Concussion Flashcards
- What is a concussion?
A concussion is a type of traumatic brain injury caused by a direct blow to the head, neck, or body that results in an impulsive force being transmitted to the brain. This leads to a complex pathophysiological process affecting the brain, often involving a neurotransmitter and metabolic cascade, potential axonal injury, changes in blood flow, and inflammation (Patricios et al., 2023). For example, a soccer player who collides with another player and experiences a sudden jolt to the head may sustain a concussion.
- What are the rates and incidences of concussions in the general population versus in sports?
In Canada, approximately 1 in 450 individuals aged 12 and older reported a sport-related concussion (SRC) as their most significant injury with associated disability in the previous year (Gordon & Kuhle, 2022). In Ontario, there was an average incidence of 1,153 concussions per 100,000 residents between 2008 and 2016 (Langer et al., 2020). The prevalence of SRCs increased nearly 2.5 times from 2005 to 2013, with higher rates among youth aged 12-19 compared to adults over 19 years old (Gordon & Kuhle, 2022). This highlights the increased risk of concussions in sports compared to the general population.
- What are the symptoms of concussions?
- Concussion symptoms can be classified into four clusters:
- Somatic: headache, neck pain, nausea, dizziness, blurred vision, balance problems, sensitivity to light and noise.
- Cognitive: feeling slowed down, in a fog, difficulty concentrating, difficulty remembering, confusion.
- Arousal/Sleep problems: fatigue, drowsiness, trouble falling asleep.
- Emotional: irritability, sadness, nervousness, anxiety (Echemendia et al., 2017).
For instance, a football player who sustains a concussion may experience a headache, dizziness, and difficulty concentrating in the days following the injury.
- What is the difference between a concussion and sport-related concussion?
A sport-related concussion (SRC) is a subset of concussions that occur specifically during sports or exercise-related activities. SRCs are characterized by the same pathophysiological processes as general concussions but are distinct due to their occurrence in a sporting context, necessitating specific management and return-to-play protocols tailored for athletes (Patricios et al., 2023). For example, a hockey player who sustains a concussion during a game would be diagnosed with an SRC and would follow sport-specific guidelines for recovery and return to play.
- How often do athletes typically sustain SRCs and what are the most common circumstances leading up to it?
Athletes, particularly in contact sports, have a higher incidence of SRCs. In Ontario, hockey accounted for the highest number of SRCs (44.3%), followed by soccer (19.0%) and football (12.9%) (Cusimano et al., 2013). Circumstances leading to SRCs often involve high-impact collisions, falls, or blows to the head during sports activities. For instance, a hockey player may sustain an SRC due to a body check or a soccer player may experience a concussion from a collision with another player or the ground.
- How are concussions objectively tracked and measured?
- Concussions are tracked and measured using a combination of subjective symptom reports and objective clinical assessments. Tools such as the Sport Concussion Assessment Tool (SCAT-5) provide standardized methods for evaluating symptoms, cognitive function, and neurological status. Neurocognitive tests like the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT™) battery assess cognitive functions such as attention, memory, processing speed, and reaction time (Allen & Gfeller, 2011). Advanced imaging techniques like diffusion tensor imaging (DTI) and functional MRI (fMRI) can also provide insights into brain changes post-concussion.
- Moreover, accelerometers and gyroscopes located in helmets or mouthguards can be used to gather real-time data on head impacts encountered by athletes during play. These devices measure the acceleration forces and rotational velocities experienced by the head, providing objective data on the magnitude and direction of impacts. This information can help in identifying potentially concussive blows and contribute to a better understanding of the biomechanics involved in concussions.
For example, an athlete who sustains a concussion would complete the SCAT-5 and ImPACT™ tests to objectively measure their symptoms and cognitive function, which could be supplemented by data from accelerometers to understand the impact forces involved in the injury. This comprehensive approach helps clinicians make more informed decisions about diagnosis and management.
- What is the process of getting an SRC diagnosis?
