Concussion in sports. Guidelines for the prevention of catastrophic outcome.

Kelly JP, Nichols JS, Filley CM, Lillehei KO, Rubinstein D, Kleinschmidt-DeMasters BK. JAMA 1991 Nov 27;266(20):2867-9.

Concussion (defined as a traumatically induced alteration in mental status, not necessarily with loss of consciousness) is a common form of sports-related injury too often dismissed as trivial by physicians, athletic trainers, coaches, sports reporters, and athletes themselves. While head injuries can occur in virtually any form of athletic activity, they occur most frequently in contact sports, such as football, boxing, and martial arts competition, or from high-velocity collisions or falls in basketball, soccer, and ice hockey. The pathophysiology of concussion is less well understood than that of severe head injury, and it has received less attention as a result. We describe a high school football player who died of diffuse brain swelling after repeated concussions without loss of consciousness. Guidelines have been developed to reduce the risk of such serious catastrophic outcomes after concussion in sports.

Cerebral concussion in sport. Management and prevention.

Cantu RC. Sports Med 1992 Jul;14(1):64-74.

This article explains the various stresses (tensile, compressive, and shearing) that can affect the brain, and how they may produce the different types of brain injury. The biomechanical forces and dynamics that produce coup versus contra coup injury are covered, as are the common intracranial athletic head injuries, i.e. concussion and the various intracranial haematomas (epidural, subdural, subarachnoid and intracerebral). Though less common in occurrence, because their outcome is so catastrophic, space is also devoted to the recognition, the treatment and (especially in the latter case) the prevention of the malignant brain oedema syndrome of the adolescent and the second impact syndrome of the adult. A major emphasis of this paper is the recognition of the 3 grades of cerebral concussion and the delineation of clear guidelines as to when it is safe to return to collision sports after sustaining such injuries, for the first, second or third time during a given season. Clear guidelines are also presented as to when to discontinue collision sport competition for the remainder of the season after multiple concussions. Because of the concern for the second impact syndrome, the requirement to never allow an athlete with postconcussion syndrome symptoms to return to competition is emphasised. Also covered is the prevention of head injuries, which sports are at greatest risk, and the need for additional research on the cumulative effects of concussion.

Assessment and management of concussion in sports.

Harmon KG. Am Fam Physician 1999 Sep 1;60(3):887-92, 894.

The most common head injury in sports is concussion. Athletes who sustain a prolonged loss of consciousness should be transported immediately to a hospital for further evaluation. Assessment of less severe injuries should include a thorough neurologic examination. The duration of symptoms and the presence or absence of post-traumatic amnesia and loss of consciousness should be noted. To avoid premature return to play, a good understanding of the possible hazards is important. Potential hazards of premature return to play include the possibility of death from second-impact syndrome, permanent neurologic impairment from cumulative trauma, and the postconcussion syndrome.

Neuropsychological impairment in amateur soccer players.

Matser EJ, Kessels AG, Lezak MD, Jordan BD, Troost J. JAMA 1999 Sep 8;282(10):971-3.

CONTEXT.
Soccer players incur concussions during matches and training sessions, as well as numerous subconcussive blows to the head from impacts with the soccer ball (headers). The combination of soccer-related concussions and the number of headers may be a risk for chronic traumatic brain injury (CTBI).

OBJECTIVE.
To determine whether amateur soccer players have evidence of CTBI. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional study of 33 amateur soccer players and 27 amateur athletes involved in swimming and track (controls) in the Netherlands who underwent interviews and neuropsychological testing.

MAIN OUTCOME MEASURES.
Performance of soccer players vs controls on 16 neuropsychological tests having 27 outcomes.

RESULTS.
Compared with control athletes, amateur soccer players exhibited impaired performance on tests of planning (39% vs 13%; P=.001) and memory (27% vs 7%; P=.004). Among soccer players, 9 (27%) had incurred 1 soccer-related concussion and 7 (23%) had had 2 to 5 concussions during their career. The number of concussions incurred in soccer was inversely related to the neuropsychological performance on 6 of the neuropsychological tests.

CONCLUSIONS.
Our results indicate that participation in amateur soccer in general and concussion specifically is associated with impaired performance in memory and planning functions. Due to the worldwide popularity of soccer, these observations may have important public health implications.

Fatalities from head and cervical spine injuries occurring in tackle football: 50 years’ experience.

Mueller FO. Clin Sports Med 1998 Jan;17(1):169-82.

Football head and cervical spine fatalities have been related to 84.9% of all football fatalities from 1945 through 1994. The decade from 1965 through 1974 was responsible for the greatest number and percentage of head and cervical spine fatalities, and the two decades from 1975 through 1994 were associated with the smallest number and percentage. The data reveal that most head and cervical spine fatalities are related to high school football players either tackling or being tackled in a game. Most head fatalities are subdural hematomas, and almost all of the cervical spine fatalities are fractures, dislocations, or fracture-dislocations. There has been a dramatic reduction in these types of fatalities during the last two decades, 1975 through 1994, and the preventive measures that have received most of the credit have been the 1976 rule change that prohibits initial contact with the head and face when blocking and tackling, the NOCSAE helmet standard that went into effect in colleges in 1978 and high schools in 1980, better coaching in the techniques of blocking and tackling, and improved medical care. There has been a reduction of head and cervical spine fatalities, but the analysis of data for the next decade, 1995 through 2004, will reveal the continued effects of the preventive measures discussed and continued research efforts. A number of researchers have stated that in order for the head and cervical spine fatalities to continue decreasing, there must be increased helmet research with an emphasis on concussions and neck injuries. Will the number of fatalities continue to decrease? Only time will tell.