Concussion Flashcards

Question

26. Describe the key takeaway from the newest Concussion Consensus Statement in Amsterdam.

Answer 1

* The key takeaway from the 6th International Consensus Statement on Concussion in Sport held in Amsterdam in October 2022 is that there is no perfect diagnostic test or biomarker for acute concussion, and diagnosis remains a clinical judgment. * The consensus statement emphasizes the importance of a multimodal assessment approach, including clinical history, symptom evaluation, cognitive assessment, and neurological examination. * It also highlights the need for a standardized approach to diagnosis, management, and return-to-play decisions, while acknowledging the complex nature of concussion and the ongoing challenges in its assessment and treatment * It emphasizes early, light-intensity physical activity within 24-48 hours post-concussion and the use of sub-symptom threshold aerobic exercise within 2-10 days post-injury. This approach is recommended to reduce persistent symptoms and promote recovery. For example, an athlete who sustains a concussion would be advised to engage in light physical activity, such as walking or stationary cycling, within the first few days of the injury, and progress to sub-symptom threshold aerobic exercise within the first two weeks to promote recovery and reduce the risk of persistent symptoms.

Answer 2

Risk of Concussions: Females are generally at a higher risk of sustaining a concussion compared to males, especially in sports. Studies have shown that female athletes have a 1.5 to 2 times greater risk of concussion than their male counterparts playing the same sports. Anatomical and Physiological Differences: Females typically have smaller and weaker neck muscles compared to males, which may result in greater head and neck acceleration during an impact, leading to more brain movement and a higher risk of concussion. Females also have a smaller average brain size, which may make them more susceptible to the effects of brain trauma. Hormonal Differences: Hormonal fluctuations throughout the menstrual cycle in females may affect the brain's vulnerability to concussion and its ability to recover from injury. Estrogen, for example, has been shown to have neuroprotective effects, and changes in its levels may influence the risk and severity of concussions. Biomechanical Factors: Females tend to have different biomechanical characteristics, such as center of gravity, muscle activation patterns, and landing mechanics, which may contribute to a higher risk of head impacts and concussions, particularly in sports. Reporting and Diagnosis: Females may be more likely to report concussion symptoms, which can lead to a higher rate of diagnosis compared to males, who may be more reluctant to report their symptoms. Sport and Activity Participation: The types of sports and activities that females participate in may also contribute to their higher concussion risk. For example, sports like soccer and basketball, which involve more head-to-head or head-to-ground contact, are popular among female athletes. Previous Concussion History: Females with a history of previous concussions may be at an even higher risk of sustaining subsequent concussions, as the brain may be more vulnerable to further injury. Underreporting of Concussions: Males are more likely to underreport their concussion symptoms and continue playing or engaging in physical activity despite a suspected concussion. This is often due to cultural norms, perceived toughness, and a desire to avoid being removed from play. Prolonged Concussion Recovery: Females tend to have a longer recovery time and experience more persistent symptoms following a concussion compared to males. This may be due to a combination of factors, including hormonal differences, smaller brain size, and differences in neck strength and musculature.

Answer 3

* Instead, relative rest, which involves engaging in activities of daily living and limiting screen time, is recommended for the first 1-2 days following the injury (Leddy et al., 2023). * Convergent evidence indicates that carefully controlled exercise may be beneficial in promoting recovery and shortening the duration of symptoms associated with SRC (Kurowski et al., 2017; Leddy et al., 2013; Maerlender et al., 2015; Schneider et al., 2017). * For example, Maerlender et al. (2015) investigated the effects of immediate (median = 2 days) post-SRC exercise compared to a no-exercise control group in collegiate athletes. The study found that moderate physical activity did not significantly affect recovery time, and SRC symptoms following exercise were only present initially and dissipated over subsequent exercise sessions. These findings suggest that moderate physical activity is safe during the initial phase of SRC recovery * Kurowski et al. (2017) investigated the effects of a structured aerobic exercise program versus full-body stretching on recovery time and symptom burden in adolescents with mTBI experiencing persistent symptoms for 4-16 weeks. The aerobic exercise group demonstrated greater improvement in the Post-Concussion Symptom Inventory (PCSI) total score and the emotional and fatigue subscales compared to the stretching group, suggesting that structured aerobic exercise may be an effective treatment for adolescents with persistent post-mTBI symptoms. * Leddy et al. (2013) compared fMRI activation patterns, exercise capacity, and symptoms in PCS patients and healthy controls at baseline and after approximately 12 weeks, during which they received either exercise treatment or placebo stretching. Exercise PCS patients showed similar fMRI activation to healthy controls after 12 weeks, whereas placebo-stretching PCS patients had significantly decreased resting-state cortical and subcortical activity. As well, Schneider et al.’s (2017) review of rest, treatment and rehabilitation techniques following SRC, reported that athletes in submaximal exercise groups reported fewer symptoms, exhibited shorter recovery times to baseline cognitive and balance scores, and demonstrated more efficient fMRI activation patterns compared to matched controls.

