If you have played contact sports or hit your head hard, then you may know what a concussion feels like. Dizziness. Changes in vision. Balance issues. Difficulty with thinking or remembering. Even loss of consciousness can occur if the trauma is severe enough. When I played high school football in the 1990’s, I was told I had my “bell rung” when a hard hit caused these symptoms and not to worry about it, often returning to action the very next play. Of course we now know it IS something to worry about.
A Concussion is an Injury to the Brain
A concussion, as defined by the Centers for Disease Control (CDC), is a type of traumatic brain injury (TBI) caused by a bump, blow, or jolt to the head or by a hit to the body that causes the head and brain to move rapidly back and forth. This sudden movement can cause the brain to bounce around or twist in the skull, creating chemical and physical changes to the tissue. Most people with a concussion recover well from symptoms experienced at the time of the injury. But for some people, the symptoms can last for days, weeks, or longer. Those who have had a concussion in the past are at risk of having another. The more concussions that occur (especially back to back), the longer it can take to recover and the more lasting damage can occur to the brain. According to the CDC, symptoms usually fall into four categories: thinking/remembering, physical, emotional/mood, and sleep.
Vision Problems Often Overlooked
The visual pathway, or brain wiring, that allows us to see clearly at distance, while reading, and allows our eyes to shift from one target to the next begins at the front of the head and extends all the way to the back of the head. If the brain is injured, it makes sense that there would be a high probability of disruption to visual function. There is much more to vision than having clear 20/20 vision. The following is a list of symptoms of visual problems which can result from a concussion:
- Blurred vision
- Sensitivity to light, glare sensitivity
- Reading difficulties; words appear to move
- Comprehension difficulty
- Attention and concentration difficulty
- Memory difficulty
- Double vision
- Aching eyes
- Headaches with visual tasks
- Inability to maintain visual contact or focus
- Reduction or loss of visual field (Visual Field Loss)
- Difficulties with eye movements, such as:
- ocular pursuits (eye tracking ability)
- saccades (shifting gaze quickly from one point to the other)
- accommodative inability (focusing)
- binocular vision (eye alignment, eye teaming, depth perception, 3D vision, stereopsis)
These visual problems are common following a concussion in adults and children. In a study looking at 72 children age 11 to 17 years old who had a concussion and recruited from the Minds Matter Concussion Program at The Children’s Hospital of Philadelphia, 49 (68%) were found to have one or more vision problems. The most common problems were convergence insufficiency (47.2%); accommodative insufficiency (33.3%); saccadic dysfunction (30.5%); and accommodative infacility (11.1%). The investigators also found that 64% of the children with convergence insufficiency also had an accommodative disorder.
Due to the high visual demands of schoolwork, performance can decline significantly with any of these visual problems. A comprehensive eye exam, with emphasis on testing visual function, should be part of the post-concussion protocol. For some, a prescription for spectacle lenses can dramatically help regain visual function as the brain heals. For others, neuro-optometric rehabilitation can decrease or eliminate visual problems.
More Than Football Players
The major motion picture Concussion (Sony Pictures 2015) starring Will Smith put the concussion crisis in the national spot light. Based on a true story, Smith plays Dr. Bennet Omalu, the brilliant forensic neuropathologist who made the first discovery of chronic traumatic encephalopathy (CTE), a progressive degenerative disease of the brain in people with a history of repetitive brain trauma, in a pro football player named Mike Webster. “Iron Mike”, considered one of the best centers in NFL history for the Pittsburgh Steelers, had drastic changes in mood and behavior before tragically ending his own life. Since then, numerous other former pro-football players have followed a similar path. Boston University’s CTE Center has taken the lead on researching the disease. Out of over one hundred former NFL players’ analyzed, CTE was present in 99% of their brains. This degenerative process has also been found in combat veterans, hockey players, soccer players, and in athletes as young as 18 years old. Female athletes, soccer in particular, have been found to have the highest rates of concussions compared to male athletes of any sport. What is perhaps most alarming is recently, BU CTE Center has shown it is hits, not concussions, that cause CTE. If CTE can occur even in the absence of signs of a concussion, how are we to know how to help our veterans, athletes, and children avoid it? At this point, the best advice from the experts is to avoid repeated blows to the head.
While on faculty at the Illinois College of Optometry, colleagues of mine were studying how an eye-movement test can help diagnosis concussions in athletes while on the sidelines in an effort to create a protocol to remove athletes from a game. At the same time, the world premiere of a documentary about concussions in athletes called Head Games (2014) was aired in Chicago. Along with other faculty, I was invited to attend. It was eye-opening. I wish I had known more about concussions as a teenage football player. When I see patients that have vision problems following a concussion, I always share this documentary. If you are a parent with children in sports, especially contact sports, I encourage you to watch it and have a conversation with your family.