- Diagnosing a sport-related concussion (SRC) involves a multi-step and multi-domain approach, integrating clinical evaluations, symptom reporting, cognitive testing, and sometimes neuroimaging. The process is designed to ensure a thorough and accurate assessment to guide appropriate management and return-to-play decisions.
- Immediate Evaluation and Initial Assessment
- On-Field Examination
○ Primary Survey: Immediately after a suspected head injury, the focus is on primary survey protocols — checking airway, breathing, circulation, and conducting a spinal evaluation to rule out any severe injuries.
○ Observable Symptoms: The clinician will look for signs such as unconsciousness, confusion, balance issues, and other neurological symptoms.
○ Brief Cognitive and Physical Assessments: Tools such as the sideline concussion assessment tool (part of SCAT-5) help in initial assessment. This includes orientation questions (e.g., “What venue are we at?”, “Which half is it?”), immediate memory tests, and a brief neurological examination. - Removal from Play
- If an SRC is suspected, the athlete is immediately removed from play to prevent further injury and to allow for a more comprehensive evaluation.
- Comprehensive Clinical Evaluation
- Detailed History Taking
○ Mechanism of Injury: Understanding how the injury occurred, including the forces involved and any previous history of concussions, is critical.
○ Symptom Timeline: Documenting when symptoms appeared, their severity, and any changes over time. - Comprehensive Symptom Evaluation
○ Symptom Checklists: The SCAT-5 includes a symptom scale where athletes rate 22 symptoms (like headache, dizziness, nausea) on a severity scale. This provides a quantitative tool to track symptom progression.
○ Daily Activities Impact: Evaluating how symptoms affect daily activities, such as school or work, helps gauge the concussion’s impact on the individual’s functionality. - Cognitive Function Testing
- Standardized Tests
○ SCAT-5 Cognitive Components: This includes orientation questions and memory tests involving word recall and concentration tests like digit span tasks.
○ Computerized Neurocognitive Testing (e.g., ImPACT™): These tests measure domains such as memory, processing speed, reaction time, and attention. ImPACT™ involves baseline testing for comparison post-injury, offering a reliable method to identify cognitive impairments. - Clinical Neuropsychological Assessment
- For complex cases, detailed neuropsychological testing assesses cognitive deficits more comprehensively, examining domains such as executive function, language, and visual-spatial skills.
- Physical and Neurological Examination
- Balance and Coordination Assessments
○ Balance Error Scoring System (BESS): This test involves the athlete performing a series of balance tasks, with errors in performance recorded.
○ Vestibular/Oculomotor Screening (VOMS): Evaluates balance and eye movements, including smooth pursuits, saccades, convergence, and the vestibulo-ocular reflex (VOR). - Neurological Exam
- A full neurological examination checks cranial nerves, strength, sensation, reflexes, and coordination to rule out more serious neurological conditions.
- Advanced Diagnostics (Optional)
- Neuroimaging
○ CT Scans and MRI: While not typically used for routine SRC diagnosis, these can be essential if structural brain damage or other emergencies (e.g., skull fracture, intracranial hemorrhage) are suspected.
○ Functional Imaging (e.g., fMRI, DTI): Cutting-edge imaging techniques like functional MRI (fMRI) and diffusion tensor imaging (DTI) can provide insights into brain function and structural connectivity. These are generally used in research settings or complex clinical cases. - Biomarkers
○ Blood and CSF Biomarkers: Research is ongoing into specific biomarkers that could indicate brain injury, such as tau proteins or neurofilament light, although routine clinical use is currently limited. - Integration of Data and Diagnosis
- Combining clinical findings, symptoms, cognitive and physical assessments, and any additional data like imaging results, the clinician makes an informed diagnosis.
- Differential Diagnosis
- It is essential to rule out other medical conditions that may present similarly to concussions, such as neck injuries, psychological conditions, or other neurological disorders.
- Patient and Family Education
- Educating the athlete and their family about the nature of the injury, expected symptoms, recovery trajectory, and the importance of adhering to prescribed management plans is crucial. This includes providing information about signs of worsening symptoms that necessitate immediate medical attention.
