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.

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.

Characteristics of patients included and enrolled in studies on the prognostic value of serum biomarkers for prediction of postconcussion symptoms following a mild traumatic brain injury: a systematic review

OBJECTIVE

Mild traumatic brain injury (mTBI) has been insufficiently researched, and its definition remains elusive. Investigators are confronted by heterogeneity in patients, mechanism of injury and outcomes. Findings are thus often limited in generalisability and clinical application. Serum protein biomarkers are increasingly assessed to enhance prognostication of outcomes, but their translation into clinical practice has yet to be achieved. A systematic review was performed to describe the adult populations included and enrolled in studies that evaluated the prognostic value of protein biomarkers to predict postconcussion symptoms following an mTBI.

DATA SOURCES

Searches of MEDLINE, Embase, CENTRAL, CINAHL, Web of Science, PsycBITE and PsycINFO up to October 2016.

DATA SELECTION AND EXTRACTION

Two reviewers independently screened for potentially eligible studies, extracted data and assessed the overall quality of evidence by outcome using the Grading of Recommendations Assessment, Development and Evaluation approach.

RESULTS

A total of 23 298 citations were obtained from which 166 manuscripts were reviewed. Thirty-six cohort studies (2812 patients) having enrolled between 7 and 311 patients (median 89) fulfilled our inclusion criteria. Most studies excluded patients based on advanced age (n=10 (28%)), neurological disorders (n=20 (56%)), psychiatric disorders (n=17 (47%)), substance abuse disorders (n=13 (36%)) or previous traumatic brain injury (n=10 (28%)). Twenty-one studies (58%) used at least two of these exclusion criteria. The pooled mean age of included patients was 39.3 (SD 4.6) years old (34 studies). The criteria used to define a mTBI were inconsistent. The most frequently reported outcome was postconcussion syndrome using the Rivermead Post-Concussion Symptoms Questionnaire (n=18 (50%)) with follow-ups ranging from 7 days to 5 years after the mTBI.

CONCLUSIONS

Most studies have recruited samples that are not representative and generalisable to the mTBI population. These exclusion criteria limit the potential use and translation of promising serum protein biomarkers to predict postconcussion symptoms.

Quality of return to work in patients with mild traumatic brain injury: a prospective investigation of associations among post-concussion symptoms, neuropsychological functions, working status and stability

PRIMARY OBJECTIVE

Although 'return to work' (RTW) has been always emphasized for patients with mild traumatic brain injury (MTBI), methodological drawbacks weakened its representativeness. This study thus aims to evaluate the 'work quality' (WQ) which originated from 'working status' and 'working stability' simultaneously, and to further explore the associations among post-concussion symptoms (PCS), neuropsychological functions and WQ.

METHODS AND PROCEDURES

A total of 179 participants, which included 132 patients with MTBI and 47 healthy participants, were prospectively recruited. The work quality index (WQI) was developed to evaluate WQ. All patients were evaluated for their PCS, neuropsychological functions and WQ at two weeks post-injury (T1), while PCS and WQ were recorded by one month post-injury (T2).

RESULTS

More than half of the patients were not able to retain their pre-injury jobs at T1, while 26% of the patients still failed to regain previous works at T2. Interestingly, WQ was significantly associated with educational levels and physical PCS, such as headache and dizziness.

CONCLUSIONS

Simultaneously considering working status and stability to reveal the quality of RTW is merited. A higher educational level might be a protective factor for successful RTW, and ameliorating physical symptoms is also necessary to get favourable WQ by one month after MTBI.

The Course of Concussion Recovery in Children 6-12 Years of Age: Experience From an Interdisciplinary Rehabilitation Clinic

BACKGROUND

Current concussion evidence is derived largely from teenagers and adults. Concussion in younger children occurs within the context of neuromaturation, with differing age-based pathophysiological responses to injury. Therefore, our current understanding of concussion in older children and adults is unlikely to directly apply to younger children.

OBJECTIVE

To describe patient variables, clinical course, and factors associated with time to discharge from concussion care in children 6-12 years of age with concussion treated in an interdisciplinary rehabilitation-based concussion clinic.

DESIGN

Retrospective chart review.

SETTING

Interdisciplinary concussion clinic at an academically affiliated rehabilitation center.

PATIENTS

Children aged 6-12 years (n = 105; mean 10.8 years of age, 70% male) seen within 60 days of concussive injury.

MAIN OUTCOME MEASUREMENTS

Descriptive statistics explored demographic, injury, and clinical features. The primary outcome measure, time to discharge from concussion care, was estimated with survival-analysis methods based on the date of discharge from the clinic. Multivariate models were used to examine factors associated with longer time to discharge.

