).

METHOD

Participants included 58 youths (39 male) with complicated-mild TBI (cmTBI; n = 12, age =  12.6 ± 2.0), moderate/severe TBI (msTBI; n =  16, age =  11.4 ± 2.9) and a comparison group with orthopedic injury (OI; n =  24, age =  11.7 ± 2.1), at least 1 year post-injury. Participants underwent diffusion tensor imaging and parents rated children's behavioral and adaptive function on the CBCL and ABAS-3, respectively. Probabilistic tractography quantified streamline density. Group differences were analyzed for structural connectivity and behavioral outcomes.

RESULTS

Groups differed in structural connectivity within regions of the default mode and central executive networks (ps < .05, FDR corrected). The msTBI group displayed decreased connectivity relative to cmTBI and OI, whereas the cmTBI group displayed increased connectivity relative to msTBI and OI. Similar patterns emerged in several behavioral domains. Ordinary least squares path analyses showed that structural connectivity mediated the relationship between injury severity and multiple parent-reported outcomes for msTBI.

INTERPRETATION

White matter structural connectivity may explain unique variance in long-term psychosocial and adaptive outcome in children with TBI, particularly in cases of moderate-to-severe injury.

Parent-Reported Academic Outcomes After a Mild Traumatic Brain Injury in the Pediatric Population

BACKGROUND

Millions of children are diagnosed with a traumatic brain injury (TBI) each year, most being mild TBI (mTBI). The effect of mTBIs on academic performance is of significant importance. We investigate mTBI's impact on parent-reported academic outcomes in school-aged pediatric participants.

METHODS

This cross-sectional survey study queried parents (N = 285) regarding letter grade performance and the presence or absence of academic accommodations before and after an mTBI, including complicated mTBI (c-mTBI, or mTBI with radiographic abnormality).

RESULTS

We found a parent-reported decline in letter grades following c-mTBI (p < .001), with no significant change following uncomplicated mTBIs. Degree and length of recovery were also associated with grade changes (p < .05). Those with no academic accommodations prior to the injury showed significant decreases in grades after injury regardless of post-injury accommodation status (p < .05).

IMPLICATIONS OF SCHOOL HEALTH POLICY, PRACTICE, AND EQUITY

This study underscores the need for an improved framework of support to maximize academic performance of children following mTBI, especially in those with a c-mTBI and still recovering from their injury.

CONCLUSION

Our study identifies children who are at risk for adverse academic outcomes following mTBI. We encourage efforts to better support school nurses in this effort, including improved communication between health care teams and school teams.

Accelerated Aging after Traumatic Brain Injury: An ENIGMA Multi-Cohort Mega-Analysis

OBJECTIVE

The long-term consequences of traumatic brain injury (TBI) on brain structure remain uncertain. Given evidence that a single significant brain injury event increases the risk of dementia, brain-age estimation could provide a novel and efficient indexing of the long-term consequences of TBI. Brain-age procedures use predictive modeling to calculate brain-age scores for an individual using structural magnetic resonance imaging (MRI) data. Complicated mild, moderate, and severe TBI (cmsTBI) is associated with a higher predicted age difference (PAD), but the progression of PAD over time remains unclear. We sought to examine whether PAD increases as a function of time since injury (TSI) and if injury severity and sex interacted to influence this progression.

METHODS

Through the ENIGMA Adult Moderate and Severe (AMS)-TBI working group, we examine the largest TBI sample to date (n = 343), along with controls, for a total sample size of n = 540, to replicate and extend prior findings in the study of TBI brain age. Cross-sectional T1w-MRI data were aggregated across 7 cohorts, and brain age was established using a similar brain age algorithm to prior work in TBI.

RESULTS

Findings show that PAD widens with longer TSI, and there was evidence for differences between sexes in PAD, with men showing more advanced brain age. We did not find strong evidence supporting a link between PAD and cognitive performance.

INTERPRETATION

This work provides evidence that changes in brain structure after cmsTBI are dynamic, with an initial period of change, followed by relative stability in brain morphometry, eventually leading to further changes in the decades after a single cmsTBI. ANN NEUROL 2024;96:365-377.

