PROBLEMS IN DETECTING CONCUSSIONS
Part of the underreporting of concussions stems from the fact that the injury cannot be seen. With a concussion, there is no obvious injury such as when an arm or leg is dislocated. Athletic trainer and sports medicine expert Dr. Kevin Guskiewicz emphasized that “Concussion is a difficult injury to diagnose.”
X-rays and other imaging of the brain often cannot detect signs of a concussion. Concussions sometimes can cause small amounts of bleeding usually in multiple areas of the brain, according
SIGNS OF CONCUSSION
Kelly JP and Rosenberg JH. 1997 Diagnosis and management of concussion in sports. Neurology.
to neurologist Dr. James Kelly. He said physicians might be able to detect this blood staining of the brain using magnetic resonance imaging (MRI).
But as neuroimaging expert Dr. Shawn Gale pointed out, most doctors do not order an MRI for a concussion patient unless they suspect they have a life-threatening condition, such as major bleeding in the brain or brain swelling. This is because MRIs are more expensive and difficult to do than computerized axial tomography (CAT) scans, he said. But CAT scans usually cannot detect signs of a concussion in the brain.
To diagnose a concussion, consequently, physicians generally rely on the symptoms that the concussed individual reports or other abnormal signs such as disorientation or memory problems. But many of the symptoms of concussions also occur in people without the condition, and, as several speakers pointed out, some of the most widely known symptoms, such as amnesia or loss of consciousness, are frequently lacking in concussed individuals.
Definition and Symptoms of Concussion
Dr. Kelly defined a concussion as a traumatically induced alteration in mental status and suggested that it lies on a spectrum of brain injury somewhere between “being dazed” at the lower end to coma at the other extreme. “The real kicker is that you have to observe and test mental status,” Dr. Kelly said.
Unfortunately, as Dr. Kirkendall pointed out, such observation and testing usually isn’t done during the heat of a soccer game. He showed a
video of a soccer player experiencing a head collision during a soccer game. Although she was lying on the ground afterwards, the referee did not stop the game.
Contrary to popular belief, concussion does not necessarily involve loss of consciousness, which is just one of many symptoms of concussion. Loss of consciousness frequently lasts only seconds to minutes, so it is often not even detected because of the delay in stopping a game and assessing the condition of a player following a head collision, said Dr. Hergenroeder. “A player will be down on the soccer field and the ref won’t stop play. A minute later you go out, and the player’s eyes are open, they are responding, so everything looks mild, but you don’t know if they lost consciousness,” he said. This is a problem since most grading systems use loss of consciousness to indicate a more severe concussion.
Another symptom of concussion is loss of memory (amnesia) and the presence of this symptom usually boosts a concussion from a low grade to an intermediate grade in most grading scales used, said Dr. Guiskiewicz. But in a large study he conducted of concussions in high school and collegiate football players, he found that only about one quarter of all their concussions were accompanied by the symptom of amnesia and only nine percent involved any loss of consciousness. “While I think these are two very important components or parameters to look at when we are evaluating concussion,” he said, “we can’t forget about all these other things that show up. We’re missing the boat if we just focus on these two parameters.”
Another symptom of concussion is headache. But this symptom can be problematic when diagnosing concussions because soccer and football players frequently report having headaches without experiencing head collisions, especially female athletes, pointed out Dr. Brooks. “The important thing to realize is that posttraumatic headache is difficult to differentiate from any of the other types of chronically recurring headaches players experience,” she said. For example, stress, dehydration, or fatigue can all cause headaches.
Dr. Kelly reported that other early signs and symptoms of concussion are a vacant stare and a slowness to answer questions or follow instruc
GRADES OF CONCUSSION
Although other guidelines have been established, these are the most widely used by concussion researchers. Note that these are guidelines, established by expert consensus. The studies necessary to establish the link between these or any other concussion grading schemes and the underlying mechanisms of brain injury have not been conducted.
Practice Parameter, Quality Standards Subcommittee, American Academy of Neurology 1997
tions, disorientation and muddled thinking, slurred or incoherent speech, stumbling and inability to walk in a straight line, balance problems, dizziness, and nausea and vomiting.
Some symptoms do not appear until days to weeks following a concussion, Dr. Kelly added. These symptoms include persistent headache, lightheadedness, diminished attention and concentration, poor memory, easy fatigability, irritability and anxiety and depressed mood, intolerance of bright lights or loud noises and difficulty focusing vision, and sleep disturbance.
Contrary to popular belief, concussion does not necessarily involve loss of consciousness, which is just one of many symptoms of concussion.
There are also more newly discovered subtle signs of a concussion that occur later and appear to be more persistent than the traditional symptoms. Two neuropsychologists, Drs. Barth and Echemendia, reported evidence at the workshop that brain functions are impaired even after the obvious symptoms of concussion disappear.
In two separate studies, they gave college freshmen athletes a battery of tests that measured a number of abilities including attention and concentration, memory, reaction time, problem solving, and verbal learning. They then conducted the same tests in those athletes that suffered concussions during the studies, at various time intervals following the concussions.
Both studies showed that these athletes tended to do the poorest on these tests at 24 or 48 hours following the concussion. Conducting
a similar battery of tests as well as assessing balance problems on college athletes who experience concussions, Dr. Guskiewicz also found poorest performance on the day following the concussion.
“We are learning that we have underestimated how long it takes to recover from a concussion,” noted Dr. Kelly.
In Dr. Echemendia’s study, the athletes’ brain functioning assessed by these tests usually was the worst at 48 hours after the concussion. Interestingly, few of the athletes reported any concussion symptoms at this time. “This suggests that these tests can give us some additional information over and above the symptoms and tells us that the symptoms in and of themselves may not be enough,” said Dr. Echemendia.
Most of the athletes’ scores did not return to the levels they were at the beginning of the study until 10 to 30 days after the concussion. “We are learning that we have underestimated how long it takes to recover from a concussion,” noted Dr. Kelly.