- Follow-up and Monitoring
- Regular Follow-up
○ Symptom and Cognitive Monitoring: Reassessing symptoms and cognitive function regularly to track recovery and identify any persisting issues.
○ Engagement in Rehabilitation: If symptoms persist, involving physical therapists, cognitive rehabilitation specialists, or other professionals as needed. - Return-to-Play Protocols
○ Stage-based Rehabilitation: Following the graduated return-to-play protocol, progressing from symptom-limited activities to full sport-specific exercise under healthcare provider supervision.
○ Final Clearance: Only when the athlete remains symptom-free at rest and with exertion, has normal cognitive function, and has no neurological deficits, is full return to play considered appropriate. - The diagnosis and management of SRCs require a multidisciplinary approach and individualized care to ensure a safe and successful recovery.
- What are some of the most popular diagnostic tools for SRCs and what do they entail?
- Popular diagnostic tools for SRCs include:
- Sport Concussion Assessment Tool (SCAT-5): Evaluates symptoms, cognitive function, and neurological status.
- Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT™): Assesses cognitive functions such as attention, memory, and reaction time.
- Vestibular and oculomotor screening: Assesses balance and eye movements (Echemendia et al., 2017; Allen & Gfeller, 2011).
- These tools provide a comprehensive evaluation of the various domains affected by SRCs and help healthcare providers make accurate diagnoses and treatment plans.
Describe the SCAT-5 in detail.
- The SCAT-5 includes several components:
- Immediate/on-field assessment: Evaluates immediate symptoms and observable signs following an injury using questions about the mechanism of injury and observable signs such as loss of consciousness or balance disturbances.
- Symptom evaluation: Assesses the frequency and severity of 22 symptoms (e.g., headache, dizziness, nausea) on a 7-point Likert scale, to quantify the athlete’s experience post-injury.
- Cognitive screening: Includes orientation questions (e.g., asking the date), immediate memory recall tests (e.g., word lists), and concentration tests (e.g., digit span).
- Neurological Screening: Assesses balance using the modified Balance Error Scoring System (mBESS), coordination tests (e.g., finger-to-nose), and delayed recall of memory items.
- Delayed recall: Tests memory 5-10 minutes after the initial memory test to evaluate short-term memory retention.
- The SCAT-5 is designed to provide a comprehensive evaluation of the domains affected by SRCs (Echemendia et al., 2017). For example, the immediate/on-field assessment would be used to evaluate an athlete’s symptoms and cognitive function immediately after a suspected concussion, while the symptom evaluation and cognitive screening would be used to track their recovery over time.
What is the current return-to-sport protocol?
- The current return-to-sport (RTS) protocol involves a graduated, stepwise approach consisting of six stages:
- Symptom-limited activity: Activities of daily living that do not provoke symptoms.
- Light aerobic exercise: Gentle aerobic activities like walking or stationary cycling at slow to medium pace. No resistance training.
- Sport-specific exercise: Running or skating drills without head impact activities.
- Non-contact training drills: More complex training drills, such as passing drills or practice activities without direct contact. May start progressive resistance training.
- Full-contact practice: Following medical clearance, participate in normal training activities.
- Return to sport: Normal game play.
- Progression through each stage depends on the absence of symptom exacerbation and the athlete’s clinical status (Patricios et al., 2023). For instance, an athlete who sustains a concussion would begin with symptom-limited activity and gradually progress through each stage as their symptoms improve and they demonstrate tolerance for increased physical and cognitive demands.
- How has research supporting strict rest post-SRC shifted to the current support for graded aerobic exercise and relative rest with symptom-limited physical activity?
Existing research suggests that strict rest may not be beneficial for recovery following a concussion. A randomized controlled trial by Thomas et al. found that strict rest after acute concussion did not provide additional benefits compared to a more gradual return to activity (Thomas et al., 2015). Furthermore, a case-control study by Silverberg demonstrated that advising individuals to rest for more than 2 days after mild traumatic brain injury was associated with delayed return to productivity (Silverberg, 2019).
