Sports medicine

Sports-related chronic repetitive head trauma as a cause of pituitary dysfunction

Authors: Dubourg J, Messerer M.

Traumatic brain injury (TBI) is recognized as a cause of hypopituitarism even after mild TBI. Although over the past decade, a growing body of research has detailed neuroendocrine changes induced by TBI, the mechanisms and risk factors responsible for this pituitary dysfunction are still unclear. Around the world, sports-especially combative sports-are very popular. However, sports are not generally considered as a cause of TBI in most epidemiological studies, and the link between sports-related head trauma and hypopituitarism has not been investigated until recently. Thus, there is a paucity of data regarding this important concern. Because of the large number of young sports participants with near-normal life expectancy, the implications of undiagnosed or untreated postconcussion pituitary dysfunction can be dramatic. Understanding the pathophysiological mechanisms and risk factors of hypopituitarism caused by sports injuries is thus an important issue that concerns both medical staff and sponsors of sports. The aim of this paper was to summarize the best evidence for understanding the pathophysiological mechanisms and to discuss the current data and recommendations on sports-related head trauma as a cause of hypopituitarism.

Chronic traumatic encephalopathy in an Iraqi war veteran with posttraumatic stress disorder who committed suicide

Authors: Omalu B, Hammers JL, Bailes J, Hamilton RL, Kamboh MI, Webster G, Fitzsimmons RP.

Following his discovery of chronic traumatic encephalopathy (CTE) in football players in 2002, Dr. Bennet Omalu hypothesized that posttraumatic stress disorder (PTSD) in military veterans may belong to the CTE spectrum of diseases. The CTE surveillance at the Brain Injury Research Institute was therefore expanded to include deceased military veterans diagnosed with PTSD. The authors report the case of a 27-year-old United States Marine Corps (USMC) Iraqi war veteran, an amphibious assault vehicle crewman, who committed suicide by hanging after two deployments to Fallujah and Ramadi. He experienced combat and was exposed to mortar blasts and improvised explosive device blasts less than 50 m away. Following his second deployment he developed a progressive history of cognitive impairment, impaired memory, behavioral and mood disorders, and alcohol abuse. Neuropsychiatric assessment revealed a diagnosis of PTSD with hyperarousal (irritability and insomnia) and numbing. He committed suicide approximately 8 months after his honorable discharge from the USMC. His brain at autopsy appeared grossly unremarkable except for congestive brain swelling. There was no atrophy or remote focal traumatic brain injury such as contusional necrosis or hemorrhage. Histochemical and immunohistochemical brain tissue analysis revealed CTE changes comprising multifocal, neocortical, and subcortical neurofibrillary tangles and neuritic threads (ranging from none, to sparse, to frequent) with the skip phenomenon, accentuated in the depths of sulci and in the frontal cortex. The subcortical white matter showed mild rarefaction, sparse perivascular and neuropil infiltration by histiocytes, and mild fibrillary astrogliosis. Apolipoprotein E genotype was 3/4. The authors report this case as a sentinel case of CTE in an Iraqi war veteran diagnosed with PTSD to possibly stimulate new lines of thought and research in the possible pathoetiology and pathogenesis of PTSD in military veterans as part of the CTE spectrum of diseases, and as chronic sequelae and outcomes of repetitive traumatic brain injuries.

Animal model for sport-related concussion; ICP and cognitive function

Authors: Bolouri H, Säljö A, Viano DC, Hamberger A.

Background -  We have recently developed and characterized a rat model of mild traumatic brain injury which simulates the concussive injuries frequently encountered by players in American professional football. Objectives -  To study the effect of multiple impacts to the head on intracranial pressure, cognitive function, and exploratory behavior. Materials and Methods -  The model was employed to cause concussion. Intracranial pressure, cognitive function, and exploratory behavior were examined following the multiple impacts of a 50 or 100 g projectile at a velocity of 9.3 or 11.2 m/s to the helmet protected head. Results -  Intracranial pressure measured at 6 and 10 h, and 1, 2, 3, 5, and 7 days. It was maximally elevated 10 h after impact and returned to the control levels 7 days later. Morris Water Maze assessment, 48 h after impact, revealed impaired cognitive function. Open field testing 2-4 days and 1 and 2 weeks after impacts indicated consistently reduced spontaneous exploratory activity. Conclusion -  Multiple impacts to the head raise intracranial pressure and impair cognitive function and exploratory activity in this animal model.

