Last week I had my first experience with four-wheeling. I had no idea that driving a vehicle through mud puddles, over rocks, and trailblazing could be so exhilarating. One of my kids was screaming with joy the whole ride. I must admit that I only wore a helmet on my first ride, and on my second ride without a helmet I realized it was easier to see, hear and communicate with my friends.
Why are helmets so important when riding a four-wheeler, bicycle, or motorcycle? I hope the information I have found will help us all to remember to wear them, even if they are inconvenient.
Motor vehicle accidents are the most common cause of head injuries in young adults, with falls being the most common cause in older adults. Traumatic brain injuries occur in about 1.7 million people annually in the U.S. Recreational accidents account for about 10 percent of head injuries. Estimates of head injuries in high school football players are as high as 20 percent per season. Almost 90 percent of people who die from trauma before arriving at the hospital have traumatic brain injuries. Disability following brain injury affects about 1-2 percent of the population.
The brain is often injured due to rapid acceleration or deceleration causing shearing forces to the brain, or by a direct blow to the head. The brain is bathed in a liquid called cerebrospinal fluid, with fibrous coverings basically suspending the brain inside the skull. When there is a rapid change in speed, the forces can cause tearing of the coverings, or the surrounding blood vessels, or the brain can become bruised by direct impact against the skull. Bleeding inside the skull then displaces the cerebrospinal fluid, and if it continues unchecked, can start to compress the brain itself, since the volume inside the skull is fixed.
Sometimes, brain injury is minor, generally called a concussion, and there are no visible abnormalities of the brain on imaging tests. A concussion occurs after a head trauma with initial amnesia, confusion or loss of consciousness, but at the time of evaluation, the person has regained consciousness, is oriented, and is not complaining of headaches or vomiting. The mechanism of mild brain injury is thought to involve disruption of the axons, or brain cells, which connect to one another.
About 3 percent of people who seem to only have a mild concussion initially can deteriorate and demonstrate more severe brain injury, so close observation is important following injury. Five percent of people who suffer concussions can develop problems with seizures in the future. Recurrent concussions, such as occur in sports like boxing or football, can lead to early dementia and even death due to diffuse cerebral swelling.
Moderate or severe brain injury is characterized by altered level of consciousness, prolonged symptoms of disorientation, and abnormalities in speech, motor response or cognition. Many people with severe head injury require the care of neurosurgeon, as some conditions may improve with surgical intervention. The risk of developing a seizure disorder or long-term disability after head injury is higher with more severe head injury.
Prevention of brain injuries is important because they can be permanently debilitating, and 3 percent of brain injuries are fatal. Helmets have been shown to reduce severity of head injury due to bicycle, motor vehicle, or sports-related accidents. Seat belt use is also essential for prevention to keep passengers and drivers from hitting the windshield or from being ejected out of the vehicle.
Let’s make safety our priority this summer as we enjoy exploring Kodiak: Wear a helmet, don’t operate a vehicle while under the influence of drugs or alcohol, and follow recommended safety precautions for children.
“Who has put wisdom in the inward parts or given understanding to the mind?” (Job 38:36).
Janet Abadir is a board certified general surgeon practicing at the Specialty Clinic at Providence Kodiak Island Medical Center.