Mild Traumatic Brain Injury and Post-concussion Syndrome: Treatment and Related Sequela for Persistent Symptomatic Disease

Unveiling the predictive power of biomarkers in traumatic brain injury: A narrative review focused on clinical outcomes

Traumatic brain injury (TBI) has long-term consequences, including neurodegenerative disease risk. Current diagnostic tools are limited in detecting subtle brain damage. This review explores emerging biomarkers for TBI, including those related to neuronal injury, inflammation, EVs, and ncRNAs, evaluating their potential to predict clinical outcomes like mortality, recovery, and cognitive impairment. It addresses challenges and opportunities for implementing biomarkers in clinical practice, aiming to improve TBI diagnosis, prognosis, and treatment.

Identifying Growth Hormone Deficiency in Brain-Injured Patients: The Quality of Life Scale-99

Traumatic brain injury (TBI) is frequently associated with hypopituitarism. The hypothalamic-pituitary axis appears to be susceptible to the same forces that cause injury to the parenchyma of the brain. Following even a mild TBI (mTBI), patients may suffer transient or permanent decreases in anterior pituitary hormones, including somatotropin (growth hormone [GH]), gonadotropins (luteinizing hormone and follicle-stimulating hormone), thyrotropin, and adrenocorticotropic hormone, with the most frequent long-term deficiency being GH deficiency (GHD). GHD is common after mTBI and is often the cause of persistent post-concussive symptoms a year or more post-injury. GHD is known to cause physical and cognitive fatigue, cognitive inefficiency, metabolic changes, and a range of psychological symptoms. Confusing the picture is that some symptoms of GHD are also common to brain injury itself. To facilitate the detection of GHD when comorbid with TBI, we utilized a new symptom inventory, the Quality-of-Life Scale-99 (QoLS-99), and administered it to a cohort of chronic TBI subjects with and without GHD, distinguished using the insulin tolerance test (ITT). Between 2018 and 2023, 371 patients completed the QoLS-99, of which 263 underwent GH testing with the ITT. Of these 263 patients, 136 (52%) were diagnosed with GHD. A retrospective comparison of QoLS-99 scores found that loss of libido (p < 0.006), a reliance on sleep aids (p < 0.011), and feeling overweight (p < 0.015) were the strongest univariate predictors of GHD. Most survey items did not elicit a significant difference in response between the GHD groups, and for those that did, effect sizes were mild to moderate. Still, initial findings demonstrate strong predictive value in a subset of survey items (i.e., GHD symptoms) that are most discriminating in the sample of patients with TBI. A multivariate prediction model using this subset of questions was able to differentiate GHD status in patients with TBI, correctly identifying 88% of GHD cases with a 37% false positive rate. Based on these findings, we recommend that clinicians inquire about libido, insomnia, and body image as potential markers for GHD. Furthermore, given the amenability of patients with GHD to growth hormone replacement therapy, we strongly encourage clinicians and basic scientists to develop interventions for the large and underserved population of patients with TBI with comorbid GHD.

Effects of mTBI with loss of consciousness on neurobehavioral symptoms, depression, and insomnia in former collegiate and NFL football athletes

OBJECTIVE

Considering that diagnostic decisions about mTBI are often predicated on clinical symptom criteria, it is imperative to determine which initial presentation features of mTBI have prognostic significance for identifying those at high risk for long-term functional impairment.

SETTING

Zoom interview Participants: Male, former NCAA Division I, and professional-level National Football League (NFL) athletes (n = 177) between the ages of 27 and 85 (M = 54.1, SD = 14.7).

DESIGN

Cross-sectional case-control. Main Measures: History of mild TBI, history of loss of consciousness (LOC), depression symptoms, insomnia, neurobehavioral symptoms.

RESULTS

Number of mTBI exposures did not predict neurobehavioral symptoms (B = 0.21, SE = 0.18, p = 0.23), but number of mTBI + LOC events did (B = 2.27, SE = 0.64, p = <.001). Further analysis revealed that the number of mTBI + LOC events predicted neurobehavioral symptoms indirectly through both depression (B = 0.85, 95% CI = [0.27, 1.52) and insomnia (B = 0.81, 95% CI = [0.3, 1.4]). Further, the direct effect of mTBI + LOC events on neurobehavioral symptoms became non-significant when depression and insomnia were added to the model (B = 0.78, SE = 0.45, p = 0.08).

CONCLUSIONS

Findings support LOC at time of injury as an important predictor of long-term outcomes. Additionally, results suggest depression and insomnia as potential mediators in the association between mTBI + LOC and neurobehavioral symptoms. These findings provide justification for early depression and insomnia symptom monitoring following mTBI + LOC.

Expanding capabilities to evaluate readiness for return to duty after mTBI: The CAMP study protocol

Physical Therapists affiliated with Intrepid Spirit Centers evaluate and treat Active Duty Service Members (ADSM) who have duty-limiting post-concussion symptoms to improve the ability to perform challenging tasks associated with military service. The Complex Assessment of Military Performance (CAMP) is a test battery that more closely approximates the occupational demands of ADSM without specific adherence to a particular branch of service or military occupational specialty. Subtasks were developed with military collaborators to include high level skills that all service members must be able to perform such as reacting quickly, maintaining visual stability while moving and changing positions, and scanning for, noting, and/or remembering operationally relevant information under conditions of physical exertion.

