Archive for the ‘Safety Studies’ Category

New York State Athletic Commission chief medical officer and practicing neurologist Dr. Sethi published an article in the latest edition of the South African Journal of Sports Medicine addressing best practices for medical stoppages of boxing bouts with the sensible conclusion that it is better to err on the side of safety.

In the article, titled “Good versus bad medical stoppages in boxing: Stopping a fight in time” Dr. Sethi reaches the following conclusion after addressing what he believes to be considerations ringside physicians should keep in mind when stopping a bout –

It is recommended that the above proposed best practice guidelines be debated vigorously by ringside physicians and the wider scientific community and that evidence-based guidelines on medical stoppages be developed by the medical community in conjunction with the professional boxing governing bodies. Boxing can be made safer but it shall be foolhardy to forget that frequently there is a very fine line between a good medical stoppage (i.e. medical stoppage done at the right time during the bout and for the right indication) versus a bad medical stoppage (i.e. medical stoppage done either too late, too prematurely, or for the wrong indication). It is far better to stop a fight early rather than too late. A ringside physician should never forget that in boxing one punch can change everything.

The full article can be found here – Dr. Sethi Artilce re Medical Stoppages of Boxing Bouts

An interesting article was published in the latest edition of the International Journal of Pathology and Clinical Research diagnosing what is believed to be the first known case of an individual having Chronic Traumatic Encephalopathy who did not have a history of concussions.

In the article, titled “Chronic Traumatic Encephalopathy-like Neuropathological Findings Without a History of Trauma” a 45 year old man who was found dead in his sleep had his brain examined post mortem and CTE like changes were revealed.  This was noteworthy to researchers as the patient had no known history of head trauma.  The authors note as follows

To our knowledge, this is the first description of a patient with neuropathological features of CTE-MND in the absence of a history traumatic brain injury. Interestingly, despite cortical tau pathology, our patient never exhibited cognitive impairment, which speculatively could be explained by the relative sparing of the nucleus basalis of Meynert. This highlights the uncertainty surrounding the pathogenesis and pathophysiology of CTE and underscores the need for further detailed studies to elucidate the causative role of trauma. Nevertheless, our case report has several important limitations. For example, the lack of a trauma history comes only from the recollection of the patient’s wife and early life subconcussive blows cannot be entirely excluded. There are also inherent limitations to drawing conclusions from the results of a single patient.

To date, repetitive traumatic brain injury has been shown to be associated with no neuropathological changes, with CTE alone, with -CTE and another neurodegenerative disease, or with non-CTE neurodegeneration. Since CTE is a postmortem diagnosis, the majority of samples have come from brains of symptomatic individuals referred by family; these individuals are more likely to demonstrate some type of neuropathology thus introducing a selection bias. Our case adds to this complexity given the observation that CTE-like changes can occur in the absence of any known head injury; casting doubt that trauma is always the inciting etiological factor. Future studies should assess whether CTE-like pathology is prevalent in non-concussed patient populations.

The full article can be found here.

 

Adding to this site’s archived combat sports safety studies a recent study was published at the University of Cambridge discussing the efficacy of MRI and Neuropsychological testing to detect early signs of brain damage in amateur boxers.

In the study, titled “Advanced magnetic resonance imaging and neuropsychological assessment for detecting brain injury in a prospective cohort of university amateur boxers” the authors queried whether early brain injury could be detected using this combination of diagnostic tools.

40 amateur boxers were recruited although only 10 stayed in the study to its conclusion contributing the needed longitudinal assessment protocol.

The authors concluded that this combination of testing “could not detect any evidence of brain injury” in the participants.

