A concussion is a type of traumatic brain injury in which a forceful bump, blow or jolt to the head causes the brain to move inside the skull. This can result in headache, confusion, nausea, dizziness, blurred vision, and sluggishness, and in some cases, a loss of consciousness. Collectively, these symptoms make up what’s called Post-Concussion Syndrome. Symptoms typically appear within the first 7-10 days and often resolve within weeks or months and may persist for more than a year.
Nearly 4-million concussions occur annually in the US, and according to an NPR-Truven Health Analytics Poll, 1 in 4 Americans has suffered a concussion at some point in their lives and more than one-third have suffered 2 0r 3 concussions.
Depending on the severity of the trauma, when the brain moves inside the skull, there may be changes in brain chemistry, bruising, bleeding, and stretching of and damage to brain cells. These changes may have consequences long after the initial symptoms resolve.
A lesser-known potential result of concussion is its association with a significant increased risk of Alzheimer’s disease and other dementias even 30 years later. It may also accelerate the age of onset for cognitive decline.
The exact reasons why head trauma is linked to dementia are not well understood, however there are some potential explanations. One possibility is that head injury leads to inflammation in the brain, which is a hallmark of Alzheimer’s disease. Studies have found a correlation between head trauma and increased levels of inflammatory markers in the brain. Another potential explanation is that brain injury can lead to the production of free radicals, which can damage neurons. Additionally, trauma to the brain can damage small blood vessels and reduce the flow of oxygen to brain cells. Finally, brain injury may cause the accumulation of abnormal proteins, similar to what happens in Alzheimer’s disease, leading to neuron death. While more research is needed to fully understand the relationship between head trauma and dementia, these potential explanations provide some clues.
Much of the studies of brain injury and subsequent risk of dementia have focused on athletes and combat veterans. Former Chicago Bears quarterback Jim McMahon is the athlete who put the relationship between traumatic brain injury in sports and dementia on the public map. Having suffered four concussions on the field, in 2012 he shared his diagnosis of early-onset dementia at age 50. Later, Mark Gastineau, who played for the New York Jets, revealed that he had received a double diagnosis of Alzheimer’s disease and Parkinson’s disease, which he attributes to his ten-season career in football.
A study in Neurology Reviews reported professional football players are four times more likely to develop Alzheimer’s disease than the general population. The evidence for the risk posed to professional football players has become so substantial the NFL entered into a settlement with 5,000 former players (or their estates) who were already suffering from, had died from, or were expected to suffer from, various forms of dementia and other concussion-related diseases as a result of their profession.
Soccer players have become equally concerned about their long-term cognitive health. The Field Study, conducted by the University of Glasgow’s Brain Injury Group, found a five-fold increased risk of Alzheimer’s disease among former professional soccer players compared to the general public. It’s noteworthy that goalkeepers, who do not head the ball, do not share the elevated risk.
When exposed to blast-related trauma from IEDs and other explosives, the brains of combat veterans show a unique signature in the form of a honeycomb pattern of broken and swollen nerve fibers that is not present in the brains of victims with head trauma from other activities. A study of 178,779 Afghanistan and Iraq war veterans found an increased risk of dementia that was 2.5 times greater in those who experienced mild concussion without a loss of consciousness, 2.8 times if there was a loss of consciousness, and 3.8 times in severe brain injury with a loss of consciousness.
Despite the greater focus on the higher risk associated with athletics and combat, falls remain the most common cause of traumatic brain injury.
Obviously, we are wise to do everything within our power to prevent head trauma. We should wear appropriate protective headgear while skiing, cycling, horseback riding, and ice-skating, among other sports. However, as the NFL studies show, a helmet may not be sufficient to prevent injury to the brain in certain circumstances.
To reduce the chance of falls in the house, consider installing grab bars around tubs, toilets, and inside showers. Be sure that rugs and carpeting are affixed securely to the floor using non-slip rug pads or Velcro. Avoid leaving trip hazards like books, magazines, or other papers on the floor. Instead of socks, wear a house shoe or slipper that has a rubber sole.
It’s estimated that despite their seriousness, 5 in 10 concussions go unreported or undetected. Even in the absence of symptoms every case of head injury is potentially serious and warrants a timely evaluation by a medical expert. There are new therapies that target specific symptoms and medications that may be neuroprotective and minimize the likelihood of post-concussive syndrome.
Joseph Keon is an investigative writer in the field of preventive medicine. He holds fitness expert certifications from both the Cooper Institute for Aerobics Research and the American Council on Exercise. In his work as a wellness consultant in the public and private sphere for over 20 years, Keon focused on chronic degenerative diseases and their relationship to modifiable lifestyle choices. He is a past member of the Board of Directors of the Wild Oats Wellness Foundation and Dr. Helen Caldicott’s Nuclear Policy Research Institute as well as the Marin Health Council, an advisory to the Marin County Board of Supervisors. Keon is currently a member of the American College of Lifestyle Medicine. Keon is the author of The Alzheimer’s Revolution as well as three other books including Whitewash: The Disturbing Truth about Cow’s Milk and Your Health.