Accelerated repetitive transcranial magnetic stimulation in the treatment of post-concussion symptoms due to mild traumatic brain injury: a pilot study

Objective: To investigate the feasibility, tolerability, and efficacy of twice-daily, low frequency (LF) repetitive transcranial magnetic stimulation (rTMS) over the right dorsolateral prefrontal cortex (DLPFC) in the reduction of chronic post-concussion symptoms (PCS) in patients who have suffered a mild traumatic brain injury (mTBI).Methods: 15 patients with mTBI received 30 sessions of twice-daily LF rTMS (1 Hz) over the right DLPFC. Post-concussion symptoms, pain, disability, fatigue, apathy, agitation, and mood were assessed by a psychiatrist pre- and post-treatment. Cognitive testing was also performed pre-, mid-, and post-rTMS.Results: All participants completed treatment with no serious adverse events. Significant improvements were observed in overall post-concussion symptoms, disability and pain ratings, as well as depression and anxiety symptoms. There was no significant change in overall executive functioning, fatigue severity, apathy, or agitation. Cognitive testing revealed improvements in verbal fluency, working memory, selective attention, and cognitive processing speed.Conclusions: This small-sample pilot study suggests that twice-daily, LF rTMS over the right DLPFC can be safely and tolerably applied and has the potential to improve post-concussion symptoms as well as elements of mood and cognition in patients with mTBI. Larger, sham-controlled studies will be important to confirm these observations.

The structure of post-concussion symptoms in adolescent student athletes: confirmatory factor analysis and measurement invariance

Objective: This study examined factor models for the Post-Concussion Symptom Scale (PCSS) at baseline and after suspected sport-related concussion, and measurement invariance from pre-injury to post-injury assessments and across age, gender, and health history groups (e.g., attention-deficit/hyperactivity disorder, psychiatric history). Methods: Adolescent student athletes (ages 13-18) completed a baseline PCSS (n = 39,015; 54.3% boys) and a subsample within 21 days of a suspected concussion (n = 1,554; 56.7% boys) completed a post-injury PCSS. Five models were evaluated for fit and invariance. Results: Confirmatory factor analyses showed good baseline and post-injury model fit for a previously supported four-factor model (i.e., cognitive-sensory, sleep-arousal, vestibular-somatic, and affective), an alternative four-factor model (i.e., cognitive, sleep-arousal, physical, and affective), and an incomplete bifactor model with vestibular-somatic and affective specific factors, along with partial invariance from pre-injury to post-injury assessments. Partial-to-full invariance was established for each model at baseline across demographic and health history groups. Conclusions: Results showed empirical and conceptual support for both PCSS subscales (i.e., cognitive, sleep-arousal, physical, and affective) and a total score for use in pre-injury to post-injury assessments and across demographic and health history groups at baseline. Future normative data, stratified by demographics and health history, could provide more precise symptom assessments for concussion management.

Traumatic Brain Injury in Children: The Psychological Effects of Mild Traumatic Brain Injury

Concussion, or mild traumatic brain injury (mTBI), results from a force to the head and can cause acute physical, cognitive, and psychological symptoms. The majority of concussion symptoms will resolve within a month, but upward of a third of patients will have persistent, chronic symptoms. When these symptoms become chronic and persist beyond 1-3 months, this is termed post-concussion syndrome (PCS). Psychological changes associated with PCS may in part be due to a traumatic event and the injury itself and therefore post-traumatic stress reactions may contribute. In addition, alterations to daily life and alteration of lifestyle as a result of the injury can cause feelings of disconnection which in turn can feed anxiety and depression symptoms. A preinjury diagnosis or history of psychiatric or mood disorder, migraine, or family history of psychiatric illness is one the greatest risk factors for the development of PCS. It is recommended that evaluation of concussion and those with PCS take a multidisciplinary approach including evaluation by psychology, psychiatry, and/or neuropsychology. While most concussions do not require treatment, those with PCS will not likely see the resolution of their physical and psychological symptoms without intervention. Treatment is limited, but cognitive behavioral treatment has shown promise in the management of PCS symptoms. It is important to recognize the role psychology plays in the development and persistence of PCS and to recognize and seek collaborative care when treating these patients.

Transcranial low-frequency pulsating electromagnetic fields (T-PEMF) as post-concussion syndrome treatment

Background

Treatment options for the subgroup of people who develop long‐lasting symptoms following mild traumatic brain injury are limited. Transcranial pulsating low‐frequency electromagnetic stimulation (T‐PEMF) in other patient groups has shown promising results in several studies with proposed neuroprotective and anti‐inflammatory effects.

Objective

The present pilot study was conducted to access feasibility and tolerability of T‐PEMF in treating post‐concussion syndrome.

Methods

Seven patients with post‐concussion syndrome received 5 weeks of daily 30 minutes T‐PEMF treatment with evaluation after 2 and 5 weeks and 3 months after ending treatment.

Results

Compliance was high as all subject completed the full treatment. Two patients however experienced a worsening of their concussion symptoms during the course of treatment. The remaining patients had some discomfort in relation to treatment, mainly headache, but passing and less for each treatment. The majority (n = 5) had a reduction in symptoms overall, up to 61% (2%‐61%) based on the Rivermead Post‐Concussion Symptoms Questionnaire.

Conclusion

Further studies on T‐PEMF as a treatment option for post‐concussion syndrome are warranted.

Multi-modal management of sport and non-sport related concussion by chiropractic sports specialists: a case series

This case series describes the multi-modal treatment plans delivered by two chiropractic sports specialists for the management of post-concussive symptoms (PCS). Three concussion cases are presented each with different mechanisms of injury (two sportrelated and one non-sport-related) and each within a different stage of recovery (acute, sub-acute, and chronic). Treatment plans included patient education, sub-symptom threshold exercise, soft-tissue therapy, spinal manipulation, and cervical spine as well as visual/vestibular rehabilitation exercises. This series highlights three important observations: (1) the efficacy of individualized, multi-modal treatment plans based on suggested clinical profiles for patients with PCS of various stages; (2) that the delineation of concussion literature based on mechanism of injury (i.e. sport- vs. non-sport-related) may be unnecessary; and (3) these cases provide encouraging evidence to support the inclusion of manual therapists with advanced knowledge of concussion treatment, such as chiropractors, as part of the interdisciplinary healthcare team when managing patients with PCS.

Robotic Semi-Automated Transcranial Doppler Assessment of Cerebrovascular Autoregulation in Post-Concussion Syndrome: Methodological Considerations

Post-concussion syndrome (PCS) refers to a constellation of physical, cognitive, and emotional symptoms after traumatic brain injury (TBI). Despite its incidence and impact, the underlying mechanisms of PCS are unclear. We hypothesized that impaired cerebral autoregulation (CA) is a contributor. In this article, we present our protocol for non-invasively assessing CA in patients with TBI and PCS in a real-world clinical setting. A prospective, observational study was integrated into outpatient clinics at a tertiary neurosurgical center. Data points included: demographics, symptom profile (Post-Concussion Symptom Scale [PCSS]) and neuropsychological assessment (Cambridge Neuropsychological Test Automated-Battery [CANTAB]). Cerebrovascular metrics (nMxa co-efficient and the transient hyperaemic-response ratio [THRR]) were collected using transcranial Doppler (TCD), finger plethysmography, and bespoke software (ICM+). Twelve participants were initially recruited but 2 were excluded after unsuccessful insonation of the middle cerebral artery (MCA); 10 participants (5 patients with TBI, 5 healthy controls) were included in the analysis (median age 26.5 years, male to female ratio: 7:3). Median PCSS scores were 6/126 for the TBI patient sub-groups. Median CANTAB percentiles were 78 (healthy controls) and 25 (TBI). nMxa was calculated for 90% of included patients, whereas THRR was calculated for 50%. Median study time was 127.5 min and feedback (n = 6) highlighted the perceived acceptability of the study. This pilot study has demonstrated a reproducible assessment of PCS and CA metrics (non-invasively) in a real-world setting. This protocol is feasible and is acceptable to participants. By scaling this methodology, we hope to test whether CA changes are correlated with symptomatic PCS in patients post-TBI.

Complicated versus uncomplicated mild traumatic brain injuries: A comparison of psychological, cognitive, and post-concussion symptom outcomes

INTRODUCTION

A complicated mild traumatic brain injury (MTBI) is defined as mild by all clinical severity indicators but is complicated due to a traumatic intracranial abnormality visible on neuroimaging. Researchers have reported mixed findings regarding whether neuropsychological and functional outcomes following complicated MTBI are worse than, or similar to, outcomes following uncomplicated MTBI. This study examined patients referred from a Taiwanese emergency department to a neurosurgical outpatient clinic. Participants with complicated MTBI, uncomplicated MTBI, and those who did not undergo head computed tomography (CT) were compared on psychological, neuropsychological, and post-concussion symptom outcomes within 21 days of injury.

METHOD

Participants with complicated MTBI (n = 42), uncomplicated MTBI (n = 77), and no head CT (n = 172) completed the Paced Auditory Serial Attention Test, Taiwanese Word Sequence Learning Test, a semantic Verbal Fluency Test, the Checklist of Post-Concussion Symptoms, and the Beck Depression and Anxiety Inventories.

RESULTS

No significant differences were observed between groups on any measure. For individual post-concussion symptoms, dizziness, anxiety, and attention difficulty were endorsed more often after uncomplicated MTBIs, but these group differences were not significant after controlling for multiple comparisons.

CONCLUSIONS

Participants with complicated MTBIs did not have worse acute or subacute outcomes than participants with uncomplicated MTBIs or no head CT. These results are consistent with many studies finding comparable outcomes between those with complicated and uncomplicated MTBIs. This study is limited by small sample size and minimal information on intracranial abnormalities, broadly categorizing groups based on positive or negative neuroimaging as opposed to specific lesion types and locations.