Recall and recognition of similarities items in neuropsychological assessment: Memory, validity, and meaning

The current study examined whether the Memory Similarities Extended Test (M-SET), a memory test based on the Similarities subtest of the Wechsler Abbreviated Scale of Intelligence, Second Edition (WASI-II), has value in neuropsychological testing. The relationship of M-SET measures of cued recall (CR) and recognition memory (REC) to brain injury severity and memory scores from the Wechsler Memory Scale, Fourth Edition (WMS-IV) was analyzed in examinees with traumatic brain injuries ranging from mild to severe. Examinees who passed standard validity tests were divided into groups with intracranial injury (CT + ve, n = 18) and without intracranial injury (CT-ve, n = 50). In CT + ve only, CR was significantly correlated with Logical Memory I (LMI: rs = .62) and Logical Memory II (LMII: rs = .65). In both groups, there were smaller correlations with delayed visual memory (VRII: rs = .38; rs = .44) and psychomotor speed (Coding: rs = .29; rs = .29). The REC score was neither an indicator of memory ability nor an internal indicator of performance validity. There were no differences in M-SET or WMS-IV scores for CT-ve and CT + ve, and reasons for this are discussed. It is concluded that M-SET has utility as an incidental cued recall measure.

Innovative Insights into Traumatic Brain Injuries: Biomarkers and New Pharmacological Targets

A traumatic brain injury (TBI) is a major health issue affecting many people across the world, causing significant morbidity and mortality. TBIs often have long-lasting effects, disrupting daily life and functionality. They cause two types of damage to the brain: primary and secondary. Secondary damage is particularly critical as it involves complex processes unfolding after the initial injury. These processes can lead to cell damage and death in the brain. Understanding how these processes damage the brain is crucial for finding new treatments. This review examines a wide range of literature from 2021 to 2023, focusing on biomarkers and molecular mechanisms in TBIs to pinpoint therapeutic advancements. Baseline levels of biomarkers, including neurofilament light chain (NF-L), ubiquitin carboxy-terminal hydrolase-L1 (UCH-L1), Tau, and glial fibrillary acidic protein (GFAP) in TBI, have demonstrated prognostic value for cognitive outcomes, laying the groundwork for personalized treatment strategies. In terms of pharmacological progress, the most promising approaches currently target neuroinflammation, oxidative stress, and apoptotic mechanisms. Agents that can modulate these pathways offer the potential to reduce a TBI's impact and aid in neurological rehabilitation. Future research is poised to refine these therapeutic approaches, potentially revolutionizing TBI treatment.

Olfactory training effects in children after mild traumatic brain injury

OBJECTIVE

Mild traumatic brain injury (mTBI) might impair the sense of smell and cognitive functioning. Repeated, systematic exposure to odors, i.e., olfactory training (OT) has been proposed for treatment of olfactory dysfunctions, including post-traumatic smell loss. Additionally, OT has been shown to mitigate cognitive deterioration in older population and enhance selected cognitive functions in adults. We aimed to investigate olfactory and cognitive effects of OT in the pediatric population after mTBI, likely to exhibit cognitive and olfactory deficits.

METHODS

Our study comprised 159 children after mTBI and healthy controls aged 6-16 years (M = 9.68 ± 2.78 years, 107 males), who performed 6-months-long OT with a set of 4 either high- or low-concentrated odors. Before and after OT we assessed olfactory functions, fluid intelligence, and executive functions.

RESULTS

OT with low-concentrated odors increased olfactory sensitivity in children after mTBI. Regardless of health status, children who underwent OT with low-concentrated odors had higher fluid intelligence scores at post-training measurement, whereas scores of children performing OT with high-concentrated odors did not change.

CONCLUSION

Our study suggests that OT with low-concentrated odors might accelerate rehabilitation of olfactory sensitivity in children after mTBI and support cognitive functions in the area of fluid intelligence regardless of head trauma.