Military- and Sports-Related Mild Traumatic Brain Injury: An Overview
Elaine R. Peskind, MD
David Brody, MD, PhD
Ibolja Cernak, MD, ME, MHS, PhD
Ann McKee, MD
Robert L. Ruff, MD, PhD
Awareness of potential serious long-term effects of mTBI has increased, especially in military service members and veterans and those who play contact sports. Elaine R. Peskind, MD, chaired a discussion among experts on the effects, management, and prevention of military- and sports-related mTBI. Highlights of their discussion are presented here. (For an expanded version, please see the Commentary in the February 2013 issue of The Journal of Clinical Psychiatry.)
Defining mTBI and CTE
Dr Brody: Traumatic brain injury, or TBI, is damage to the brain’s structure and function caused by an acute external physical force. A widely used definition of mild TBI is loss of consciousness for up to 30 minutes, a change in mental status for up to 24 hours, or posttraumatic amnesia for up to 24 hours1; a concussion is an mTBI. Acute symptoms may appear immediately or a few minutes after the injury.2 Most people recover from mTBI within 7 days.3 Symptoms vary in duration and type (AV 1).4
Dr McKee: A possible consequence of repetitive mTBI is CTE, or chronic traumatic encephalopathy, which is a progressive neurodegenerative disorder. Early CTE symptoms include difficulty concentrating, depression, personality changes, short-term memory loss, and cognitive changes.5 As the disease progresses, typically slowly, patients may develop dementia and parkinsonism. Some individuals with CTE also show signs of motor neuron disease.
Effects of the Frequency and Nature of mTBI
Dr Peskind: How do patients with repetitive mTBI differ clinically from those with a single mTBI?
Dr Ruff: We have found that the rate of neurologic deficits increases proportionally with the number of mTBI episodes.6 Service members with multiple mTBIs also have a significantly higher frequency of depression, anxiety, and PTSD than those with a single mTBI.7
With a blast (versus a blunt impact), the person frequently has 2 episodes of head trauma, often within seconds (see Figure 1 in Cernak and Noble-Haeusslein8). After the blast itself, which may cause minimal injury, secondary and tertiary blast mechanisms may cause injury, such as an impact mTBI from being blown out of a military personnel vehicle.
Dr Cernak: In my experience, one of the most important clinical differences between blast and impact mTBI is a greater incidence of somatic consequences from blast-induced mTBI. Namely, while in the vicinity of an explosion, the soldier’s entire body—not only his/her head—is exposed to the blast and interacts with blast effects. Consequently, blast TBI is caused by multiple, interwoven mechanisms of systemic, local, and cerebral responses to blast exposure, often occurring simultaneously. Indeed, accumulating clinical and experimental evidence shows that systemic and local alterations initiated by a blast significantly influence the brain’s response and thus contribute to the pathobiology of acute and/or chronic deficits due to the blast.9–11 The frequent complaints that veterans often report about impaired olfaction, gastrointestinal complications, chronic pain, and unstable blood pressure support the importance of these multi-organ changes due to a blast.
Patients’ Daily Challenges Following Repetitive mTBI
Dr Brody: In the military context, the problems that I see are anxiety disorders (including PTSD), sleep disorders, headaches, and subjective cognitive impairment, such as concentration and memory problems.
In the civilian context, people with repetitive injuries often have a great deal of depression. Like the military group, this group often experiences sleep disorders, headaches, and subjective cognitive complaints. Changes in personality are also common.
In the sports context, I have seen a high degree of variability. Many former professional football players who have had multiple concussive injuries are remarkably free of symptoms. If they do have symptoms, changes in personality, impulsiveness, and behavioral disturbances, such as aggression and mood instability, can be major problems. Chronic headaches may also occur.
Dr Ruff: In service members and veterans with mTBI, depression is often comorbid with a persistent anxiety disorder or PTSD.7 Lack of sleep can compound attention difficulties and short tempers.
