OBJECTIVE:To evaluate whether the axonal protein neurofilament light (NFL) in serum is a sensitive biomarker to detect subtle brain injury or concussion in contact sports athletes.
METHODS:Two ...prospective cohort studies involving (1) 14 Swedish amateur boxers who underwent fluid biomarker assessments at 7–10 days after bout and after 3 months of rest from boxing and (2) 35 Swedish professional hockey players who underwent blood biomarker assessment at 1, 12, 36, and 144 hours after concussion and when the players returned to play were performed. Fourteen healthy nonathletic controls and 12 athletic controls were also enrolled. Serum NFL was measured using ultrasensitive single molecule array technology.
RESULTS:Serum NFL concentrations were increased in boxers 7–10 days after bout as compared to the levels after 3 months rest as well as compared with controls (p = 0.0007 and p < 0.0001, respectively). NFL decreased following 3 months of rest, but was still higher than in controls (p < 0.0001). Boxers who received many (>15) hits to the head or were groggy after bout had higher concentrations of serum NFL as compared to those who received fewer hits to the head (p = 0.0023). Serum NFL increased over time in hockey players, and the levels returned to normal at return to play. Importantly, serum NFL could separate players with rapidly resolving postconcussion symptoms (PCS) from those with prolonged PCS.
CONCLUSIONS:The results from these 2 independent cohort studies suggest that serum NFL is a highly sensitive biomarker for concussion.
OBJECTIVETo compare neurofilament light (NfL) and tau as blood-based biomarkers for acute sports-related concussion (SRC) and determine whether their concentrations at different time points after the ...injury are associated with prolonged time to return to play (RTP).
METHODSA total of 288 professional hockey players were followed longitudinally from September 1, 2012, to April 30, 2015. Data collection and biomarker analyses were conducted between 2015 and 2017. Associations were tested between blood concentrations of NfL and tau, and RTP time. Serum concentrations of S100B and neuron-specific enolase (NSE) were also measured for comparison.
RESULTSOf 288 players, 105 sustained an SRC. Of these, 87 underwent blood sampling 1, 12, 36, and 144 hours after SRC and at the RTP time point. Serum NfL concentrations 1, 12, 36, and 144 hours after SRC were related to prolonged RTP time, and could separate players with RTP >10 days from those with RTP ≤10 days (area under the receiver operating characteristic curve AUROC 0.82). Also, serum NfL 144 hours after SRC discriminated players who resigned from the game due to persistent postconcussion symptoms (PCS) from those who returned to play (AUROC 0.89). Plasma tau 1 hour after SRC was related to RTP but less strongly than NfL, while S100B and NSE showed no such associations.
CONCLUSIONSerum NfL outperformed tau, S100B, and NSE as a biomarker for SRC. From a clinical standpoint, serum NfL may be useful to identify individuals at risk of prolonged PCS, and may aid in biomarker-informed decisions with regard to when RTP should be considered.This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0 (CC BY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Axonal white matter injury is believed to be a major determinant of adverse outcomes following traumatic brain injury (TBI). We hypothesized that measurement of neurofilament light protein (NF-L), a ...protein found in long white-matter axons, in blood samples, may serve as a suitable biomarker for neuronal damage in TBI patients. To test our hypotheses, we designed a study in two parts: i) we developed an immunoassay based on Single molecule array technology for quantification of NF-L in blood, and ii) in a proof-of-concept study, we tested our newly developed method on serial serum samples from severe TBI (sTBI) patients (n = 72) and controls (n = 35). We also compared the diagnostic and prognostic utility of NF-L with the established blood biomarker S100B. NF-L levels were markedly increased in sTBI patients compared with controls. NF-L at admission yielded an AUC of 0.99 to detect TBI versus controls (AUC 0.96 for S100B), and increased to 1.00 at day 12 (0.65 for S100B). Importantly, initial NF-L levels predicted poor 12-month clinical outcome. In contrast, S100B was not related to outcome. Taken together, our data suggests that measurement of serum NF-L may be useful to assess the severity of neuronal injury following sTBI.
Sport-related concussions are an increasingly recognized health problem. Soccer is the most popular sport in the world although recent studies on concussion incidence are scarce. Here, a nationwide ...prospective study on concussion incidence, symptom severity, risk factors, gender differences, and return-to-play after concussion was performed in 51 Swedish elite soccer teams during the 2017 season.