OBJECTIVE

The purpose of this observational longitudinal study is to: 1- establish typical performance parameters for ADSM on the CAMP test battery 2- determine the element of the CAMP battery that demonstrate the greatest differences from standard performance and serve as predictors for successful return to duty and 3- develop clinician-facing feedback algorithms and displays and 4-develop materials for clinical dissemination. This ongoing multi-site study is currently funded through the CDMRP and has been approved by the Naval Medical Center Portsmouth IRB.

METHODS

ADSM undergoing post-concussion rehabilitation at the Intrepid Spirit Centers will be tested within one week of their initial Physical Therapy evaluation and after completing Physical Therapy. Control participants will include males, females, and ADSM from the Special Operations community. Participants will complete an intake form that includes questions about demographics, military service, deployment and concussion history, and profile and duty status. Other measures include those that explore concussion symptoms, sleep quality, post-traumatic stress, and perceptions of resilience. The CAMP includes three separate 10-15 minute tasks. Movement is recorded by wearable inertial sensors and heart rate variability is recorded with a POLAR10 monitor. The "Run-Roll" task requires rapid position changes, combat rolls and quick running forwards and backwards while carrying a simulated weapon. Visual stability before and after the task is also performed. The "Dual-Task Agility" task includes rapid running with and without a weighted vest and a working memory task. The "Patrol Exertion" task requires repeated stepping onto an exercise step while watching a virtual patrol video. Additional tasks include monitoring direction of travel, observing for signs of enemy presence, and reacting to multiple auditory signals embedded in the video.

DISCUSSION

Measures that evaluate relevant skills are vital to support safe return to duty for ADSM who may be exposed to imminent danger as part of training or mission demands. The CAMP is designed to be an ecologically valid and clinically feasible assessment that may be more sensitive to capturing subtle impairments that impact duty performance as test skills are integrated into dual and multi-tasks that reflect occupational demands. Assessment results may serve as a more robust indicator of readiness for full return to duty after concussion.

Clinical Theragnostic Signature of Extracellular Vesicles in Traumatic Brain Injury (TBI)

Traumatic brain injury (TBI) is a common cause of disability and fatality worldwide. Depending on the clinical presentation, it is a type of acquired brain damage that can be mild, moderate, or severe. The degree of patient's discomfort, prognosis, therapeutic approach, survival rates, and recurrence can all be strongly impacted by an accurate diagnosis made early on. The Glasgow Coma Scale (GCS), along with neuroimaging (MRI (Magnetic Resonance Imaging) and CT scan), is a neurological assessment tools used to evaluate and categorize the severity of TBI based on the patient's level of consciousness, eye opening, and motor response. Extracellular vesicles (EVs) are a growing domain, explaining neurological complications in a more detailed manner. EVs, in general, play a role in cellular communication. Its molecular signature such as DNA, RNA, protein, etc. contributes to the status (health or pathological stage) of the parental cell. Brain-derived EVs support more specific screening (diagnostic and prognostic) in TBI research. Therapeutic impact of EVs are more promising for aiding in TBI healing. It is nontoxic, biocompatible, and capable of crossing the blood-brain barrier (BBB) to transport therapeutic molecules. This review has highlighted the relationships between EVs and TBI theranostics, EVs and TBI-related clinical trials, and related research domain-associated challenges and solutions. This review motivates further exploration of associations between EVs and TBI and develops a better approach to TBI management.

Dual task cost in adults with persistent concussion symptoms

BACKGROUND

Persistent concussion symptoms (PCS) negatively affects common activities of daily living including deficits in both single and dual-task (DT) gait. DT gait deficits are present post-concussion; however, task prioritization and the effects of differing cognitive challenge remain unexplored in the PCS population.

RESEARCH QUESTION

The purpose of this study was to investigate single and dual-task gait performance in individuals with persistent concussion symptoms and to identify task priorization strategies during DT trials.

METHODS

Fifteen adults with PCS (age: 43.9+11.7 y.o.) and 23 healthy control participants (age: 42.1+10.3 y.o.) completed five trials of single task gait followed by fifteen trials of dual task gait along a 10-m walkway. The cognitive challenges consisted of five trials each of visual stroop, verbal fluency, and working memory cognitive challenges. Groups were compared on DT cost stepping characteristics with independent samples t-test or Mann-Whitney U tests.

RESULTS

There were significant overall gait Dual Task Cost (DTC)difference between groups for gait speed (p = 0.009, d=0.92) and step length (p = 0.023, d=0.76). Specific to each DT challenge, PCS participants were slower during Verbal Fluency (0.98 + 0.15 m/s and 1.12 + 0.12 m/s, p = 0.008; d=1.03), Visual Stroop (1.06 + 0.19 m/s and 1.20 + 0.12 m/s, p = 0.012, d=0.88), and Working Memory (1.02 + 0.15 m/s and 1.16 + 0.14 m/s, p = 0.006, d=0.96). There were significant cognitive DTC differences between groups for WM accuracy (p = 0.008, d=0.96), but not for VS accuracy (p = 0.841, d=0.061) or VF total words (p = 0.112, d=0.56).

SIGNIFICANCE

The PCS participants displayed a posture-second strategy whereby gait performance generally decreased in the absence of cognitive changes. However, during the Working Memory DT, PCS participants had a mutual interference response whereby both motor and cognitive performance decreased suggesting the cognitive task plays a key role in the DT gait performance of PCS patients.

