NFL, Cannabis, and Concussions (7/22/21 newsletter)

Aug 12

During our Concussion Education & Advocacy Internship Program we are publishing weekly. Thanks for reading!

We would like to acknowledge our interns who wrote for this newsletter:

Writers: Lori Mae Yvette Calibuso Acob, Melissa Brown, Julia Brzac, Nathan Campbell, Emma Chin, Christine Hau, Wyatt Hill, Chelsea Ryan, and Elizabeth Zhao.

Editors: Conor Gormally and Malayka Gormally.

Do you find the Concussion Update helpful? If so, forward this to a friend and suggest they subscribe.

Opportunities

July 28-30: 2021 Virtual World Congress on Brain Injury, a joint initiative of the International Brain Injury Association (IBIA), the North American Brain Injury Association (NABIS), Acquired Brain Injury Ireland, and other organizations. Register in advance.

Cannabis & Psychedelics

NFL, cannabis, and concussions

Wyatt Hill, one of our summer interns, has written a page for our website about the NFL and cannabis; the following is a synopsis.

Orthopedic injuries and concussions are widespread in the National Football League (NFL). As a consequence of the injuries, many players experience chronic pain and post-concussion symptoms. To help alleviate symptoms associated with these injuries, approximately half of NFL players use opioid pain medication. Of the players who use opioid painkillers, a large portion develops problematic use patterns.

Cannabis provides a possible alternative, as it may provide relief on par with opioids without many of their downsides. A survey of 2897 medical cannabis patients assessed the efficacy of cannabis as a painkiller. Of those who had used both medical cannabis and opioid painkillers, 92% of participants agreed that cannabis’ side effects were more tolerable than those of opioid-based medications, 81% agreed that cannabis was more effective in treating their symptoms, and 61% agreed that cannabis helped them decrease their opioid consumption.

In addition to treating symptoms, there are also indications that cannabis may offer some neuroprotective benefits for concussions, traumatic brain injuries (TBI), and chronic traumatic encephalopathy (CTE). One study found that testing positive for THC after an injury event was associated with better outcomes of TBI. Another article has suggested that cannabinoids’ antioxidant effects may offer protective benefits from glutamate excitotoxicity (which can lead to neuronal death) caused by TBI and CTE.

Despite cannabis’ promising attributes, the NFL still prohibits its use. However, due to a new collective bargaining agreement, the NFL will not test players for THC from April 20 to August 9, when training camps begin. The threshold for testing positive has been quadrupled, and suspension for testing positive has been dropped; instead, there will be a fine "for up to three weeks' pay."

Self-care

Tips for navigating relationships after injury

In an article published by The Good Men Project, Dr. Jayde Kennedy Ball describes prevalent psychological struggles following traumatic brain injury (TBI), giving insight into overcoming the changes in relationships with loved ones and yourself. The article does not specify what level of TBI severity it is addressing, but we think these suggestions may be helpful for those dealing with persistent post-concussion symptoms.

Life following TBI can be filled with doctor appointments, therapy sessions, and so much at once that practicing self-care and gratitude is often forgotten. Post-TBI can be a stressful time, especially when support systems may be unstable. However, it is essential to normalize the change in roles that loved ones play in the patient’s life. As treatment and rehabilitation continue throughout recovery, learning new tasks and communication skills may be challenging; it takes a robust community to build the psychological and emotional support to persevere through adversities.

Dr. Ball encourages all parties to practice the skills of patience and giving gratitude to smooth the shift in roles that can occur. Showing appreciation to loved ones not only strengthens relationships but also provides reassurance regarding their actions. Additionally, TBI can also change how you view yourself within the world, and you may even experience a shift in your identity. Thus, it is essential that the patient’s identity is thoroughly self-explored and understood to maintain a positive attitude towards recovery.

Though Dr. Ball encourages self-reflection, it is critical not to compare and romanticize a “healthy” image of yourself pre-TBI because that can be emotionally difficult and unproductive. In all, awareness and communication of these emotional changes will be key to a smooth transition into life post-TBI and help navigate the adversities of living with TBI.

Therapies Currently Available

Impairment of sensory reweighting in those with a recent concussion–potential target for rehabilitation

A study published in Sports Medicine examined vision and balance impairments, which commonly affect mTBI patients. The study’s results indicate that recently concussed individuals may have greater difficulty integrating sensory information necessary for balance than individuals who sustained a concussion over a year ago and have recovered. Targeted rehabilitation for these impairments may speed recovery and subsequently lower risk for reinjury.

When you shut your eyes and try to balance on one leg, you rely on your vestibular and proprioceptive systems for postural control rather than visual input. This process, termed sensory reweighting, involves the adjustment of sensory contributions to control balance. Since those with trouble balancing may sway as they stand, the researchers measured center of balance and sway velocities as indicators of impaired sensory reweighting.

