Chronic symptoms increase risk of visually-induced motion sickness (8/1/24 Internship Newsletter)
This week’s lead article, Chronic symptoms increase risk of visually-induced motion sickness, is in the Pathophysiology category.
This summer, we are delighted to publish weekly newsletters written by our fantastic cohort of interns. You can learn more about the internship program here.
In this newsletter: Opportunities, Education, Pathophysiology, Veterans & Service Members, Culture, and CTE & Neurodegeneration Issues.
We appreciate the Concussion Alliance interns who created this edition:
Writers: Zoe Marquis, Gabriel Marotti, Runa Katayama, Sahil Bains, and Adalia Shultz
Editors: Malayka Gormally and Conor Gormally
Do you find the Concussion Update helpful? If so, forward this to a friend and suggest they subscribe.
Opportunities
The story of the founding of Concussion Alliance is also a story about a young person who developed persisting symptoms after multiple concussions and a mother who faced challenges in finding appropriate care for her son. They went on to found Concussion Alliance to support others struggling to manage their concussion or persisting symptoms. Concussion Alliance is a 501(c)3 nonprofit organization; Conor and Malayka collaborate with a coalition of clinicians and researchers who serve on the organization’s Board of Directors and Expert Advisory Board.
You can listen to our Co-founders, Conor Gormally and Malayka Gormally, tell their story on Headfirst: The Concussion Podcast, hosted by Reece Granger, BSc (Hons), BChiro. Concussion Alliance Expert Advisory Board Members have given terrific interviews: listen to Stephen Casper, PhD on the “History of Brain Injuries and Concussion” and Julie Stamm, PhD, LAT, ATC, on “Navigating Youth Sports and Concussion with Dr. Julie Stamm.” Also available on Apple Podcasts.
Education
Analysis of interviews with secondary school educators reveals the need for better concussion education and protocols
A recent analysis published in Psychology in the Schools found that concussion knowledge often depends on personal experience, teachers were “not exposed to concussion education as part of their training,” and that structured concussion education and recognition protocols are needed immediately in Irish secondary schools. Researchers Caomhan Conaghan et al. note that “teachers repeatedly suggested… [concussion education] could be very successful if delivered as a form of continued professional development… which is a requirement for Irish secondary school teachers.” The researchers note that up to 20% of Irish 15 and 16-year-olds have experienced a concussion and that concussions “can negatively impact academic performance” and classroom behavior in adolescents, particularly for those students who have experienced multiple concussions. They called for better communication pathways and dissemination of concussion materials in Irish secondary schools, protocols for medical emergencies, and academic adjustments and accommodations for concussed students.
Researchers conducted semi-structured interviews with 18 Irish secondary school teachers. Eleven of the teachers were male, and seven were female; the teachers had a variety of experiences with athletics and coaching, plus a variety of previous experience with concussion, including concussions suffered or witnessed and concussion education. The researchers analyzed the interviews using reflexive thematic analysis. This structured process involves identifying patterns in the data by coding the transcript according to topics and then generating themes using those codes. Caomhan Conaghan et al. identified five themes and 22 subthemes across the interviews: teacher’s background experience, consequences of concussion, concussion in school, educating educators, and existing standards. The researchers found that teachers had “safer attitudes observed in those who have witnessed or experienced concussions.” The researchers conclude that concussion education could be developed to fulfill the required continuous professional development (CPD) hours, thus “increasing teacher buy-in.”
Pathophysiology
Chronic symptoms increase risk of visually-induced motion sickness
In a study published in Neuroscience Letters, researchers discovered that individuals with chronic post-concussion symptoms (symptoms lasting three months or more post-injury) had a significantly increased risk for and severity of visually induced motion sickness (VIMS). Researchers Behrang Keshavarz et al. exposed 31 adult participants to a virtual reality simulation in a dome-shaped VR lab, where they moved (virtually) down a grocery store aisle at different speeds in order to test for VIMS as well as visual dependence, dizziness, and other somatic symptoms.
VIMS feels similar to traditional motion sickness, but VIMS is not tied to actual, physical movement the way motion sickness is. Common VIMS symptoms are cold sweating, dizziness, nausea, pallor, eyestrain, fatigue, or headache. Concussion patients who are experiencing vestibular symptoms may rely more on visual cues than on vestibular cues (called visual dependence), creating a visual-vestibular conflict that bolsters the rate and severity of VIMS. The study notes that “We found evidence that concussion can significantly increase VIMS severity in individuals who currently experience concussion symptoms (e.g., dizziness).”
