Mild Traumatic Brain Injury (MTBI): The Silent Epidemic

By: Robert S. Kennedy, MA

Introduction

Sports-related mild traumatic brain injury (MTBI) has been identified as a major concern for athletes, with approximately 1.6 - 3.8 million concussions occurring annually, and are particularly common in football and ice hockey.^1,2 According to the Consensus Statement on Concussion in Sport, the term mild traumatic brain injury is used interchangeably with the term concussion. An MTBI or concussion is defined as a "complex pathophysiologic process affecting the brain, induced by traumatic biomechanical forces secondary to direct or indirect forces to the head. MTBI is caused by a blow or jolt to the head that disrupts the function of the brain. This disturbance of brain function is typically associated with normal structural neuroimaging findings (e.g. CT Scan or MRI)."³

MTBI results in a constellation of symptoms that can be physical, cognitive, emotional, or sleep-related. These symptoms may or may not involve a loss of consciousness. The duration of symptoms is highly variable and may last from several minutes to days, weeks, months, or even longer in some cases.⁴ There are many causes of MTBI. Those seen in emergency departments primarily occur through falls, motor vehicle trauma, being unintentionally struck by an object, assault, and sports.⁵ MTBI is also an important concern among military personnel returning from war zones. Symptoms of MTBI can be missed or may not be noticed until the individuals have returned from military service.⁵ Identification and management can be complicated by the presence of post-traumatic stress disorder (PTSD).^5,6 For this review, we will focus on sports-related MTBI.

Concussion is a common, contact-sport injury. There is growing concern that repetitive head trauma can lead to the pathologic findings associated with chronic traumatic encephalopathy (CTE), a progressive, neurodegenerative process leading to emotional disturbances and cognitive dysfunction.^7,8 The number of impacts per an athlete receives in a season can be staggering. In a combined four-year high school and four-year college football career, a player could sustain 8,000 impacts.⁹ Despite the large number of impacts in a career, there are relatively few reported concussions. This raises the issue that athletes and their coaches may underreport injuries and increases the concern that asymptomatic hits may have cumulative effects.¹⁰

Signs and Symptoms

Signs and symptoms of MTBI generally fall into four categories: physical, cognitive, emotional and sleep.^11,12 (See Table.)

Neuropathophysiology of MTBI

The disturbance of brain function seen in MTBI is different from what is observed in more severe traumatic brain injuries (TBIs). Rather than structural injury or damage, it is currently believed that the changes associated with MTBI are more related to dysfunctional brain metabolism with a focus on neuronal dysfunction involving a complex cascade of ionic, metabolic, and physiologic events rather than anatomic damage. Clinical symptoms present in MTBI—such as poor memory, speed of processing, dizziness, and fatigue—may result from these neurometabolic changes.¹³

Diagnosis

The challenge to diagnosing MTBIs is that many of its symptoms are also common to other medical conditions such as PTSD, headache syndromes, and depression. Moreover, the onset and recognition of symptoms may occur days or weeks after the initial injury.^5,6

Assessment of an injury and its manifestations by clinicians should be systematic and is essential to proper management and reduced morbidity. The Acute Concussion Evaluation (ACE) checklist was developed by Gioia and colleagues and used by the Centers for Disease Control and Prevention to provide physicians with an evidence-based protocol to conduct an initial evaluation and diagnose  both children and adults with known or suspected MTBI.¹¹ ACE is a tool that can be used for both acute assessment as well as ongoing evaluation to track symptom recovery over time. It provides a systematic protocol for assessing the key components for diagnosing an MTBI. It was developed to help physicians assess MTBI and guide the management, recovery, and possible need for referral of patients with such injuries.^4,11

ACE contains three major components that require evaluation¹¹:

• Characteristics of the injury (description, cause, presence of amnesia and type, loss of consciousness, signs observed by others, or presence of seizures)
• Types and severity of the symptoms (signs and symptoms, whether these worsen with exercise, overall change from pre-injury self, or signs of deteriorating neurological function observed over the first 24 ‒ 48 hours)
• Risk factors that can lead to a protracted period of recovery (history of concussion, headaches, developmental history, or psychiatric history)