Anxiety, Depression, and Quality of Life: A Long-Term Follow-Up Study of Patients with Persisting Concussion Symptoms

Persisting concussion symptoms (PCS) can last for months, years, or indefinitely and affect a considerable number of concussion patients. The objectives of this study were to evaluate the prevalence of clinical symptoms of anxiety and depression and the relationship between PCS and quality of life in patients examined at the Canadian Concussion Centre. The Depression and Anxiety Stress Scale-42 (DASS-42) and the World Health Organization Quality of Life Assessment-BREF (WHOQOL-BREF) were sent to 526 adult patients diagnosed with PCS. Median with interquartile range follow-up time was 5 (4-7) years. Of the 105 respondents, 35.2% displayed mild or greater symptoms of anxiety, depression, or both. Importantly, the number of previous concussions was correlated with elevations on the DASS-42 Anxiety (p = 0.030) and Depression (p = 0.018) subscale scores, suggesting an acquired cause of symptoms. Patients with clinical elevations of depression, anxiety, or both exhibited poorer mean WHOQOL-BREF scores in each domain (p < 0.001) compared to those who scored in the normal range on the DASS-42. These findings indicate that depression and anxiety in PCS can endure for years and are associated with diminished quality of life. Consequently, depression and anxiety should be identified and treated early in PCS populations in order to optimize recovery. Although the underlying etiology of depression and anxiety cannot be ascertained with certainty in the present study, the association between depression and anxiety and the number of concussions may indicate an organic explanation. In the future, quality-of-life measures should be incorporated into treatment and research in PCS to improve intervention strategies and enhance understanding of the trajectory of recovery in this population.

The cost of a single concussion in American high school football: a retrospective cohort study

Aim:

The potential financial burden of American football-related concussions (FRC) is unknown. Our objective was to describe the healthcare costs associated with an FRC and determine factors associated with increased costs.

Methodology/results:

A retrospective cohort study of concussed high school football players presenting between November 2017 and March 2020 was undertaken; 144 male high school football players were included. Total costs were about $115,000, for an average direct healthcare cost of $800.10/concussion. Visiting the emergency department (β = 502.29, 95% CI: 105.79–898.61; p = 0.01), the initial post-concussion symptom scale score (β = 0.39, 95% CI: 0.11–0.66; p = 0.01) and a post-concussion syndrome diagnosis (β = 670.37, 95% CI: 98.96–1241.79; p = 0.02) were each independently associated with total costs.

Conclusion:

A granular understanding of cost-driving factors associated with FRC is the first step in understanding the cost–effectiveness of prevention and treatment methods.

The healthcare costs, or the costs incurred by the healthcare system, associated with a single concussion in American high school football are unknown. We reviewed the records of 144 high school football players who received concussion care at our sport concussion center and calculated the direct healthcare costs associated with the appointments, imaging studies and therapies received, when applicable. We found that each concussion results in about $800 of healthcare system spending. A few factors were associated with greater costs, including visiting the emergency department and having symptoms for over 1 month. Furthermore, the more symptoms an athlete had at their first clinic visit, the higher total cost of care. Understanding these costs can potentially help clinicians and researchers determine the best ways to maximize care while minimizing the costs.

The Ketogenic Diet in the Treatment of Post-concussion Syndrome-A Feasibility Study

Concussion is the most common form of mild traumatic brain injury (mTBI). Although most patients' symptoms resolve within a month, patients with post-concussion syndrome (PCS) may continue to experience symptoms for years and have limited treatment options. This pilot study assessed the feasibility and symptom-related effects of a ketogenic diet (KD) in patients with PCS symptoms. The Ketogenic Diet in Post-Concussion Syndrome (KD-PCS) was a single-arm trial of a 2-month KD high in non-starchy vegetables and supplemented with medium-chain triglyceride (MCT) oil. Macronutrient targets were ≥70% fat, ≤10% carbohydrate, and the remainder as protein as energy. We assessed feasibility by daily self-reported measure of urine acetoacetate and collection of 3-day food records and serum beta-hydroxybutyrate at multiple timepoints. We assessed symptoms by administering the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) and Modified Balance Error Scoring System (M-BESS) at baseline and month 2 and the Post-Concussion Symptom Scale (PCSS) at baseline, month 1, and month 2. Fourteen participants enrolled in the KD-PCS. Twelve participants completed the study and 11 implemented the KD (73% fat, 9% carbohydrate, and 18% protein) and achieved ketosis. One participant complained of MCT-related diarrhea that resolved and another reported nausea and fatigue that resulted in withdrawal from the study. Among compliant participants, the visual memory domain of the ImPACT improved by 12 points (p = 0.02) and PCSS scores improved by 9 points, although not statistically significant. This pilot trial suggests that the KD is a feasible experimental treatment for PCS and justifies further study of its efficacy.

Herbal Medicine for Traumatic Brain Injury: A Systematic Review and Meta-Analysis of Randomized Controlled Trials and Limitations

Background: This systematic review aimed to evaluate the effectiveness (functional outcomes and clinical symptoms) and safety (incidence of adverse events) of herbal medicine (HM) as monotherapy or adjunctive therapy to conventional treatment (CT) for traumatic brain injury (TBI).

Methods: We comprehensively searched 14 databases from their inception until July 2019. Randomized controlled trials (RCTs) using HM as monotherapy or adjunctive therapy to treat TBI patients were included. The primary outcome was functional outcomes, consciousness state, morbidity, and mortality. Meta-analysis was performed to calculate a risk ratio (RR) or mean difference (MD) with 95% confidence intervals (CIs), when appropriate data were available. Methodological quality of RCTs and the strength of evidence were also assessed.

Results: Thirty-seven RCTs with 3,374 participants were included. According to meta-analysis, HM as a monotherapy (RR 1.29, 95% CI: 1.21–1.37) or an adjunctive therapy to CT (RR 1.21, 95% CI: 1.16–1.27) showed significantly better total effective rate based on clinical symptoms, compared to CT alone. Subgroup analysis showed that HM had significantly improved post-concussion syndrome, dizziness, headache, epilepsy, and mild TBI, but not traumatic brain edema, compared to CT. Moreover, HM combined with CT had significantly improved post-concussion syndrome, mental disorder, headache, epilepsy, and mild TBI-like symptoms, but not cognitive dysfunction and posttraumatic hydrocephalus, compared to CT alone. When HM was combined with CT, functional outcomes such as activities of daily living and neurological function were significantly better than in patients treated using CT alone. In terms of the incidence of adverse events, HM did not differ from either CT (RR 0.88, 95% CI: 0.33–2.30) or placebo (RR 2.29, 95% CI: 0.83–6.32). However, HM combined with CT showed better safety profile than CT alone (RR 0.64, 95% CI: 0.44–0.93). Most studies had a high risk of performance bias, and the quality of evidence was mostly rated “very low” to “moderate,” mostly because the included studies had a high risk of bias and imprecise quantitative synthesis results.

Conclusion: The current evidence suggests that there is insufficient evidence for recommending HM for TBI in clinical practice. Therefore, further larger, high-quality, rigorous RCTs should be conducted.

Feasibility of Smartphone-Delivered Progressive Muscle Relaxation in Persistent Post-Traumatic Headache Patients

Persistent post-traumatic headache (PPTH) is often the most common injury after mild traumatic brain injury (mTBI), reported by 47-95% of patients. Progressive muscle relaxation (PMR) has level A evidence in preventing migraine and tension headaches. However, research on this behavioral therapy for PPTH, let alone smartphone delivered, is limited. We performed a single-arm study of prospective patients calling our Concussion Center between June 2017 and July 2018. Inclusion criteria were that subjects had to meet International Classification of Headache Disorders, 3rd Edition criteria for PPTH secondary to mTBI, have four or more headache days a month, be age 18-85 years and 3-12 months post-injury, own a smartphone, and not tried headache behavioral therapy within the year. We recorded baseline headache and neuropsychiatric data. Using the RELAXaHEAD smartphone application, which has a headache diary and PMR audio files, participants were instructed to record headache symptoms and practice 20 min of PMR daily. There were three monthly follow-up assessments. There were 49 subjects enrolled. Basic demographics were: 33 (67%) female with mean age 40.1 ± 14.6 [20, 75] years. Of the 49 subjects, 15 (31%) had pre-existing headaches. In 11 (22%) subjects, mTBI was sports related. Subjects reported 17.7 ± 9.3 [4, 31] headache days in the month before enrollment, and 49 (100%) experienced over three concussion symptoms. Participants inputted data in the RELAXaHEAD app on average 18.3 ± 12.0 days [0, 31] the first month. Number of participants who did PMR over four times per week was 12 (24.5%) the first month, 9 (22.5%) the second month, and 6 (15%) the third month. After 3 months, 17 (42.5 %) participants continued doing PMR. Participants cited time constraints, forgetfulness, application glitches, and repetitiveness as obstacles to practicing PMR. It is feasible to get PPTH subjects to practice behavioral therapy through low-cost smartphone-based PMR two times weekly. Future work will assess efficacy and examine how to optimize barriers to PMR.