These findings suggest that future research must acknowledge the role varying visual stimuli have on those with and without concussion. A press release from the UHN Foundation notes that although virtual reality was used within the methodology of this study, the importance of visual stimuli playing a role in concussion symptoms may suggest that it can also influence concussion recovery. As the author of this article states, “These insights offer a valuable foundation for further exploration into optimizing virtual reality-based interventions,” such as reducing triggering of VIMS when using VR for concussion rehabilitation, “ultimately improving recovery experiences for concussion patients.”
For the study, seven participants were categorized as symptomatic concussion (they had symptoms persisting three or more months past the injury onset), nine were categorized as asymptomatic concussion (they had a history of concussion but no longer had symptoms), and fifteen served as a healthy control group without a history of concussion. When compared to the asymptomatic concussion and healthy control groups, the patients with chronic concussion symptoms were at a higher risk of VIMS.
Further research must be conducted using a larger sample size than Keshavarz et al. had available in order to expand the findings on the importance of visual stimuli and the role of virtual reality in concussion diagnosis and recovery.
Veterans & Service Members
Internet-guided cognitive behavioral therapy for insomnia results in improvement in insomnia among military service members and veterans with mTBI
In a randomized clinical trial published by Neurology, researchers took a preexisting app that delivers cognitive behavioral therapy for insomnia (CBT-I) and customized it for military service members and veterans with a history of mild traumatic brain injury (mTBI). This study is the first to test the customization of a CBT-I app for the military population. (CBT-I is now considered the first choice for in-person treatment of insomnia, and CBT-I apps have been found effective; see the CBT section on our Self-Care page.) In this study, the “automated internet-guided eCBTi program” was delivered over the course of 9 weeks; a control group was provided online sleep education. Malarkey et al. identified that insomnia was reduced significantly in the eCBT-i group: 6.0 points on the Insomnia Severity Index (ISI) for military service members and veterans who completed the eCBT-I compared to the 2.3 points of those who completed the sleep educational materials. ISI scores range from 0-28, with 14+ indicating clinical insomnia; the eCBT-I group’s scores dropped to 13.7 on average, while the sleep education group’s scores fell to 16.6. Based on these scores, the eCBT-I group, on average, dropped into the “sub-clinical insomnia” range after the intervention. The extent of improvement in insomnia correlated with the extent of improvements in depression symptoms, PTSD symptoms, sleep quality, and fatigue.
The research team randomized 50 military service members and veterans with a history of mTBI and “at least moderately severe insomnia” into two groups: one group participated in the eCBT-I program, and the other group was given educational material about sleep. The eCBT-I is a fully remote 9-week intervention with six weekly lesson modules and assigned homework activities. In contrast, the sleep education material, which was also accessed online, lacked any interactive elements. The study was fully remote, with participants being assessed (via telephone) at baseline, post-intervention about 9 weeks after giving consent, and at a 3-month follow-up to measure the ISI score and changes in self-reported secondary outcomes such as depression, post-traumatic stress disorder (PTSD), sleep quality, migraine-related disability, and fatigue-related symptoms.
Researchers conclude that remote eCBT-I can be effective in military service members and veterans with a history of TBI and insomnia. The study authors note that “optimization of [eCBTi program] completion rates remains a challenge.” While in-person CBT-I interventions are limited by the low availability and high costs of qualified CBT-I clinicians, eCBT-I increases availability to anyone with access to the internet, allows flexible scheduling, lowers cost, and improves privacy. Further research is needed to validate the intervention’s efficacy by using home-based objective sleep assessments and ensure retention throughout the study.
Concussion Alliance assisted in this research by recruiting study participants via the Concussion Update newsletter, including disseminating these flyers, here and here.
Culture
The Invisible Battle: Navigating Australia's Concussion Care Crisis
Hayley Gleeson’s article for ABC News Australia, “The year I lost myself to concussion,” highlights the challenges of persistent post-concussion symptoms and inadequate treatment options in Australia. Gleeson shares her personal struggle with prolonged concussion symptoms after a “seemingly minor accident.” While some people recover from concussion within weeks, about 30% experience persistent symptoms for months or years, including headaches, fatigue, cognitive difficulties, and mood changes.