Depressive Symptoms in Individuals With Persistent Postconcussion Symptoms: A Systematic Review and Meta-Analysis

IMPORTANCE

Approximately 15% to 30% of individuals with a history of concussion present with persistent postconcussion symptoms (PPCS). Individuals with PPCS are at greater risk of experiencing depressive symptoms.

OBJECTIVE

To synthesize the association between depressive symptoms and PPCS in children, adolescents, and adults via meta-analysis and to investigate potential moderators of that association.

DATA SOURCES

Systematic search of Ovid Medline, CINAHL, PsycInfo, and Embase from 1995 to January 2022 was performed. Additionally, references from included studies were hand-searched to ensure relevant articles were captured in the search.

STUDY SELECTION

Studies that involved participants who experienced PPCS and quantified depressive symptoms were included. The definition of PPCS was limited to physician-diagnosed or self-reported concussion, with symptoms lasting for a minimum of 4 weeks postinjury. Two authors independently screened all articles to determine study eligibility.

DATA EXTRACTION AND SYNTHESIS

Study characteristics were extracted independently by 2 trained investigators. Study data were meta-analyzed using a random-effects meta-analysis.

EXPOSURE

PPCS.

MAIN OUTCOMES AND MEASURES

The the primary outcome was depressive symptoms.

RESULTS

Data were extracted from 18 studies with a total of 9101 participants. Of the 18 studies, all were cohort studies, and 13 (72%) comprised adult populations. The mean (SD) time since concussion was 21.3 (18.7) weeks. After accounting for potential publication bias, the random-effects meta-analysis found a significant positive association between PPCS and depressive symptoms, (odds ratio, 4.56; 95% CI, 2.82-7.37; P < .001). There were no significant moderators, likely due to the small number of studies included.

CONCLUSIONS AND RELEVANCE

In this meta-analysis, experiencing PPCS was associated with a higher risk of experiencing depressive symptoms. There are several important clinical and health policy implications of the findings. Most notably, the development of strategies for effective prevention and earlier intervention to optimize mental health recovery following a concussion should be supported.

Assessing Cognitive Behavioral Therapy for Insomnia to Improve Sleep Outcomes in Individuals With a Concussion: Protocol for a Delayed Randomized Controlled Trial

BACKGROUND

Sleep disturbances post concussion have been associated with more frequent and severe concussion symptoms and may contribute to poorer recovery. Cognitive behavioral therapy for insomnia (CBT-I) is an effective treatment for insomnia; however, it remains unclear if this treatment method is effective in improving sleep outcomes and reducing concomitant postconcussion symptoms.

OBJECTIVE

The hypotheses for this study are that (1) CBT-I will improve sleep outcomes and (2) CBT-I will improve concomitant postconcussion symptoms.

METHODS

In total, 40 individuals who are within ≥4 weeks of postconcussion injury and have insomnia symptoms will be enrolled in this randomized controlled trial. Participants will be randomized into either a group that starts a 6-week CBT-I program immediately after baseline or a waitlist control group that starts CBT-I following a 6-week waiting period. All participants will be reassessed 6, 12, and 18 weeks after baseline. Standardized assessments measuring sleep outcomes, postconcussion symptoms, and mood will be used. Linear regression and t tests will be used for statistical analyses.

RESULTS

Enrollment of 40 participants was completed July 2022, data collection will be completed in November 2022, and publication of main findings is anticipated in May 2023. It is anticipated that participants experience reduced insomnia symptoms and postconcussion symptoms following CBT-I and these improvements will be retained for at least 12 weeks. Additionally, we expect to observe a positive correlation between sleep and postconcussion symptom improvement.

CONCLUSIONS

Successful completion of this pilot study will allow for a better understanding of the treatment of insomnia and postconcussion symptoms in individuals following a concussion.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04885205; https://clinicaltrials.gov/ct2/show/NCT04885205.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/38608.

A Case Series of 39 United States Veterans with Mild Traumatic Brain Injury Treated with Hyperbaric Oxygen Therapy

Importance: The Defense and Veterans Brain Injury Center reported 358,088 mild traumatic brain injury (mTBI) among U.S. service members worldwide between the years 2000 and 2020. Veterans with mTBI have higher rates of Post-Traumatic Stress Disorder (PTSD), depressive disorder, substance use disorder, anxiety disorder, and suicide than their healthy counterparts. Currently, there is no effective treatment for mTBI. Objective: To assess the efficacy of hyperbaric oxygen therapy (HBOT) as a treatment option for mTBI. Design, Setting, Participants: This is a case series of 39 U.S. Veterans diagnosed with mTBI and treated with HBOT. Of these participants, 36 were men and 3 women, and their ages ranged between 28 and 69. The treatment was administered by The 22 Project (a veteran-centered nonprofit organization) using monoplace hyperbaric chambers located in Delray Beach, Florida. Neuroimaging using Single Photon Emission Computer Tomography (SPECT) brain scans performed pre- and post-HBOT were made available for secondary analysis. Nilearn Python Library was utilized to visualize the corresponding neuroimaging data. A two-sided paired t-test in R was used to compare the pre- and post-treatment results. Intervention: A full treatment of HBOT involved 40 sessions. Each session consisted of the administration of 100% oxygen at 1.5 atmospheres for 90 min, twice a day, for 20 days, Mondays to Fridays only. Main Outcome and Measure: Perfusion in the brain’s Brodmann Areas (BA) comparing pre- and post-HBOT using NeuroGam software analysis from brain SPECT scan neuroimaging and multi-symptom self-reports. Results: A comparison between the pre- and post-HBOT brain scans showed significant improvement in the brain perfusion, and the difference was statistically significant (p < 0.001). Separately, participants reported reduced pain, improved mood, and better sleep, an outcome that translated into an average of about 46.6% improvement in the measured symptoms. Conclusions and Relevance: This series demonstrated that HBOT could be a useful treatment for mTBI in U.S. veterans. The participants in the study showed marked improvement in both brain perfusion measured on SPECT scan imaging and measured mTBI symptoms. This is the first study to use brain SPECT scans with quantitative numerical measurements to demonstrate improvement in brain perfusion in veterans with mild TBI treated with HBOT and measured mTBI symptoms. Future research studies are currently being done to validate these important findings.

