I read with curiosity and some amount of skepticism the opinion published in the New York Times advising parents to Stop Obsessing Over Concussions. I was surprised to read this from a doctor, when it can be a life-changing situation. My advice to parents - obsessing is good.
I'm not arguing to stop letting our children play sports. I've played contact sports, but I've also seen the changes that happen when the brain is injured. Because of this, I'm quite comfortable with exercising an "excessive sense of caution" - especially when it comes to our children.
The author, Steven M. Rothman, advocates that a concussion "crisis" has developed because concussion has acquired a "looser definition" since 1977. This decades old definition required a temporary loss of consciousness. Essentially Rothman urges that a "redefinition" is needed such that a new level of head injury, one that the author calls "noncussion," emerges.
Medicine has made incredible advances since 1977 regarding the unique symptoms and treatment of concussive brain injuries. The variability of concussive brain injuries changes drastically from patient to patient. Modern medicine has long abandoned the requirement of a loss of consciousness to diagnose a concussion. The "looser definition" that has evolved since 1977 is strongly supported in medical literature.
In 1998, the National Institute of Health (NIH) issued a consensus statement on TBI. This statement made it clear that no loss of consciousness was required to diagnose a concussion. In 2016, to suggest otherwise is to ignore an entire body of peer-reviewed medical literature and decades of advancement and understanding.
Randolph Evans, M.D., one of the authors of Prognosis of Neurological Disorders, identifies the constellation of symptoms patients can experience following a concussive brain injury. While certainly not an exhaustive list, concussive brain injury involves: (1) cognitive symptoms of impaired memory, attention, concentration, processing speed, difficulty maintaining focus, problems with encoding information, and auditory processing; (2) physical symptoms including headaches, nausea, visual disturbance, fatigue, dizziness, balance problems; sensitivity to light and/or sound, and (3) emotional symptoms including irritability, depression, and changes in personality. In the student athlete, or even the pediatric setting, it is not hard to conceive how any combination of these symptoms could potentially affect the child's return to learning. Not all patients suffer the entirety of the constellation; all patients are as different as their residual symptoms. Dr. Evans underscores that a loss of consciousness is not required to injure the brain or for the post-concussive syndrome to result.
According to the Mayo Clinic: "a concussion is a traumatic brain injury, usually occurring after a blow to the head. Loss of consciousness isn't required for a diagnosis of concussion or post concussive syndrome."
James Kelly, M.D., wrote about concussion and returning to play: "it is important to correct a common misconception that concussion only occurs if an individual is rendered unconscious." He points out that concussive brain injury is not determined by conventional neuroimaging studies like CT or MRI scans and that "neuropsychological testing is our most sensitive measure of cognitive dysfunction after concussion and it is the most useful method of determining readiness to return to play."
An article published just this week documented a 25 year-old student athlete who never played professional sports, but did have a history of concussive injuries. Despite a 3.8 GPA in high school, he began failing courses in college following another concussion his freshman year. He eventually left school with a GPA of 1.9 and 12 credits short of a degree. Neuropsychological testing confirmed his injury; CTE was confirmed pathologically.
The good news: most patients experience a full recovery following a concussion. The bad news: some do not. For parents of children that suffer these injuries, obsess over how they are functioning, not on the playing field but in the classroom. Pay attention to their ability to return to learn. Find the right doctor to evaluate and care for your child. Your child's future could depend on it. And that might be more important than the next big play.
 Centers for Disease Control and Prevention (CDC) (2015) Report to Congress on Traumatic Brain Injury in the United States: Epidemiology and Rehabilitation. National Center for Injury Prevention and Control; Division of Unintentional Injury Prevention. Atlanta, GA., GA
 Oxford University Press, 2002, 2nd edition
 Mayo Clinic, 2015
 The Journal of Athletic Training, Loss of Consciousness: Pathophysiology and Implications in Grading and Safe Return to Play, 2001 Jul-Sep; 36(3): 249-252
 Journal of the American Medical Association (JAMA) Neurology, January 4, 2016 (jamaneurology.com)