Chapter 12 Concussion Flashcards
Concussion
Concussion is defined as a complex pathophysiological process affecting the brain, induced by traumatic _________ forces. It may be caused by a direct blow to the head or any other part of the body that leads to impulsive forces transmitted to the head, causing the rapid onset of short-lived neurologic impairment, which may or may not involve the loss of _________. Acute symptoms result from a functional disturbance rather than a structural brain injury, which is further supported by the absence of abnormalities on standard neuroimaging.
Concussion
Concussion is defined as a complex pathophysiological process affecting the brain, induced by traumatic biochemical forces. It may be caused by a direct blow to the head or any other part of the body that leads to impulsive forces transmitted to the head, causing the rapid onset of short-lived neurologic impairment, which may or may not involve the loss of consciousness. Acute symptoms result from a functional disturbance rather than a structural brain injury, which is further supported by the absence of abnormalities on standard neuroimaging.
Concussions are _________ injuries with _________ dysfunction as the culprit for the acute and subacute symptoms. Immediately after a concussion, there are multiple cascades of _________, _________, and physiologic events. The earliest changes involve the release of _________ amino acids and a large efflux of _________ causing _________. This is followed by persistent _________ influx thought to cause neurovascular _________ which protects the brain from massive swelling. These events result in an increase in energy demand but a decrease in energy supply, which leads to a cellular energy crisis. It is this crisis that is thought to be the mechanism for postconcussive vulnerability because the brain is thought to be less equipped to respond to a second head injury leading to long-lasting effects. After hyperglycolysis, the brain experiences depressed metabolism, complicated by the persistent and elevated calcium levels, which may impair oxidative metabolism and activate pathways leading to cell death. Animal models have shown that the metabolic dysfunction lasts up to 2 weeks; it is postulated that the period of derangement is longer in humans.
Concussions are metabolic injuries with cellular dysfunction as the culprit for the acute and subacute symptoms. Immediately after a concussion, there are multiple cascades of ionic, metabolic, and physiologic events. The earliest changes involve the release of excitatory amino acids and a large efflux of potassium causing hyperglycolysis. This is followed by persistent calcium influx thought to cause neurovascular constriction which protects the brain from massive swelling. These events result in an increase in energy demand but a decrease in energy supply, which leads to a cellular energy crisis. It is this crisis that is thought to be the mechanism for postconcussive vulnerability because the brain is thought to be less equipped to respond to a second head injury leading to long-lasting effects. After hyperglycolysis, the brain experiences depressed metabolism, complicated by the persistent and elevated calcium levels, which may impair oxidative metabolism and activate pathways leading to cell death. Animal models have shown that the metabolic dysfunction lasts up to 2 weeks; it is postulated that the period of derangement is longer in humans.
Symptoms of concussion
Symptoms of concussion can be _________, _________, and/or emotional. _________ is the most common symptom of concussion and may develop immediately or _________ to _________ after injury. Loss of consciousness can occur but is relatively _________ and, contrary to prior practice, is not a necessary sign for the diagnosis of concussion. In fact, _________ and _________ and/or _________ _________ are the more common forms of altered mental status after a concussion, with one study suggesting that _________ is most predictive of postinjury difficulties and those with persistent memory deficits were more likely to have more symptoms, longer duration of symptoms, and poorer performance on neurocognitive tests. One or more of the following additional symptoms and signs can be experienced or observed with a concussion: loss of consciousness, immediate motor phenomena, dizziness, blurry vision, poor balance, tinnitus, confusion, sleep disturbances, fatigue, slow mental processing, and mood disturbances.
Symptoms of concussion
Symptoms of concussion can be somatic, cognitive, and/or emotional. Headache is the most common symptom of concussion and may develop immediately or minutes to hours after injury. Loss of consciousness can occur but is relatively uncommon and, contrary to prior practice, is not a necessary sign for the diagnosis of concussion. In fact, confusion and retrograde and/or anterograde amnesia are the more common forms of altered mental status after a concussion, with one study suggesting that amnesia is most predictive of postinjury difficulties and those with persistent memory deficits were more likely to have more symptoms, longer duration of symptoms, and poorer performance on neurocognitive tests. One or more of the following additional symptoms and signs can be experienced or observed with a concussion: loss of consciousness, immediate motor phenomena, dizziness, blurry vision, poor balance, tinnitus, confusion, sleep disturbances, fatigue, slow mental processing, and mood disturbances.