The University of Kansas Health System Outpatient Clinical Concussion Comprehensive Protocol: An Interdisciplinary Approach

Objective:

The concussion team at The University of Kansas Health System outpatient rehabilitation spine center is comprised of experienced multi-disciplinary experts including physical therapists and a speech language pathologist. The team set forth with a purpose of creating and organizing an internal physical therapy clinical recommendation protocol for initial evaluations and subsequent treatments for the concussed patient. The aim of this paper is to share these recommendation protocols with other therapy teams and provide a foundational layout for treating the patient with post-concussion symptoms in an outpatient physical therapy clinical setting.

Study design:

Clinical recommendation protocol provides guidance for patients ages 10+ from initial evaluation through discharge with emphasis on evidence-based research in the areas of: oculomotor, cervical, vestibular, post-concussion migraine influence, mood disorders(such as anxiety and depression), exertion, and cognitive communicative dysfunction.

Results:

Finding a written, comprehensive clinical resource protocol for post-concussion outpatient evaluation(s) and treatment strategies can be difficult. This document serves as a resource for other outpatient concussion rehabilitation clinics, providing rationale, and objective measurement tools, for assessing and treating concussion patients. To the authors’ knowledge, no other research has produced a practical, efficient evaluation tool to be utilized at bed side, condensing evidence-based research into an easy-to-use form.

Conclusion:

The University of Kansas Health System outpatient concussion rehabilitation center developed clinical recommendation protocols for concussion care. The intent was to standardize assessment and treatment for concussion patients and to share these objective measurement tools and procedures, focused on a team approach of concussion providers, as a clinical outline for both the novice and seasoned clinician specializing in the field of concussion work in an outpatient rehabilitation setting.

Effect of Sleep-Related Symptoms on Recovery From a Sport-Related Concussion

Background

Sleep issues are commonly reported in athletes after a sport-related concussion (SRC). Further studies are needed to evaluate screening methods for sleep disturbances and the risk of persisting symptoms after an SRC.

Purpose

To evaluate the association between the Sport Concussion Assessment Tool 5 (SCAT5) symptoms of trouble falling asleep, fatigue (or low energy), and drowsiness and the risk of persisting symptoms (≥28 days to recovery) in adolescent athletes.

Study Design

Cohort study; Level of evidence, 3.

Methods

A total of 519 athletes aged 13 to 18 years reported any sleep-related symptoms with an SRC, scored as none (0), mild (1-2), moderate (3-4), or severe (5-6), at their initial office visit (median, 5.4 days after an SRC). Scores were correlated with the risk of persisting symptoms. A composite "sleep cluster" score (range, 0-18) was calculated by summing the SCAT5 component items for trouble falling asleep, fatigue, and drowsiness.

Results

The results indicated that, compared with athletes who reported that they did not have each symptom, (1) athletes who reported mild, moderate, or severe trouble falling asleep were 3.0, 4.6, and 6.7 times more likely to have persisting symptoms, respectively; (2) athletes reporting mild, moderate, or severe fatigue (or low energy) were 2.6, 4.8, and 7.6 times more likely to have persisting symptoms, respectively; and (3) athletes reporting mild, moderate, or severe drowsiness were 1.9, 4.6, and 6.8 times more likely to have persisting symptoms, respectively (P < .001 for all). For every 1-point increase in the sleep cluster score, there was a 1.2-fold increased risk of persisting symptoms and an additional 2.4 days of recovery required (P < .001 for both).

Conclusion

Athletes who reported mild, moderate, or severe sleep-related symptoms on the SCAT5 were at a proportionally increased risk of persisting symptoms at the initial office visit.

Use of Novel Concussion Protocol With Infralow Frequency Neuromodulation Demonstrates Significant Treatment Response in Patients With Persistent Postconcussion Symptoms, a Retrospective Study

Introduction

Concussion is a growing public health concern. No uniformly established therapy exists; neurofeedback studies report treatment value. We use infralow frequency neuromodulation (ILF) to remediate disabling neurological symptoms caused by traumatic brain injury (TBI) and noted improved outcomes with a novel concussion protocol. Postconcussion symptoms (PCS) and persistent postconcussion symptoms (PPCS; >3 months post head injury) are designated timelines for protracted neurological complaints following TBI. We performed a retrospective study to explore effectiveness of ILF in PCS/PPCS and investigated the value of using this concussion protocol.

Method

Patients with PCS/PPCS seen for their first neurology office visit or received their first neurofeedback session between 1 August 2018 and 31 January 2021 were entered. Outcomes were compared following treatment as usual (TAU) vs. TAU with ILF neurotherapy (TAU+ILF). The study cohort was limited to PPCS patients; the TAU+ILF group was restricted further to PPCS patients receiving at least 10 neurotherapy sessions. Within the TAU+ILF group, comparisons were made between those who trained at least 10 sessions using concussion protocol (TAU+ILF+CP) and those who trained for at least 10 sessions of ILF regardless of protocol (TAU+ILF-CP).