Below is the study’s full abstract –

Abstract
Background/aim:Background/aim: The safety of amateur and professional boxing is a contentious issue. We hypothesised that advanced magnetic resonance imaging and neuropsychological testing could provide evidence of acute and early brain injury in amateur boxers. Methods:Methods: We recruited 30 participants from a university amateur boxing club in a prospective cohort study. Magnetic resonance imaging (MRI) and neuropsychological testing was performed at three time points: prior to starting training; within 48 hours following a first major competition to detect acute brain injury; and one year follow-up. A single MRI acquisition was made from control participants. Imaging analysis included cortical thickness measurements with Advanced Normalization Tools (ANTS) and FreeSurfer, voxel based morphometry (VBM), and Tract Based Spatial Statistics (TBSS). A computerized battery of neuropsychological tests was performed assessing attention, learning, memory and impulsivity. Results:Results: During the study period, one boxer developed seizures controlled with medication while another developed a chronic subdural hematoma requiring neurosurgical drainage. A total of 10 boxers contributed data at to the longitudinal assessment protocol. Reasons for withdrawal were: logistics (10), stopping boxing (7), withdrawal of consent (2), and development of a chronic subdural hematoma (1). No significant changes were detected using VBM, TBSS, cortical thickness measured with FreeSurfer or ANTS, either cross-sectionally at baseline, or longitudinally. Neuropsychological assessment of boxers found attention/concentration improved over time while planning and problem solving ability latency decreased after a bout but recovered after one year. Conclusion:Conclusion: While this neuroimaging and neuropsychological assessment protocol could not detect any evidence of brain injury, one boxer developed seizures and another developed a chronic sub-dural haematoma.

The California State Athletic Commission has taken a step which has received little publicity but is deserving of attention by the combative sports community.  They have produced a series of videos focusing on fighter health and safety issues, namely acute traumatic brain injury, cumulative concussions and dangers of dehydration.  With CTE being a potential reality in any contact sport these are important topics to understand.

If you are a combat sports fighter, trainer, manager or other stakeholder these videos are well worth your time to get up to speed on these important topics.  With fighter safety being the primary reason for an Athletic Commission’s existence  Andy Foster and the CSAC deserve a public thank you for a job well done in producing these insightful videos.

Adding to this site’s archived combat sports safety studies a recent study was published in the British Journal of Sports Medicine addressing head injury rates in high level karate competitions.

In the study, titled “Low Risk of Concussions in Top Level Karate Competitions” the authors reviewed injuries that took place in 4 consecutive karate world championships.  They found there was only “1 concussion in every 1156 fights, or 0.43/1000 athlete-exposures“.

The full article can be purchased here.  The abstract reads as follows:

Background Although it is well known that injuries occur in combat sports, the true incidence of concussions is not clearly defined in the literature for karate competition

Aim To determine the incidence of concussions in top-level (World Karate Federation World Championships) karate competition.

Methods Injuries that took place in 4 consecutive World Karate Championships (from 2008 to 2014) were prospectively registered. A total of 4625 fights (2916 in the male category and 1709 in the female category) were scrutinised, and concussions were identified and analysed separately for frequency (rate per fight) and injury risk.

Results A total of 4 concussions were diagnosed by the attending physicians after carrying out athlete examinations. Globally, there was 1 concussion in every 1156 fights, or 0.43/1000 athlete-exposures (AE). In male athletes, the rate of concussion was 1/5832 min of fighting, and in female athletes, it was 1/6836 min. OR for concussion in women is 0.57 (95% CI 0.06 to 5.47; z=0.489; p=0.6249) and risk ratio for concussions in men is RR 1.478 (95% CI 0.271 to 8.072), p=0.528, representing a higher risk of definite concussions in men than in women, but not statistically significant. There is not a significantly higher risk of concussions in team competition (no weight limit) when compared with individual competition (held with strict weight limits for each category).

Conclusion The risk of concussions in top-level karate competition is low, with a tendency for an increased risk for men and for competition without weight limits, but not statistically significant with respect to women or individual competition.

An article was published in the latest edition of the South African Journal of Sports Medicine levying criticism at professional boxing’s lack of standardized protocols for athletes to return to training/competition after suffering concussive injury.

The article, authored by Dr. Sethi from the Department of Neurology, New York Presbyterian Hospital is titled “Post-concussion return to boxing protocol” and can be found here.

Dr. Sethi fairly points out that

Immediately following a concussion, an athlete is usually advised physical and cognitive rest until post-concussion symptoms abate. The athlete then enters a stepwise return-to-play protocol. Premature return to play risks a second concussion, second impact syndrome, exacerbation and persistence of post-concussive symptoms. Various sports governing organisations such as the National Football League have developed postconcussion return to play protocols”

After noting professional boxing lacks a standardized protocol for return to sport following concussion Dr. Sethi proposes the following criteria to be adopted:

The following post-concussion return to boxing protocol is proposed based on evidence from other sports and clinical acumen:

Once the boxer is symptom free for at least 24 hours and a release has been signed by the treating physician, he/she can begin a graded return to boxing as detailed below.