Resolution of symptoms
Resolution of symptoms, clinical and cognitive, occurs in a sequential order, with most adult concussions resolving in _________ to _________ days, and it is considered within normal limitations for symptoms to last up to _________ months postinjury. Multiple studies have revealed that younger athletes are more likely to have a longer recovery time when compared with college and professional athletes. There is also evidence suggesting that athletes with a history of multiple concussions may take longer to recover from a concussion.
Resolution of symptoms
Resolution of symptoms, clinical and cognitive, occurs in a sequential order, with most adult concussions resolving in 7 to 10 days, and it is considered within normal limitations for symptoms to last up to 3 months postinjury. Multiple studies have revealed that younger athletes are more likely to have a longer recovery time when compared with college and professional athletes. There is also evidence suggesting that athletes with a history of multiple concussions may take longer to recover from a concussion.
Postconcussion syndrome
Postconcussion syndrome is a controversial term, lacking a generalized consensus among medical professionals on a universally accepted definition; it is a collection of symptoms occurring within the initial _________ of an injury and lasting up to _________ months or more. Signs and symptoms are the same as those associated with a concussion and cause _________ and _________ difficulties requiring a multidisciplinary team approach for testing and treatment. The team may consist of a neuropsychologist, physiatrist, neurologist, psychiatrist, and/or primary care physician providing the following resources: _________ rehabilitation, _________, _________ management, _________ counseling, and medications.
Postconcussion syndrome
Postconcussion syndrome is a controversial term, lacking a generalized consensus among medical professionals on a universally accepted definition; it is a collection of symptoms occurring within the initial week of an injury and lasting up to 3 months or more. Signs and symptoms are the same as those associated with a concussion and cause social and vocational difficulties requiring a multidisciplinary team approach for testing and treatment. The team may consist of a neuropsychologist, physiatrist, neurologist, psychiatrist, and/or primary care physician providing the following resources: cognitive rehabilitation, psychotherapy, stress management, vocational counseling, and medications.
Second impact syndrome (SIS)
Second impact syndrome (SIS), a term coined in 1984 by Saunders and Harbaugh, is a rare occurrence where an athlete, still suffering from postconcussive symptoms from an initial head injury, sustains a second head injury that results in a loss of _________ of cerebral vasculature, leading to vascular _________, _________ swelling, and brain _________ that is usually fatal. Other than boxers, reports of SIS have never been described in anyone older than 19 years of age. There is controversy over the actual incidence of SIS and little epidemiologic data about supporting the existence of SIS. The United States has a higher incidence of cases among football players as compared with Australia. In Australia, the injury rate is higher but reported less.
Second impact syndrome (SIS)
Second impact syndrome (SIS), a term coined in 1984 by Saunders and Harbaugh, is a rare occurrence where an athlete, still suffering from postconcussive symptoms from an initial head injury, sustains a second head injury that results in a loss of autoregulation of cerebral vasculature, leading to vascular engorgement, cerebral swelling, and brain herniation that is usually fatal. Other than boxers, reports of SIS have never been described in anyone older than 19 years of age. There is controversy over the actual incidence of SIS and little epidemiologic data about supporting the existence of SIS. The United States has a higher incidence of cases among football players as compared with Australia. In Australia, the injury rate is higher but reported less.
Second impact syndrome (SIS)
When evaluating an injured player, one must recognize the symptoms and signs of a concussion, which can be delayed for _________ postinjury. Once a player shows any features of a concussion, they should be either medically evaluated on-site by a health care provider or removed from the game with urgent physician referral. Once first aid issues have been addressed on field and the player had been ruled out for more serious medical conditions, sideline evaluation of cognitive function should be assessed with the use of brief neuropsychological tests. There are many accepted _________ assessment tools used in the acute and sub-acute settings; however, details of such studies are beyond the scope of this chapter. Further investigation of concussion does not involve neuro-imaging unless there is a high suspicion for structural intracerebral injury, including, but not limited to, subdural or epidural hematomas.
Second impact syndrome (SIS)
When evaluating an injured player, one must recognize the symptoms and signs of a concussion, which can be delayed for hours postinjury. Once a player shows any features of a concussion, they should be either medically evaluated on-site by a health care provider or removed from the game with urgent physician referral. Once first aid issues have been addressed on field and the player had been ruled out for more serious medical conditions, sideline evaluation of cognitive function should be assessed with the use of brief neuropsychological tests. There are many accepted neuropsychological assessment tools used in the acute and sub-acute settings; however, details of such studies are beyond the scope of this chapter. Further investigation of concussion does not involve neuro-imaging unless there is a high suspicion for structural intracerebral injury, including, but not limited to, subdural or epidural hematomas.