Is the Rivermead Post-Concussion Symptoms Questionnaire a Reliable and Valid Measure to Assess Long-Term Symptoms in Traumatic Brain Injury and Orthopedic Injury Patients? A Novel Investigation Using Rasch Analysis

Persistent post-concussion syndrome (PCS) symptoms are known to last years after traumatic brain injury (TBI), and similar symptoms are increasingly being documented among those who have not experienced a TBI. There remains however, a dearth of empirical evidence on the structural composition of symptoms beyond the post-acute symptom phase after TBI, and little is known about the potential use of PCS symptom scales to measure PCS-like symptoms in non-TBI individuals. Our objective was therefore to examine the psychometric performance and dimensionality of the Rivermead Post-Concussion Symptoms Questionnaire (RPQ) as a measure of long-term PCS symptoms among a TBI and non-TBI sample. A case-control sample of 223 patients with injury, consisting of age- and sex-matched TBI participants (n = 109) and orthopedic participants (n = 114) were recruited from a regional trauma registry in New Zealand (NZ), and assessed at mean 2.5 years post-injury. Results from the Rasch analysis showed that the RPQ achieved fit to the Rasch model, demonstrating very good reliability (Person Separation Index [PSI] = 0.87), thereby indicating that the measure can be used reliably for individual and group assessment of symptoms among both TBI and orthopedic patients. In this study we demonstrated evidence of a unidimensional construct of PCS symptoms in both groups, which helps alleviate previous uncertainty about factor structure, and permits the calculation of a total RPQ score. Conversion of ordinal to interval total scores presented within are recommended for clinicians and researchers, to improve instrument precision, and to facilitate the interpretation of change scores and use of parametric methods in data analysis.

Early versus Late Profiles of Inflammatory Cytokines after Mild Traumatic Brain Injury and Their Association with Neuropsychological Outcomes

Despite pre-clinical evidence for the role of inflammation in traumatic brain injury (TBI), there is limited data on inflammatory biomarkers in mild TBI (mTBI). In this study, we describe the profile of plasma inflammatory cytokines and explore associations between these cytokines and neuropsychological outcomes after mTBI. Patients with mTBI with negative computed tomography and orthopedic injury (OI) controls without mTBI were prospectively recruited from emergency rooms at three trauma centers. Plasma inflammatory cytokine levels were measured from venous whole-blood samples that were collected at enrollment (within 24 h of injury) and at 6 months after injury. Neuropsychological tests were performed at 1 week, 1 month, 3 months, and 6 months after the injury. Multivariate regression analysis was performed to identify associations between inflammatory cytokines and neuropsychological outcomes. A total of 53 mTBI and 24 OI controls were included in this study. The majority of patients were male (62.3%), and injured in motor vehicle accidents (37.7%). Plasma interleukin (IL)-2 (p = 0.01) and IL-6 (p = 0.01) within 24 h post-injury were significantly higher for mTBI patients compared with OI controls. Elevated plasma IL-2 at 24 h was associated with more severe 1-week post-concussive symptoms (p = 0.001). At 6 months, elevated plasma IL-10 was associated with greater depression scores (p = 0.004) and more severe post-traumatic stress disorder (PTSD) symptoms (p = 0.001). Plasma cytokine levels (within 24 h and at 6 months post-injury) were significantly associated with early and late post-concussive symptoms, PTSD, and depression scores after mTBI. These results highlight the potential role of inflammation in the pathophysiology of post-traumatic symptoms after mTBI.

Rating of pre-injury symptoms over time in patients with mild traumatic brain injury: the good-old-days bias revisited

OBJECTIVE

Post-concussion syndrome (PCS) occurs following mild traumatic brain injury (mTBI). Patients with mTBI are often assessed using self-report instruments that rely on perception of current symptoms compared to how they felt and functioned pre-injury. The objective was to examine reliability of patients' post-injury reporting of their pre-injury symptoms.

METHODS

We included two control groups (trauma patients without brain injury history and healthy controls) who were recruited at an outpatient surgical clinic and among the working and social environment of the researchers, respectively. The Head Injury Symptom Checklist (HISC) was used to assess pre-injury and current symptoms at four time points post injury. We included 836 patients with mTBIs, 191 trauma patients without brain injury history, and 100 healthy controls.

RESULTS

Patients with mTBI reported significantly more pre-injury symptoms than both control groups (p < .001). Forty-five percent of patients with mTBI were inconsistent in their pre-injury ratings across four assessments. Patients with post-injury PCS reported much greater pre-injury symptoms and were more often inconsistent.

CONCLUSION

Accurately assessing PCS by comparing pre with post-injury complaints is difficult, and may have implications for diagnosis when using self-report instruments. Therefore, post-injury PCS diagnosis should be interpreted with caution and PCS should ideally be examined using clinical examination.

White Matter Integrity and Its Relationship to Cognitive-Motor Integration in Females with and without Post-Concussion Syndrome

Fifteen percent of individuals who sustain a concussion go on to develop post-concussion syndrome (PCS). These persistent symptoms are believed to be attributed to damage to white matter tracts and impaired neurotransmission. Specifically, declines in white matter integrity after concussion have been found along the long-coursing axons underlying the frontoparietal network. This network is essential for the performance of visuomotor transformation tasks requiring cognitive-motor integration (CMI). We have previously observed deficits in performance on CMI-based tasks in those who have a history of concussion, but were asymptomatic. The aim of this study was to investigate performance on a CMI task, as well as white matter integrity differences along frontoparietal-cerebellar white matter tracts, in those with PCS compared to healthy controls. We hypothesized an association between the behavioral and brain structural measures. Twenty-six female participants (13 with PCS for ≥6 months and 13 healthy controls) completed four computer-based visuomotor CMI tasks. In addition, diffusion tensor images (DTIs) were acquired. No statistically significant differences were found in CMI performance between groups (p > 0.05). Further, there were no statistically significant differences between groups on any DTI metrics (p > 0.05). However, examination of the data collapsed across participants revealed significant associations between performance on a CMI task and white matter integrity. Further investigation into additional causes of symptoms in those with PCS (including psychological and cervicogenic factors) will strengthen our understanding of this diverse group. Nonetheless, this study demonstrates that white matter integrity is related to levels of performance in tasks that require rule-based movement control.

Correlation between Ocular and Vestibular Abnormalities and Convergence Insufficiency in Post-Concussion Syndrome

The vestibular and oculomotor/visual systems are commonly affected in post-concussion syndrome (PCS). Convergence insufficiency (CI) is the most common ocular abnormality after concussion. Electrovestibulography (EVestG) is a relatively new non-invasive method that measures the peripheral vestibular responses; it has shown abnormal vestibular responses in a PCS. Here, we report the results of investigating the correlation between the vestibular and oculomotor systems in PCS population using EVestG and CI measures. Forty-eight PCS patients were tested using EVestG, out of which 20 also completed the Rivermead post-concussion questionnaire (RPQ). An EVestG feature (Field Potential (FP)-area) was extracted from the stationary part of the EVestG signals. A neuro-ophthalmologist (author BM) measured participants' CI at near vision using cross-cover examination and a prism-bar. Results indicate: (1) vestibular abnormality (i.e. FP-area) and CI values are significantly correlated in PCS (R = 0.68, p < .01), and (2) there are significant correlations between severity of concussion (i.e. RPQ3) and CI (R = 0.70, p < .01) and between RPQ3 and FP-area (R = -0.56, p < .02). To the best of our knowledge, this is the first study that objectively demonstrates a significant positive correlation between the CI and vestibular systems' abnormality. These findings are scientifically important as they help localise the pathology of PCS, and are clinically valuable as they help physicians in their decision-making about PCS diagnosis and rehabilitation strategies.

Serum SNTF, a Surrogate Marker of Axonal Injury, Is Prognostic for Lasting Brain Dysfunction in Mild TBI Treated in the Emergency Department

Mild traumatic brain injury (mTBI) causes persisting post-concussion syndrome for many patients without abnormalities on conventional neuroimaging. Currently, there is no method for identifying at-risk cases at an early stage for directing concussion management and treatment. SNTF is a calpain-derived N-terminal proteolytic fragment of spectrin (α_II-spectrin1-1176) generated in damaged axons following mTBI. Preliminary human studies suggest that elevated blood SNTF on the day of mTBI correlates with white matter disruption and lasting brain dysfunction. Here, we further evaluated serum SNTF as a prognostic marker for persistent brain dysfunction in uncomplicated mTBI patients treated in a Level I trauma center emergency department. Compared with healthy controls (n = 40), serum SNTF increased by 92% within 24 h of mTBI (n = 95; p < 0.0001), and as a diagnostic marker exhibited 100% specificity and 37% sensitivity (AUC = 0.87). To determine whether the subset of mTBI cases positive for SNTF preferentially developed lasting brain dysfunction, serum levels on the day of mTBI were compared with multiple measures of brain performance at 90 days post-injury. Elevated serum SNTF correlated significantly with persistent impairments in cognition and sensory-motor integration, and predicted worse performance in each test on a case by case basis (AUC = 0.68 and 0.76, respectively). SNTF also predicted poorer recovery of cognitive stress function from 30 to 90 days (AUC = 0.79–0.90). These results suggest that serum SNTF, a surrogate marker for axonal injury after mTBI, may have potential for the rapid prognosis of lasting post-concussion syndrome and impaired functional recovery following CT-negative mTBI. They provide further evidence linking axonal injury to persisting brain dysfunction after uncomplicated mTBI. A SNTF blood test, either alone or combined with other markers of axonal injury, may have important utilities for research, prognosis, management and treatment of concussion.