In the 1st and 2nd soccer leagues for men and women, a Sport Concussion Assessment Tool (SCAT)-based questionnaire study was performed at preseason (baseline) and from 48 hours to 3 months post-concussion.
We followed 959 players (389 women, 570 men) for 25 146 player game hours (9867 hours for women, 15 279 hours for men). Concussion incidence (n = 36 concussions during the season) was 1.19/1000 player game hours (females 1.22/1000 hours, males 1.18/1000 hours; P = .85). Twenty-seven percent of all players (8% of females, 40% of males) continued to play immediately after the concussion. When compared to male players, female players had worse initial symptom severity scores (median and IQR 30 (17-50.5) vs 11 (4-26.25), P = .02) on SCAT and longer return-to-play (P = .02). Risk factors for concussion were baseline symptoms and previous concussion.
In Swedish elite soccer, the concussion incidence was 1.19/1000 without gender differences. Most players recovered to play within 4 weeks post-injury. Almost one third of players continued to play at time of concussion. Female players had worse initial symptoms and longer return-to-play time than males, and a prolonged recovery beyond 3 months was only observed among female players.
Background
Professional ice hockey players may contract irritant and allergic contact dermatitis.
Aims
To investigate the presence of contact allergy (CA) in professional ice hockey players in ...Sweden.
Methods
Ten teams from the two top leagues were assessed for potential occupational exposure to sensitizers. Exactly 107 players were patch tested with an extended baseline series and a working series, in total 74 test preparations. The CA rates were compared between the ice hockey players and controls from the general population and dermatitis patients.
Results
One out of 4 players had at least one contact allergy. The most common sensitizers were Amerchol L 101, nickel and oxidized limonene. CA was as common in the ice hockey players as in dermatitis patients and significantly more common than in the general population. Fragrances and combined sensitizers in cosmetic products (fragrances + preservatives + emulsifier) were significantly more common in ice hockey players compared with the general population.
Conclusion
The possible relationship between CA to fragrances and cosmetic products on the one hand and the presence of dermatitis on the other should be explored further.
Ice hockey players' skin is exposed daily to chemicals, topical medication, adhesives and protection equipment.
Background In 1982, the Lysholm score was first published as a physician-administered score in the American Journal of Sports Medicine. The Tegner activity scale was published in 1985.
Hypothesis The ...Lysholm and Tegner scores are valid as patient-administered scores and responsive at early time points after treatment
of anterior cruciate ligament tears.
Study Design Cohort study (Diagnosis); Level of evidence, 1.
Methods All patients were treated for an anterior cruciate ligament tear. For responsiveness, the Lysholm score (n = 1075) and Tegner
activity level (n = 505) were measured preoperatively and 6, 9, 12, and 24 months postoperatively. For test-retest (n = 50),
scores were measured at 2 years postoperatively and again within 4 weeks by questionnaire. For criterion validity (n = 170),
patients completed the Short Form-12 and the International Knee Documentation Committee score in addition to Lysholm and Tegner
instruments. For all other analyses, preoperative Lysholm score (n = 1783) or Tegner activity levels (n = 687) were collected.
Results There was acceptable test-retest reliability for both the Lysholm (intraclass correlation coefficient = 0.9) and Tegner (intraclass
correlation coefficient = 0.8) scores. The minimum detectable change for Lysholm was 8.9 and for Tegner was 1. The Lysholm
demonstrated acceptable internal consistency. The Lysholm correlated with the International Knee Documentation Committee ( r = .8) and the Short Form-12 ( r = .4), and Tegner correlated with the Short Form-12 ( r = .2). Both scores had acceptable floor and ceiling effects and all hypotheses were significant. The Lysholm and Tegner were
responsive to change at each of the time points.
Conclusion After 25 years of changes in treatment of anterior cruciate ligament injuries, the Lysholm knee score and the Tegner activity
scale demonstrated acceptable psychometric parameters as patient-administered scores and showed acceptable responsiveness
to be used in early return to function after anterior cruciate ligament treatment.
