Note: Trackside medicine is intended to provide a general medical guideline and is not intended to replace the clinical judgment of a doctor or take the place of the medical doctor’s diagnostic or treatment recommendations. These articles will always err on the conservative side for safety purposes.Let’s face it: Motocross is a dangerous sport. And while no injury is a good one, head and back injuries are potentially the most devastating. If you ride motocross long enough, you’re bound to have a dinger to your head sooner or later. The real question when this happens is, do you seek medical care? Well, concussions are separated into four grades: the classic dinger/bell ringer and grades 1, 2 and 3. A concussion is when you receive injury to the brain. This is usually caused by a blow to the head but may happen even without direct impact to your noggin.The grading of concussions is based on the duration of symptoms, presence of posttraumatic amnesia (memory loss) and loss of consciousness. The loss of consciousness even for a few seconds is considered a grade 3 concussion by most medical standards and requires transport to a hospital for medical evaluation with a CAT scan or MRI. Less than 10 percent of all concussions result in loss of consciousness.Some signs of a concussion are: headache, vision changes, dizziness, loss of balance, confusion, memory loss (called amnesia), ringing in ears (tinnitus), difficulty concentrating, nausea/vomiting, sleepiness and any loss of consciousness. Unfortunately, severe concussions or recurrent concussions can result in death, which really sucks for everyone involved.Grade 1 concussions consist of symptoms lasting less than 15 minutes with no amnesia and no loss of consciousness. First-time grade 1 concussions with a normal neurological status are allowed to return to activity when no symptoms are present for 20 minutes with exertion activity testing. Second-time grade 1 concussions may return to activity when no symptoms are present for seven days. So no second moto-pack it up, go home and see your doctor. The general consensus on third-time grade 1 concussions is to return to activity in three months.The reason for the criterion of recurrence is due to Second Impact Syndrome. Second Impact Syndrome is one of several serious risks associated with a premature return to activity. When an individual returns to activity before symptoms of the initial concussion have resolved, a second blow to the head-even a very minor one-can result in a loss of the auto regulation of the brain’s blood supply, leading to vascular engorgement and subsequent herniation of the brain, which is usually fatal.Grade 2 concussions consist of symptoms lasting longer than 15 minutes, and may or may not involve posttraumatic amnesia (memory loss) that lasts less than 30 minutes and with no loss of consciousness. This type of concussion requires medical evaluation. The return to activity for first-time concussions is usually a wait of at least one week, while recurrent concussions would need one to three months based on the number of episodes.Grade 3 concussions are based on posttraumatic amnesia lasting longer than 30 minutes and/or any loss of consciousness. This individual requires immediate transport to a hospital for a CAT scan or MRI of the brain.Returning to activity too soon may also increase the likelihood of Post-Concussive Syndrome characterized by headaches, fatigue, balance issues and difficulty concentrating that may last weeks to months after the injury. Any individual who continues to have symptoms of concussion for more than one week, no matter how mild, should see a medical doctor for a neurological evaluation and possibly a CAT scan or MRI.