A Head-On Solution: Concussion Impairment Can Potentially Be Detected Using the Colour of Words
Image from: Chris Chow (Unsplashed)
Most of us have experienced hits, bumps, or blows over the course of our everyday lives. However, when these injuries occur to the head, damage can occur—whether we realize it or not.
According to the CDC (Centers for Disease Control and Prevention), a concussion is a type of traumatic brain injury caused by a direct bump, blow, or jolt to the head, or indirectly by a hit to the body that causes the head and brain to move rapidly back and forth1. This movement damages nerve fibers within the brain and can change how the brain functions2.
Many people are familiar with the high incidence of concussions in contact sports such as football, soccer, hockey, and others3. The probability of experiencing a concussion for an athlete in contact sports is 19% per year played; to put it another way, most contact sports athletes will experience a concussion over 5 years of play4.
However, you don’t have to be an athlete to be at risk for a concussion. Concussions also occur over the course of daily life, such as on the playground or during a fall5. In fact, motor vehicle collisions are the most common cause of concussions6.
Sometimes, concussions can produce noticeable symptoms such as headache, loss of memory (amnesia), and confusion7 that may prompt individuals to see a doctor or visit the ER. However, these symptoms are not always present in the immediate aftermath of a concussion8 and contrary to popular perception, only 10% of concussions involve loss of consciousness9.
As a result, concussions and the possible damage that accompanies them often go unrecognized and undiagnosed—with potentially devastating consequences.
Some of the long-term consequences of concussions include memory problems, personality changes, sleep disturbance10, and a 40% increased risk of developing a mental disorder* in children and youth11. But the costs extend beyond health; the financial burden of concussions are also steep. Nearly 148,000 Ontarians are diagnosed with a concussion every year12, yet the costs for traumatic brain injuries on the Ontario health care system are about $120 million in the first year of injury alone13, with lifetime costs estimated to be $945 million in 200914.
In terms of healthcare and finances, the costs of concussion are clear. Yet, despite the devastating impact of concussions on patients, we still lack a reliable method or biomarker to diagnose a concussion15. Early detection is crucial to effectively manage concussion and mitigate adverse consequences; however, scans from common imaging techniques like Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) that are used to detect bleeding or swelling in the brain16 typically do not show any significant changes resulting from concussion damage.4,5,16
Since MRI and CT scans are poor diagnostic tools for concussion, are there any other tests that could be done to identify individuals with impairment resulting from concussion?
One potential solution was identified by PhD candidate Clara Stafford and colleagues at Western University. Their study aimed to determine differences in cognitive tests between individuals who experienced concussion vs. concussion-free individuals in both the public and in varsity football athletes.
For most of the cognitive tests, test performance was similar between individuals with at least one concussion and individuals without concussion. However, there was one notable exception: The Stroop Test.
In the Stroop Test, participants are given a list of colour names that have various font colours (see below for a sample list) and are then asked to state the font colour of each word as quickly as possible.
List modified from Wikiversity (17)
Sometimes, the word matches the font colour (e.g., the word “Red” is printed in red), but other times, the word does not match the font colour (e.g., the word “Red” is printed in green).
Despite appearing simple at first glance, the Stroop Test is more difficult than it seems due to requiring inhibitory control. That is, a default and automatic tendency (reading the word aloud) must be inhibited or controlled to complete a less automatic task (saying the font colour)18,19. Thus, when the word and font colour are not the same, accuracy is lower.
The study participants performed a variant of the Stroop Test that was modified for web use (clicking the correct font colour instead of verbally stating it), but the core principle of testing for inhibitory control remained the same.
Stafford and colleagues found that compared to concussion-free individuals, both members of the public and varsity football athletes with at least one concussion performed significantly worse in the Stroop Test when the word and font colour do not match. Therefore, individuals with an experienced concussion have deficits in inhibitory control that could be detected through the Stroop Test.
The implications of these findings are clear: The Stroop Test could be used to identify individuals with impairment after concussion—formal diagnosis or not.
Future research should verify the findings by Stafford and colleagues and determine if this test can be used for early detection of concussion. If proven, this would mean that an online Stroop Test could be administered as a simple, accessible, and inexpensive early screening tool for concussion diagnosis. By enabling all individuals experiencing impairment from concussion to receive proper treatment, the Stroop Test has the potential to alleviate health and financial costs of undiagnosed concussions and colour the future of concussion diagnosis in the general population and athletes for the better.
* Mental disorder as used here includes: anxiety and neurotic disorders, adjustment reactions, behavioral disorders, mood and eating disorders, schizophrenia, substance use disorder, suicidal ideation, and disorders of psychological development11.
Original article: Stafford, C. A., Stojanoski, B., Wild, C. J., Brewer-Deluce, D., Wilson, T. D., & Owen, A. M. (2020). Concussion-related deficits in the general population predict impairments in varsity footballers. Journal of Neurology, 267(7), 1970–1979. https://doi.org/10.1007/s00415-020-09749-9
References:
1. https://www.cdc.gov/headsup/basics/concussion_whatis.html
2. https://www.injuryresearch.bc.ca/injury-priorities/concussion/
3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1748409/
4. https://www.aans.org/en/Patients/Neurosurgical-Conditions-and-Treatments/Concussion
5.https://www.ucsf.edu/news/2018/10/412006/dangers-everyday-concussions-revealed-scientists-race-find-solutions
6. https://biad.ca/about-brain-injury/
7. https://www.webmd.com/brain/concussion-traumatic-brain-injury-symptoms-causes-treatments
8. https://www.mayoclinic.org/diseases-conditions/concussion/symptoms-causes/syc-20355594
9. https://www.injuryresearch.bc.ca/injury-priorities/concussion/
10. https://healthcare.utah.edu/healthfeed/postings/2016/11/concussion.php
11. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8902648/
12. https://pubmed.ncbi.nlm.nih.gov/31246881/
13. https://bmcneurol.biomedcentral.com/articles/10.1186/1471-2377-12-76
14.https://www.cambridge.org/core/journals/canadian-journal-of-neurological-sciences/article/health-economic-burden-of-traumatic-brain-injury-in-the-emergency-department/DA7D9CEB3EB1A4D0C373447ED67FBA69
15. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3735746/
16. https://www.ncbi.nlm.nih.gov/books/NBK185340/
17. https://en.wikiversity.org/wiki/Psycholinguistics/Chronometry
18. https://www.tandfonline.com/doi/abs/10.1080/00221300109598901
19.https://www.sciencedirect.com/referencework/9780128165119/encyclopedia-of-infant-and-early-childhood-development