Post-Concussion Syndrome and Sleep Apnea: A Retrospective Study

Background: Concussion symptoms typically resolve within 7–10 days, but 10–25% of patients do not fully recover. They can develop post-concussion syndrome (PCS), which includes sleep abnormalities such as obstructive sleep apnea. It is unclear how specific sleep problems manifest in PCS and how it relates to cognition and symptomology. Methods: A retrospective chart review was conducted on PCS patients seen at the University Health Network (UHN) Concussion Clinic and sent for sleep study. Neuropsychology tests, concussion features, PCS symptoms, and demographics were abstracted from clinical charts. Sleep measures were abstracted from the overnight sleep study. Data were analyzed using chi-squared tests and linear regression. Results: Fifty-one patients completed the sleep study; 78% of these were diagnosed with sleep apnea. Patients with sleep apnea reported significantly more memory symptoms. A trend existed for higher total symptom number. Age was significantly different between the two groups. Women and men were equally at risk of being diagnosed with sleep apnea. Conclusions: Sleep apnea is common in PCS patients complaining of non-restorative sleep and/or waking up with headaches. Sleep apnea was associated with more memory symptoms. PCS patients are at higher risk for sleep apnea and sleep study should be considered if complaining of non-restorative sleep and/or waking up with headaches, regardless of sex and other known risk factors.

Atypical Somatic Symptoms in Adults With Prolonged Recovery From Mild Traumatic Brain Injury

Somatization may contribute to persistent symptoms after mild traumatic brain injury (mTBI). In two independently-recruited study samples, we characterized the extent to which symptoms atypical of mTBI but typical for patients suffering from somatization (e.g., gastrointestinal upset, musculoskeletal, and cardiorespiratory complaints) were present in adult patients with prolonged recovery following mTBI. The first sample was cross-sectional and consisted of mTBI patients recruited from the community who reported ongoing symptoms attributable to a previous mTBI (n = 16) along with a healthy control group (n = 15). The second sample consisted of patients with mTBI prospectively recruited from a Level 1 trauma center who had either good recovery (GOSE = 8; n = 32) or poor recovery (GOSE < 8; n = 29). In all participants, we evaluated atypical somatic symptoms using the Patient Health Questionnaire-15 and typical post-concussion symptoms with the Rivermead Post-Concussion Symptom Questionnaire. Participants with poor recovery from mTBI had significantly higher "atypical" somatic symptoms as compared to the healthy control group in Sample 1 (b = 4.308, p < 0.001) and to mTBI patients with good recovery in Sample 2 (b = 3.169, p < 0.001). As would be expected, participants with poor outcome in Sample 2 had a higher burden of typical rather than atypical symptoms [t ₍₂₈₎ = 4.750, p < 0.001, d = 0.88]. However, participants with poor recovery still reported atypical somatic symptoms that were significantly higher (1.4 standard deviations, on average) than those with good recovery. Our results suggest that although "typical" post-concussion symptoms predominate after mTBI, a broad range of somatic symptoms also frequently accompanies mTBI, and that somatization may represent an important, modifiable factor in mTBI recovery.

Age, symptoms, and functional outcome after mild traumatic brain injury

OBJECTIVES

Previous older adult studies have examined outcome from moderate-to-severe traumatic brain injury (TBI), but fewer have focused on the effects of milder brain injuries. This study examined age-related differences in symptom reporting and whether symptoms are differentially related to functional outcome based on age.

MATERIALS & METHODS

Patients presenting with a head injury at the Tampere University Hospital emergency department (N = 325, aged 18-100) were evaluated at 1 week post injury on the Modified Rankin Scale and Rivermead Post Concussion Symptoms Questionnaire (RPQ).

RESULTS

A quarter of participants had missing RPQ data, with missingness associated with greater age and strongly associated with pre-existing functional impairment, dementia, and/or neurological conditions. Among participants with complete data, participants <65 years old endorsed headaches, noise/light sensitivity, irritability, and frustration/impatience at a greater frequency than participants ≥65 years old. However, no differences were found in the number of symptoms endorsed or the total symptom severity score. The correlations between the severity of symptoms and change in function were similar between the two age groups.

CONCLUSIONS

Older adults tended to report fewer symptoms, but symptoms had a roughly equivalent relationship with declines in functioning across age groups. A large percentage of older adults in this study had pre-injury dementia or neurological disease that contributed to missing data on the 1-week outcome measures. The results provide insight into the impact of mild spectrum TBI on older adults compared to younger patients.

Perceived Change in Physical, Cognitive, and Emotional Symptoms after Mild Traumatic Brain Injury in Patients with Pre-Injury Anxiety or Depression

The objective of this study was to compare patients with acute-to-subacute mild traumatic brain injury (mTBI) on post-concussion symptom reporting based on whether they retrospectively recalled experiencing pre-injury anxiety or depression. Patients with mTBI (n = 297; 40.4% men; mean = 38.2 years old, standard deviation [SD] = 14.0, range = 17-65), referred from an emergency department in Taipei, Taiwan, were seen in a neurosurgical outpatient clinic on average 7.7 days since injury (SD = 5.7, range = 0 - 21 days), at which time they completed a checklist of post-concussion symptoms. Patients rated their current symptom severity and retrospectively rated their pre-injury symptom severity on 15 physical, cognitive, and emotional symptoms. Patients were grouped based on whether they did or did not have mild or greater pre-injury anxiety or depression based on this scale. Those with pre-injury anxiety or depression had greater pre-injury (all p's < 0.001, d range: 0.92-2.03) and post-injury (all p's < 0.001, d range: 0.65-1.00) symptom severity. However, when analyzing perceived change in symptoms (i.e., post-injury ratings minus pre-injury ratings), only perceived change in cognitive symptoms differed across groups (p = 0.018, d = 0.29), which became non-significant after controlling for gender. Greater post-concussion symptom severity in patients with pre-existing mental health problems may be mostly attributable to elevated symptoms before injury. These findings demonstrate the clinical value of retrospective pre-injury symptom assessment in mTBI management. Greater post-concussion symptom severity in patients with pre-injury mental health problems may represent a continuation of greater pre-injury symptom severity rather than a greater increase in symptom severity after mTBI.

[Current possibilities of complex diagnosis and treatment of the consequences of traumatic brain injury]

Article is devoted to topical issues of complex diagnosis and treatment of the consequences of traumatic brain injury (TBI) in children, adolescents and adults. Craniocerebral trauma is one of the most important problems of modern neurology, due to the high frequency and severity of disability. In recent years, there has been a steady increase in effects of TBI, a significant part of which are asthenic, autonomic, cognitive, emotional and motor disorders. Factors affecting the severity of the consequences of TBI are: the severity of the injury, the age, at which the injury occurred, the time elapsed since the injury, the localization of the lesion. After mild TBI, the structure of cognitive impairment is dominated by memory and attention disorders (75%), visual-motor coordination, as well as asthenic disorders (88%), chronic headaches (95%). After moderate and severe TBI, there are more pronounced impairment of cognitive and motor functions accompanied by pathological neurological symptoms in 94-100% of children, which leads to difficulties in learning, self-service and has a negative impact on social adaptation. The article describes in detail the modern methods of complex diagnosis, as well as pathogenetically justified methods of drug therapy of cognitive disorders in patients with the consequences of TBI. The high efficacy of the modern cytoprotective drug Cytoflavin in the treatment of the effects of TBI is shown.

Post-Concussion Symptoms in Complicated vs. Uncomplicated Mild Traumatic Brain Injury Patients at Three and Six Months Post-Injury: Results from the CENTER-TBI Study

The aim of this study was to assess the occurrence of post-concussion symptoms and post-concussion syndrome (PCS) in a large cohort of patients after complicated and uncomplicated mild traumatic brain injury (mTBI) at three and six months post-injury. Patients were included through the prospective cohort study: Collaborative European NeuroTrauma Effectiveness Research (CENTER-TBI). Patients enrolled with mTBI (Glasgow Coma Scale 13-15) were further differentiated into complicated and uncomplicated mTBI based on the presence or absence of computed tomography abnormalities, respectively. The Rivermead Post-Concussion Symptoms Questionnaire (RPQ) assessed post-concussion symptoms and PCS according to the mapped ICD-10 classification method. The occurrence of post-concussion symptoms and syndrome at both time points was calculated. Chi square tests were used to test for differences between and within groups. Logistic regression was performed to analyse the association between complicated versus uncomplicated mTBI and the prevalence of PCS. Patients after complicated mTBI reported slightly more post-concussion symptoms compared to those after uncomplicated mTBI. A higher percentage of patients after complicated mTBI were classified as having PCS at three (complicated: 46% vs. uncomplicated: 35%) and six months (complicated: 43% vs. uncomplicated 34%). After adjusting for baseline covariates, the effect of complicated versus uncomplicated mTBI at three months appeared minimal: odds ratio 1.25 (95% confidence interval: 0.95-1.66). Although patients after complicated mTBI report slightly more post-concussion symptoms and show higher PCS rates compared to those after uncomplicated mTBI at three and six months, complicated mTBI was only found a weak indicator for these problems.