The diagnosis of sports-related concussion is mainly based on subjective clinical symptoms and neuropsychological tests. Therefore, reliable brain injury biomarkers to assess when it is safe to ...return to play are highly desirable. The overall objective of this study was to evaluate the utility of two newly described tau fragments for diagnosis and prognosis of sports-related concussions. This multi-center prospective cohort study involved all 12 teams of the top professional ice hockey league in Sweden. A total of 288 players consented to participate in the study. Thirty-five players sustained concussions, of whom 28 underwent repeated blood samplings at 1, 12, 36, and 144 h after the trauma, or when the player returned to play (7 to >90 days). There was no significant increase in the levels of Tau-A in post-concussion samples compared with preseason values. However, serum levels of Tau-C were significantly higher in post-concussion samples compared with preseason. Further, levels of Tau-A correlated with the duration of post-concussive symptoms. Tau-A in serum, which is newly discovered biomarker, could be used to predict when it is safe to return to play after a sports-related concussion.
To verify the reliability and validity of Chinese versions of the Lysholm score and the Tegner activity scale for knee arthroplasty.
Sixty-four patients undergoing total knee arthroplasty and 28 ...healthy volunteers were included in this study. Participants were divided into 4 groups: a pre-operation group; a 3 months post-operation group; a 1-year post-operation group; and a control group of healthy volunteers. Participants completed the Lysholm score and Tegner activity scale twice over a period of 3-7 days.
The intraclass correlation coefficients of the Lysholm score and Tegner scale were both relatively high, at 0.99 and 0.97, respectively. Moreover, the Cronbach's alpha of the Lysholm score was 0.71. The items "locking" and "instability" differed slightly between groups (Kruskal-Wallis: for locking, χ2 (p) = 13.48, p = 0.0037; for instability, χ2 (p) = 4.32, p = 0.2292).
The simplified-Chinese versions of the Lysholm score and the Tegner scale are applicable for use with patients undergoing total knee arthroplasty, and have relatively high validity and reliability. The items "locking" and "instability" should be combined with clinical data to make the Lysholm score more suitable for assessment of total knee arthroplasty.
Abstract
A sports-related concussion (SRC) is often caused by rapid head rotation at impact, leading to shearing and stretching of axons in the white matter and initiation of secondary inflammatory ...processes that may exacerbate the initial injury. We hypothesized that athletes with persistent post-concussive symptoms (PPCS) display signs of ongoing neuroinflammation, as reflected by altered profiles of cerebrospinal fluid (CSF) biomarkers, in turn relating to symptom severity. We recruited athletes with PPCS preventing sports participation as well as limiting work, school and/or social activities for ≥ 6 months for symptom rating using the Sport Concussion Assessment Tool, version 5 (SCAT-5) and for cognitive assessment using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Following a spinal tap, we analysed 27 CSF inflammatory biomarkers (pro-inflammatory chemokines and cytokine panels) by a multiplex immunoassay using antibodies as electrochemiluminescent labels to quantify concentrations in PPCS athletes, and in healthy age- and sex-matched controls exercising ≤ 2 times/week at low-to-moderate intensity. Thirty-six subjects were included, 24 athletes with PPCS and 12 controls. The SRC athletes had sustained a median of five concussions, the most recent at a median of 17 months prior to the investigation. CSF cytokines and chemokines levels were significantly increased in eight (IL-2, TNF-α, IL-15, TNF-β, VEGF, Eotaxin, IP-10, and TARC), significantly decreased in one (Eotaxin-3), and unaltered in 16 in SRC athletes when compared to controls, and two were un-detectable. The SRC athletes reported many and severe post-concussive symptoms on SCAT5, and 10 out of 24 athletes performed in the impaired range (
Z
< − 1.5) on cognitive testing. Individual biomarker concentrations did not strongly correlate with symptom rating or cognitive function. Limitations include evaluation at a single post-injury time point in relatively small cohorts, and no control group of concussed athletes without persisting symptoms was included. Based on CSF inflammatory marker profiling we find signs of ongoing neuroinflammation persisting months to years after the last SRC in athletes with persistent post-concussive symptoms. Since an ongoing inflammatory response may exacerbate the brain injury these results encourage studies of treatments targeting the post-injury inflammatory response in sports-related concussion.
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