The article reveals a critical lack of awareness that concussions are mild traumatic brain injuries (mTBIs) requiring careful management. It also exposes a shortage of multidisciplinary concussion clinics, especially in rural areas. Experts, including Professor Jennie Ponsford and Professor Barry Willer, emphasize the significance of better general practice (GP) training and implementation of evidence-based treatments, such as early, controlled exercise. Neurocognitive rehabilitation therapist Natalie Foley discusses the gaps in the Australian healthcare system for concussion patients and the need for clear referral pathways to specialized clinics.
The invisible nature of concussion symptoms often leads to misunderstanding, adding to patients’ psychological burden. Gleeson poignantly describes her struggles, recounting moments of intense sensory overload and the strain on her self-esteem and relationships, underscoring the profound impact of these invisible symptoms on daily life and mental health.
The article explores the current state of concussion research, noting that while sports-related concussions receive significant attention, they only account for about 20% of mTBI cases in adults. The majority stem from falls, motor vehicle accidents, and assaults. This misalignment in research focus has led to gaps in understanding and treating non-sports-related concussions.
A fundamental limitation in current concussion management, as pointed out by the experts interviewed, is the lack of standardized guidelines for mTBI treatment in Australia. This absence contributes to inconsistent care and often leaves patients to navigate their recovery journey alone.
Overall, there are calls for urgent action to address these gaps, including establishing more public multidisciplinary clinics, improving general practice training, clear referral pathways to specialist care, and increasing research funding for effective treatments for persistent symptoms.
CTE & Neurodegeneration
CTE and Parkinsonism are affected by the number of years of repetitive head impacts from contact sport
In a cross-sectional study of contact sports athletes diagnosed with chronic traumatic encephalopathy (CTE) post mortem, published by JAMA Neurology, researchers found an association between Parkinsonism––an “umbrella term that refers to brain conditions that cause slowed movements, rigidity (stiffness) and tremors” and the number of years of playing contact sports involving repetitive head impacts (RHI). The study found that in brain donors with CTE, the number of years of contact sports was associated with not only the loss of neurons and tau pathology but with the rate of Parkinsonism as well. For the group of 481 male brain donors in this study, the overall rate of Parkinsonism was 24.7%. Further, “an additional eight years of contact sport play was associated with 50% increased risk of more severe disease in a specific area of the brainstem that controls movement,” according to study author Daniel Kirsch in a press release published by Science Daily. This study focused on individuals who participated in American football. Adams et al. conclude that “Repetitive head impacts may incite neuropathologic processes that lead to symptoms of parkinsonism in individuals with CTE.”
The Science Daily press release highlights the lack of Lewy body pathology in this group of brain donors despite Lewy body pathology being a “classic” marker of Parkinson’s disease. Instead, the study found that “76% of individuals with CTE and parkinsonism did not have Lewy body pathology.” The brain donors with CTE and Parkinsonism had an increased likelihood of “more severe CTE-related brain cell death” in regions controlling movement, according to Thor Stein, MD, PhD.
The study involved the brains of 481 male donors with “diagnosed CTE without other significant neurodegenerative disease,” such as Alzheimer’s disease or motor neuron disease, from the Understanding Neurologic Injury and Traumatic Encephalopathy brain bank; the team analyzed the brains of participants with “years of contact sports participation” whose brains were donated between July 2015 and May 2022. Postmortem interviews, surveys, and medical record reviews were administered by staff “trained to assess for RHI [repetitive head impact] exposure and neurodegenerative diseases,” followed by the presentation of cases to an expert panel. The authors included participants’ race due to socioeconomic factors that may play a role in the development and symptoms of Parkinsonism. Limitations include that there were “few brain donors without CTE and with Parkinsonism,” and only male participants were selected, further emphasizing the need for additional studies into Parkinsonism and RHI as a whole in order to gain a fuller understanding of its affiliations within the brain.
As the largest study of its kind to date, these findings shed light on the multitude of unknowns regarding CTE and Parkinsonism, as well as the need for further research into the long-term effects of CTE and the neuronal loss/degeneration associated with it.