Dr Peskind: Service members’ and veterans’ complaints are grounded in real problems, but during cognitive testing, their abilities sometimes have to be pushed to demonstrate the impairment; it is not always obvious during testing. Their perception of their cognitive impairment may also be influenced by depression, anxiety, or PTSD.12
Effect of mTBI on the Risk for Suicide and PTSD
Dr Peskind: Studies have found rates of suicide 2 to 3 times greater among those with a history of mTBI than among those without mTBI.13,14 Part of the suicide risk is the frequent co-occurrence of mTBI with disorders that increase suicide risk, such as PTSD and depression.15,16 People with mTBI can also have increased impulsivity due to changes in frontal white matter.17 Besides the increased risk of suicide, does the risk of PTSD increase with mTBI?
Dr Brody: A study18 of military personnel with mTBI from blunt trauma, blast trauma, or both reported that any mTBI was associated with a greater incidence of PTSD than was no mTBI (AV 2).
Dr Ruff: A number of symptoms of mTBI can be equally attributable to PTSD, such as difficulty falling or staying asleep, irritability, and poor concentration.19 Migraine features, however, are not characteristic of PTSD, nor are some of the subtle impairments in neurologic examinations that occur with mTBI.
Dr Peskind: In a study20 of veterans with blast-induced mTBI, my colleagues and I used the Neurobehavioral Symptom Inventory. Some of the moderate-to-severe symptoms they endorsed cannot be attributed to PTSD, such as migraine-type headache, ringing in the ears, hearing difficulty, and forgetfulness.
CTE Risk After Repetitive mTBI
Dr Peskind: Dr McKee, you and your colleagues21 recently described postmortem cases of CTE in veterans who had experienced blasts and/or concussions. What are the implications of these cases for veterans and service members?
Dr McKee: These cases emphasize the need to identify and properly manage acute blast and concussive injuries. The injured person needs to undergo examinations by medical professionals, rest until he or she is asymptomatic, and not return to the battlefield until fully recovered.
Service members and veterans who have received blast or concussive injuries are at risk for CTE, although we do not know how great the risk is or how many individuals will be affected. The research gives the imperative to be able to diagnose this condition in living military personnel so that we can hopefully come up with ways of treating it and monitor its progression.
Dr Peskind: Why have we been hearing a lot in the news about professional American football players with CTE?
Dr McKee: A number of high-profile athletes have died, some by suicide. Several had requested that their brains be donated for scientific study, and many showed evidence of CTE.22,23 People used to believe that the concussive and subconcussive hits experienced by athletes were inconsequential, but evidence now shows that the damage can trigger a progressive deterioration in some individuals.24
Dr Cernak: In football players, hockey players, boxers, and those who play any sport with high-velocity impact, the impact is not just to the head but to the whole body.25 The greater force applied to the brain may be associated with a higher frequency of CTE compared with contact sports that do not have the potential for high-velocity, whole-body impact.
Dr Peskind: What are the state-of-the-art procedures for clinical assessment and management of patients with repetitive mTBI?
Dr Brody: The best method for clinical assessment is to gather a detailed history not only from the patient but also from a reliable source who has known the patient well both before and after the various injuries were sustained, since both the patients and their medical records may not be completely accurate. Questions should be specific to symptoms that frequently occur, eg, sleep difficulties, impulsivity, changes in personality, difficulty controlling violent temper impulses, and poor restraint in using drugs and alcohol or in spending money. Neurologic examinations and imaging are currently only partially helpful in assessment.
While this condition has no cure or definitive treatment, we can manage symptoms and comfort and educate the patient. I also provide information to the patient and family about prevention of further injuries to reduce the likelihood that this condition will progress or worsen.
Dr Peskind: We give study participants high-quality bicycle helmets. We also educate them about using seat belts in vehicles and taking safety precautions in sports that have a high risk of brain injury.
What should we tell patients about the prognosis of mTBI?
Dr Brody: Unfortunately, I cannot give anyone a really accurate prognosis because not enough information is available; however, CTE is a possible outcome. For patients with a history of multiple concussions and probable CTE, I introduce them to a support group.
Children, Contact Sports, and mTBI
Dr Peskind: Dr McKee, you have reported that symptoms of CTE have been seen in athletes as young as 25 years old.23
Dr McKee: Yes; we need to be careful when allowing our children to participate in contact sports. Parents need to know that their child’s coaching staff is well aware of what a concussion is, how to look for a concussion, and how to manage a concussion properly. Sports organizations for children should also limit the use of the head and hits to the head.
