ICE CREAM BUCKETS AND BELL RINGINGS
Have you had a big crash and kept on riding? We see it plenty of times in the World Cup downhill racing, and in the World Cup XCO – plus in freeride videos. What makes mountain bikers so special when other sports treat head injuries with more caution? When was the last time you crashed and hit your head? Did you get straight back up? Did you seek medical attention? Back in the day, football players would be knocked out cold, get slapped in the face and sprayed with water until they roused, then be back playing in a few minutes, lolling all over the field. Now, football codes all have stringent head-injury protocols after a spate of NFL players in the USA were diagnosed with Chronic Traumatic Encephalopathy (CTE) after a long career of head-knocks. CTE has been linked to increased rates of dementia, cognitive impairment, and personality changes. While concussion can be diagnosed from a single traumatic event, these longer lasting changes often take a much longer time to appear. Perhaps we should unpack what a head injury is.
WHAT IS A HEAD INJURY?
The Monroe-Kellie Doctrine is, as a university lecturer once explained, the law relating to the physiological phenomenon of the brain and skull; essentially that the brain is a big squishy thing with a complex vasculature, bathed in spinal fluid, which is stuck inside a hard box (your skull). A rapid acceleration/deceleration or direct blow can cause the ratio of these constituents to increase (such as in the case of a cerebral bleed), causing intracranial pressure to increase and resulting in much badness, including herniation, changes in conscious state and in the worst case, death. A direct blow isn’t necessary to create trauma, a sudden acceleration/deceleration can create the shredding forces that create neuron damage. Head injuries are classified using a scale called the Glasgow Coma Scale (GCS), and sorted into minor, moderate and severe depending on the best response to verbal, motor and eye assessments. But GCS has limitations; someone can present fully orientated, without a loss of consciousness, and still have a concussion. In fact, CT scans can come back clear and the patient can still be concussed. Most of us will know the obvious signs of a moderate to severe head injury; changes in conscious state, nausea and vomiting, severe headache, inability to talk, memory loss, obvious head trauma, dizziness, seizure and inability to walk in a straight line. What is less obvious are the more subtle, occult signs of concussion post-trauma; blurred vision, photosensitivity, emotionality, difficulty concentrating, fatigue, irritability, memory difficulties, decrease in balance, general headache, aggression, insomnia, and changes in reaction time. The thing is, the brain has had a big knock and requires rest to repair neurons and get back to normal function. That doesn’t mean hopping back on your bike and riding, it means complete lack of stimulation and resting until symptom free. But we have HELMETS guys, it’s going to be OK!