The study participants came from the same university and had one of three conditions:

A recent concussion (n=13)
A history of concussion (> 1-year post-concussion, n=12)
No concussion (Control, n=26)

The researchers applied visual, vestibular, and proprioceptive stimuli at varying intensities to determine the contribution of each of these sensory inputs to sensory reweighting for each group. While the researchers hypothesized that both concussion groups would have sensory reweighting impairments, the data indicated only those with a recent concussion showed abnormal dependence on visual and vestibular feedback. They also found that recently concussed individuals swayed faster while standing than those who had recovered from a concussion. Individuals who had recovered from a concussion may have compensated for impaired visual and vestibular feedback by relying on sensory integration to cancel noise.

Potential limitations to this study include small sample sizes and variability of recovery time in the concussion history group. The researchers suggest analyzing the effects of targeted rehabilitation interventions on the improvement of sensory information integration.

Mental Health

New study highlights how neuroimaging biomarkers may support the relationship between TBI and new-onset psychiatric disorders

A review article by Andrew R. Mayer, Ph.D., and Davin K. Quinn, MD, examines neuroimaging's role in investigating the relationship between TBI and new-onset neurocognitive disorders (NCD), depression, and post-traumatic stress disorder (PTSD). This study included mTBI in its analysis alongside a broader range of TBI. Despite the results' nonexclusivity to mTBI, the information in the study may still be valuable, especially in cases of persistent post-concussion symptoms or chronic mTBI.

After evaluating various neuroimaging techniques, the authors discovered that when gray and white matter are affected by TBI, there is a "disconnect" between the central network nodes that contribute to cognitive, emotional, and social functioning. TBI also disrupts the distribution of essential neurotransmitters associated with mood regulation and arousal. As a result, signals between cells are disturbed, causing the brain to undergo stress and inflammation. Ultimately, this causes cells in the brain to die, serving as "a possible biological agent of new-onset psychiatric disorders."

Based on their evaluation, there is evidence suggesting that "NCD is greatest within the first year of injury and can remain elevated up to thirty years post-injury." They found evidence that 25-44% of TBI survivors experience depression in the first year after their injury, with the risk being the highest (31-56%) in the first three months post-injury. Evidence also shows that people who experience TBI have a 1.5-fold increased risk of developing new-onset PTSD.

The review, published in Biological Psychiatry, states that although neuroimaging is not yet a definitive diagnosis for the relationship between TBI and new-onset psychiatric disorders, it does hold promise for identifying causal links between the two.

Statistics

Concussion history exacerbates specific migraine symptoms & disability

When treating concussions, it is essential to know the patient’s entire medical history. Dr. Ryotaro Ishii of the Phoenix Mayo Clinic presented new evidence of the correlation between concussion and exacerbated migraines. This connection was presented at the American Headache Society’s 63rd Annual Scientific Meeting and summarized by Thomas R. Collins in Neurology Today.

The study found a startling 40% of migraine sufferers have a history of concussion. These migraine patients with concussion history presented a higher percentage of some symptoms than those with migraine without a history of TBI. These mTBI migraine patients had increased symptom burden related to dizziness (both vertigo-related and unrelated), difficulty finding words, depression, and anxiety. Another significant difference was in the triggers for the participant’s migraines. Those with an mTBI history had migraines triggered by reading, lack of sleep, and bright lights at higher rates than those without an mTBI.

Dr. Ishii highlighted the importance of this research direction; post-traumatic headaches (PTH) and migraines are very similar and are often researched in singularity, with studies excluding patients with a history of either PTH or migraine. Therefore, there is not much knowledge of how PTH and migraines intersect.

Dr. Amaal Starling, from the Mayo Clinic in Scottsdale, stated that she was not surprised by these findings due to the known increase in these symptoms from a concussion standpoint. She mentions that increases in dizziness and reading-triggered migraines may be “a component of visual vestibular dysfunction” frequently associated with concussion, and vestibular rehabilitation may improve symptoms and “reduce reading as a trigger for migraine attacks.” The study was based on a survey of 1098 migraineurs in the American Registry for Migraine Research between 2016 and 2020.

Youth

Exposure to subconcussive head impacts in young athletes could cause concerning long-term symptoms

One growing concern for young athletes, especially in youth and high school football, is the idea of head impact exposure (HIE). HIE refers to numerous subconcussive head impacts, which, if sustained over multiple sports seasons, could potentially result in adverse long-term effects commensurate with those associated with a diagnosed concussion.

A 2017 study found that head impact acceleration levels increased among youth athletes with age and weight; the study also found that more impacts occurred during competitions among all levels of play. Additionally, “Athletes at lower levels experienced a greater percentage of their high magnitude impacts (≥ 80g) in practice, whereas those at the highest level experienced a greater percentage of their high magnitude impacts in competition.”

In an interview with Medical Research, study author Mireille Kelley explained that diffusion tensor imaging showed changes in head imaging metrics correlated with HIE changes. She encouraged further research of HIE and suggested that researchers could find a more significant link between HIE and changes in neuroimaging.

A recent study by Kelley, published in the Journal of Neurosurgery, found a much more significant correlation between reported HIE statistics and white matter abnormalities discovered through neuroimaging. Her results suggested that, though the immediate concussion-like symptoms are not apparent in athletes who suffered multiple subconcussive impacts, “multiple consecutive seasons of HIE” could present similarly concerning long-term effects. Kelley suggests reducing head impacts in practices, especially for athletes at a young age, to reduce abnormal white matter findings and prevent long-term symptoms from head impact exposure.

