Reaction time and cognitive-linguistic performance in adults with mild traumatic brain injury

A systematic review and meta-analysis of sleep following mild traumatic brain injury: A synthesis of the literature according to age and time-since-injury

This systematic review and meta-analysis (PROSPERO: CRD42021287081) compared sleep in individuals with prior mTBI against that of controls. PubMed, Scopus, and EMBASE were searched through to November 2, 2024. Mean differences were calculated for objective (sleep duration, sleep efficiency, sleep stage [N1-3, REM] proportions) and subjective (Pittsburgh Sleep Quality Index [PSQI]) sleep measures, with analyses conducted based on age (adult ≥18y; child <18y) and time-since-injury/recovery phase (<1w, <1m, 1-12m, ≥1y). Qualitative syntheses were also conducted according to age and recovery phase. Sixty-nine studies met criteria. In children and adults, mean differences in objective sleep duration and sleep efficiency were not statistically significant for any recovery phase. Relative to controls, adults with mTBI had proportionately more N1 (Mean diff. [95%CI], 1.28 % [0.63 %,1.93 %], p = 0.014) and less N3 (-1.16 % [-2.08 %,-0.23 %], p = 0.033) sleep at 1-12-month follow-up, and less REM (-3.37 % [-6.28 %,-0.46 %], p = 0.023) at ≥1 year follow-up; however, these statistical differences did not remain when studies confounded by selection bias were removed. Subjectively, relative to controls, adults with mTBI had higher PSQI scores at <1-week (2.53 [1.43,3.62] points, p = 0.005), <1-month (2.26 [1.47, 3.04], p < 0.001), 1-12-month (2.86 [1.26,4.45], p < 0.001) and ≥1-year (2.62 [1.96, 3.28], p < 0.001) follow-up. The literature suggests individuals with prior mTBI have poorer subjective sleep than controls, but supportive objective data are limited. A limitation to consider when interpreting these findings is that a minority (45 %) of studies had low risk of bias. More research examining objective sleep post-mTBI is needed, especially for children with mTBI.

Neuromechanical Models of Mild Traumatic Brain Injury Conditioned on Reaction Time: A Systematic Review and Meta-Analysis

The accurate, repeatable, and cost-effective quantitative characterization of mild traumatic brain injuries (mTBIs) is crucial for safeguarding the long-term health and performance of high-risk groups, including athletes, emergency responders, and military personnel. However, gaps remain in optimizing mTBI assessment methods, especially regarding the integration of neuromechanical metrics such as reaction time (RT) in predictive models. Background/Objectives: This review synthesizes existing research on the use of neuromechanical probabilistic models as tools for assessing mTBI, with an emphasis on RT's role in predictive diagnostics. Methods: We examined 57 published studies on recent sensing technologies such as advanced electromyographic (EMG) systems that contribute data for probabilistic neural imaging, and we also consider measurement models for real-time RT tracking as a diagnostic measure. Results: The analysis identifies three primary contributions: (1) a comprehensive survey of probabilistic approaches for mTBI characterization based on RT, (2) a technical examination of these probabilistic algorithms in terms of reliability and clinical utility, and (3) a detailed outline of experimental requirements for using RT-based metrics in psychomotor tasks to advance mTBI diagnostics. Conclusions: This review provides insights into implementing RT-based neuromechanical metrics within experimental frameworks for mTBI diagnosis, suggesting that such metrics may enhance the sensitivity and utility of assessment and rehabilitation protocols. Further validation studies are recommended to refine RT-based probabilistic models for mTBI applications.

Frequency and extent of cognitive complaint following adult civilian mild traumatic brain injury: a systematic review and meta-analysis

OBJECTIVE

Cognitive symptoms are associated with return to work, healthcare use and quality of life after mild traumatic brain injury (mTBI). Additionally, while overall 'post-concussion' symptoms are often present at similar levels in mTBI and control groups, cognitive complaints may be specifically elevated in mTBI. A systematic review and meta-analysis was conducted to investigate the frequency and extent of cognitive complaints following adult civilian mTBI, and compare it to the frequency and extent of complaints in control populations (PROSPERO: CRD42020151284).

METHOD

This review included studies published up to March 2022. Thirteen studies were included in the systematic review, and six were included in the meta-analysis. Data extraction and quality assessment were conducted by two independent reviewers.

RESULTS

Cognitive complaints are common after mTBI, although reported rates differed greatly across studies. Results suggested that mTBI groups report cognitive complaints to a significantly greater extent than control groups (Hedges' g = 0.85, 95% CI 0.31-1.40, p = .0102). Heterogeneity between studies was high (τ2 = 0.20, 95% CI 0.04-1.58; I2 = 75.0%, 95% CI 43.4%-89.0%). Between-group differences in symptom reporting were most often found when healthy rather than injured controls were employed.