Clinical Management

After assessing the patient, the next step is to devise a plan of action for follow-up. This can ensure continuity of care and improve patient outcomes in MTBI.^3,4

• Office Management: In general, if the number and severity of symptoms steadily decrease over time or fully resolve in three to five days, then office monitoring is appropriate. If the symptoms have not lessened or if they have worsened, then a referral to a specialist should be considered.
• Referral to an MTBI Specialist: Referral to an MTBI specialist is appropriate if symptom reduction has not taken place within three to five days after injury, or sooner if the severity of the injury warrants such a referral. Specialist referrals can be especially helpful for patients with complex presentations or for a determination of when a patient can return to sports, school, or work.
• Referral for Diagnostic Testing: Diagnostic testing may be warranted during the acute phase. These include neuroimaging (CT or MRI scan) or neuropsychological testing. Neuropsychological tests evaluate a range of abilities and cognitive tasks—such as memory, concentration, information-processing, executive function, and reaction time—and can be very helpful for confirming self-reported symptoms as well as tracking recovery. Testing can also be can be useful for identifying specific deficits and needed supports for return to daily activities, school, or work.

Approaches to Management

Guiding individual patients in their recovery is important and the approach should be based on current symptom presentation. Recommendations for the care plan  were developed as part of the ACE toolkit to assist physicians in actively managing patients with MTBI.^3,4,11

Managing Activity Levels

The conceptualization of MTBI has evolved considerably, but clinical strategies to facilitate recovery lag behind. At present, rest and “watchful waiting” for symptom resolution constitute usual care following an athletic injury.³ The keys to recovery are careful management of physical and cognitive activity and avoidance of high risk activities. The “best medicine” for MTBI has long been considered to be rest. Before the 1940s, common practice was to impose weeks of complete bed rest for patients with a loss of consciousness of any duration.¹⁴ Current practice guidelines for MTBI continue to universally recommend an initial period of rest.^4,12,15 The Zurich Consensus guidelines for sports-related concussion highlight rest as the “cornerstone of concussion management.”¹² When patients present for medical attention after an MTBI, rest is the most common recommendation that they will receive. Patient educational materials also encourage rest. There is, however, less agreement by health care professionals on the exact nature and duration of the rest period, and generally they will interpret what is believed to be best for a particular patient.

According to Silverberg and colleagues, “Rest may be the most prescribed medical intervention in history.” He points out that recommendations for rest after MTBI are derived from expert consensus; unfortunately, there is little evidence for rest as an effective treatment. His review of the evidence suggests that the best approach is a gradual return to physical activity and to concentrated cognitive work.¹⁶ The current guidelines suggest that when symptoms are no longer reported or experienced, patients may slowly, gradually, and carefully return to their daily activities (both physical and cognitive). Children and adolescents will need the help and guidance of their parents, teachers, coaches, athletic trainers, and others to monitor and assist with their recovery. Post-MTBI management planning should involve all domains of the patient’s life, including home, school, work, and social-recreational activities, because any—or all—of these areas may be affected.^11,12

Prevention

Patients and parents should be advised about ways to either prevent a concussion or reduce the risk of sustaining an additional concussion or a more serious TBI. Encouraging patients to follow recommendations, like wearing a helmet that fits well and is maintained, is important in contact sports or activities like biking, skating, skateboarding, baseball, horseback riding, skiing, or sledding. Maintaining sporting equipment, playground surfaces, and equipment, as well as following the rules of good sportsmanship, is also a recommendation that most clinicians do not discuss with patients or parents.⁴

The Need for Clinician Education

In a recent study evaluating knowledge about concussions among graduating medical students and neurology/neurosurgery residents, a significant number of medical students and residents had incomplete knowledge about concussion diagnosis and management. Gender, participation in sports, and personal concussion history did not predict the number of questions answered correctly by the students and residents. Several knowledge gaps were identified in the sample population as a whole. While residents answered more questions correctly than students did, approximately half of the medical students and residents did not recognize that chronic traumatic encephalopathy, also known as the second-impact syndrome, may be possible consequences of repetitive concussions. Also, 24% of the medical students did not think that “every concussed individual should see a physician” as part of management.¹⁷