Second impact syndrome (SIS)
The essentials of concussion management are _________ and _________ _________ until the symptoms resolve. During the period of recovery while the patient is still symptomatic, physical activity as well as activities requiring concentration and attention should be avoided because they may exacerbate symptoms and delay recovery. No further intervention is required during this time of rest; however, pharmacological therapy is applicable when managing specific prolonged symptoms, commonly associated with cognition and mood; drug therapy may also be initiated to modify the underlying pathophysiological process of a concussion, although studies supporting this approach of treatment are based on severe brain injury and have not been established in mild traumatic brain injuries.
Second impact syndrome (SIS)
The essentials of concussion management are physical and cognitive rest until the symptoms resolve. During the period of recovery while the patient is still symptomatic, physical activity as well as activities requiring concentration and attention should be avoided because they may exacerbate symptoms and delay recovery. No further intervention is required during this time of rest; however, pharmacological therapy is applicable when managing specific prolonged symptoms, commonly associated with cognition and mood; drug therapy may also be initiated to modify the underlying pathophysiological process of a concussion, although studies supporting this approach of treatment are based on severe brain injury and have not been established in mild traumatic brain injuries.
There are factors, such as loss of consciousness, that are symptom modifiers, indicating additional cognitive and physical investigations and contributing to a more comprehensive management strategy. _________ is a considerable modifying factor, as well as the loss of _________. Although it is not an appropriate measure of injury severity, prolonged loss of consciousness of more than _________ minute is a factor that may modify management. Although not an exhaustive list, the following are additional modifying factors: _________, _________, and _________ of symptoms; concussive _________; _________ and timing between prior and current concussion, if applicable; age; comorbidities; behavior; medications; and type of sport or activity.
There are factors, such as loss of consciousness, that are symptom modifiers, indicating additional cognitive and physical investigations and contributing to a more comprehensive management strategy. Age is a considerable modifying factor, as well as the loss of consciousness. Although it is not an appropriate measure of injury severity, prolonged loss of consciousness of more than 1 minute is a factor that may modify management. Although not an exhaustive list, the following are additional modifying factors: number, duration, and severity of symptoms; concussive convulsions; frequency and timing between prior and current concussion, if applicable; age; comorbidities; behavior; medications; and type of sport or activity.
There are numerous grading scales or guidelines for concussion management in athletes that are widely used by medical professionals, although only one scale is evidence based. Most studies differ greatly in the relative importance of loss of consciousness. To date, no study has been evaluated by a double-blinded prospective study testing the validity of these numerous grading scales. A correct assessment of the level of severity after concussion can only be made when symptoms have disappeared. Despite the controversies, the grading scales are still widely used to assist in acute management of the athlete, especially the _________ and _________ Guidelines (Table 12-1).
There are numerous grading scales or guidelines for concussion management in athletes that are widely used by medical professionals, although only one scale is evidence based. Most studies differ greatly in the relative importance of loss of consciousness. To date, no study has been evaluated by a double-blinded prospective study testing the validity of these numerous grading scales. A correct assessment of the level of severity after concussion can only be made when symptoms have disappeared. Despite the controversies, the grading scales are still widely used to assist in acute management of the athlete, especially the Colorado and Cantu Guidelines (Table 12-1).
At the Zurich Conference in 2008, the most recent “Return to Play” (RTP) protocol was established; it is a graded program of exertion that an athlete follows once they are symptom free. Each step is approximately _________ hours and the athlete progresses to the next level if they are asymptomatic, unless they develop _________ symptoms or signs that would then push them back to the previous asymptomatic level. In certain circumstances, adult athletes may RTP more rapidly, including same day of injury without risk of sequela, when assessment is performed by an experienced physician with appropriate and available resources. It was only at the collegiate and high school levels where athletes were documented to have delayed onset of symptoms and neuropsychological deficits after injury (Table 12-2).
At the Zurich Conference in 2008, the most recent “Return to Play” (RTP) protocol was established; it is a graded program of exertion that an athlete follows once they are symptom free. Each step is approximately 24 hours and the athlete progresses to the next level if they are asymptomatic, unless they develop postconcussive symptoms or signs that would then push them back to the previous asymptomatic level. In certain circumstances, adult athletes may RTP more rapidly, including same day of injury without risk of sequela, when assessment is performed by an experienced physician with appropriate and available resources. It was only at the collegiate and high school levels where athletes were documented to have delayed onset of symptoms and neuropsychological deficits after injury (Table 12-2).