A Review of Return to Play Issues and Sports-Related Concussion

Authors: Doolan AW, Day DD, Maerlender AC, Goforth M, Gunnar Brolinson P.

Mild traumatic brain injury in sports has become a significant public health concern which has not only received the general public's attention through multiple news media stories involving athletic concussions, but has also resulted in local, state, and national legislative efforts to improve recognition and management. The purpose of this article is to review the current literature for return to play (RTP) guidelines. State, regional, national, and professional legislation on sport-related concussion RTP management issues will be reviewed. This article will be helpful in developing a generalized systematic approach to concussion management and highlight specific RTP guidelines. The article will also touch upon specific contraindications to RTP, the role of neuropsychological testing in RTP, and other considerations and complications that affect an athlete's ability to return to competition. Finally, considerations for terminating an athlete's competitive season or ending a career after sustaining a concussion resulting in prolonged and protracted symptomatology or repeated concussions will be reviewed. PubMed and Google were searched using the key terms mentioned below. In addition, the author's library of concussion-related articles was reviewed for the relevant literature.

Functionally-Detected Cognitive Impairment in High School Football Players Without Clinically-Diagnosed Concussion

Authors: Thomas M. Talavage, Eric Nauman, Evan L. Breedlove, Umit Yoruk, Anne E Dye, Katie Morigaki, Henry Feuer, Larry J. Leverenz.

Head trauma and concussion in football players has recently received considerable attention. Post-mortem evidence suggests that accrual of damage to the brain may occur with repeated blows to the head, even when individual blows fail to produce clinical symptoms. There is an urgent need for improved detection and characterization of head trauma to reduce future injury risk and promote development of new therapies. This study examined neurologic performance and health in the presence of head collision events in high school football players, using longitudinal measures of collision events (HIT system), neurocognitive testing (ImPACT), and functional MRI (fMRI). Longitudinal assessment (including baseline) was conducted in 11 males (ages 15-19) participating on the varsity and junior varsity football teams at a single high school. We expected and observed subjects in two previously described categories: (1) no clinically-diagnosed concussion and no changes in neurological behavior and (2) clinically-diagnosed concussion with changes in neurological behavior. Additionally, we observed players in a previously undiscovered third category who exhibited no clinically-observed symptoms associated with concussion, but who demonstrated measurable neurocognitive (primarily visual working memory) and neurophysiologic (altered activation in dorsolateral prefrontal cortex, DLPFC) impairments. This new category was associated with significantly higher numbers of head collision events to the top-front of the head, directly above DLPFC. Observation of this category suggests that more players are suffering neurologic injury than are presently detected via traditional concussion-assessment mechanisms. These individuals are unlikely to undergo clinical evaluation and thus continue to participate in football-related activities even when changes in brain physiology (and potential brain health) are present, likely increasing risk of future neurologic injury.

Brain Injury In Sports

Source: Brain Injury Resource Center

An estimated 300,000 sports related traumatic brain injuries, TBIs, of mild to moderate severity , most of which can be classified as concussions, (i.e., conditions of temporary altered mental status as a result of head trauma, occur in the United States each year.  The proportion of these concussions that are repeat injuries is unknown; however, there is an increased risk for subsequent TBI among persons who have had at least one previous TBI .  Repeated mild brain injuries occurring over an extended period (i.e., months or years can result in cumulative neurologic and cognitive deficits, but repeated mild brain injuries occurring within a short period (i.e., hours, days, weeks) can be catastrophic or fatal.  The latter phenomenon, termed "second impact syndrome" has been reported more frequently since it was first characterized in 1984.  This page describes two cases of second impact syndrome and presents recommendations developed by the American Academy of Neurology to prevent recurrent brain injuries in sports and their adverse consequences.

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