Understanding Subconcussions: The Hidden Dangers

Understanding Subconcussions: The Hidden Dangers

The Critical Role of Objectively Measuring Mental Fatigue in Sports
By Dr. Ryan C. N. D'Arcy, President & Chief Scientific Officer, NeuroCatch Inc.
March 27, 2024

Concussions have gained significant attention in the past decade, and we are now starting to better understand the importance of taking precautions to prevent and manage these traumatic brain injuries. However, lurking beneath the surface is a lesser-known condition called subconcussion, which deserves our attention as well.

In the absence of a diagnosed concussion, subconcussive impairments are related to cumulative exposure to direct and indirect head impacts over an extended duration. While the physical impact may appear minor, repeated subconcussions over time can lead to longer-term impairment, such as significant delays in cognitive processing. The concept of subconcussion is increasingly being studied in relation to more devasting conditions like chronic traumatic encephalopathy.[1]

Although subconcussive impacts may not exhibit immediate or distinct symptoms, they can still impair brain function. Research suggests that repeated subconcussions can lead to cumulative changes in medical imaging and increased detection of slowed cognitive processing. Cognitive processing changes may include lower level sensory processing, attention, and even a higher-level cognitive semantic processing.[2],[3]

Causes of Subconcussions

Subconcussion exposure can result from various activities and situations involving cumulative exposure to direct and indirect impacts, most commonly reported from contact sports. While some may associate subconcussion mainly with athletic endeavors, it's crucial to recognize that they can occur in everyday life as well, with any repetitive impact exposure being a potential factor. Even seemingly harmless activities involving re-occurring impact exposure over time (e.g., organized fights, movie stunts, construction, sniper rifle recoil, etc.) can result in subconcussion, making it essential to take preventive measures.

Prevention Strategies for Subconcussions

  1. Proper Protective Gear: When engaging in sports or recreational activities, always wear appropriate protective gear such as helmets, mouthguards, and padding. This equipment can absorb the impact and reduce the risk of subconcussion.
  2. Baselining & Monitoring: Even in the absence of injury, sensitive cognitive assessment tools can be used to monitor players pre and post season to identify any subtle changes in cognition that could be related to concussion or subconcussion.[4],[5]
  3. Education and Awareness: Increase your knowledge about subconcussion to recognize potential risks and symptoms. Stay informed about the activities you participate in and understand the importance of seeking medical attention even after minor head injuries.
  4. Building Strength and Coordination: Participate in activities that promote good balance and coordination skills, such as yoga, Pilates, and other exercises focused on core strength. This can help improve stability, reducing the risk of falls and subsequent subconcussions.
  5. Avoid Risky Behaviors: Practice responsible behavior, avoiding activities like excessive alcohol consumption and recreational drug use. These substances hinder judgment and coordination, increasing the likelihood of accidents and subconcussions. Also, consider the amount of contact in sports and whether the risk is worth it to you.

Subconcussion may not always be apparent, but their cumulative effect on brain health over time can have longer-term consequences. By understanding what subconcussion is, the potential effects, and taking preventive measures, we can safeguard our brain health. Whether engaging in contact sports, working in a high-risk environment, or simply going about our daily lives, it is crucial to prioritize safety and take steps to prevent subconcussion. Health starts with the brain, so stay informed, exercise caution, and encourage others to do the same.


[1]  Chad A Tagge, Andrew M Fisher, Olga V Minaeva, Amanda Gaudreau-Balderrama, Juliet A Moncaster, Xiao-Lei Zhang, Mark W Wojnarowicz, Noel Casey, Haiyan Lu, Olga N Kokiko-Cochran, Sudad Saman, Maria Ericsson, Kristen D Onos, Ronel Veksler, Vladimir V Senatorov, Asami Kondo, Xiao Z Zhou, Omid Miry, Linnea R Vose, Katisha R Gopaul, Chirag Upreti, Christopher J Nowinski, Robert C Cantu, Victor E Alvarez, Audrey M Hildebrandt, Erich S Franz, Janusz Konrad, James A Hamilton, Ning Hua, Yorghos Tripodis, Andrew T Anderson, Gareth R Howell, Daniela Kaufer, Garth F Hall, Kun P Lu, Richard M Ransohoff, Robin O Cleveland, Neil W Kowall, Thor D Stein, Bruce T Lamb, Bertrand R Huber, William C Moss, Alon Friedman, Patric K Stanton, Ann C McKee, Lee E Goldstein, Concussion, microvascular injury, and early tauopathy in young athletes after impact head injury and an impact concussion mouse model, Brain, Volume 141, Issue 2, February 2018, Pages 422–458, https://doi.org/10.1093/brain/awx350

[2] Dioso E, Cerillo J, Azab M, Foster D, Smith I, Leary O, Goutnik M, Lucke-Wold B. Subconcussion, Concussion, and Cognitive Decline: The Impact of Sports Related Collisions. J Med Res Surg. 2022;3(4):54-63. doi: 10.52916/jmrs224081. Epub 2022 Jul 20. PMID: 35966951; PMCID: PMC9371364.

[3] Johnson B, Neuberger T, Gay M, Hallett M, Slobounov S. Effects of subconcussive head trauma on the default mode network of the brain. J Neurotrauma. 2014 Dec 1;31(23):1907-13. doi: 10.1089/neu.2014.3415. Epub 2014 Oct 16. PMID: 25010992; PMCID: PMC4238241.

[4] Shaun D Fickling, Aynsley M Smith, Michael J Stuart, David W Dodick, Kyle Farrell, Sara C Pender, Ryan C N D’Arcy, Subconcussive brain vital signs changes predict head-impact exposure in ice hockey players, Brain Communications, Volume 3, Issue 2, 2021, fcab019, https://doi.org/10.1093/braincomms/fcab019

[5] Shaun D Fickling, Daniel N Poel, Jason C Dorman, Ryan C N D’Arcy, Thayne A Munce, Subconcussive changes in youth football players: objective evidence using brain vital signs and instrumented accelerometers, Brain Communications, Volume 4, Issue 2, 2022, fcab286, https://doi.org/10.1093/braincomms/fcab286