March 17, 2022
The field of sports concussion has evolved rapidly, enduring many changes in the last 20 years, with neurology rising to the forefront in its management.
A new subspecialty—sports neurology—has emerged—and it has spawned the establishment of sports neurology fellowship training programs across the country.
“Sports concussion historically had been treated by many different disciplines, including orthopedics, neurosurgery, sports medicine, and physical medicine and rehabilitation,” said Nicole Reams, MD, FAAN, a sports neurologist and director of the multidisciplinary concussion program at NorthShore University HealthSystem in Evanston, IL. “Neurology is now proud to lead the charge with the treatment of athlete brain injury and brain health.”
However, there is still a crucial need for comprehensive care. Whenever possible, that care allows for the integration between the aforementioned areas of medicine and experts in athletic training, physical therapy, cognitive therapy, neuropsychology, mental health, and other disciplines, “which can be essential for the best care of the athlete,” Dr. Reams said.
That amalgamation of care for individuals who have experienced concussions is a testament to how far the field has come during the long careers of senior neurologists. When Anthony G. Alessi, MD, MMM, FAAN, was completing medical school and residency training in the late 1970s to early 1980s, the word “concussion” barely received any mention.
“Back then, it was such a vague term that it didn’t really carry with it any definitive pathology,” said Dr. Alessi, professor of neurology and orthopedics at the University of Connecticut School of Medicine in Farmington. “But over time, we have seen the term ‘concussion’ become better defined, especially with respect to athletes.”
A sense of vagueness eventually gave way to more clarity as research augmented the field’s understanding of how a concussion affected the brain. Initially, “concussion was considered more of a benign entity,” said Brian Hainline, MD, FAAN, a neurologist and chief medical officer at the National Collegiate Athletic Association (NCAA) in Indianapolis. So, when case reports linking concussions to chronic traumatic encephalopathy (CTE) appeared, “it kind of turned the whole concussion world upside down.” He noted that many individuals who were playing contact collision sports feared that a concussion could lead to a neurodegenerative disease.
Nonetheless, there was a silver lining to their concerns as increased awareness sparked a desire to gain more insight into this issue. “It really opened the doors to doing more meaningful research into concussion,” said Dr. Hainline, who is chair of the AAN Sports Neurology Section AN.
That keen interest, he pointed out, led to the largest study in the world on the history of concussion and bolstered the importance of obtaining objective markers. The study, known as the Concussion Assessment Research and Education (CARE) Consortium, is a joint endeavor between the NCAA and the US Department of Defense.
After more research, many scientists around the world began doubting that concussion could cause CTE. Investigations started to shift their focus to repetitive head impact exposure. An accelerometer became useful in determining the magnitude and number of both linear and rotational impacts in individual athletes. Such data are being assessed with regard to short-term and long-term impacts of head impact exposure, Dr. Hainline said.
How Classification Has Changed
The system for classifying concussions also underwent modifications as more information came to light. It used to rely on a numerical grading system for the severity of injury (specifically, grade 1, 2, or 3) based on certain symptoms and the presence or absence of the loss of consciousness. That approach fell out of favor, Dr. Reams said, as experts learned that these factors do not predict the recovery trajectory or long-term brain health.
“While the diagnosis of concussion largely remains a clinical one, there has been an exponential growth in the number of diagnostic tools available to aid the clinician in concussion diagnosis,” she said. Examples range from the EEG, event related potentials technology, and accelerometers to virtual reality oculomotor tracking devices — “all in an attempt to add some objectivity to our clinical judgment,” Dr. Reams said.