In contrast, recent work has suggested that light to moderate exercise can have positive effects on cognitive function and symptom improvement in individuals with traumatic brain injuries.
Chin et al. examined cognitive function in individuals with mild-to-moderate chronic traumatic brain injury. Participants who engaged in treadmill exercise three times per week for 30 minutes at 70-80% of their heart rate reserve demonstrated significant improvements in processing speed and executive function following the exercise training (Chin et al., Year).
Additionally, Leddy et al. found that male adolescents with sports-related concussions who engaged in early prescribed aerobic exercise experienced better recovery outcomes compared to those who were advised to rest. The exercise group had significantly fewer participants who remained symptomatic in physical, cognitive, and sleep domains (Leddy et al., Year).
Similarly, Dematteo et al. evaluated the response of youth with persistent post-concussive symptoms to an exertion test involving gradual increases in cycling workload. Participants experienced significant improvements in cognitive-sensory, affective, and sleep-arousal symptoms following the acute exercise assessment and 24 hours later (Dematteo et al., Year).
Collectively, these findings suggest that light to moderate exercise may be more beneficial than strict rest in promoting recovery and symptom resolution following a concussion. Individualized approaches to activity resumption based on the type and severity of concussion are recommended (Silverberg, 2013).
At which stage is physical activity, specifically exercise safe for a person with an SRC?
Physical activity is safe during the symptom-limited activity stage, which is the first stage of the RTS protocol. Light-intensity activities such as walking or stationary cycling are recommended within 24-48 hours post-injury, provided they do not exacerbate symptoms beyond mild levels (Patricios et al., 2023). Early engagement in gentle, non-strenuous activities helps mitigate the negative effects of prolonged rest and supports physical and psychological recovery. For instance, an athlete who sustains a concussion may be advised to take short walks, engage in light stretching exercises, or perform mild stationary biking within the first few days of the injury, as long as these activities do not worsen their symptoms.
What does the recovery trajectory look like for an athlete with an SRC versus a normal healthy adult?
Athletes with SRCs typically recover within 24 days, with recovery influenced by factors such as injury severity, age, concussion history, and adherence to rehabilitation protocols. Adolescents may take longer than adults to recover due to ongoing brain development and higher activity levels. Normal healthy adults, particularly those outside of athletic settings, usually recover within 14 days. Persistent symptoms beyond these timelines can lead to post-concussion syndrome, characterized by prolonged cognitive, physical, and emotional disturbances (McCrory et al., 2017; McAllister et al., 2023). For example, a high school athlete who sustains an SRC may take longer to recover compared to an adult who experiences a concussion in a non-sports setting, due to differences in brain development, functional demands, and pressure to return to play.
Are there neuroprotective effects for playing sports?
Engaging in sports may have neuroprotective effects by promoting cardiovascular fitness, which enhances brain health, cognitive function, and neurogenesis. Physical activity is associated with improved vascular health, reduced neuroinflammation, and better mood regulation. However, the risk of concussions must be managed to prevent potential long-term consequences such as chronic traumatic encephalopathy (CTE) (McKee et al., 2013). For instance, participating in non-contact sports or using proper protective equipment, adhering to safe playing techniques, and following graduated return-to-play protocols can help athletes reap the benefits of physical activity while minimizing the risk of concussions.
How does being part of a varsity team and having superior cardiovascular fitness affect one’s response to sustaining a concussion and their prognosis?
- Being part of a varsity team and having superior cardiovascular fitness can positively influence an athlete’s response to sustaining a concussion and their prognosis. Superior cardiovascular fitness is linked to better cerebral blood flow and recovery from brain injury. Fit athletes often have better baseline cognitive functioning and quicker recovery times. Moreover, being part of a varsity team provides access to structured medical care, supportive team environments, and professional rehabilitation resources. These factors can facilitate adherence to concussion management protocols, resulting in a more effective and timely recovery. However, the increased pressure to return to play quickly must be carefully managed to avoid compromising long-term brain health.