Previous research looking at collegiate football players over the course of an entire season found no significant neurocognitive changes over a football season.¹⁸ A recent study by Mulligan and colleagues suggests that many more college football players have a neurocognitive or balance change following a football game in which they did not report sustaining a concussion or blow to the head. This study contradicts previous results and suggests that there may be a change in neurocognitive and balance performance following a football game or as a result of the repetitive contact that occurs throughout a season. The difference in findings may be attributed to the fact that the previous study collected postseason data within two weeks of the final game of the season, whereas the current study collected data within 48 hours of the final game.¹⁹

Using helmets in sports can help reduce the incidence of skull fractures and severe brain injury; however, they have not been shown to protect against concussion.²⁰ Concussions are often underreported or unreported among athletes and coaching staff because of their lack of knowledge regarding concussion and desire to keep the athlete in the game.²¹ If the athlete has a second concussion before recovering from the first one, a potentially fatal condition known as second-impact syndrome can result.²² For this reason, the California Interscholastic Federation passed a bylaw in 2010 allowing game referees to remove players from games when concussion is suspected and requiring medical clearance from a physician before these athletes’ return to play.²³

Neuropsychological Assessment

The diagnosis of concussion is largely based on the clinical examination, yet certain imaging studies can be considered, such as computed tomography or magnetic resonance imaging, if an intracranial bleed is suspected.²⁴ In addition, several commercial neuropsychological assessment programs are available, such as Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT), the Computerized Cognitive Assessment Tool (CCAT), and Automated Neuropsychological Assessment Metrics (ANAM). These have been advocated by some sport groups and schools and can be helpful in making the decision about when to return to play. These tests are most helpful when baseline testing is done and then used for comparison to monitor improved test scores as an athlete recovers. No large, well-designed studies, as yet, have shown that these commercial tests improve health outcomes over good clinical follow-up in athletes with concussion.^25,26 Another test that is often used to evaluate an athlete for a transient injury to the brain with balance or vestibular involvement is called the Balance Error Scoring System.²²

National Awareness

A program called Protecting Athletes through Concussion Education (PACE)—along with its spokesperson, Drew Brees, the quarterback for the New Orleans Saints—has launched a national campaign to educate schools and the public about the dangers involved with playing football, as well as other contact sports, professionally. The PACE campaign teams with ImPACT, the widely-used computerized concussion evaluation system mentioned above, to accomplish its goal of making sports safer. All the National Football League (NFL) teams and many National Hockey League teams are currently using this technology.²⁷

PACE also provides free concussion testing for more than 3,300 middle and high schools and youth sports organizations nationwide. The program’s ultimate goal is to have one million children tested this year, making it the largest-ever program to concussion baselines. Baseline tests are important because they show what cannot be seen—cognitive function. Baseline testing, together with a preseason evaluation, keeps concussions to a minimum, and reduces their effects when they happen. PACE is the first national program of its kind to offer the ImPACT baseline tests. The program was started by the Dick’s Sporting Goods Foundation. Beginning in June 2012, parents, athletes, coaches, teachers, and others who want their school to sign up can log onto http://www.dsgpace.org/ to receive free testing.²⁷

This year, a lawsuit filed against the NFL by thousands of ex-players and their families is seeking damages for head injuries sustained on the field and consolidates over 80 lawsuits into a single legal action filed in United States District Court of the Eastern District of Pennsylvania. The challenge of the lawsuit is to determine whether the NFL is liable for injuries that players sustain while playing professional football and, particularly, for the long-term effects of concussions.²⁸  

The National Center for Injury Prevention and Control of the Centers for Disease Control and Prevention (CDC)  has created a website called “Heads Up: Brain Injury in Your Practice.” It offers a wealth of information and free tools for youth and high school sports coaches, parents, athletes, and health care professionals that provide important information on preventing, recognizing, and responding to a concussion. In addition, the CDC has created two free online courses—one for health care professionals and another for youth and high school sports coaches, parents, athletes—both of which provide important information about concussion.⁴

For clinicians, the CDC has put together a toolkit based on the ACE toolkit that includes assessment tools, checklists, and other valuable information about MTBI (see http://www.cdc.gov/concussion/HeadsUp/physicians_tool_kit.html).