Treatment of Persistent Post-Traumatic Headache and Post-Concussion Symptoms Using Repetitive Transcranial Magnetic Stimulation: A Pilot, Double-Blind, Randomized Controlled Trial

Persistent post-traumatic headache (PTH) after mild traumatic brain injury is one of the most prominent and highly reported persistent post-concussion symptoms (PPCS). Non-pharmacological treatments, including non-invasive neurostimulation technologies, have been proposed for use. Our objective was to evaluate headache characteristics at 1 month after repetitive transcranial magnetic stimulation (rTMS) treatment in participants with PTH and PPCS. A double-blind, randomized, sham-controlled, pilot clinical trial was performed on 20 participants (18-65 years) with persistent PTH (International Classification of Headache Disorders, 3rd edition) and PPCS (International Classification of Diseases, Tenth Revision). Ten sessions of rTMS therapy (10 Hz, 600 pulses, 70% resting motor threshold amplitude) were delivered to the left dorsolateral pre-frontal cortex. The primary outcome was a change in headache frequency or severity at 1 month post-rTMS. Two-week-long daily headache diaries and clinical questionnaires assessing function, PPCS, cognition, quality of life, and mood were completed at baseline, post-treatment, and at 1, 3, and 6 months post-rTMS. A two-way (treatment × time) mixed analyisis of variance indicated a significant overall time effect for average headache severity (F_(3,54) = 3.214; p = 0.03) and a reduction in headache frequency at 1 month post-treatment (#/2 weeks, REAL -5.2 [standard deviation {SD} = 5.8]; SHAM, -3.3 [SD = 7.7]). Secondary outcomes revealed an overall time interaction for headache impact, depression, post-concussion symptoms, and quality of life. There was a significant reduction in depression rating in the REAL group between baseline and 1 month post-treatment, with no change in the SHAM group (Personal Health Questionnaire-9; REAL, -4.3 [SD = 3.7[ p = 0.020]; SHAM, -0.7 [SD = 4.7; p = 1.0]; Bonferroni corrected). In the REAL group, 60% returned to work whereas only 10% returned in the SHAM group (p = 0.027). This pilot study demonstrates an overall time effect on headache severity, functional impact, depression, PPCS, and quality of life after rTMS treatment in participants with persistent PTH; however, findings were below clinical significance thresholds. There was a 100% response rate, no dropouts, and minimal adverse effects, warranting a larger phase II study. Clinicaltrials.gov: NCT03691272.

A Nonliquid Crystal Display Screen Computer for Treatment of Photosensitivity and Computer Screen Intolerance in Post-Concussion Syndrome

Liquid crystal display (LCD) screens refresh at a rate of 60 times per second, which can be perceived by concussed individuals who have photosensitivity, leading to computer intolerance. A non-LCD computer screen that refreshes at a much lower rate could relieve this photosensitivity and computer screen intolerance in patients with post-concussion syndrome (PCS). Twenty-nine patients with PCS, computer intolerance, and photosensitivity performed a reading task for a maximum of 30 min, with an LCD computer or a non-LCD device, and were given a comprehension test after completion of the reading task. The Sport Concussion Assessment Tool 3 was administered before and after each reading task. Symptom scores, amount of time spent reading, and performance on the comprehension tests were compared between the two devices. Patients also completed a self-report questionnaire of their subjective experience. The LCD screen computer produced significantly greater symptom exacerbation (median difference = 5, W = 315, p < 0.01) and a greater number of symptoms (median difference = 1, W = 148, p < 0.01) than the non-LCD screens. The non-LCD screen resulted in a longer symptom-free reading time (median = 48 sec, W = 147, p < 0.01), but not a greater number of words read (median = 281, W = 148, p = 0.098). Females were more likely to have greater symptom exacerbation with the LCD screen (U = 14.0, p < 0.01). No significant difference was found in performance on the comprehension test. Subjective reports showed that the non-LCD experience was more favorable, and most patients stated they would recommend this device for other patients with PCS. This study is the first to show the clinical utility of non-LCD screen computers in the management of photosensitivity and computer screen intolerance in patients with PCS. The non-LCD screen computer has the potential to facilitate return-to-work or return-to-school in concussed individuals.

Efficacy of Psychoeducation and Cognitive Rehabilitation After Mild Traumatic Brain Injury for Preventing Post-concussional Syndrome in Individuals With High Risk of Poor Prognosis: A Randomized Clinical Trial

Unfavorable outcomes (UO) occur in 15-20% of patients with mild traumatic brain injury (mTBI). Early identification of patients at risk of UO is crucial for suitable management to be initiated, increasing the chances of full recovery. We previously developed a prognostic tool for early identification (8-21 days after the injury) of patients likely to develop UO. Patients whose initial risk factors indicate UO are at risk of developing post-concussion syndrome (PCS). In the present study, we examined the beneficial effects of early multidimensional management (MM) on prognosis. We used our prognostic tool to classify 221 mTBI patients into a UO (97) group or a favorable outcome (FO) group (124). We randomized the UO patients into two subgroups: a group that underwent MM (involving psychoeducation and cognitive rehabilitation) (34) and a control group with no specific treatment other than psychoeducation (46). At 6 months, these two groups were compared to assess the impact of MM. Among the followed-up patients initially classified as having FO (101), 95% had FO at 6 months and only five had PCS [as defined by the Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV classification]. Among the followed-up MM patients, 94% did not have PCS 6 months after injury, whereas 52% of the control patients had PCS. The effect of MM on the recovery of patients at 6 months, once adjusted for the main confounding factors, was significant (p < 0.001). These results show that the initiation of MM after early identification of at-risk mTBI patients can considerably improve their outcomes. Clinical Trials Registration: The study was registered at ClinicalTrials.gov (NCT03811626).

Vergence Endurance Test: A Pilot Study for a Concussion Biomarker

The Vergence Endurance Test (VET), a quantitative and objective eye movement assessment, was utilized to differentiate control from concussed subjects. Nine symptomatic concussed (2 male; 30.8 ± 11 years) and 9 asymptomatic control (6 male; 25.1 ± 1.4 years) subjects participated in the VET. Symmetrical disparity vergence step targets were presented with and without visual distractors. A masked data analyst measured vergence latency, peak velocity, response amplitude, settling time, and the percentage of trials which contained blinks. A Binocular Precision Index (BPI) and a Binocular Accuracy Index (BAI) were calculated to quantify the changes that occur in the vergence parameters over the duration of the VET. Convergence and divergence peak velocity, divergence response amplitude, the percentage of trials that contained blinks during the transient portion of the response, and the BAI were significantly (p < 0.05) different between the concussed and the control subjects. For these parameters, the BAI and divergence response amplitude yielded the greatest accuracy, 78%, in their ability to discriminate between the groups. The VET objectively measures the change in vergence performance over time and shows promise as a method to diagnose a concussion. Future studies will determine whether the VET can be used to assess the extent of natural recovery and the effectiveness of therapeutic interventions.

The consequences of traumatic brain injury from the classroom to the courtroom: understanding pathways through structural equation modelling

Purpose: Paediatric traumatic brain injury (TBI) can have resultant ongoing significant impairments which can impact life outcomes. The primary aim of this research was to explore whether TBI contributes to the relationship between poor educational outcomes and offending trajectories.Materials and methods: Through analysis of a dataset consisting of self-reported health, educational, and offending histories of 70 incarcerated young males, structural equation modelling was used to explore the mediation of educational outcomes and patterns in offending behaviour by chronic symptoms following TBI.Results: Symptoms related to TBI significantly mediated the relationship between decreased educational attainment and more frequent convictions. It did not mediate any relationships involving age at first conviction.Conclusions: Traumatic brain injury appears to have more influence over frequency of offending patterns than age at first conviction. However, TBI remains a pervasive factor in both higher rates of offending and poorer educational attainment. In order to tackle this effect on adverse social outcomes, greater attention to the impact of TBI is required in education and criminal justice systems.IMPLICATIONS FOR REHABILITATIONHighlights traumatic brain injury as a contributory factor in some education to offending pathways, suggesting that greater focus on rehabilitation within the education and criminal justice systems is required.Reinforces that greater understanding of educational pathways post-injury is needed to better facilitate rehabilitation within the school system.

Molecular imaging of neuroinflammation in patients after mild traumatic brain injury: a longitudinal 123 I-CLINDE single photon emission computed tomography study

BACKGROUND AND PURPOSE

Neuroinflammation has been proposed as part of the pathogenesis of post-concussion symptoms (PCS), but the inflammatory response of the human brain to mild traumatic brain injury (mTBI) remains unknown. We hypothesized that a neuroinflammatory response is present in mTBI at 1-2 weeks post-injury and persists in patients with PCS.

METHODS

We scanned 14 patients with mTBI without signs of structural damage at 1-2 weeks and 3-4 months post-injury and 22 healthy controls once using the single photon emission computed tomography tracer ¹²³ I-CLINDE, which visualizes translocator protein (TSPO), a protein upregulated in active immune cells. PCS was defined as three or more persisting symptoms from the Rivermead Post Concussion Symptoms Questionnaire at 3 months post-injury.

RESULTS

Across brain regions, patients had significantly higher ¹²³ I-CLINDE binding to TSPO than healthy controls, both at 1-2 weeks after the injury in all patients (P = 0.011) and at 3-4 months in the seven patients with PCS (P = 0.006) and in the six patients with good recovery (P = 0.018). When the nine brain regions were tested separately and results were corrected for multiple comparisons, no individual region differed significantly, but all estimated parameters indicated increased ¹²³ I-CLINDE binding to TSPO, ranging from 2% to 19% in all patients at 1-2 weeks, 13% to 27% in patients with PCS at 3-4 months and -9% to 17% in patients with good recovery at 3-4 months.

CONCLUSIONS

Neuroinflammation was present in mTBI at 1-2 weeks post-injury and persisted at 3-4 months post-injury with a tendency to be most pronounced in patients with PCS.

Prevalence of post-concussion-like symptoms in the general population in Italy, The Netherlands and the United Kingdom

Objectives: To evaluate the frequency of post-concussion symptoms and prevalence and risk factors of post-concussion syndrome (PCS) in the general population, investigate the association between the Rivermead Post-Concussion Symptoms Questionnaire (RPQ) and self-perceived health, and evaluate differences between three European countries. Methods: A web-based survey including the RPQ and EQ-5D was conducted among representative samples in three European countries. Results: A total of 11,759 respondents completed the questionnaire. The most frequently reported symptom was fatigue (49.9%). Almost half (45.1%) of the respondents were classified as having PCS considering rating score 2 (three RPQ items with score ≥ 2) as a cut-off. Chronic health complaints were found as a significant risk factor for PCS. All items of the RPQ were positively correlated with the EQ-5D and the strongest positive correlation (0.633, p<0.001) was between RPQ item 'feeling depressed or tearful' and EQ-5D domain 'anxiety/depression'. Conclusions: We found a high frequency of post-concussion-like symptoms and PCS in the general population, indicating that these symptoms are not specific for patients with traumatic brain injury (TBI), and PCS is not a unique syndrome after TBI. Therefore, the use of post-concussion symptoms and PCS as outcome following mild TBI should be interpreted with caution.