CONCLUSIONS

Cognitive complaints are consistently reported after mTBI, and are present at greater levels in mTBI patients than in controls. Despite the importance of these complaints, including in regards to return to work, healthcare use and quality of life, there has been limited research in this area, and heterogeneity in research methodology is common.

Salivary microRNA as a prospective tool for concussion diagnosis and management: A scoping review

BACKGROUND

Despite increased efforts directed toward research, concussions are a growing concern and can be a complex injury for healthcare professionals to manage. Current practices are largely dependent on patients self-reporting symptoms and a clinical assessment, which uses objective tools that lack effectiveness. With the demonstrated effects of concussions, it is imperative that a more valid or reliable objective tool, like a clinical biomarker, be identified to improve outcomes. One potential biomarker that has shown promise is salivary microRNA. However, there is no objective consensus as to which microRNA offers the most clinical value regarding concussions, hence this review. Therefore, the purpose of this scoping review was to identify salivary miRNAs associated with concussions.

METHODS

Two independent reviewers performed a literature search to identify research articles. Studies using human subjects, collected salivary miRNA, and were published in English were included. Data of interest were salivary miRNA, collection timing, and relation to concussion diagnosis or management.

RESULTS

This paper reviews nine studies that analyzed salivary miRNA for concussion diagnosis and management.

CONCLUSIONS

In total, the studies have identified 49 salivary miRNA that show promise in assisting with concussion practices. With continued research, the use of salivary miRNA may enhance clinicians' abilities to diagnose and manage concussions.

Self-Perception of Cognitive-Communication Functions After Mild Traumatic Brain Injury

PURPOSE

A mixed-method approach was used to investigate the lived experiences of adults with mild traumatic brain injury (mTBI). The study aimed to understand the perceived relationship between cognitive-communication problems, thinking and communication concerns, and neurobehavioral symptoms. We hypothesized that individuals with cognitive-communication problems would attribute their problems with communication to their mTBI history and their self-perceived problems would be correlated with symptomatology.

METHOD

The Neurobehavioral Symptom Inventory (NSI) and an online cognitive-communication survey was used to conduct a study of 30 adults with mTBI history. Quantitative survey and NSI scores were analyzed with content analysis and correlational statistics.

RESULTS

The average NSI Total score was 17 with the following subscale scores: somatic (5), affective (8), and cognitive (3.9). Participants reported problems with expressive communication (56%), comprehension (80%), thinking (63%), and social skills (60%). Content analysis revealed problems in the following areas: expression (e.g., verbal, and written language), comprehension (reading and verbal comprehension), cognition (e.g., attention, memory and speed of processing, error regulation), and functional consequences (e.g., academic work, social problems, and anxiety and stress). A Pearson correlation indicated a statistically significant relationship (p < .01) between the Communication Survey Total and the Total, Somatic, Affective, and Cognitive subscales.

CONCLUSIONS

This study highlights a multifactorial basis of cognitive-communication impairment in adults with mTBI. We show that those with mTBI history perceive difficulties with cognitive-communication skills: conversations, writing, and short-term memory/attention. Furthermore, those with mTBI perceive their cognitive-communication problems after injury have impacted their vocational, social, and academic success.

Psychiatric disorders in post-traumatic brain injury patients: A scoping review

Background

Traumatic Brain Injury (TBI) is an important antecedent in the evaluation of patients with psychiatric disorders. The association between TBI and the subsequent appearance of psychiatric disorders has been documented, however, the findings found in the literature are diverse and controversial.

Objective

To identify the most prevalent psychiatric disorders after head trauma.

Design

An exploratory review (SCOPING) was carried out using the PRISMA extension protocol. Articles published between the years 2010-2022 were used to identify and describe the most prevalent psychiatric disorders after a TBI. Psychiatric disorders were classified according to clinical characteristics in neurotic syndromes, psychotic syndromes, cognitive disorders, among others.

Results

A total of 32 articles were included. In the framework of neurotic syndromes, depression is the most prevalent psychiatric alteration after a TBI, becoming a sequel that shows a higher incidence in the first year after the traumatic event. The findings found in relation to post-traumatic stress disorder are controversial, showing great variability regarding the degree of severity of the injury. The prevalence of psychotic syndromes is relatively low because it is difficult to determine if the psychosis is a direct consequence of a TBI. In the cognitive sphere, it was found that people with TBI presented alterations in cognitive functions.