Results

Among our resultant PPCS cohort (n = 59) leading persistent neurological complaints were headache (67.8%), memory impairment (57.6%), and brain fog (50.8%). PPCS patients in TAU+ILF+CP (n = 25) demonstrated greater net (p = 0.004) and percent (p = 0.026) improvement of symptoms compared to PPCS subjects in TAU (n = 26). PPCS patients in TAU+ILF-CP (n = 8) trended toward significant symptom improvements compared to TAU, and TAU+ILF+CP trended toward greater efficacy than TAU+ILF-CP.

Conclusion

PPCS patients who received TAU+ILF+CP demonstrated significantly greater improvement as a group when compared to TAU. When used as an integrative modality to treatment as usual in managing patients with PPCS, ILF neuromodulation with use of concussion protocol provided significant symptom improvements.

Effects of acupuncture treatment on posttraumatic headache after traumatic brain injury in patients: A protocol for systematic review

BACKGROUND

Posttraumatic headache (PTH) after traumatic brain injury (TBI) is a common clinical symptom, which refers to a headache that occurs after TBI. Acupuncture is often used for the treatment of such patients in China, and significant clinical effects have been achieved. However, to date, its efficacy has not been methodically evaluated. The purpose of this systematic review is to provide evidence to prove the effectiveness of acupuncture in the treatment of PTH in patients with TBI.

METHODS

This systematic review will be conducted in accordance with the preferred reporting items for systematic review and meta-analysis protocols. The following electronic databases will be searched from their inception to February 2022: PubMed, Web of Science, Embase, PsycINFO, the Cochrane Library, and Chinese databases such as Chinese Biomedical Literature (CBM), Chinese Medical Current Content (CMCC), Chinese Scientific Journal Database (VIP), WanFang Database, and China National Knowledge Infrastructure (CNKI). No language restrictions will be applied to the search strategy. Randomized controlled trials and cohort and case-control studies that met the inclusion and exclusion criteria will be included in this study. The meta-analysis will be performed using RevMan 5.3 software. Each session of this systematic review will be conducted independently by 2 members.

RESULTS

This review evaluates the efficacy of acupuncture in the treatment of PTH after TBI.

CONCLUSION

This review provides substantial evidence for the clinical application of acupuncture in PTH treatment after TBI.

ETHICS AND DISSEMINATION

Since the data in this study will be retrieved from published trials, therefore the Patient Consent Statement and Ethical Approval are not required. We will disseminate our results by publishing the research in a peer-reviewed journal.

TRAIL REGISTRATION NUMBER

The protocol was registered in INPLASY (INPLASY 202220073).

Mild Traumatic Brain Injury and Postconcussive Symptom Endorsement: A Parallel Comparison Between Two Nonclinical Cohorts

INTRODUCTION

The prevalence of mild traumatic brain injury (mTBI) is commonly estimated based on indirect metrics such as emergency department visits and self-reporting tools. The study of postconcussive symptoms faces similar challenges because of their unspecific character and indistinct causality. In this article, we compare two nonclinical, epidemiological studies that addressed these two elements and were performed within a relatively narrow period in the state of Colorado.

MATERIALS AND METHODS

De-identified datasets were obtained from a random digit-dialed survey study conducted by the Craig Hospital and a study surveying soldiers returning from deployment by Defense and Veteran Traumatic Brain Injury Center. Information pertinent to participants' demographics, a history of mTBI, and symptom endorsement was extracted and homogenized in order to establish a parallel comparison between the populations of the two studies.

RESULTS

From the 1,558 (Warrior Strong, 679; Craig Hospital, 879) records selected for analysis, 43% reported a history of at least one mTBI. The prevalence was significantly higher among individuals from the Defense and Veteran Traumatic Brain Injury Center study independent of gender or race. Repetitive injuries were reported by 15% of the total combined cohort and were more prevalent among males. Symptom endorsement was significantly higher in individuals with a positive history of mTBI, but over 80% of those with a negative history of mTBI endorsed at least one of the symptoms interrogated. Significant differences were observed between the military and the civilian populations in terms of the types and frequencies of the symptoms endorsed.

CONCLUSIONS

The prevalence of mTBI and associated symptoms identified in the two study populations is higher than that of previously reported. This suggests that not all individuals sustaining concussion seek medical care and highlights the limitations of using clinical reports to assess such estimates. The lack of appropriate mechanisms to determine symptom presence and causality remains a challenge. However, the differences observed in symptom reporting between cohorts raise questions about the nature of the symptoms, the impact on the quality of life for different individuals, and the effects on military health and force readiness.