Day 1: Light aerobic activity (walking or stationary bike for 10 minutes, no resistance training)

Day 2: Sport-specific activity (jumping rope, shadow boxing)

Day 3: Non-contact training drills (Skill drills-pad work, speed bag, heavy bag)

Day 4: Full-contact practice (sparring with head gear)

Day 5: Return to boxing (return to competitive boxing occurs when the period of mandatory medical suspension has expired)

Each of the above steps should take 24 hours so that a boxer would take approximately one week to progress through the full post-concussion protocol once they are asymptomatic at rest. If any post- concussion symptoms occur while in the stepwise return to boxing programme, then the boxer should be instructed to return to the previous asymptomatic level and try to progress again after a further 24-hour period of rest has passed.

CTE Brain Image.PNG(Image via this PBS article)

A worthwhile study was recently published in the Journal of Vascular and Interventional Neurology discussing what is known and not known about CTE in athletes competing in contact sports.

In the study, titled “Chronic Traumatic Encephalopathy in Athletes Involved with High-Impact Sports” the authors reviewed major clinical studies identifying CTE cases in athletes looking for conclusions and shortcomings in the data.

Among the conclusions drawn are that, of known athletes with CTE, professional boxers demonstrated the most debilitating symptoms.  Also of note the authors suggest that strengthening neck muscles (a topic previously canvassed here) can help minimize the risks of CTE for contact sports athletes.

The study is worth reading in full and can be accessed here.

In addressing the increased symptoms in boxers vs football players and discussing possible strategies to reduce risk the authors note as follows:

Clinical and pathological features of CTE can manifest differently between sports, as rTBI exposure and mechanisms of impact can vary considerably. In fact, an analysis of previously reported CTE cases by Montenigro et al. [29] showed a vast difference in clinical presentation. 83% (5/6) of professional boxers, who had more debilitating motor impairments, compared to 18.8% (3/16) of professional football players. In addition, severe dentate neurofibrillary tangles were present in 17% (2/12) and 80% (4/5) of professional football players and boxers, respectively, indicating a more pernicious progression in boxers [29]. The difference in symptoms and neuropathology may be explained through the frequency of linear and rotational impact forces that occur in both sports.

Rotational forces causing angular accelerations are frequent in boxing. Boxers face their greatest danger when their opponent lands a hook punch, where impact near the lateral side of the head cause rapid outward rotation of the skull and twisting forces the brain [29]. Lateral bending of the neck can also occur, but linear forces from a punch are often below the mTBI threshold [58]. The rotational movement of the brain causes shearing forces that can lead to axonal damage [59]. Shearing forces are most prominent near areas such as the midbrain section, where glial and axonal injury could result in severely debilitating consequences [29,58].

As opposed to punches, helmet-to-helmet or helmet-to-ground contact forces cause the majority of mTBI injuries in professional football players. Viano et al. [58] have shown that in professional football concussions, inertial forces can be up to 30% greater than inertial forces in professional boxers who endure a hook punch. The greater inertial forces correlate with a higher linear acceleration endured by football players, suggesting that linear forces are prominent in causing concussive and subconcussive impacts in professional football players. In support of this mechanism, brain modeling shows that rotational accelerations from uppercuts or hook punches are much greater than rotational accelerations in professional football helmet-to-helmet impacts [58]. The linear to rotational force ratio difference between boxers and football players could explain the differences in clinical presentation between the two sports.

In professional football, helmet-to-helmet collisions can cause the head to move in the anterior or posterior direction. The incidence rates of mTBI have been shown to vary depending on position, with running backs and wide receivers suffering from mTBI more than linemen [60]. Neck musculature acts to stabilize the position of the head, and a more developed musculature is directly correlated to lowered mTBI risk [61]. Linemen have been found to have stronger necks and larger girth compared to running backs, which could act to slow linear accelerations of the head and reduce risk of mTBI [62]. The differences in neck strength between positions may explain the varying incidence rates of mTBI. Additionally, it should be noted that different player positions may be more prone to certain types of impacts—linemen may experience more frequent subconcussive helmet-to-helmet impact, while wide receivers could endure more threatening forces while being tackled. The pathological repercussions of variations in impact type and frequency between boxing and football have yet to be elucidated in full detail, but they may partially explain the difference in clinical presentation between different types of athletes.