Minor Head Injury Symptoms and Recovery From Whiplash Injury: A 1-Year Prospective Study

Aim:

To examine concussion-related disability in neck injuries, the Rivermead Head Injury Follow-Up Questionnaire (RHFUQ) was applied. Furthermore, we wanted to investigate symptoms found in post-concussion syndrome (PCS) and global pain, neck pain intensities obtained from acute whiplash patients within 1 week and at 6 months after injury in a prospective study on 1-year work disability.

Methods:

A total of 143 consecutive acute whiplash-injured patients were admitted to the study from the Emergency Unit (Aarhus University Hospital). Patients with direct head trauma or reported retro- or anterograde amnesia were excluded from the study. Average neck pain and global pain intensity were measured on a Visual Analogue Scale (VAS 0-10). The RHFUQ (10 items, score from 0 to 4, total score from 0 to 40) was fulfilled after 1 week and 6 months. Patients underwent neurological examination within 1 week after injury. Recovery (return to work) was assessed 1 year post-injury.

Results:

In total, 97% completed the study, and 9% (12/138) did not recover. Non-recovered patients reported more neck pain and global pain after 1 week (P < .003) and 6 months (P < .008) and higher PCS symptom score after 1 week (P < .001) and 6 months (P < .002). Using the RHFUQ total score as a predictive test, a receiver-operating characteristic curve (ROC) area of 0.77 (0.61-0.92) and a cut-off at 10 points revealed a sensitivity of 75% and a specificity of 67.2%. At 1 week, 8 of 10 items reached higher scores among non-recovered and 10 of 10 items after 6 months post-injury.

Conclusions:

RHFUQ is useful in acute whiplash patients for predicting 1-year work disability. PCS-related symptoms along with neck pain and global pain are more burdensome in the non-recovered group. This emphasizes that post-concussion symptoms are not a sign of brain injury alone, but are found in other types of mishaps like whiplash injuries.

The Predictive Capacity of the Buffalo Concussion Treadmill Test After Sport-Related Concussion in Adolescents

The Buffalo Concussion Treadmill Test (BCTT) identifies the heart rate threshold (HRt) of exercise tolerance in concussed patients. A previous study found that an absolute HRt of < 135 bpm was associated with prolonged recovery (>30 days) from sport-related concussion (SRC). In this study, we assessed the relationship of ΔHR (difference between resting HR and HRt) and recovery from SRC. Using a retrospective cohort design, we compared acutely (<10 days since injury) concussed adolescents who were prescribed either (1) relative rest (RG, n = 27, 15.2 ± 1 years, 33% female, median 17 days to recovery, ΔHR = 69.6 ± 28 bpm), (2) a placebo-stretching program (PG, n = 51, 15.4 ± 2 years, 49% female, median 17 days to recovery, ΔHR = 60.9 ± 22 bpm), or (3) sub-threshold aerobic exercise (AG, n = 52, 15.3 ± 2 years, 46% female, median 13 days to recovery, ΔHR = 62.4 ± 26 bpm). Linear regression showed that ΔHR significantly correlated with duration of clinical recovery for RG (p = 0.012, R ² = 0.228) and PG (p = 0.011, R ² = 0.126) but not for AG (p = 0.084, R ² = 0.059). ΔHR values were significantly lower in participants with prolonged recovery (>30 days) in RG (p = 0.01) and PG (p = 0.04). A ΔHR of ≤50 bpm on the BCTT is 73% sensitive and 78% specific for predicting prolonged recovery in concussed adolescents who were prescribed the current standard of care (i.e., cognitive and physical rest).

The National Brain Injury Rescue and Rehabilitation Study - a multicenter observational study of hyperbaric oxygen for mild traumatic brain injury with post-concussive symptoms

The National Brain Injury Rescue and Rehabilitation Project was established as a preliminary study to test the safety and practicality of multi-center hyperbaric oxygen administration for the post-concussive symptoms of chronic mild traumatic brain injury as a precursor to a pivotal, independent, multi-center, controlled clinical trial. This report presents the results for 32 subjects who completed a preliminary trial of hyperbaric oxygen several years before the passage of the 21 ^st Century Cures Act. This study anticipated the Act and its reassessment of clinical research. Subjects received 40-82 one-hour treatments at 1.5 atmospheres absolute 100% oxygen. Outcome measures included repeated self-assessment measures and automated neurocognitive tests. The subjects demonstrated improvement in 21 of 25 neurocognitive test measures observed. The objective neurocognitive test components showed improvement in 13 of 17 measures. Earlier administration of hyperbaric oxygen post injury, younger age at the time of injury and hyperbaric oxygen administration, military status, and increased number of hyperbaric oxygen administrations were characteristics associated with improved outcomes. There were no adverse events. Hyperbaric oxygen was found to be safe, inexpensive and worthy of clinical application in the 21 ^st Century model of facile data collection provided by recent research regulatory shifts in medicine. The study was approved by the ethics review committee of the Western Institutional Review Board (WIRB; Protocol #20090761).

Diagnostic Algorithms to Study Post-Concussion Syndrome Using Electronic Health Records: Validating a Method to Capture an Important Patient Population

Post-concussion syndrome (PCS) is characterized by persistent cognitive, somatic, and emotional symptoms after a mild traumatic brain injury (mTBI). Genetic and other biological variables may contribute to PCS etiology, and the emergence of biobanks linked to electronic health records (EHRs) offers new opportunities for research on PCS. We sought to validate the EHR data of PCS patients by comparing two diagnostic algorithms deployed in the Vanderbilt University Medical Center de-identified database of 2.8 million patient EHRs. The algorithms identified individuals with PCS by: 1) natural language processing (NLP) of narrative text in the EHR combined with structured demographic, diagnostic, and encounter data; or 2) coded billing and procedure data. The predictive value of each algorithm was assessed, and cases and controls identified by each approach were compared on demographic and medical characteristics. The NLP algorithm identified 507 cases and 10,857 controls. The negative predictive value in controls was 78% and the positive predictive value (PPV) in cases was 82%. Conversely, the coded algorithm identified 1142 patients with two or more PCS billing codes and had a PPV of 76%. Comparisons of PCS controls to both case groups recovered known epidemiology of PCS: cases were more likely than controls to be female and to have pre-morbid diagnoses of anxiety, migraine, and post-traumatic stress disorder. In contrast, controls and cases were equally likely to have attention deficit hyperactive disorder and learning disabilities, in accordance with the findings of recent systematic reviews of PCS risk factors. We conclude that EHRs are a valuable research tool for PCS. Ascertainment based on coded data alone had a predictive value comparable to an NLP algorithm, recovered known PCS risk factors, and maximized the number of included patients.

Sex-dependent and chronic alterations in behavior and mitochondrial function in a rat model of pediatric mild traumatic brain injury

OBJECTIVE

To determine if chronic changes in mitochondrial function occur following a mild traumatic brain injury in young rats.

RESEARCH DESIGN

Closed-head, weight drop model was used to cause mTBI by applying rotational forces to the brain without surgery. Behavioral battery was used to assess multiple dimensions of impairment across time. Analysis of brain tissue carried out at three-weeks post-injury represents a chronic time point to complement previous work examining acute time points.

METHODS AND PROCEDURES

Twenty-three male and 22 female rats one month of age were divided equally into sham and mTBI groups with the latter undergoing the weight drop. Multiple behavioral tests in combination with energetic (oxygen consumption), molecular (immunoblotting), and imaging (electron microscopy) characterization of brain mitochondria were performed.

MAIN OUTCOMES AND RESULTS

Mitochondria isolated from sham juvenile female rats had higher basal oxygen consumption compared to juvenile male rats (514.875 ± 171.091 pmol/min vs. 267 ± 73.906 pmol/min, p < 0.0001). Chronic sex-dependent differences were observed in females after mTBI in basal (514.875 ± 171.091 pmol/min vs. 600.688 ± 124.422 pmol/min, p = 0.0264) and maximal oxygen consumption (298.938 ± 119.964 pmol/min vs. 403.281 ± 112.922 pmol/min, p = 0.0001) and proton leak (59.46 ± 7.807 vs. 84.32 ± 5.80 pmol/min, p = 0.0001).

CONCLUSIONS

The juvenile rat brain displays sex differences in mitochondrial function at (1) baseline and (2) in long-term outcomes after mTBI. These results offer new insight into a potential mechanism for persistent, individualized impairments following pediatric mTBI.

Post traumatic headache (PTH) in a cohort of UK compensation claimants

AIM

To explore post traumatic headache characteristics and risk factors in compensation claimants by observational retrospective cohort analysis.

CASE RESULTS

Medicolegal reports on 116 consecutive compensation claimants aged 41.9 ± 15.0 years were reviewed 21 ± 14 months after injury. Eighty eight had suffered head and neck injuries, 21 reported only neck injury and seven had "other injuries". Ninety four percent of the head injuries were "mild". The incidence of post traumatic headache following neck injury did not differ from that following head and neck injury, and none of the "other injuries" cases developed post traumatic headache. We anticipated that all head and neck injury claimants would seek compensation for post traumatic headache, but 25% denied developing headache. Post traumatic headache was very strongly correlated with a past history of primary headache ( p < 0.0001) but no other risk factors were identified. Post traumatic headache semiology was consistent with "migraine" or "probable migraine" in 90% of cases. Headache resolved in 30% of claimants between 3 and 24 months after injury but 70% continued to suffer headaches at the time of assessment. Forty one percent of claimants had received no treatment for post traumatic headache in primary care.