Conclusion

Sports are highly structured, institutionalized, competitive activities that for some students, parents, and coaches go beyond the realm of play. These activities use complex athletic skills that involve physical exertion. They require more than physical skills and demand a complex integration of body and mind. These skills are honed over many years and often are guided by trainers, coaches, or other means of support.²⁹ Competing also requires a great deal of self-confidence in one’s abilities and sufficient drive to mobilize the energy and skill to perform under pressure.

According to a sports blog entitled “The Battered Fan,” the so-called “Cloak of Invincibility” is an athlete’s best and worst friend. The article points out that to attain success in a sport like football, an athlete must be able to play with “a sense of fearlessness—or invincibility.” For example, a 220-pound lineman taking on a 320-pound linebacker head-on must be quite self-confident. To thrive in such a contact sport, athletes must play with a reckless abandon, draped in their own “cloak of invincibility.” While such bravado is often fundamental to athletes’ success on the field, unfortunately it can also work against them.³⁰

The minor injuries and bruises that are an everyday part of contact sports are often seen by the athlete, coaches, and parents as a way of life in sports and are thus easily made trivial. Unfortunately, this approach sets the stage for minimizing head injuries and perpetuates false beliefs such as, “Concussions cannot happen if one wears a helmet.” Education can change our approach to sports and improve everyone's understanding of MTBI. National campaigns have begun the process, but clinicians need to add this dialogue to everyday clinical discussions to make a real difference.

Clinicians can certainly play a key role in helping prevent mild traumatic brain injury and improving care, when it does occur, through identification, diagnosis, and management. Patient outcomes can also be improved by implementing early management and appropriate referral. MTBI symptoms may often appear mild but can lead to significant, life-long impairment that affects all areas of functioning. This silent epidemic can also become a silent killer.

Clinical Connections

• Concussions, or MTBIs, are much more common in contact sports than is generally known.
• MTBIs are generally underreported.
• Early assessment and recognition of MTBI are critical to preventing possible, serious, cumulative effects.
• MTBI can affect physical, cognitive, emotional, and sleep domains.
• Rather than show structural damage, MTBIs result in neurometabolic changes in the brain.
• Rest and a gradual return to normal activities are the best treatments for MTBI.

Resources

Centers for Disease Control and Prevention

• Heads Up: Concussion in Youth Sports: Information for coaches, parents, athletes, at http://www.cdc.gov/concussion/HeadsUp/youth.html
• Heads Up to Clinicians: Concussion in Youth Sports, at http://www.cdc.gov/concussion/clinician.html
• Heads Up: Preventing Concussion fact sheet: Information for patients (Spanish version available), at http://www.cdc.gov/concussion/headsup/pdf/Heads_Up_factsheet_english-a.pdf
• Acute Concussion Evaluation (ACE) form, at http://www.cdc.gov/concussion/headsup/pdf/ACE-a.pdf
• Sport Concussion Assessment Tool (SCAT2), at www.cces.ca/files/pdfs/SCAT2[1].pdf
• ACE Care Plan:  
  • Work version, at http://www.cdc.gov/concussion/headsup/pdf/ACE_care_plan_returning_to_work-a.pdf
• School version, at http://www.cdc.gov/concussion/headsup/pdf/ACE_care_plan_school_version_a.pdf

Neuropsychological Testing

• ImPACT Test, at http://impacttest.com/about/background
• Axon Sports Computerized Cognitive Assessment Tool (CCAT), at http://www.axonsports.com/index.cfm
• Automated Neuropsychological Assessment Metrics (ANAM), at http://www.armymedicine.army.mil/r2d/anam.html

Post-Compass Questions™

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