Answer 4

* To the best of my knowledge, only three studies to date have investigated antisaccades in healthy young adults with SRC. * Johnson et al. (2015a; 2015b) examined behavioural data and fMRI measures of antisaccades in athletes with an SRC and age- and sex-matched controls at two distinct time points: initially (<7 days post-injury) and at follow-up (30 days post-injury). The concussed group exhibited longer antisaccade RTs and more directional errors at both assessments, with fMRI data showing hypo- and hyperactivity patterns across cortical and subcortical structures in the concussed group; however, follow-up fMRI findings did not significantly differ between groups. * More recently, Webb et al. (2018) investigated athletes with an SRC and age- and sex-matched controls at 2-6 days post-injury (initial assessment) and 14-20 days after the initial assessment (follow-up assessment). At the initial assessment, the SRC group exhibited longer antisaccade RTs and more directional errors, whereas follow-up RTs were comparable between groups. Notably, however, the SRC group demonstrated more directional errors at the follow-up assessment even though they had been medically cleared for RTS. These findings suggest that antisaccades are sensitive to executive-related concussive deficits in both early and later stages of recovery. Moreover, the increased frequency of antisaccade directional errors reflects a failure to engage the high-level EF task-set required to evoke non-standard responses (Everling & Johnston, 2013). Although often considered purely inhibitory control tasks (Munoz & Everling, 2004), antisaccades also require working memory and cognitive flexibility to maintain the goal of performing an antisaccade instead of a prosaccade. Only deliberate practice can reduce antisaccade directional errors, as they represent a nonstandard task-set (Dyckman & McDowell, 2005). Thus, the increased directional errors in the SRC group, despite RTS clearance, suggest an oculomotor EF deficit (Everling & Johnston, 2013). * Ayala et al. (2020) investigated whether oculomotor deficits associated with SRC result from impaired EF planning mechanisms or task-based increases in SRC symptomology. The authors employed SCAT-5, antisaccade performance, and pupillometry metrics in individuals with SRC during the early (≤12 days post-SRC) and later (14-30 days post-SRC) stages of recovery. The early assessment revealed longer RTs, more directional error, and larger task-evoked pupil dilations (TEPD) in the SRC group compared to controls. At the later stage of assessment, RTs did not significantly differ between groups; however, the SRC group continued to demonstrate increased directional errors and TEPDs. Notably, Ayala and Heath observed that SCAT-5 symptom scores at early and later assessments did not vary from pre- to post-oculomotor assessments; that is, oculomotor assessment did not result in an increase in task-based symptom burden. Taken as a whole, these studies highlight the potential of the antisaccade to serve as a valuable tool for detecting SRC EF deficits and monitoring recovery and safe RTS.

Answer 5

Centroidal contact: Linear acceleration without head rotation, causing minimal brain motion/deformation. Non-centroidal contact without linear acceleration: Rotational acceleration, leading to diffuse axonal injury. Non-centroidal contact with linear acceleration: Both linear and rotational acceleration, causing microscopic shearing and stretching of brain structures.

Answer 6

* The IMPACT (Immediate Post-Concussion Assessment and Cognitive Testing) assessment and SCAT (Sport Concussion Assessment Tool) are both comprehensive concussion assessment batteries, but they have some key differences: * 1. Computerized vs. Paper-and-Pencil: * IMPACT is a computerized, neurocognitive test battery. * SCAT is a paper-and-pencil assessment, with some components that can be administered digitally. * 2. Cognitive Assessment: * IMPACT focuses more on detailed, objective neurocognitive testing, including measures of verbal memory, visual memory, processing speed, and reaction time. * SCAT includes more general cognitive screening tests, such as the Maddocks questions and the Standardized Assessment of Concussion (SAC). * 3. Balance Assessment: * IMPACT includes a standardized balance assessment, such as the Balance Error Scoring System (BESS). * SCAT also includes a balance assessment, but it may be less comprehensive than the IMPACT balance evaluation. * 4. Symptom Evaluation: * Both IMPACT and SCAT include a symptom evaluation, but they may use different symptom checklists and rating scales. * 5. Clinician Involvement: * IMPACT is primarily a computerized assessment, with clinician involvement in interpreting the results. * SCAT involves more direct clinician observation and assessment, with a more comprehensive clinical interview. * 6. Normative Data * IMPACT has a larger database of normative data, as it is more widely used, particularly in the United States. * SCAT may have more limited normative data, as it is used more globally. * 7. Administration Time: * IMPACT typically takes 20-30 minutes to administer. * SCAT can take 15-30 minutes, depending on the clinical interview and additional assessments. In summary, IMPACT is more focused on objective, computerized neurocognitive testing, while SCAT provides a more comprehensive, clinician-administered assessment of various concussion-related domains. Both tools are valuable for the evaluation and management of sports-related concussions, and clinicians may use a combination of the two depending on the specific needs and resources of their sports medicine progra

Answer 7

* Research on individuals with acute concussions (typically within the first 2 weeks post-injury) has consistently demonstrated reduced activation and functional connectivity within the dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC) during the performance of executive function (EF) tasks, when compared to healthy control subjects. * This phenomenon is thought to be a direct consequence of the concussion-related reduction in cerebral blood flow (CBF), which occurs in the acute post-injury period. * The acute concussive event triggers a complex neurometabolic cascade, which includes transient alterations in ion homeostasis, neurotransmitter release, and energy substrate availability. * The decreased CBF impairs the ability of these critical brain regions to adequately support the increased metabolic demands required for successful EF task performance. * This reduction in activation and connectivity within the DLPFC and ACC likely reflects a temporary disruption in the normal neurovascular coupling and metabolic processes that underlie cognitive functioning. * Over time, as the neurometabolic cascade resolves and the brain's compensatory mechanisms become more effective, the DLPFC and ACC may exhibit increased activation and connectivity during EF tasks as part of the recovery process.

Concussion Flashcards

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