Women's Health

High levels of head trauma in victims of intimate partner violence

A study published in the Journal of Interpersonal Violence explored frequency and mechanisms of injury in victims of intimate partner violence (IPV). Meyer et al. observed high levels of head trauma, with the majority of participants reporting at least one impact to the head and at least half sustaining at least one impact that resulted in a mild traumatic brain injury (mTBI).

Previous research finds that victims of IPV are at high risk for sustaining TBI and hypoxic brain injuries (HBI). HBIs occur due to reduced oxygen in the brain. Mechanisms of HBI include strangulation, which reduces the ability to take in oxygen and blood flow to the brain. This study identifies the amount and frequency of head trauma, including potential hypoxic events, including those that don’t meet TBI or HBI diagnosis criteria.

Researchers conducted clinical interviews with a community-based sample of 47 female participants “with a history of at least one relationship that included physical violence.” They assessed participants for head trauma that could lead to TBI or HBI, such as mechanisms of impact and frequency or averages of impacts to the head.

The majority of participants (89.4%) reported sustaining at least one impact to their head during the course of their violent relationship(s). The most common mechanisms of head trauma were being shaken (72.3%) and being struck with their partner(s) open hand (63.8%). Approximately one-third of participants (29.8%) reported at least one incident of mild HBI. The most common mechanisms of HBI were being strangled (94%) and being held down by the neck (5%).

Several of the study’s limitations are its small sample size, limited diversity, retrospective reporting, and the overlap in mTBI symptoms with those of psychological trauma – for this reason, researchers chose not to include post-injury symptoms in their diagnostic criteria. The results of this study support previous research on head trauma in IPV victims and highlight the need for clinical and community service providers to screen victims of physical IPV for head trauma and brain injury.

CTE and Neurodegeneration

UK researchers, press tackle the link between pro soccer and neurodegenerative disease

The Guardian published a question and answer article related to the link between dementia and footballers (soccer players). Author Michael Aylwin discusses how the science is still in its infancy but is developing every day. Aylwin discusses famous UK athlete Jeff Astle, who died in 2002 (aged 59). Astle’s cause of death was ruled as an ‘industrial disease,’ which describes an illness, condition, or death resulting from exposure to unsafe substances, fumes, or practice in the workplace. Astle reportedly once described, “heading a football is like heading a bag of bricks." Astle suffered from early-onset dementia and, at his death in 2014, an autopsy found that he had Chronic Traumatic Encepathology (CTE).

A major study by the Queen Elizabeth University Hospital claims that football increases the risk of neurodegenerative disease by a factor of 3.5, though the absolute increase (1.0% to 2.9%) was relatively low. The research by Daniel F. Mackay, PhD et al., published in The New England Journal of Medicine, was carried out retrospectively. These types of studies are beneficial when investigating risks and outcomes. The authors evaluated an extensive database of former footballers born before 1977, alongside a control group of similar age, location, socio-economic level, and medications taken.

The researchers then set out to investigate the likelihood of all-cause mortality (death from any cause) compared to their controls. The study found that the risk of neurodegenerative illness was substantially higher for professional footballers, with 1.7% of former players and 0.5% of controls dying from neurodegenerative disease as a primary cause. The authors also noted that former footballers were nearly five times as likely to receive prescription dementia medication.

Concussion Alliance would like to note that the results found related to players born before 1977, so it is unknown whether the results would apply to current players. In addition, the study did not investigate the reasons behind the results to understand the cause of the increased risk.

Culture

Opinion: NFL race-norming practice that disadvantages concussion-related injuries in Black players highlights organization’s immersion in legacy of slavery

An opinion article published in Scientific American critiqued the recently discontinued practice of race-norming, suggesting that race-norming is an outcome of the NFL’s relation to the legacy of slavery. Until its discontinuation in June 2021, race-norming, the practice of assuming a lower baseline of cognitive abilities in Black players, worked to limit legal settlements and compensation requests submitted by Black football players suffering from sports-related concussion (SRC) injuries.

In a lawsuit filed against the NFL by Pittsburgh Steelers Kevin Henry and Najeh Davenport, they state, “Black former players are automatically assumed...to have started with worse cognitive functioning than White former players. As a result, if a Black former player and a White former player receive the exact same raw scores on a battery of tests designed to measure their current cognitive functioning, the Black player is presumed to have suffered less impairment [based purely on race], and he is therefore less likely to qualify for compensation.”

Authors and anthropologists Tracie Canada, Ph.D., and Chelsey R. Carter, MPD, Ph.D., posit that the practice of race-norming exemplifies the lasting impact of slavery on American football and the NFL. Canada and Carter claim that despite its use in the contemporary world, race-norming can be traced back to America’s long history of false science used to justify the belief in inferior racial groups, particularly during plantation slavery.

This phenomenon is not unique to cognitive function health tests either. Canada and Carter list several race-normed health assessments the NFL uses to determine the health of their players. According to the authors, the legacy of slavery has dire consequences, not only on legal settlements from former NFL players but also on Black Americans' general health and well-being.