CONCLUSIONS

Our data suggest that post traumatic headache is essentially "migraine" provoked by head or neck concussion. It is not clear why so many post traumatic headache sufferers receive poor or inadequate treatment for this condition.

Scale for retrospective assessment of immediate concussion symptoms

The retrospective diagnosis of concussion is often missed by clinicians. We present a brief scale for retrospective assessment of the immediate concussion symptoms (ICS) to facilitate the diagnosis of patients without visible head injury or full loss of consciousness. We administered the scale to 90 survivors of car accidents (mean age 42.0, SD=13.6; 33 males, 57 females) at 2 to 33 months after their accident. Our scale consists of 6 items and these were endorsed by the following % of our respondents: feeling dazed (64.4% of our 90 respondents), stunned (73.3%), confused (70.0%), disoriented (62.2%), dizzy (57.8%), and loss of consciousness (22.2%). The statistical properties of the scale are satisfactory (Cronbach alpha = 0.74). The scale correlates with post-accident insomnia (r=0.28), depression (r=0.29), and also with Rivermead measure of the chronic post-concussion syndrome (r=0.34). The ICS scale could be used as a starting point in longitudinal research with brain imaging procedures to evaluate the stages of recovery from the initial concussion. Attached are the English, Spanish, French, German, Italian, Russian, and Czech versions of our scale.

Design of an early intervention for persistent post-concussion symptoms in adolescents and young adults: A feasibility study

BACKGROUND

About 5-15 % of patients with concussion experience persistent post-concussion symptoms (PCS) longer than 3 months post-injury.

OBJECTIVE

To explore the feasibility of a new intervention for young patients with persistent PCS and long-term changes after intervention.

METHODS

Thirty-two consecutive patients (15-30 years) with persistent PCS 2-4 months post-injury were recruited from a cohort study or referred to a non-randomized feasibility study of an individually tailored, 8-week, multidisciplinary intervention. Assessment was performed at baseline, end of intervention (EOI), and at 3- and 12-month follow-up (FU). Main measures were The Experience of Service Questionnaire (ESQ), Rivermead Post-Concussion Symptoms Questionnaire (RPQ) and The Quality of Life after Brain Injury - Overall Scale (QOLIBRI-OS).

RESULTS

Twenty-three (72%) patients completed the intervention. The ESQ demonstrated high patient satisfaction. There was a decrease of PCS and an increase in quality of life from baseline to EOI: RPQ score -8.9 points, 95% CI 4.5 to 13.3, p < 0.001; QOLIBRI-OS score +10.5 points, 95% CI 2.5 to 18.5, p = 0.010. Improvement was maintained at 3- and 12-month FU.

CONCLUSION

The new early intervention is feasible and may prevent chronification of PCS. An RCT is currently performed to evaluate the effect of the intervention.

Physical activity following acute concussion and persistent postconcussive symptoms in children and adolescents

The management of concussion in pediatric patients has always been guided by treatment guidelines that have been drawn from consensus statements rather than clinical research projects. Grool and colleagues conducted a clinical research project on an early return to physical activity and its effect on post-concussion symptoms. The study enrolled 3063 pediatric patients, age 5.0 to 17.99 years of age who presented to one of nine Pediatric Emergency Research Centers in Canada. 2413 patients completed the primary outcome for exposure. A total of 1677 patients (69.5%) instituted some level of early physical activity, including light aerobic exercise (n = 795 or 32.9%), sport-specific exercise (n = 214 or 8.9%), non-contact drills (n = 143 or 5.9%), full-contact practice (n = 106 or 4.4%), or full competition (n = 419 or 17.4%), while 736 (30.5%) instituted no physical activity. Patients were evaluated by a web-based survey or a telephone-based survey at days 7 and 28 after their initial visit, and their symptoms were evaluated by using the Post Concussive Symptom Inventory (PCSI). Early return to physical activity was associated with a lower risk of Persistent Post-Concussive Syndrome (PPCS) than in patients reporting no physical activity at 28 days (24.6% vs. 43.5%, Absolute risk difference, (ARD), 18.9% (95% CI 14.7-23.0%). Among the sub-group of patients who were symptomatic at day 28 (n = 803), PPCS was more present in the patients that reported no physical activity, (n = 584: PPCS 52.9%), than those with light aerobic activity (n = 494 [46.4%; ARD, 6.5%; 95% CI 5.7-12.5%], moderate activity [n = 176 (38.6%; ARD, 14.3%; 95% CI 5.9%-22.2%], or full contact activity [n = 133 (36.1%; ARD, 16.8%; 95% CI 7.5%- 25.5%]. Therefore, in patients aged 5 to 18 years with acute concussion, a return to physical activity within 7 days of acute injury was associated with less symptoms at 28 days than in patients who had a period of prolonged rest rather than an early return to physical activity.

Effect of hyperbaric oxygenation therapy on post-concussion syndrome

The present review evaluated the effect of hyperbaric oxygenation (HBO) therapy on post-concussion syndrome (PCS). Searches for publications from the earliest date possible up until the first week of 2016 were conducted using the electronic databases Cochrane, EBSCOhost, Embase, Ovid MEDLINE, PubMed and Web of Science. Additional trials were identified through reference list scanning. Randomized controlled trials assessing the effectiveness of HBO therapy in PCS were selected and tested for eligibility for inclusion in the present review. Two independent reviewers conducted data extraction and the Cochrane Collaboration's recommended method was used to assess the risk of bias in each study included. Review Manager 5.3 software was used for data synthesis and analysis and the standardized mean difference (SMD) or mean difference (MD) was estimated with a fixed or random effects model using a 95% confidence interval (CI). A total of 127 articles were identified, 4 of which were eligible for final analysis. The meta-analysis identified no difference in the Rivermead Post-Concussion Symptoms Questionnaire (MD=1.23; 95% CI, -3.47-5.94; P>0.05; I2=35%) or Post-Traumatic Stress Disorder Checklist (PCL) scores (SMD=0.12; 95% CI, -0.31-0.54; P>0.05; I2=0%) scores between groups receiving different oxygen doses. The differences in PCL scores (SMD=-0.13, 95% CI, -0.80-0.53; P>0.05; I2=63%) and neurobehavioral symptoms (SMD=-1.00, 95% CI, -2.58-0.58; P>0.05; I2=92%) between the HBO and sham groups were not significant. The current study demonstrated that HBO therapy has no significant effect on PCS compared with the sham group. Therefore, it was determined that effective design and execution of a large clinical trial, which includes treatment, control and sham groups is required in the future.

Protocol for the mixed-methods development of a concussion-specific health-related quality of life outcome measure based on the international classification of functioning, disability and health

INTRODUCTION

Recovery from concussion has traditionally been evaluated by patient-reported symptoms, objective measures such as loss of consciousness, specific dimensions such as depression or fatigue, cognitive status, employment status, level of physical activity and the more complex construct of disability. Increasingly, patient-reported outcome measures of health-related quality of life (HRQOL) are being emphasised as an important end point in patient care, clinical trial and health policy decisions. Currently, no standardised concussion-specific HRQOL outcome measure exists. The process for developing a concussion-specific HRQOL outcome measure based on the international classification of functioning, disability and health is outlined.

METHODS AND ANALYSIS

A multistage, patient-centred approach to developing the outcome measure will integrate evidence from systematic reviews, qualitative research and cognitive interviewing into a self-report questionnaire to guide clinical decision-making. The psychometric properties of the questionnaire will be evaluated to assess the inter-rater reliability and construct validity of the measure in individuals with persistent post-concussion symptoms. To date, the systematic review and the clinical expert interviews within the preparatory phase have been completed and work is progressing on the subsequent phases. It is anticipated that the outcome measure will be ready for psychometric testing in September 2018.

ETHICS AND DISSEMINATION

Ethical approval was granted by the Ottawa Health Science Network Research Ethics Board (Protocol #20170720-01H) on 31 October 2017 to conduct the patient and clinical expert interviews. Ethical approval for psychometric testing of the outcome measure will be sought by the Ottawa Health Science Network Research Ethics Board in Phase II, after the development of the final HRQOL questionnaire. Results will be disseminated through peer-reviewed journals and professional conferences.

PROSPERO REGISTRATION

Phase I systematic review registration number CRD42017075588 (15 June 2017). Phase II systematic review registration number CRD42017075588 (27 September 2017).

Divergent Classification Methods of Post-Concussion Syndrome after Mild Traumatic Brain Injury: Prevalence Rates, Risk Factors, and Functional Outcome

Mild traumatic brain injury (mTBI) is a common diagnosis and approximately one third of mTBI patients experience a variety of cognitive, emotional, psychosocial, and behavioral post-concussion symptoms. When a cluster of these symptoms persists for more than 3 months they are often classified as post-concussion syndrome (PCS). The objective of this study was to determine prevalence rates, risk factors, and functional outcome associated with PCS 6 months after mTBI, applying divergent classification methods. Follow-up questionnaires at 6 months after mTBI included the Rivermead Post-Concussion Symptoms Questionnaire (RPQ) and the Glasgow Outcome Scale Extended (GOSE). The RPQ was analyzed according to different classification methods: the mapped International Classification of Diseases, 10th revision (ICD-10)/Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV), the RPQ total score, the RPQ3 and the three-factor model using two different cutoff points (mild or worse and moderate or worse). Our results from a sample of 731 mTBI patients showed that prevalence rates of PCS ranged from 11.4% to 38.7% using divergent classification methods. According to all eight methods, 6.3% (n = 46) of mTBI patients experienced PCS. Applying the divergent classification methods resulted in a different set of predictors being statistically significantly associated with PCS, and a different percentage of overlap with functional impairment, measured with the GOSE. In conclusion, depending on the classification method and rating score used, prevalence rates of PCS deviated considerably. For future research, consensus regarding the diagnostic criteria for PCS and the analysis of the RPQ should be reached, to enhance comparability of studies regarding PCS after mTBI.

