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Indiana University School of Medicine designates this enduring material for a maximum of 1.0 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.
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In accordance with the Accreditation Council for Continuing Medical Education (ACCME) Standards for Commercial Support, educational programs sponsored by Indiana University School of Medicine (IUSM) must demonstrate balance, independence, objectivity, and scientific rigor. All faculty, authors, editors, and planning committee members participating in an IUSM-sponsored activity are required to disclose any relevant financial interest or other relationship with the manufacturer(s) of any commercial product(s) and/or provider(s) of commercial services that are discussed in an educational activity.
Committee and Author Disclosure
Statements of Disclosure of Relevant Financial Relationships have been obtained from Thomas McAllister, MD. Dr. McAllister has disclosed that he has no relevant financial relationships with any commercial interests.
After reading this article, the reader should be able to:
- Identify the potential cognitive, physical, and emotional/behavioral sequelae of concussion.
- Discuss the usual course of mild traumatic brain injury (mTBI).
- Review the typical post-concussion symptoms.
- Describe the link between concussion and depression.
- Summarize the management components of post-concussion depression.
Date of original release: January 2014
Date of expiration: January 2015
Note: While it offers CME credits, this activity is not intended to provide extensive training or certification in the field.
Overview of Concussion
Each year in the United States, up to 3.8 million persons suffer mild traumatic brain injury (mTBI), also referred to as concussion, linked to sports participation.1 These brain injuries are most commonly associated with football and ice hockey2 and result from contact/impact forces (e.g., the head hitting the ground or ice), inertial forces (i.e., rapid brain acceleration or deceleration), or both. The disruption in neurometabolic function that follows manifests as a variety of cognitive, physical, and emotional/behavioral sequelae (Table 1). These signs and symptoms, which may or may not include a loss of consciousness, begin to appear immediately or within a few minutes of brain injury.
Several validated instruments are available for the sideline evaluation of possible concussion. Once mTBI is diagnosed, the player is not allowed to return to a game or practice. After he or she undergoes a thorough physical and neuropsychiatric examination at an emergency department or clinician’s office, curtailment of physical and cognitive activity is usually prescribed. Clearance to return to play is generally withheld until the athlete is symptom-free, even during vigorous exertion.
“A major concern in individuals who have experienced a previous sports-related mTBI is their heightened risk for sustaining subsequent concussions, which may occur with progressively decreased force and may be associated with slower recovery,” explains Thomas McAllister, MD, professor and chairman of the Department of Psychiatry at Indiana University School of Medicine. “Long-term, repetitive concussions may lead to chronic traumatic encephalopathy in some athletes, a condition characterized by depression, cognitive dysfunction, psychotic symptoms, and dementia.
“When—and if—an athlete with a history of mTBI should return to play is a difficult decision,” Dr. McAllister continues. “There is no magic number of ‘safe’ concussions. While three is often used as a benchmark, this number is arbitrary and as yet has little science behind it. Perhaps a more relevant gauge is a pattern of increasingly frequent concussions and longer recovery times, especially with head impacts of lesser magnitude.”
A 21-year-old Division 1 college football player (wide receiver) with a history of two previous concussions is tackled while attempting to catch a pass, falls backward, and hits the ground helmet-first. He is unconscious for a few seconds, then appears dazed and disoriented and is assisted off the field. The team physician performs a sideline assessment, makes the diagnosis of concussion, and informs the coach that the athlete cannot return to the game. Over the next few days, the young man reports typical symptoms of mild traumatic brain injury—headache, dizziness, confusion, fatigue, and disequilibrium.
Case Study (cont.)
When his symptoms fail to resolve within two weeks, and the athlete is unable to resume football practice, he and his family consult with a specialist in TBI. He is diagnosed with post-concussion syndrome, and magnetic resonance imaging (MRI) is performed. No abnormalities are detected on imaging, and the patient is reassured that his symptoms should improve within a few weeks.
Symptoms of mTBI in athletes generally dissipate within seven days, but some patients with mild brain injuries experience persistent post-concussion symptoms (PCS). The severity of injury does not clearly correlate with PCS, but at least one study suggests that a previous history of concussion increases the likelihood of prolonged symptoms after mTBI.3
Evaluation of athletes with PCS often includes brain imaging with computed tomography (CT) and/or MRI. A very small percentage of such CT scans are abnormal, showing mild subarachnoid hemorrhage, subdural hemorrhage, or contusions. MRI is more sensitive and may detect abnormalities in patients with normal head CT scans. Other advanced neuroimaging modalities for assessing concussion currently under investigation include functional MRI, magnetic resonance spectroscopy, and diffusion tensor imaging. One study found that patients with evidence of traumatic axonal injury on diffusion tensor imaging are more likely to demonstrate objective evidence of cognitive impairment than are patients with normal studies.4
Treatment of PCS is tailored to a patient’s particular issues and complaints. Simple reassurance is often the only intervention, as the condition improves within three months in most cases.
“Persistent cognitive deficits, especially in the areas of memory and learning, concentration, and speed of information processing, are the most frequent post-concussion complaints and present significant challenges to a return to normal daily activities,” Dr. McAllister says. “Additionally, patients and their families and friends may describe ‘personality changes’—alterations in emotional and behavioral regulation after mTBI.”
Concussion also appears to increase the risk of psychiatric disorders, in particular depression, which occurs with an incidence of 10 to 77 percent.5 Depression after mTBI is associated with increases in the number and perceived severity of other post-concussive symptoms (e.g., headache, dizziness); may intensify anger, aggression, suicidal thoughts, and cognitive dysfunction; and interferes with rehabilitation. Both neurobiologic (i.e., injury-related) and psychosocial factors contribute to the development and persistence of depression after mTBI.