Conclusions

The findings found in the review respond to the hypothesis initially raised, which assumes that head trauma is an important etiological factor in the appearance of psychiatric disorders.

Is sentence ambiguity comprehension affected after mild traumatic brain injury? Results suggest cognitive control is more important than diagnosis

BACKGROUND

Individuals with mild traumatic brain injury (mTBI) may experience chronic cognitive-linguistic impairments that are difficult to evaluate with existing measures. Garden path sentences are linguistically complex sentences that lead readers down a path to an incorrect interpretation. Previous research indicates many individuals, with or without mTBI, may have difficulty fully resolving the ambiguity of garden path sentences, a skill which may require cognitive control. Evidence suggests cognitive control can be impacted by mTBI. Thus, impairments in cognitive control are expected to correlate with interpreting ambiguous sentences.

AIMS

To examine the relationship between cognitive control and the processing of ambiguous garden path sentences in adults with mTBI. We predict individuals with mTBI will perform more poorly on ambiguous sentence tasks compared with a control group. Further, we predict that performance on this task will correlate with measures of cognitive control and working memory.

METHODS & PROCEDURES

A total of 20 adults with mTBI history and 44 adults with no significant neurological history were recruited from the community. Participants completed a computerized, ambiguous sentence measure with carefully designed comprehension questions and an abbreviated neuropsychological battery of cognitive-linguistic tasks.

OUTCOMES & RESULTS

Participants performed similarly on sentence ambiguity resolution measures across groups with a wide range in performance. A comprehension measure aimed at identifying full ambiguity resolution correlated with cognitive control across groups.

CONCLUSIONS & IMPLICATIONS

A link between cognitive control and linguistic ambiguity is confirmed in a comprehension measure by the current findings. mTBI history did not appear to change the nature of the relationship between cognitive control and ambiguity resolution. High individual variability on sentence and cognitive control measures across groups suggest that if an impairment were present, it would affect both types of tasks. Thus, testing cognitive communication following mTBI should specifically examine complex cognitive and linguistic processing.

WHAT THIS PAPER ADDS

What is already known on the subject Cognitive control and ambiguous sentence processing are known to be linked, but the circumstances and individual variability associated with when cognitive control is recruited to support sentence processing are not fully understood. Very little is known about sentence processing following TBI history, despite cognitive control commonly being impaired following mild TBI. Thus, our study was necessary to explore the theoretical and clinical relationships between cognitive control and ambiguous sentence processing in individuals with mild TBI history. What this paper adds to existing knowledge This study adds to our understanding of how cognitive control and ambiguous sentence processing are linked in those with mild TBI history, and similar to the few previous studies, there were no group differences in cognitive or sentence measures. The positive correlation between cognitive control on Stroop and a particular ambiguous sentence comprehension question targeting inhibitory control highlights that any relationship between abilities or assessment tasks must be very specific to tasks with overlapping requirements, such as inhibition. What are the potential or actual clinical implications of this work? The relationship between cognitive and ambiguous sentence measures highlights the need to assess all areas of cognition and communication in those with mild TBI history without assuming that impairments in cognitive performance will relate to communication. The overlap between abilities is highly specific and must be explored on a case-by-case basis in those with mild TBI. Evaluation and treatment should still be individualized based on the functional communication profile of the client.

Analysis of Discourse Production to Assess Cognitive Communication Deficits Following Mild Traumatic Brain Injury With and Without Posttraumatic Stress

PURPOSE

Cognitive communication deficits can be difficult to assess in individuals with mild traumatic brain injury (mTBI). However, the use of discourse analysis as a direct and sensitive metric of cognitive communication skills has shown promising clinical utility for other TBI severity levels. This exploratory study investigated discourse production in service members and veterans (SMVs) with uncomplicated mTBI with and without posttraumatic stress disorder (PTSD) and SMVs with neither mTBI or PTSD.

METHOD

Fifteen SMVs with mTBI and PTSD, 26 with mTBI, and 25 controls with no brain injury (NBI) and without PTSD were given a wordless picture story to elicit spontaneous discourse. Discourse samples were analyzed for global coherence, word count, the use of negative emotion words, cognitive process words, nonfluencies, and story completeness.

RESULTS

Results revealed a significant difference between the mTBI (Mdn = 3.33) and NBI (Mdn = 3.50) groups, χ²(3) = 6.044, p = .017, ε² = .03, for global coherence. Word count differed significantly between the mTBI + PTSD (Mdn = 135) and NBI (Mdn = 195) groups, χ²(3) = 7.968, p = .006, ε² = .06. No other group differences were observed.