Chronic Effects of Neurotrauma Consortium (CENC) multicentre study interim analysis: Differences between participants with positive versus negative mild TBI histories

OBJECTIVES

Compare characteristics and outcomes of combat-exposed military personnel with positive versus negative mild traumatic brain injury (mTBI) histories.

SETTING

Recruitment was from registration lists and ambulatory clinics at four veterans administration hospitals.

PARTICIPANTS

Consented veterans and service members completing initial evaluation by September 2016 (n = 492).

DESIGN

Observational with cross-sectional analyses.

MAIN MEASURES

Multimodal assessments including structured interviews, record review, questionnaires, neuroendocrine labs and neurocognitive and sensorimotor performance.

RESULTS

In unadjusted comparisons to those absent lifetime mTBI, the mTBI positive group (84%) had greater combat exposure, more potential concussive events, less social support and more comorbidities, including asthma, sleeping problems and post-traumatic stress disorder. They also fared worse on all sensory and pain symptom scores and self-reported functional and global outcomes. They had poorer scores on Wechsler Adult Intelligence Scale-IV coding (processing speed), TMT-B (visual-motor integration and executive function) and two posturography subtests, but were otherwise equal to TBI negative participants on neurocognitive and sensorimotor testing and neuroendocrine levels.

CONCLUSIONS

Although differences in characteristics exist which were not adjusted for, participants with historical mTBI have greater symptomatology and life functioning difficulties compared with non-TBI. Performance measures were less dissimilar between groups. These findings will guide further research within this accruing cohort.

Transcranial light-emitting diode therapy for neuropsychological improvement after traumatic brain injury: a new perspective for diffuse axonal lesion management

The cost of traumatic brain injury (TBI) for public health policies is undeniable today. Even patients who suffer from mild TBI may persist with cognitive symptoms weeks after the accident. Most of them show no lesion in computed tomography or conventional magnetic resonance imaging, but microstructural white matter abnormalities (diffuse axonal lesion) can be found in diffusion tensor imaging. Different brain networks work together to form an important part of the cognition process, and they can be affected by TBI. The default mode network (DMN) plays an important central role in normal brain activities, presenting greater relative deactivation during more cognitively demanding tasks. After deactivation, it allows a distinct network to activate. This network (the central executive network) acts mainly during tasks involving executive functions. The salience network is another network necessary for normal executive function, and its activation leads to deactivation of the DMN. The use of red or near-infrared (NIR) light to stimulate or regenerate tissue is known as photobiomodulation. It was discovered that NIR (wavelength 800-900 nm) and red (wavelength 600 nm) light-emitting diodes (LEDs) are able to penetrate through scalp and skull and have the potential to improve the subnormal, cellular activity of compromised brain tissue. Based on this, different experimental and clinical studies were done to test LED therapy for TBI, and promising results were found. It leads us to consider developing different approaches to maximize the positive effects of this therapy and improve the quality of life of TBI patients.

Prognostic Value of S-100β Protein for Prediction of Post-Concussion Symptoms after a Mild Traumatic Brain Injury: Systematic Review and Meta-Analysis

This systematic review and meta-analysis aimed to determine the prognostic value of S-100β protein to identify patients with post-concussion symptoms after a mild traumatic brain injury (mTBI). A search strategy was submitted to seven databases from their inception to October 2016. Individual patient data were requested. Cohort studies evaluating the association between S-100β protein level and post-concussion symptoms assessed at least seven days after the mTBI were considered. Outcomes were dichotomized as persistent (≥3 months) or early (≥7 days <3 months). Our search strategy yielded 23,298 citations of which 29 studies including between seven and 223 patients (n = 2505) were included. Post-concussion syndrome (PCS) (16 studies) and neuropsychological symptoms (9 studies) were the most frequently assessed outcomes. The odds of having persistent PCS (odds ratio [OR] 0.62, 95% confidence interval [CI]: 0.34-1.12, p = 0.11, I² 0% [n = five studies]) in patients with an elevated S-100β protein serum level were not significantly different from those of patients with normal values while the odds of having early PCS (OR 1.67, 95% CI: 0.98-2.85, p = 0.06, I² 38% [n = five studies]) were close to statistical significance. Similarly, having an elevated S-100β protein serum level was not associated with the odds of returning to work at six months (OR 2.31, 95% CI: 0.50-10.64, p = 0.28, I² 22% [n = two studies]). Overall risk of bias was considered moderate. Results suggest that the prognostic biomarker S-100β protein has a low clinical value to identify patients at risk of persistent post-concussion symptoms. Variability in injury to S-100ß protein sample time, mTBI populations, and outcomes assessed could potentially explain the lack of association and needs further evaluation.

Team versus individual sport participation as a modifying factor in the development of post-concussion syndrome after first concussion: A pilot study

Identification of modifying factors that influence the development of post-concussion syndrome (PCS) following sport-related concussion (SRC) has drawn considerable interest. In this pilot study, we investigate the effect of team vs. individual sport participation on the development of PCS in a sample of 136 high school and college student-athletes. Controlling for several confounding variables, we employed a binary logistic regression and chi-squared test. Results of this pilot study indicate that participation in team versus individual sport is not a significant factor in the development of PCS. The identification of other forms of protective mechanisms is discussed.

Concussion and the autonomic nervous system: An introduction to the field and the results of a systematic review

BACKGROUND

Recent evidence suggests that autonomic nervous dysfunction may be one of many potential factors contributing to persisting post-concussion symptoms.

OBJECTIVE

This is the first systematic review to explore the impact of concussion on multiple aspects of autonomic nervous system functioning.

METHODS

The methods employed are in compliance with the American Academy of Neurology (AAN) and PRISMA standards. Embase, MEDLINE, PsychINFO, and Science Citation Index literature searches were performed using relevant indexing terms for articles published prior to the end of December 2016. Data extraction was performed by two independent groups, including study quality indicators to determine potential risk for bias according to the 4-tiered classification scheme of the AAN.

RESULTS

Thirty-six articles qualified for inclusion in the analysis. Only three studies (one Class II and two Class IV) did not identify anomalies in measures of ANS functioning in concussed populations.

CONCLUSIONS

The evidence supports the conclusion that it is likely that concussion causes autonomic nervous system anomalies. An awareness of this relationship increases our understanding of the physical impact of concussion, partially explains the overlap of concussion symptoms with other medical conditions, presents opportunities for further research, and has the potential to powerfully inform treatment decisions.

Early Detection of Poor Outcome after Mild Traumatic Brain Injury: Predictive Factors Using a Multidimensional Approach a Pilot Study

Mild traumatic brain injury (MTBI) is a common condition within the general population, usually with good clinical outcome. However, in 10-25% of cases, a post-concussive syndrome (PCS) occurs. Identifying early prognostic factors for the development of PCS can ensure widespread clinical and economic benefits. The aim of this study was to demonstrate the potential value of a comprehensive neuropsychological evaluation to identify early prognostic factors following MTBI. We performed a multi-center open, prospective, longitudinal study that included 72 MTBI patients and 42 healthy volunteers matched for age, gender, and socioeconomic status. MTBI patients were evaluated 8-21 days after injury, and 6 months thereafter, with a full neurological and psychological examination and brain MRI. At 6 months follow-up, MTBI patients were categorized into two subgroups according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) as having either favorable or unfavorable evolution (UE), corresponding to the presence of major or mild neurocognitive disorder due to traumatic brain injury. Univariate and multivariate logistical regression analysis demonstrated the importance of patient complaints, quality of life, and cognition in the outcome of MTBI patients, but only 6/23 UE patients were detected early via the multivariate logistic regression model. Using several variables from each of these three categories of variables, we built a model that assigns a score to each patient presuming the possibility of UE. Statistical analyses showed this last model to be reliable and sensitive, allowing early identification of patients at risk of developing PCS with 95.7% sensitivity and 77.6% specificity.

Prognostic value of neuron-specific enolase (NSE) for prediction of post-concussion symptoms following a mild traumatic brain injury: a systematic review

BACKGROUND

This systematic review aimed to determine the prognostic value of neuron-specific enolase (NSE) to predict post-concussion symptoms following mild traumatic brain injury (TBI).

METHODS

Seven databases were searched for studies evaluating the association between NSE levels and post-concussion symptoms assessed ≥ 3 months (persistent) or ≥ 7 days < 3 months (early) after mild TBI. Two researchers independently screened studies for inclusion, extracted data and appraised quality using the Quality in Prognostic Studies (QUIPS) tool.

RESULTS

The search strategy yielded a total of 23,298 citations from which 8 cohorts presented in 10 studies were included. Studies included between 45 and 141 patients (total 608 patients). The outcomes most frequently assessed were post-concussion syndrome (PCS, 12 assessments) and neuropsychological performance deficits (10 assessments). No association was found between an elevated NSE serum level and PCS. Only one study reported a statistically significant association between a higher NSE serum level and alteration of at least three cognitive domains at 2 weeks but this association was no longer significant at 6 weeks. Overall, risk of bias of the included studies was considered moderate.

CONCLUSIONS

Early NSE serum level is not a strong independent predictor of post-concussion symptoms following mild TBI.