Concussion also appears to increase the risk of psychiatric disorders, in particular depression, which occurs with an incidence of 10 to 77 percent.5
“Pharmacotherapy may not only alleviate the mood disturbance but also improve post-traumatic somatic, behavioral, and cognitive problems in patients who have suffered a concussion,” emphasizes Dr. McAllister. “When drug treatment is initiated, a ‘start lower, go slower, and stop sooner’ approach is recommended, as individuals who have suffered mTBI may be more susceptible to the side effects of many psychotropic agents.”
No drugs have been approved by the US Food and Drug Administration specifically for the treatment of post-concussion depression (Table 2), and no evidence suggests that any one drug or drug class is more effective than another in this setting. Nonetheless, Dr. McAllister says that selective serotonin reuptake inhibitors (SSRIs) are usually prescribed first-line because of their lower potential for adverse reactions as compared with tricyclic antidepressants.
“Psychological and social factors contribute to the development and persistence of post-concussion depression,” notes Dr. McAllister. “Education regarding TBI and recovery expectations, reassurance, and regular support have been shown to promote better outcomes during the first year after injury. Importantly, family members and spouses may also require psychotherapeutic intervention to help them maintain their own mental health, as well as that of the injured family member.”
Case Study (cont.)
Four months after suffering mTBI, the patient has had no improvement in status and is referred to Indiana University Health for a neuropsychiatric consultation. At initial presentation, he reports persistent headache; fatigue; and cognitive deficits, including difficulty concentrating and short-term memory loss that have resulted in a marked decline in his academic performance. He also describes feeling socially isolated from his friends and former teammates. During a second visit a few days later, the patient appears more willing to talk and describes difficulty sleeping, anhedonia, and suicidal ideation. He is diagnosed with concussion-associated depression.
The SSRI escitalopram is prescribed at a dose of 5 mg/day, and psychotherapy is initiated. Two weeks later, the patient says he has experienced some improvement in symptoms. The SSRI dose is increased to 10 mg daily, and weekly psychotherapy sessions are continued.
At a follow-up visit one month after starting dual treatment, the patient reports substantial improvement in all cognitive and physical domains, including concentration, memory, and energy. His grades are improving, and he has resumed exercising and socializing with friends. He no longer has thoughts of suicide, accepts that he will not play football again, and now is able to envision his life without the sport. SSRI therapy is continued at the same dose, and the patient says he will schedule psychotherapy appointments as needed.
One year after starting antidepressant therapy, the patient has no residual symptoms of concussion and is slowly tapered off medication.
“A multidimensional approach is critical to the assessment and treatment of the neuropsychiatric sequelae of concussion,” Dr. McAllister concludes. “The most important, initial step is accurate diagnosis, which can be challenging with mTBI. Thereafter, a combination of pharmacologic and psychotherapeutic interventions can alleviate persistent symptoms and improve quality of life not only for persons who have suffered concussions, but also for their families.”
The STAR Evaluation System for Football Helmets
Tackling below the waist was first allowed in college football in 1888, and pads quickly became essential equipment for players. Yet helmets were not made mandatory until 1939 (Figure 1), and the National Football League (NFL) did not require them until 1943. Today, the Riddell Revolution (or Revo) is the most widely used helmet in the NFL and is also used in many high school and college football programs. A study in high school players conducted in 2006 by researchers at the University of Pittsburgh Medical Center showed that the Riddell Revolution and helmets like it (Figure 2) reduced the incidence of concussion by 31 percent as compared with standard football helmets.6 More recently, however, University of Wisconsin investigators reported that a specific brand of helmet did not lower concussion risk, despite manufacturers’ claims.7 Additionally, the severity of the concussions, as assessed by the number of days athletes lost from play, did not vary according to helmet brand.
The Summation of Tests for the Analysis of Risk (STAR) is a conceptual evaluation system seeking to provide a metric for assessing the relative performance of football helmets.8 STAR generalizes all possible head impacts in football into 24 drop tests consisting of four impact locations and six impact severities. Using the STAR formula, data from these drop tests, obtained from nearly 63,000 head acceleration data points collected from football players, are combined into a single number that incorporates the predicted exposure and injury risk for one player for one full season of practices and games. The researchers believe that STAR will become a valuable tool in educating consumers about helmet performance, analogous to the current New Car Assessment Program (NCAP) rating system.
Dr. McAllister received his medical degree from Dartmouth Medical School in Hanover, NH and completed his residency in psychiatry at Dartmouth-Hitchcock Medical Center. His clinical research interests focus on brain injury recovery, the biomechanical basis of concussion, and the effects of repetitive head impacts on brain structure and function in contact-sport athletes.
Dr. McAllister has written extensively on the neuropsychiatric sequelae of traumatic brain injury (TBI) and is a co-editor of the Textbook of Traumatic Brain Injury. He is the principal investigator for several grants from the National Institutes of Health (NIH), the Centers for Disease Control and Prevention (CDC), the National Operating Committee on Standards for Athletic Equipment (NOCSAE), and the Department of Defense (DoD) that explore the nature of cognitive and behavioral difficulties following mild and moderate TBI.
Prior to his appointment as the Albert Eugene Sterne Professor and chairman of the Department of Psychiatry at IU School of Medicine, Dr. McAllister was the Millennium Professor of Psychiatry and Neurology, director of the Section of Neuropsychiatry, and vice chair for Neuroscience Research for the Department of Psychiatry at Dartmouth Medical School. He is a past president of the American Neuropsychiatric Association.
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