DISCUSSION

Structural features of discourse production may serve as potential markers of cognitive communication deficits in mTBI. Furthermore, PTSD may contribute to verbal fluency deficits in individuals with mTBI. Additional research is needed to develop discourse-related measures that are more sensitive to the effects of mTBI and PTSD.

Discourse Performance in Adults With Mild Traumatic Brain Injury, Orthopedic Injuries, and Moderate to Severe Traumatic Brain Injury, and Healthy Controls

INTRODUCTION

Adults with mild traumatic brain injury (mTBI) are at risk for communication disorders, yet studies exploring cognitive-communication performance are currently lacking.

AIMS

This aim of this study was to characterize discourse-level performance by adults with mTBI on a standardized elicitation task and compare it to (a) healthy adults, (b) adults with orthopedic injuries (OIs), and (c) adults with moderate to severe TBI.

METHOD

This study used a cross-sectional design. The participants included mTBI and OI groups recruited prospectively from an emergency medicine department. Moderate to severe TBI and healthy data were acquired from TalkBank. One-way analyses of variance were used to compare mean linguistic scores.

RESULTS

Seventy participants across all groups were recruited. Groups did not differ on demographic variables. The study found significant differences in both content and productivity measures among the groups. Variables did not appear sensitive to differentiate between mTBI and OI groups.

DISCUSSION

Cognitive and language performance of adults with mTBI is a pressing clinical issue. Studies exploring language with carefully selected control groups can influence the development of sensitive measures to identify individuals with cognitive-communication deficits.

Cognitive-Linguistic outcome in moderate to severe diffuse axonal injury and association with fatigue

PURPOSE

Individuals with traumatic brain injury (TBI) often have persistent cognitive-linguistic deficits that negatively influence their life. Our objective was to examine the cognitive-linguistic outcome in individuals with moderate to severe diffuse axonal injury (DAI) with a novel test battery. As fatigue is a common symptom affecting the lives of individuals with DAI, we also wanted to assess whether the self-reported fatigue was associated with cognitive-linguistic abilities.

METHODS

Selected cognitive-linguistic subtests of the Finnish KAT test and The Mental Fatigue Scale (MFS) were applied to 48 adults with moderate to severe DAI and 27 healthy controls. The majority of the participants with DAI were in the chronic stage. The groups were compared using ANCOVA. Linear regressions were used to analyze the association between MFS and cognitive-linguistic outcomes.

RESULTS

The participants with DAI had significantly poorer scores than the controls in most cognitive-linguistic variables and reported significantly more fatigue. Two of the four cognitive-linguistic composite variables were associated with the degree of self-reported fatigue.

CONCLUSIONS

Cognitive-linguistic deficits are common in individuals with moderate to severe DAI, and The Finnish KAT test is a valuable tool to detect those. Fatigue was associated with linguistic working memory and language production.

Methodological Problems With Online Concussion Testing

Reaction time testing is widely used in online computerized concussion assessments, and most concussion studies utilizing the metric have demonstrated varying degrees of difference between concussed and non-concussed individuals. The problem with most of these online concussion assessments is that they predominantly rely on consumer grade technology. Typical administration of these reaction time tests involves presenting a visual stimulus on a computer monitor and prompting the test subject to respond as quickly as possible via keypad or computer mouse. However, inherent delays and variabilities are introduced to the reaction time measure by both computer and associated operating systems that the concussion assessment tool is installed on. The authors hypothesized systems that are typically used to collect concussion reaction time data would demonstrate significant errors in reaction time measurements. To remove human bias, a series of experiments was conducted robotically to assess timing errors introduced by reaction time tests under four different conditions. In the first condition, a visual reaction time test was conducted by flashing a visual stimulus on a computer monitor. Detection was via photodiode and mechanical response was delivered via computer mouse. The second condition employed a mobile device for the visual stimulus, and the mechanical response was delivered to the mobile device's touchscreen. The third condition simulated a tactile reaction time test, and mechanical response was delivered via computer mouse. The fourth condition also simulated a tactile reaction time test, but response was delivered to a dedicated device designed to store the interval between stimulus delivery and response, thus bypassing any problems hypothesized to be introduced by computer and/or computer software. There were significant differences in the range of responses recorded from the four different conditions with the reaction time collected from visual stimulus on a mobile device being the worst and the device with dedicated hardware designed for the task being the best. The results suggest that some of the commonly used visual tasks on consumer grade computers could be (and have been) introducing significant errors for reaction time testing and that dedicated hardware designed for the reaction time task is needed to minimize testing errors.