 

Adding to this site’s archived combat sports safety studies and weight cut reform articles, a study was recently published in the International Journal of Sports Physiology and Performance addressing the impact of rapid weight loss / gain and the outcome of boxing bouts.

In the study, titled “Weight Re-Gain is Not Linked to Success in a Real Life Multi-Day Boxing Tournament” the authors compared the weigh-in weight of 100 boxers competing in the Australian National Championships and then re-checked their weight one hour prior to competition.  The amount of body mass increase was then contrasted with performance and the results showed that athletes who gained size over their opponents through rapid weight cut / rehydration practices did not enjoy competitive advantage.

The full abstract reads as follows:

Combat sport athletes acutely reduce body mass (BM) prior to weigh-in in an attempt to gain a size/strength advantage over smaller opponents. Few studies have investigated these practices among boxers and none have explored the impact of this practice on competitive success.

One hundred (30♀/70♂) elite boxers participating in the Australian National Championships were weighed at the official weigh-in and an hour before each competition bout. Re-gain in BM after weigh-in was compared between finalists and non-finalists, winners and losers of each fight, males and females and weight divisions. Boxers were surveyed on their pre and post weigh-in nutrition practices.

The lightest male weight category displayed significantly greater relative BM re-gain than all other divisions, with no difference between other divisions. BM pre-bout was higher than official weigh-in for males (2.12±1.62% (p < 0.001; ES=0.13)) and females (1.49±1.65% (p < 0.001; ES=0.11)). No differences in BM re-gain were found between finalists and non-finalists, winners and losers of individual bouts, or between preliminary or final bouts. BM re-gain was significantly greater (0.37% BM, p < 0.001; ES=0.25) prior to an afternoon bout compared to a morning bout.

Boxers engage in acute BM loss practices before the official competition weigh-in but this does not appear to affect competition outcomes, at least when weight re-gain between weigh-in and fighting is used as a proxy for the magnitude of acute loss. While boxers recognise the importance of recovering after weigh-in, current practice is not aligned with best practice guidance.

For those who study safety issues in combative and contact sports a useful article was published in the latest edition of Neurotrauma and Critical Care News discussing the state of science connecting CTE and other brain injury to contact sports.

The article, titled “Head Impacts in Contact Sports and Long-Term Brain Degeneration” offers an easy to read, plain English summary of what’s known and what still needs to be explored in the world of repetitive head trauma from sports and CTE.

In addressing CTE specifically the authors note as follows:

A 2016 National Institutes of Health (NIH) expert neuropathological panel established that the pattern of CTE is unlike any other form of brain degenerative disease with the collections of NFT or NT occurring in a unique and distinguishing pattern (3). It is believed that the more superficial and frontal areas of the brain are involved due to the direct contact with sports-related head impacts.

These pathophysiological features are associated with a characteristic behavioral syndrome for CTE, with symptoms in four categories: cognition, behavior, mood and occasionally motor. Behavioral changes include amplified aggression, increased impulsiveness, impaired judgment, and risk taking acts. Most often, a 6- to 12-year latency period following retirement from contact sports is then associated with failure in business, financial and marital relationships, homelessness, drug and/or alcohol abuse, depression, mild cognitive impairment and dementia, and many CTE sufferers commit suicide. Researchers have reported that CTE can be considered in two major clinical categories, with one group whose initial features develop at a younger age involving behavioral and/or mood disturbance and another group whose initial symptoms develop later in life and involve cognitive impairment. The language function is usually normal, but intelligence is often ultimately affected by the numerous effects described above (4).