RESULTS

Median time to discharge was 34 days postinjury (range 5-192 days); 75% of children were discharged within 60 days of injury. A minority reported persisting symptoms at discharge. Younger age and increased symptom burden at initial evaluation predicted longer time to discharge.

CONCLUSIONS

Although children 6-12 years old treated in a specialty concussion clinic show variability in time to discharge from concussion care, most were discharged within 2 months after injury. Risk factors for prolonged recovery, such as younger age and greater symptom burden at initial visit, can be used when counseling families and planning interventions. There may be varying contributions, including psychosocial stressors, to ongoing symptoms in children who experience persisting symptoms after other concussion-related concerns have resolved. Future work focused on the subset of children who report persisting symptoms will be useful for developing an evidence base related to their care.

LEVEL OF EVIDENCE

II.

Evaluating the test-retest reliability of symptom indices associated with the ImPACT post-concussion symptom scale (PCSS)

OBJECTIVE

The Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) is a commonly used tool in sports concussion assessment. While test-retest reliabilities have been established for the ImPACT cognitive composites, few studies have evaluated the psychometric properties of the ImPACT's Post-Concussion Symptom Scale (PCSS). The purpose of this study was to establish the test-retest reliability of symptom indices associated with the PCSS.

PARTICIPANTS AND METHODS

Participants included 38 undergraduate students (50.0% male) who underwent neuropsychological testing as part of their participation in their psychology department's research subject pool. The majority of the participants were Caucasian (94.7%) and had no history of concussion (73.7%). All participants completed the ImPACT at two time points, approximately 6 weeks apart. The PCSS was the main outcome measure, and eight symptom indices were calculated (a total symptom score, three symptom summary indices, and four symptom clusters).

RESULTS

Pearson correlations (r) and intraclass correlation coefficients (ICCs) were computed as measures of test-retest reliability. Overall, reliabilities ranged from low to high (r = .44 to .80; ICC = .44 to .77). The cognitive symptom cluster exhibited the highest test-retest reliability (r = .80, ICC = .77), followed by the positive symptom total (PST) index, an indicator of the total number of symptoms endorsed (r = .71, ICC = .69). In contrast, the commonly used total symptom score showed lower test-retest reliability (r = .67, ICC = .62). Paired-samples t tests revealed no significant differences between test and retest for any of the symptom variables (all p > .01). Finally, reliable change indices (RCI) were computed to determine whether differences observed between test and retest represented clinically significant change. RCI values were provided for each symptom index at the 80%, 90%, and 95% confidence intervals.

CONCLUSION

These results suggest that evaluating additional symptom indices beyond the total symptom score from the PCSS is beneficial. Findings from this study can be applied to athlete samples to assess reliable change in symptoms following concussion.

Development of a Prediction Model for Post-Concussive Symptoms following Mild Traumatic Brain Injury: A TRACK-TBI Pilot Study

Post-concussive symptoms occur frequently after mild traumatic brain injury (mTBI) and may be categorized as cognitive, somatic, or emotional. We aimed to: 1) assess whether patient demographics and clinical variables predict development of each of these three symptom categories, and 2) develop a prediction model for 6-month post-concussive symptoms. Patients with mTBI (Glasgow Coma Scale score 13-15) from the prospective multi-center Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) Pilot study (2010-2012) who completed the Rivermead Post Concussion Symptoms Questionnaire (RPQ) at 6 months post-injury were included. Linear regression was utilized to determine the predictive value of candidate predictors for cognitive, somatic, and emotional subscales individually, as well as the overall RPQ. The final prediction model was developed using least absolute shrinkage and selection operator shrinkage and bootstrap validation. We included 277 mTBI patients (70% male; median age 42 years). No major differences in the predictive value of our set of predictors existed for the cognitive, somatic, and emotional subscales, and therefore one prediction model for the RPQ total scale was developed. Years of education, pre-injury psychiatric disorders, and prior TBI were the strongest predictors of 6-month post-concussive symptoms. The total set of predictors explained 21% of the variance, which decreased to 14% after bootstrap validation. Demographic and clinical variables at baseline are predictive of 6-month post-concussive symptoms following mTBI; however, these variables explain less than one-fifth of the total variance in outcome. Model refinement with larger datasets, more granular variables, and objective biomarkers are needed before implementation in clinical practice.

Cascade of Traumatic Brain Injury: A Correlational Study of Cognition, Postconcussion Symptoms, and Quality of Life

INTRODUCTION

Traumatic brain injury (TBI) constitutes a significant burden on health care resources in India. TBI is a dynamic process which involves damage to the brain thus leading to behavior cognitive and emotional consequences.

AIM

To study the cognitive profile, post-concussion symptoms (PCS), quality of life (QOL), and their correlation.

METHODS

A total of 60 patients with TBI were recruited and assessed for neuropsychological profile, PCS, and QOL, the correlation among the variables were analyzed.