Dr Peskind: If you had a school-aged child today, would you allow him or her to play American football?
Dr McKee: I see no reason for playing football before high school. So much remains unknown about children and the effects of the subconcussive and concussive hits that are part of the game.
Dr Brody: I would educate my children about the risks and benefits of sports. My advice is that if they have one concussion, then they should probably stop.
Dr Ruff: Prohibiting a child from playing sports may somewhat socially isolate him or her.
Dr Cernak: Team sports promote social development. We should teach our children about recognizing the problem so that they are not afraid to say, "Oh, I hit my head and now I feel dizzy." The return-to-play guidelines should be followed after impacts.26
Dr Brody: Concussions are not a universal consequence of playing contact sports.
Dr McKee: But a subconcussive impact happens in almost every play of the game in football, and players have to participate in many practices as well. Multiple subconcussive injuries may also lead to long-term brain health risks.24
Concussions are more serious than previously believed. Brain injuries, especially multiple ones, can seriously and negatively impact patients, leading to changes in personality, sleep problems, and cognitive impairment and can increase the risk for suicide, PTSD, depression, and anxiety. In some people, repetitive mTBI can lead to CTE, a neurodegenerative disorder. As awareness of mTBI in both military and sports settings increases, evidence-based treatments and targeted suicide prevention strategies will hopefully emerge. Meanwhile, symptom management and education can help those who have already received concussions, and education and the use of return-to-play guidelines can contribute to prevention among youths.
- When evaluating current and former military personnel or athletes, ask them and a collateral source (eg, family, friends) about concussion/mTBI
- In patients who have experienced concussions, screen for specific symptoms such as sleep problems, changes in personality, and impulsivity
- Manage symptoms of mTBI, and watch for new evidence-based treatments to emerge
- If a patient with a history of repetitive mTBI exhibits symptoms of dementia, consider chronic traumatic encephalopathy in the differential diagnosis
- Promote prevention of mTBI by educating children who are entering contact sports about brain safety, and educate patients who have had concussions and their families about how to avoid further brain injuries
- CTE = chronic traumatic encephalopathy
- mTBI = mild traumatic brain injury
- PTSD = posttraumatic stress disorder
- US Department of Veterans Affairs and Department of Defense. Clinical Practice Guideline for Management of Concussion/Mild Traumatic Brain Injury. Washington, DC: US Department of Veterans Affairs; 2009. http://www.healthquality.va.gov/mtbi/concussion_mtbi_full_1_0.pdf. Accessed January 8, 2013.
- American Academy of Neurology. Assessment and management of sports concussion. http://www.aan.com/globals/axon/assets/8315.pdf. Published 2011. Accessed February 22, 2013.
- McCrea M, Guskiewicz KM, Marshall SW, et al. Acute effects and recovery time following concussion in collegiate football players: the NCAA Concussion Study. JAMA. 2003;290(19):2556–2563. PubMed
- Centers for Disease Control and Prevention. Concussion: what are the signs and symptoms of concussion? http://www.cdc.gov/concussion/signs_symptoms.html. Updated March 8, 2010. Accessed January 8, 2013.
- McKee AC, Stein TD, Nowinski CJ, et al. The spectrum of disease in chronic traumatic encephalopathy [published online ahead of print December 2, 2012]. Brain. doi:10.1093/brain/aws307. PubMed
- Ruff RL, Riechers RGI, Wang X-F, et al. A case-control study examining whether neurological deficits and PTSD in combat veterans are related to episodes of mild TBI. BMJ Open. 2012;2(2):e000312. PubMed
- Vanderploeg RD, Belanger HG, Horner RD, et al. Health outcomes associated with military deployment: mild traumatic brain injury, blast, trauma, and combat associations in the Florida National Guard. Arch Phys Med Rehabil. 2012;93(11):1887–1895. PubMed
- Cernak I, Noble-Haeusslein LJ. Traumatic brain injury: an overview of pathobiology with emphasis on military populations [published correction appears in J Cereb Blood Flow Metab. 2010;30(6):1262]. J Cereb Blood Flow Metab. 2010;30(10):255–266. PubMed
- Cernak I, Savic J, Ignjatovic D, et al. Blast injury from explosive munitions. J Trauma. 1999;47(1):96–103. PubMed
- Cernak I. The importance of systemic response in the pathobiology of blast-induced neurotrauma. Front Neurol. 2010;1:151. PubMed
- Cernak I, Ahmed FA. A comparative analysis of blast-induced neurotrauma and blunt-traumatic brain injury reveals significant differences in injury mechanisms. Med Data Rev. 2010;2(4):297–304. http://www.md-medicaldata.com/files/md-08-297-304_a_comparative_analysis.pdf. Accessed January 9, 2013.
