Diagnostic terminology, athlete status, and history of concussion affect return to play expectations and anticipated symptoms following mild traumatic brain injury

On the lasting impact of mild traumatic brain injury on working memory: Behavioural and electrophysiological evidence

Despite increasing recognition of the significance of mild traumatic brain injury (mTBI), the long-term cognitive consequences of the injury remain unclear. More sensitive measures that can detect subtle cognitive changes and consideration of individual variability are needed to properly characterise cognitive outcomes following mTBI. Here, we used complex behavioural tasks, individual differences approaches, and electrophysiology to investigate the long-term cognitive effects of a history of mTBI. In Experiment 1, participants with self-reported mTBI history (n=82) showed poorer verbal working memory performance on the operation span task compared to control participants (n=88), but there were no group differences in visual working memory, multitasking, cognitive flexibility, attentional control, visuospatial ability, or information processing speed. Individual differences analyses revealed that time since injury and presence of memory loss predicted visual working memory capacity and visuospatial ability, respectively, in those with mTBI history. In Experiment 2, participants with mTBI history (n=20) again demonstrated poorer verbal working memory on the operation span task compared to control participants (n=38), but no group differences were revealed on a visuospatial complex span task or simpler visual working memory measures. We also explored the electrophysiological indices of visual working memory using EEG during a change detection task. No differences were observed in early sensory event-related potentials (P1, N1) or the later negative slow wave associated with visual working memory capacity. Together, these findings suggest that mTBI history may be associated with a lasting, isolated disruption in the subsystem underlying verbal working memory storage. The results emphasise the importance of sensitive cognitive measures and accounting for individual variability in injury characteristics when assessing mTBI outcomes.

International perspectives on trends in paediatric sports-related concussion: knowledge, management, unanswered questions

Purpose

In the last 20 years, concussion has received increased attention in the media, with distinct recognition of sports-related concussion (SRC). Much of this attention has centred on the paediatric population, due to concerns over adolescent brain development and the high numbers of teenagers playing contact sport. This qualitative study explored (1) what experts in the field of concussion perceive regarding trends in paediatric concussion awareness and management, and (2) how responses to these questions differ by country (US vs. NZ) and by discipline (research vs. sports coaching vs. sports medicine).

Methods

After the development of a semi-structured interview template, questions were coded for interviews of six (N = 6) experts in academia, medicine, and coaching: three in the United States (N = 3) and three in New Zealand (N = 3). Interviews were then transcribed and qualitatively analysed using a thematic narrative analysis. Emergent themes included concussion knowledge, management, and unanswered questions.

Results

Findings showed general commonalities on the importance of concussion education, the improvement of concussion awareness, compliance to concussion protocols, and the need to research long-term outcomes. Fewer commonalities were found regarding the level of concussion reporting, the impact of multiple concussions, whether paediatric and adult concussion should be treated similarly, and the utility of concussion tests.

Conclusions

Concussion experts agree on many areas; however, divergent opinions were apparent. Further original research is required within the paediatric population to analyse the efficacy of current concussion guidelines.

An Investigation into Helmet Use, Perceptions of Sports-Related Concussion, and Seeking Medical Care for Head Injury amongst Competitive Cyclists

The purpose of this study was to investigate competitive cyclists' helmet use, perceptions of sports-related concussion (SRC), and medical-care-seeking behaviors. A mixed-method approach was used with qualitative and quantitative data presented. The study comprised of a cross-sectional analysis of 405 competitive cyclists who completed an online survey. Results indicated that most participants believed a bicycle helmet protects against SRC (79.5%) and considerable numbers of participants would not seek medical care for potential head injury in scenarios where this would be recommended. It was also discovered that marketing of concussion reduction technology influences cyclists' helmet-purchasing behaviors. With the data presented, it is recommended that governing bodies in cycling need to develop educational resources to address gaps in knowledge regarding SRC amongst cyclists. We also suggest that more independent research on concussion reduction technologies in bicycle helmets is needed, with advertising supported by clear scientific evidence to avoid negatively influencing head injury management and reporting behaviors amongst cyclists.

Effects of Stricter Management Guidelines on Return-to-Competition Timeframes Following Concussion in Professional Australian Rules Football: An Exploratory Analysis

Background

Management of concussion remains a serious issue for professional sports, particularly with the growing knowledge on the consequences of repetitive concussion. One primary concern is the subjective assessment of recovery that dictates the time until a concussed athlete is returned-to-competition. In response to this concern, the Australian Football League (AFL) changed its policy in 2020 such that medical clearance for return-to-competition was extended from 1 day, to a minimum of 5 days, prior to the next scheduled match.

Objective

We sought to explore the impact of the AFL policy change by asking whether time to return-to-competition after concussion was increased in the 2020 season relative to previous years.

Methods

Retrospective data on injury and return-to-competition were sourced from publicly available tables published by the AFL. Our primary exploration compared the number of matches missed and the number of days missed in concussed players across 2017–2020 inclusive, with secondary exploration analysing the proportion of players returning to play 12 days or longer.

Results

Analysis of data from 166 concussed players revealed no increase in the number of matches missed in 2020 relative to previous years as would have been expected from an extended recovery protocol. Comparing 2020 relative to 2017–2019, we found that there was an overall moderate reduction in median time to return-to-competition (RTC) in 2020 (10 vs 13 days, respectively d = − 0.345) and a significant reduction in players taking more than 12 days to RTC (p = 0.046).

Conclusion

This exploratory study demonstrates that clubs may not have followed policy change around concussion management designed to increase time to RTC. Ongoing auditing is required to ensure player clearance meets policy goals, highlighting the need for objective measures for RTC after concussion.