Cerebrolysin restores balance between excitatory and inhibitory amino acids in brain following concussive head injury. Superior neuroprotective effects of TiO2 nanowired drug delivery

Concussive head injury (CHI) often associated with military personnel, soccer players and related sports personnel leads to serious clinical situation causing lifetime disabilities. About 3-4k head injury per 100k populations are recorded in the United States since 2000-2014. The annual incidence of concussion has now reached to 1.2% of population in recent years. Thus, CHI inflicts a huge financial burden on the society for rehabilitation. Thus, new efforts are needed to explore novel therapeutic strategies to treat CHI cases to enhance quality of life of the victims. CHI is well known to alter endogenous balance of excitatory and inhibitory amino acid neurotransmitters in the central nervous system (CNS) leading to brain pathology. Thus, a possibility exists that restoring the balance of amino acids in the CNS following CHI using therapeutic measures may benefit the victims in improving their quality of life. In this investigation, we used a multimodal drug Cerebrolysin (Ever NeuroPharma, Austria) that is a well-balanced composition of several neurotrophic factors and active peptide fragments in exploring its effects on CHI induced alterations in key excitatory (Glutamate, Aspartate) and inhibitory (GABA, Glycine) amino acids in the CNS in relation brain pathology in dose and time-dependent manner. CHI was produced in anesthetized rats by dropping a weight of 114.6g over the right exposed parietal skull from a distance of 20cm height (0.224N impact) and blood-brain barrier (BBB), brain edema, neuronal injuries and behavioral dysfunctions were measured 8, 24, 48 and 72h after injury. Cerebrolysin (CBL) was administered (2.5, 5 or 10mL/kg, i.v.) after 4-72h following injury. Our observations show that repeated CBL induced a dose-dependent neuroprotection in CHI (5-10mL/kg) and also improved behavioral functions. Interestingly when CBL is delivered through TiO₂ nanowires superior neuroprotective effects were observed in CHI even at a lower doses (2.5-5mL/kg). These observations are the first to demonstrate that CBL is effectively capable to attenuate CHI induced brain pathology and behavioral disturbances in a dose dependent manner, not reported earlier.

Probiotics: Potential novel therapeutics for microbiota-gut-brain axis dysfunction across gender and lifespan

Probiotics are live microorganisms, which when administered in adequate amounts, present a health benefit for the host. While the beneficial effects of probiotics on gastrointestinal function are generally well recognized, new animal research and clinical studies have found that alterations in gut microbial communities can have a broad range of effects throughout the body. Non-intestinal sites impacted include the immune, endocrine, cardiovascular and the central nervous system (CNS). In particular, there has been a growing interest and appreciation about the role that gut microbiota may play in affecting CNS-related function through the 'microbiota-gut-brain axis'. Emerging evidence suggests potential therapeutic benefits of probiotics in several CNS conditions, such as anxiety, depression, autism spectrum disorders and Parkinson's disease. There may also be some gender-specific variances in terms of probiotic mediated effects, with the gut microbiota shaping and being concurrently molded by the hormonal environment governing differences between the sexes. Probiotics may influence the ability of the gut microbiome to affect a variety of biological processes in the host, including neurotransmitter activity, vagal neurotransmission, generation of neuroactive metabolites and inflammatory response mediators. Some of these may engage in cross talk with host sex hormones, such as estrogens, which could be of relevance in relation to their effects on stress response and cognitive health. This raises the possibility of gender-specific variation with regards to the biological action of probiotics, including that on the endocrine and central nervous systems. In this review we aim to describe the current understanding in relation to the role and use of probiotics in microbiota-gut-brain axis-related dysfunction. Furthermore, we will address the conceptualization and classification of probiotics in the context of gender and lifespan as well as how restoring gut microbiota composition by clinical or dietary intervention can help in supporting health outcomes other than those related to the gastrointestinal tract. We also evaluate how these new learnings may impact industrial effort in probiotic research and the discovery and development of novel and more personalized, condition-specific, beneficial probiotic therapeutic agents.

Oculomotor Deficits and Symptom Severity Are Associated With Poorer Dynamic Mobility in Chronic Mild Traumatic Brain Injury

Oculomotor deficits, vestibular impairments, and persistent symptoms are common after a mild traumatic brain injury (mTBI); however, the relationship between visual-vestibular deficits, symptom severity, and dynamic mobility tasks is unclear. Twenty-three individuals (mean age 55.7 ± 9.3 years) with persistent symptoms after mTBI, who were between 3 months to 2 years post-injury were compared with 23 age and sex-matched controls. Oculomotor deficits [depth perception, near-point convergence, baseline visual acuity (BLVA), perception time], vestibular deficits (dynamic visual acuity in the pitch and yaw planes), dynamic mobility measured by the Functional Gait Assessment (FGA), and symptoms measured by the Post-Concussion Symptom Scale (PCSS) and Dizziness Handicap Inventory (DHI) were compared between groups. Participants with mTBI had poorer performance on the FGA (p < 0.001), higher symptom severity on the PCSS (p < 0.001), and higher DHI scores (p < 0.001) compared to controls. Significant differences were seen on specific items of the FGA between individuals with mTBI and controls during walking with horizontal head turns (p = 0.002), walking with vertical head tilts (p < 0.001), walking with eyes closed (p = 0.003), and stair climbing (p = 0.001). FGA performance was correlated with weeks since concussion (r = −0.67, p < 0.001), depth perception (r = −0.5348, p < 0.001), near point convergence (r = −0.4717, p = 0.001), baseline visual acuity (r = −0.4435, p = 0.002); as well as with symptoms on the PCSS (r = −0.668, p < 0.001), and DHI (r = −0.811, p < 0.001). Dynamic balance deficits persist in chronic mTBI and may be addressed using multifaceted rehabilitation strategies to address oculomotor dysfunction, post-concussion symptoms, and perception of handicap due to dizziness.