- Spencer RJ, Drag LL, Walker SJ, et al. Self-reported cognitive symptoms following mild traumatic brain injury are poorly associated with neuropsychological performance in OIF/OEF veterans. J Rehabil Res Dev. 2010;47(6):521–530. PubMed
- Brenner LA, Ignacio RV, Blow FC. Suicide and traumatic brain injury among individuals seeking Veterans Health Administration services. J Head Trauma Rehabil. 2011;26(4):257–264. PubMed
- Teasdale TW, Engberg AW. Suicide after traumatic brain injury: a population study. J Neurol Neurosurg Psychiatry. 2001;71(4):436–440. PubMed
- Barnes SM, Walter KH, Chard KM. Does a history of mild traumatic brain injury increase suicide risk in veterans with PTSD? Rehabil Psychol. 2012;57(1):18–26. PubMed
- Greenberg J, Tesfazion AA, Robinson CS. Screening, diagnosis, and treatment of depression. Mil Med. 2012;177(8 suppl):60–66. PubMed
- Yurgelun-Todd DA, Bueler CE, McGlade EC, et al. Neuroimaging correlates of traumatic brain injury and suicidal behavior. J Head Trauma Rehabil. 2011;26(4):276–289. PubMed
- Kontos AP, Kotwal RS, Elbin R, et al. Residual effects of combat-related mild traumatic brain injury [published online ahead of print October 2, 2012]. J Neurotrauma. doi:10.1089/neu.2012.2506. PubMed
- Ruff RL, Riechers RG II, Ruff SS. Relationships between mild traumatic brain injury sustained in combat and post-traumatic stress disorder. F1000 Med Rep. 2010;2:64. PubMed
- Peskind ER, Petrie EC, Cross DJ, et al. Cerebrocerebellar hypometabolism associated with repetitive blast exposure mild traumatic brain injury in 12 Iraq war veterans with persistent post-concussive symptoms. Neuroimage. 2011;54(suppl 1):S76–S82. PubMed
- Goldstein LE, Fisher AM, Tagge CA, et al. Chronic traumatic encephalopathy in blast-exposed military veterans and a blast neurotrauma mouse model. Sci Transl Med. 2012;4(134):134ra60. PubMed
- Omalu B, Bailes J, Hamilton RL, et al. Emerging histomorphologic phenotypes of chronic traumatic encephalopathy in American athletes. Neurosurgery. 2011;69(1):173–183. PubMed
- McKee AC, Cantu RC, Nowinski CJ, et al. Chronic traumatic encephalopathy in athletes: progressive tauopathy following repetitive head injury. J Neuropathol Exp Neurol. 2009;68(7):709–735. PubMed
- Stern RA, Riley DO, Daneshvar DH, et al. Long-term consequences of repetitive brain trauma: chronic traumatic encephalopathy. PM R. 2011;3(10 suppl 2):S460–S467. PubMed
- Barth JT, Freeman JR, Broshek DK, et al. Acceleration-deceleration sport-related concussion: the gravity of it all. J Athl Train. 2001;36(3):253–256. PubMed
- McCrory P, Meeuwisse W, Johnston K, et al. Consensus statement on concussion in sport: the 3rd International Conference on Concussion in Sport held in Zurich, November 2008. Br J Sports Med. 2009;43(suppl 1):i76–i84. PubMed
From the Series:
Independently developed by The CME Institute of Physicians Postgraduate Press, Inc.
CME Background Information
Independently developed by The CME Institute of Physicians Postgraduate Press, Inc.