While the risk of developing CTE has historically been discussed in the context of concussive injury and extensive neurotrauma exposure, emerging evidence indicates that a history of diagnosed or major concussions is not a requirement, but instead, repetitive subconcussive injury may play a prominent role in CTE development (5). This finding is based upon lack of documented concussive injury in numerous individuals diagnosed with CTE, although lack of self-reporting by athletes was common, and concussion without loss of consciousness was not recognized and treated as seriously as it is today. Evidence related to subconcussive injury and possible predilection to neurodegenerative disease includes the documented rates and severity of impacts in football linemen, a position in which retired athletes have been diagnosed with CTE (5). Additional evidence is the demonstration of neuroimaging and cognitive changes in those without a history of documented concussions as well as laboratory evidence indicating cellular and ultrastructural alterations without changes in levels of alertness or behavior. Despite the large number of people exposed to concussive and subconcussive injury through various sports and military service, CTE appears problematic for only a small subset of the population exposed to neurotrauma. Nonetheless, we currently do not know the incidence and prevalence of CTE since there has been no longitudinal study conducted to substantiate estimates of several prominent CTE research groups. The largest review to date, Maroon et. al., surveyed the clinical findings in all 153 CTE cases reported in the literature and found that 63 had a history of participation in football with majority of these having played at the professional level (6). The most common age at death of individuals with CTE was the range of 60 to 69, with 72.7 percent dying before the age of 70 (6).

Identification of other variables involved as risk factors for CTE remains in its early stage with speculation that genetics and lifestyle may be implicated. Just as in other forms of neurodegeneration such as Alzheimer’s disease, it has been postulated that the role of the ApoE ε4 (ApoE4) allele may be a susceptibility factor for the development of CTE; however, this has yet to be borne out.

Research continues to try to identify who is at greatest risk for getting concussions and ultimately, CTE. More studies are needed to follow former athletes over many years in order to know the true prevalence of CTE. A major focus of CTE research is investigating confirmation of the diagnosis of CTE in living individuals with several promising imaging technologies being evaluated, with F18DDNP PET imaging for tau and amyloid protein labeling being the most advanced (7).

Currently, there are no established treatments for CTE; therefore, reducing the risk for CTE development becomes the primary goal by limiting the exposure to concussive and subconcussive head impacts. There have been numerous positive changes in recent years involving contact sports, particularly football, resulting in greater safety for all participants. These include limiting contact in practice, eliminating head-to-head hits in practice drills, rule changes to penalize and prohibit egregious cranial hits, improvements in helmet design, new technology, such as helmet sensors and efforts to mitigate brain slosh, among others. It is hoped that in the near future CTE will be eliminated in contact sport athletes, but in the meantime, the possibility and implications of repetitive head trauma causing long-term effects, including brain degeneration, should be understood.

CTE is a part of combat sports.  In fact the disease, which used to be called dementia pugilistica (ie “punch drunk”) has its origins traced back to boxing.

MMA is not immune from CTE.  It is a real risk. Several athletes likely have the disease with fighters such as Gary Goodridge being diagnosed with CTE and being vocal about its realities.  Despite the high likelihood that many MMA athletes have CTE it is a diagnosis that cannot be made definitively until death as study of brain tissue is required.

Now, the Boston Globe Reports, MMA has its first proven case of CTE.

Former Bellator fighter, Jordan Parsons, who was recently killed in a pedestrian/vehicle collision, has been diagnosed with CTE post-mortem.

The Globe reports as follows:

Now, six months after he was struck and killed as a pedestrian by an alleged drunken driver, Parsons is the first fighter in the multibillion-dollar MMA industry to be publicly identified as having been diagnosed with the degenerative brain disease known as chronic traumatic encephalopathy (CTE)

The diagnosis was disclosed to the Globe by Dr. Bennet Omalu, a forensic pathologist who first discovered CTE in a professional football player (in 2003) and a professional wrestler (2007).

Omalu provides the following grounded and sober comments “As a scientist, a physician, and a person of faith, I beg everybody involved with these sports to come together and identify the problems and find solutions’’

Combat Sports athletes should participate only with informed consent of the sport’s real dangers.  Comments calling MMA “the safest sport in the world” do no favors.  Informed consent only comes from an acknowledgement and understanding of the science of CTE and its links to acute and repetitive head trauma.

Regulators also must grapple with this reality both in making informed choices as to when an athlete has been exposed to too much mileage and when considering safety issues such as the fact that gloves, while making for more exciting fights, do much to increase the likelihood of brain trauma.