RESULTS

The results suggest that TBI has series of consequences which is interrelated, and the study has implications for rehabilitation of TBI.

CONCLUSION

The study highlights the deficits of cognition, and its correlation with PCS and QOL, emphasizing integrated rehabilitation approach for patients with TBI.

Resilience and symptom reporting following mild traumatic brain injury in military service members

PRIMARY OBJECTIVE

The purpose of this study was to examine the relationship between resilience and symptom reporting following mild traumatic brain injury (mTBI). It was hypothesized that, as resilience increases, self-reported symptoms would decrease.

RESEARCH DESIGN

Cross-sectional design.

METHODS AND PROCEDURES

Participants were 142 US military service members who sustained a mTBI, divided into three resilience groups based on participants' responses on the Response to Stressful Experiences Scale: Moderate (n = 42); High (n = 51); and Very High (n = 49). Participants completed the Neurobehavioral Symptom Inventory (NSI) and PTSD Checklist-Civilian Version (PCL-C) within 12 months following injury.

MAIN OUTCOMES AND RESULTS

There were significant main effects for the NSI total score, cognitive cluster and affective cluster, as well as for the PCL-C total score, avoidance cluster and hyperarousal cluster. Pairwise comparisons revealed that there was a negative relationship between resilience and self-reported symptoms overall. Specifically, participants with higher resilience reported fewer post-concussion and PTSD-related symptoms than participants with lower levels of resilience.

CONCLUSIONS

These findings underscore the important role that resilience plays in symptom expression in military service members with mTBI and suggest that research on targeted interventions to increase resilience in the acute phase following injury is indicated.

Outpatient follow-up and return to school after emergency department evaluation among children with persistent post-concussion symptoms

OBJECTIVE

To describe differences in outpatient follow-up and academic accommodations received by children with and without persistent post-concussion symptoms (PPCS) after emergency department (ED) evaluation. It was hypothesized that children with PPCS would have more outpatient visits and receive academic accommodations more often than children without PPCS and that follow-up would be positively associated with receiving accommodations.

METHODS

Children aged 8-18 years with acute (≤6hours) concussion at time of presentation to a paediatric ED were enrolled in an observational study. Outcomes were assessed through a telephone survey 30 days after injury.

RESULTS

Of 234 enrolled participants, 179 (76%) completed follow-up. PPCS occurred in 21%. Only 45% of subjects had follow-up visits after ED discharge. Follow-up visit rates were similar for those with and without PPCS (58% vs. 41%, respectively; p = 0.07). Children with PPCS missed twice as many school days as those without (3 vs. 1.5; p < 0.001), but did not differ in receiving academic accommodations (36% vs. 53%; p = 0.082). Outpatient follow-up was associated with receiving academic accommodations (RR = 2.2; 95% CI = 1.4-3.5).

CONCLUSIONS

Outpatient follow-up is not routine for concussed children. Despite missing more school days, children with PPCS do not receive academic accommodations more often. Outpatient follow-up may facilitate academic accommodations.

Acute concussion symptom severity and delayed symptom resolution

BACKGROUND AND OBJECTIVES

Up to 30% of children who have concussion initially evaluated in the emergency department (ED) display delayed symptom resolution (DSR). Greater initial symptom severity may be an easily quantifiable predictor of DSR. We hypothesized that greater symptom severity immediately after injury increases the risk for DSR.

METHODS

We conducted a prospective longitudinal cohort study of children 8 to 18 years old presenting to the ED with concussion. Acute symptom severity was assessed using a graded symptom inventory. Presence of DSR was assessed 1 month later. Graded symptom inventory scores were tested for association with DSR by sensitivity analysis. We conducted a similar analysis for post-concussion syndrome (PCS) as defined by the International Statistical Classification of Diseases and Related Health Problems, 10th revision. Potential symptoms characteristic of DSR were explored by using hierarchical cluster analysis.

RESULTS

We enrolled 234 subjects; 179 (76%) completed follow-up. Thirty-eight subjects (21%) experienced DSR. Initial symptom severity was not significantly associated with DSR 1 month after concussion. A total of 22 subjects (12%) had PCS. Scores >10 (possible range, 0-28) were associated with an increased risk for PCS (RR, 3.1; 95% confidence interval 1.2-8.0). Three of 6 of the most characteristic symptoms of DSR were also most characteristic of early symptom resolution. However, cognitive symptoms were more characteristic of subjects reporting DSR.

CONCLUSIONS

Greater symptom severity measured at ED presentation does not predict DSR but is associated with PCS. Risk stratification therefore depends on how the persistent symptoms are defined. Cognitive symptoms may warrant particular attention in future study. Follow-up is recommended for all patients after ED evaluation of concussion to monitor for DSR.