After completing this educational activity, you should be able to:
- Screen patients who have experienced an event resulting in head injury for mild traumatic brain injury
- Treat mTBI according to the current guidelines for assessing and managing concussions and mTBI
The faculty for this CME activity and the CME Institute staff were asked to complete a statement regarding all relevant personal and financial relationships between themselves or their spouse/partner and any commercial interest. The CME Institute has resolved any conflicts of interest that were identified. No member of the CME Institute staff reported any relevant personal financial relationships. Faculty financial disclosures are as follows:
Dr Peskind is a consultant for Avanir and Eli Lilly, has received grant/research support from Eli Lilly, is a member of the speakers/advisory boards for Novartis and Forest, and is a stock shareholder of Elan and Bristol-Myers Squibb. Drs Brody, Cernak, McKee, and Ruff have no personal affiliations or financial relationships with any commercial interest to disclose relative to the activity.
The CME Institute of Physicians Postgraduate Press, Inc., is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.
The CME Institute of Physicians Postgraduate Press, Inc., designates this enduring material for a maximum of 0.5 AMA PRA Category 1 Credit™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.
The American Academy of Physician Assistants (AAPA) accepts certificates of participation for educational activities certified for AMA PRA Category 1 Credit™ from organizations accredited by ACCME or a recognized state medical society. Physician assistants may receive a maximum of 0.5 hours of Category I credit for completing this program.
To obtain credit for this activity, study the material and complete the CME Posttest and Evaluation.
Release, Review, and Expiration Dates
This Neurology Report was published in February 2013 and is eligible for AMA PRA Category 1 Credit™ through February 29, 2016. The latest review of this material was January 2013.
Statement of Need and Purpose
Mild traumatic brain injuries (mTBI) and/or concussions can negatively affect memory, judgment, reflexes, speech, balance, coordination, and sleep patterns, particularly when more than one injury has been sustained. Additionally, repetitive brain trauma increases the risk for depression, posttraumatic stress disorder (PTSD), and suicide and can lead to impulse control problems, aggressiveness, behavior and personality disturbances, and progressive cognitive decline and neurodegenerative diseases such as chronic traumatic encephalopathy and Alzheimer’s disease. Both active duty service members and athletes involved in physical contact sports are at an increased risk for suffering from mTBI and may be at increased for functional decline, neurodegenerative dementia, and possible death from repetitive mTBI. Diagnosing mTBI is difficult because it does not have a standardized definition, those with mTBI often do not seek treatment for some time following the injury, an mTBI diagnosis is based on the severity of the injury at the time of the event rather than over time, and those with mTBI often exhibit symptoms common to other conditions and often have premorbid or comorbid conditions, such as PTSD, which commonly co-occurs with mTBI experienced in military combat. Managing mTBI is difficult as well because service personnel who sustain a head injury in-theater are in special circumstances, and those who have suffered an mTBI generally want to return to the activity in which they were injured, thereby exposing themselves to risk for further injury (eg, athletes still want to play the game and service members want to return to their combat units). Clinicians need education about the risk factors for mTBI and available methods for recognizing and managing mTBI over the long term, including understanding the pathophysiology and clinical syndromes of mTBI, completing neuropsychological assessments and radiographic/neuroimaging evaluations, using the current guidelines on assessing and managing concussion and mTBI, and conducting cognitive rehabilitation. This activity was designed to meet the needs of participants in CME activities provided by the CME Institute of Physicians Postgraduate Press, Inc., who have requested information on mTBI.
Disclosure of Off-Label Usage
Dr Peskind has determined that, to the best of her knowledge, no investigational information about pharmaceutical agents that is outside US Food and Drug Administration–approved labeling has been presented in this activity.
The entire faculty of the series discussed the content at a peer-reviewed planning session, the Chair reviewed the activity for accuracy and fair balance, and a member of the External Advisory CME Board who is without conflict of interest reviewed the activity to determine whether the material is evidence-based and objective.
This Neurology Report is derived from the planning teleconference “Military- and Sports-Related Mild Traumatic Brain Injury: Clinical Presentation, Management, and Long-Term Consequences,” which was held on August 27, 2012, and independently developed by The CME Institute of Physicians Postgraduate Press, Inc. The opinions expressed herein are those of the faculty and do not necessarily reflect the opinions of the CME provider and publisher.