Sleep quality in the chronic stage of concussion is associated with poorer recovery: A systematic review

Background

Recovery from a concussion varies based on a multitude of factors. One such factor is sleep disturbances. In our prior review, it was observed that in the acute phase, sleep disturbances are predictive of poor outcomes following a concussion. The literature gap remains on how sleep in the chronic phase of recovery affects outcomes.

Objective

To examine the association between sleep quality during the chronic stage of concussion and post-concussion outcomes. Literature Survey: Literature searches were performed during 1 July to 1 August 2019 in selected databases along with searching grey literature. Out of the 733 results, 702 references were reviewed after duplicate removal.

Methods

Three reviewers independently reviewed and consented on abstracts meeting eligibility criteria ( n = 35). The full-text articles were assessed independently by two reviewers. Consensus was achieved, leaving four articles. Relevant data from each study was extracted using a standard data-extraction table. Quality appraisal was conducted to assess potential bias and the quality of articles.

Results

One study included children (18–60 months) and three studies included adolescents and/or adults (ranging 12–35 years). The association between sleep and cognition (two studies), physical activity (one study), and emotion symptoms (one study) was examined. Sleep quality was associated with decreased cognition and emotional symptoms, but not with meeting physical activity guidelines six months post-concussion injury.

Conclusions

The heterogeneity in age of participants and outcomes across studies and limited number of included studies made interpretations difficult. Future studies may consider if addressing sleep quality following concussion will improve outcomes.

Does cognitive-behavioural therapy improve sleep outcomes in individuals with traumatic brain injury: a scoping review

BACKGROUND

Insomnia symptoms are common after a traumatic brain injury (TBI). Cognitive-behavioural therapy (CBT) to treat sleep disturbances and insomnia (CBT-I) has been used to improve sleep outcomes. It is unclear if CBT/CBT-I is efficacious in individuals with a TBI. This review was performed to evaluate the use of CBT/CBT-I in individuals with a TBI who also endorse insomnia and concomitant symptoms.

METHODS

Literature searches were conducted in June 2019. A total of 861 articles were found. The full text of 14 articles was reviewed for inclusion/exclusion criteria. Quality appraisal was conducted to assess the risk of bias.

RESULTS

Five articles met the criteria. Two articles were pilot-randomized control trials and three were case studies. The review indicates that individuals participating in CBT/CBT-I reported increased sleep efficiency, sleep quality, and reduced insomnia symptoms and concomitant symptoms. The major source of bias is a limited number of participants across all studies.

CONCLUSION

This review provides evidence that CBT/CBT-I following a TBI can improve sleep outcomes and reduce concomitant symptoms. More robust studies are needed due to limited number of randomized control trials to determine if CBT/CBT-I is an effective treatment in individuals with TBI.

Sex and Gender Issues for Individuals With Acquired Brain Injury During COVID-19: A Commentary

Worldwide, the rehabilitation community has been affected by coronavirus disease 2019 (COVID-19). The effect of COVID-19 has been disproportionately devastating for individuals with disabilities, particularly those with acquired brain injury (ABI) owing to injury-related cognitive or sensory and physical difficulties. Many physical and psychological symptoms of COVID-19 are already well-known issues for individuals with ABI. Even in a fully functional social and health care system, post-ABI deficits can pose greater challenges to women and other marginalized groups, such as lesbian, gay, bisexual, transgender, gender-nonconforming, and queer or questioning-identified individuals. The restrictions and changes brought about by COVID-19 have the potential to broaden the existing disparities and limitations. This commentary highlights 3 key areas to attend to during this pandemic to help assuage such disparities and limitations.

Assessment of Long-Term Effects of Sports-Related Concussions: Biological Mechanisms and Exosomal Biomarkers

Concussion or mild traumatic brain injury (mTBI) in athletes can cause persistent symptoms, known as post-concussion syndrome (PCS), and repeated injuries may increase the long-term risk for an athlete to develop neurodegenerative diseases such as chronic traumatic encephalopathy (CTE), and Alzheimer's disease (AD). The Center for Disease Control estimates that up to 3.8 million sport-related mTBI are reported each year in the United States. Despite the magnitude of the phenomenon, there is a current lack of comprehensive prognostic indicators and research has shown that available monitoring tools are moderately sensitive to short-term concussion effects but less sensitive to long-term consequences. The overall aim of this review is to discuss novel, quantitative, and objective measurements that can predict long-term outcomes following repeated sports-related mTBIs. The specific objectives were (1) to provide an overview of the current clinical and biomechanical tools available to health practitioners to ensure recovery after mTBIs, (2) to synthesize potential biological mechanisms in animal models underlying the long-term adverse consequences of mTBIs, (3) to discuss the possible link between repeated mTBI and neurodegenerative diseases, and (4) to discuss the current knowledge about fluid biomarkers for mTBIs with a focus on novel exosomal biomarkers. The conclusions from this review are that current post-concussion clinical tests are not sufficiently sensitive to injury and do not accurately quantify post-concussion alterations associated with repeated mTBIs. In the current review, it is proposed that current practices should be amended to include a repeated symptom inventory, a cognitive assessment of executive function and impulse control, an instrumented assessment of balance, vestibulo-ocular assessments, and an improved panel of blood or exosome biomarkers.

Sleep Disturbances in the Acute Stage of Concussion are Associated With Poorer Long-Term Recovery: A Systematic Review

OBJECTIVE

To examine the association between sleep during the acute stage of concussion and long-term outcomes.

LITERATURE SURVEY

Literature searches were performed 1 July 2018 to 1 August 2018 in Ovid MEDLINE, CINAHL, and Web of Science, along with hand searching for gray literature and cited references. Of the 610 search results, 359 unique references were reviewed after duplicates were removed.