A Scoping Review of Registered Clinical Studies on Mild Traumatic Brain Injury and Concussion (2000 to 2019)

BACKGROUND

While many patients with mild traumatic brain injury (mTBI) or concussion recover completely, prolonged postconcussion symptoms remain a challenge for patients and an opportunity for clinical research. This has led to numerous research initiatives over the last 2 decades.

OBJECTIVE

To review the characteristics of clinical studies on management of mTBI/concussion; and to examine their definitions of mTBI/concussion.

METHODS

This scoping review included all clinical studies on diagnosis and management of patients with mTBI/concussion registered at www.clinicaltrials.gov from 2000 to June/2019. The terms “mild TBI/concussion” were used for the primary search. Definitions of mTBI/concussion were obtained from the protocols. When a definition was missing in the website, the study's investigators were contacted for clarification.

RESULTS

There were 225 interventional and 95 observational studies. Most of the studies are focused on treatment (54.7%) or diagnosis (37.5%), while 3.4% examined preventive measures, 2.8% evaluated prognostic instruments, and 1.6% developed registries. Most of the studies in this American database were single-center initiatives led by American and Canadian institutions. The definitions of mTBI/concussion differed widely among 109 studies.

CONCLUSION

The results of this review suggest that most of the clinical studies are focused on diagnosis and non-pharmacological therapies for patients with mTBI/concussion. The large number of differing definitions of mTBI/concussion among the studies creates significant limitations when comparing studies. The requirements for registering research protocols on mTBI/concussion should include the necessity to state the definition being used. There is a need for consensus on a uniform definition of concussion.

Prior head injury but not sex or sports-participation affects expectations for post-injury rest and activity in simulated mild traumatic brain injury

Rest acutely followed by a gradual return to activity is commonly recommended for mild traumatic brain injury (TBI). However, the general public's rest and activity expectations for this injury are unknown, as are the individual factors that might affect them. 165 individuals completed an online survey. A series of between-groups comparisons of expectations for the week following a mild TBI was performed. The comparisons were between individuals with or without a prior mild TBI; sports-playing versus non-sports-playing individuals, and; females versus males. Expectations were elicited for 39 everyday behaviours referred to in mild TBI patient advice. Compared to a rating indicating 'no change' in the amount of pre-injury activity, "rest" was expected for 37 items (p's < .05). Expectations were not different based on participants' sex or sports-participation. However, for seven predominantly cognitive items such as studying, a prior injury increased rest expectations (p < .05; small-to-medium effects). The findings indicate that whilst the proposed activity restrictions are appropriate for some circumstances such as acutely postinjury, they have the potential to be overly strong. To address this potential, especially with first-ever injury, clinicians and sports officials should check their patient's postinjury rest and activity plans when providing active rest advice.

An experimental study of two forms of concussion advice on planned physical activity

Background and aims

Best practice management for medically cleared concussion is to commence a graded return to activity, as tolerated, and within 24–48 h of the injury. Patients may encounter this or other advice if they search the Internet, or when they are discharged from care. It is not yet known how patients would interpret this advice, particularly for specific activities. This study compared the effect of two forms of concussion advice on physical activity plans. It was expected that compared to the advice to gradually return to activity, the advice to ‘rest’ would lead to reduced activity plans.

Methods

Concussion simulators received the generic advice to undertake 1 week of (i) rest (no physical activity [NPA], n = 115) or (ii) graded physical activity (GPA, n = 104). Activity plans were recorded using items from the Mild Traumatic Brain Injury Rest-Activity Questionnaire (MTBI-RAQ).

Results

There was a significant group difference in activity plans (NPA < GPA, total score and for all MTBI-RAQ items, p’s ≤ 0.001, medium-to-large effects). The average NPA response was for a significant reduction from pre-injury for 14 activities, with no planned change for 2 activities (walking, household chores). In the GPA group, there were plans to reduce (nitems = 7), continue (nitems = 5) or increase activities (nitems = 4; e.g., swimming). Both groups proposed to decrease ‘high-risk’ activities (e.g., heavy lifting).

Conclusion

As expected, there was a significant effect of the type of advice on physical activity plans. Compared to the GPA advice, the NPA advice led to a significant reduction of planned physical activity. If concussed patients seek or receive advice that recommends NPA, it may prompt activity plans that are unnecessarily restrictive. If GPA advice is given, it leads to varied plans, with fewer restrictions overall, and avoidance of higher risk physical activities. Generic GPA advice has the potential to facilitate active recovery for concussion; however, patients would still likely benefit from a professional consultation about their plan and support to safely implement it, and this should be investigated in future research.

An experimental study of the effect on activity intentions of postconcussion recovery advice

This study tested the effect of issuing return-to-activity advice on activity intentions at Day 2 and Day 10 days post simulated mild traumatic brain injury. One hundred and twenty-eight volunteers were randomly allocated to one of two groups who received ( n =  65) or did not receive standardized post-injury advice ( n =  63). To prime the simulation, the participants read a mild traumatic brain injury vignette about a person who is concussed while playing sport. Then the participants role-played the injured person and reported activity intentions for three activity types (cognitive, physical and restful) twice, once for each time frame (i.e. Day 2 and Day 10). The advice was to rest for the first 24–48 h and then gradually resume normal activities. There was no significant group by activity-type interaction ( p > .05) at Day 2. When both time frames were considered, there was no significant group × time frame interaction for any activity type or any item, except for an increase in non-manual (clerical) work and weight training at Day 10 compared to Day 2 in the group with the advice. In general, the intentions for all activity types were consistent with the recovery advice (i.e., rest then increasing activity), even when the advice was not given. However, at Day 10, cognitive and physical activity levels were still expected to be lower than usual (pre-injury), and many participants were uncertain about the concept of cognitive rest. These factors, along with individual patient circumstances, should be taken into account in rehabilitation planning.