METHODOLOGY

Two reviewers independently reviewed and came to consensus on which titles/abstracts met inclusion/exclusion criteria (n = 23). The 23 full-text articles were assessed independently by the same two reviewers for eligibility. Consensus was achieved, leaving four articles for quality assessment and data extraction. One person extracted relevant data from each study using a standard data-extraction table. The data extraction table was reviewed by two reviewers and consensus was achieved for completeness and accuracy. Quality appraisal was conducted to assess the risk for potential bias and quality of included articles.

SYNTHESIS

Two of the articles included children younger than 16 years old and two included a wide age range. In general, poorer sleep was associated with poorer outcomes following concussion at reassessments across any age population. In addition, poorer sleep in the acute stage of concussion was associated with poorer long-term outcomes and recovery.

CONCLUSIONS

The variability in sleep assessments used, symptoms assessed, length of time to reassessments, and comparator group included made data synthesis challenging. The use of standard valid and reliable sleep assessments is recommended. Future studies may consider if addressing sleep disturbances early following concussion will improve longer-term outcomes.

Transcranial direct current stimulation (tDCS) effects on traumatic brain injury (TBI) recovery: A systematic review

Traumatic brain injury (TBI) is a major cause of chronic disability. Less than a quarter of moderate and severe TBI patients improved in their cognition within 5 years. Non-invasive brain stimulation, including transcranial direct current stimulation (tDCS), may help neurorehabilitation by boosting adaptive neuroplasticity and reducing pathological sequelae following TBI.

Association of Salivary MicroRNA Changes With Prolonged Concussion Symptoms

IMPORTANCE

Approximately one-third of children who experience a concussion develop prolonged concussion symptoms. To our knowledge, there are currently no objective or easily administered tests for predicting prolonged concussion symptoms. Several studies have identified alterations in epigenetic molecules known as microRNAs (miRNAs) following traumatic brain injury. No studies have examined whether miRNA expression can detect prolonged concussion symptoms.

OBJECTIVE

To evaluate the efficacy of salivary miRNAs for identifying children with concussion who are at risk for prolonged symptoms.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study at the Penn State Medical Center observed 52 patients aged 7 to 21 years presenting for evaluation of concussion within 14 days of initial head injury, with follow-up at 4 and 8 weeks.

EXPOSURES

All patients had a clinical diagnosis of concussion.

MAIN OUTCOMES AND MEASURES

Salivary miRNA expression was measured at the time of initial clinical presentation in all patients. Patients with a Sport Concussion Assessment Tool (SCAT3) symptom score of 5 or greater on self-report or parent report 4 weeks after injury were designated as having prolonged symptoms.

RESULTS

Of the 52 included participants, 22 (42%) were female, and the mean (SD) age was 14 (3) years. Participants were split into the prolonged symptom group (n = 30) and acute symptom group (n = 22). Concentrations of 15 salivary miRNAs spatially differentiated prolonged and acute symptom groups on partial least squares discriminant analysis and demonstrated functional relationships with neuronal regulatory pathways. Levels of 5 miRNAs (miR-320c-1, miR-133a-5p, miR-769-5p, let-7a-3p, and miR-1307-3p) accurately identified patients with prolonged symptoms on logistic regression (area under the curve, 0.856; 95% CI, 0.822-0.890). This accuracy exceeded accuracy of symptom burden on child (area under the curve, 0.649; 95% CI, 0.388-0.887) or parent (area under the curve, 0.562; 95% CI, 0.219-0.734) SCAT3 score. Levels of 3 miRNAs were associated with specific symptoms 4 weeks after injury; miR-320c-1 was associated with memory difficulty (R, 0.55; false detection rate, 0.02), miR-629 was associated with headaches (R, 0.47; false detection rate, 0.04), and let-7b-5p was associated with fatigue (R, 0.45; false detection rate, 0.04).

CONCLUSIONS AND RELEVANCE

Salivary miRNA levels may identify the duration and character of concussion symptoms. This could reduce parental anxiety and improve care by providing a tool for concussion management. Further validation of this approach is needed.

Growing literature but limited evidence: A systematic review regarding prebiotic and probiotic interventions for those with traumatic brain injury and/or posttraumatic stress disorder

Traumatic brain injury (TBI) is highly prevalent among a wide range of populations, including civilians, military personnel, and Veterans. TBI sequelae may be further exacerbated by symptoms associated with frequently occurring comorbid psychiatric conditions, including posttraumatic stress disorder (PTSD). This is particularly true among the population of military personnel from recent conflicts in Iraq and Afghanistan, with a history of mild TBI (mTBI) and PTSD. The need for efficacious treatments for TBI and comorbid PTSD is significant, and evidence-based interventions for these frequently co-occurring conditions are limited. Based on findings suggesting that inflammation may be an underlying mechanism of both conditions, anti-inflammatory/immunoregulatory agents, including probiotics, may represent a novel strategy to treat TBI and/or PTSD-related symptoms. The focus of this systematic review was to identify and evaluate existing research regarding prebiotic and probiotic interventions for the populations of individuals with a history of TBI and/or PTSD. Only 4 studies were identified (3 severe TBI, 1 PTSD, 0 co-occurring TBI and PTSD). Although findings suggested some promise, work in this area is nascent and results to date do not support some claims within the extensive coverage of probiotics in the popular press.