J. Scott Delaney

Concussions among university football and soccer players

ObjectiveA study to examine the incidence and characteristics of concussions among Canadian university athletes during 1 full year of football and soccer participation. DesignRetrospective survey. ParticipantsThree hundred eighty Canadian university football and 240 Canadian university soccer players reporting to 1999 fall training camp. Of these, 328 football and 201 soccer players returned a completed questionnaire. Main Outcome MeasuresBased on self-reported symptoms, calculations were made to determine the number of concussions experienced during the previous full year of football or soccer participation, the duration of symptoms, the time for return to play, and any associated risk factors for concussions. ResultsOf all the athletes who returned completed questionnaires, 70.4% of the football players and 62.7% of the soccer players had experienced symptoms of a concussion during the previous year. Only 23.4% of the concussed football players and 19.8% of the concussed soccer players realized they had suffered a concussion. More than one concussion was experienced by 84.6% of the concussed football players and 81.7% of the concussed soccer players. Examining symptom duration, 27.6% of all concussed football players and 18.8% of all concussed soccer players experienced symptoms for at least 1 day or longer. Tight end and defensive lineman were the positions most commonly affected in football, while goalies were the players most commonly affected in soccer. Variables that increased the odds of suffering a concussion during the previous year for football players included a history of a traumatic loss of consciousness or a recognized concussion in the past. Variables that increased the odds of suffering a concussion during the previous year for soccer players included a past history of a recognized concussion while playing soccer and being female. ConclusionsUniversity football and soccer players seem to be experiencing a significant amount of concussions while participating in their respective sports. Variables that seem to increase the odds of suffering a concussion during the previous year for football and soccer players include a history of a recognized concussion. Despite being relatively common, symptoms of concussion may not be recognized by many players.

Concussions during the 1997 Canadian Football League season

ObjectiveTo examine the incidence and characteristics of concussions for one season in the Canadian Football League (CFL). Design Retrospective survey. Participants 289 players reporting to CFL training camp. Of these, 154 players had played in the CFL during the 1997 season. Main Outcome MeasuresBased on self-reported symptoms, calculations were made to determine the number of concussions experienced during the previous season, the duration of symptoms, the time for return to play after concussion, and any associated risk factors for concussions. ResultsOf all the athletes who played during the 1997 season, 44.8% experienced symptoms of a concussion. Only 18.8% of these concussed players recognized they had suffered a concussion. 69.6% of all concussed players experienced more than one episode. Symptoms lasted at least 1 day in 25.8% of cases. The odds of experiencing a concussion increased 13% with each game played. A past history of a loss of consciousness while playing football and a recognized concussion while playing football were both associated with increased odds of experiencing a concussion during the 1997 season. ConclusionMany players experienced a concussion during the 1997 CFL season, but the majority of these players may not have recognized that fact. Players need to be better informed about the symptoms and effects of concussions.

Mechanisms of Injury for Concussions in University Football, Ice Hockey, and Soccer A Pilot Study

ObjectiveTo examine the mechanisms of injury for concussions in university football, ice hockey, and soccer. DesignProspective analysis. SettingMcGill University. PatientsAll athletes participating in varsity football, ice hockey, and soccer. Main Outcome MeasuresAthletes participating in university varsity football, ice hockey, and soccer were followed prospectively to determine the mechanisms of injury for concussions, whether certain mechanisms of injury causing concussions were more common in any of the three sports, whether different areas of the body seem to be more vulnerable to a concussion after contact, and whether these areas might be predisposed to higher grades of concussion after contact. ResultsThere were 69 concussions in 60 athletes over a 3-year period. Being hit in the head or helmet was the most common mechanism of injury for all 3 sports. The side/temporal area of the head or helmet was the most probable area to be struck, resulting in concussion for both football and soccer. When examining the body part or object delivering the concussive blow, contact with another players helmet was the most probable mechanism in football. ConclusionThe mechanisms of injury for concussions in football are similar to previously published research on professional football players. The mechanisms of injury for concussions in soccer are similar to past research on Australian rules football and rugby.

Concussions among university football and soccer players: a pilot study.

ObjectiveA pilot study to examine the incidence and characteristics of concussions for one season of university football and soccer. DesignRetrospective survey. Participants60 football and 70 soccer players reporting to 1998 fall training camp. Of these, 44 football and 52 soccer players returned a completed questionnaire. Main Outcome MeasuresBased on self-reported symptoms, calculations were made to determine the number of concussions experienced during the previous season, the duration of symptoms, the time for return to play and any associated risk factors for concussions. ResultsOf all the athletes who returned completed questionnaires, 34.1% of the football players and 46.2% of the soccer players had experienced symptoms of a concussion during the previous season. Only 16.7% of the concussed football players and 29.2% of the concussed soccer players realized they had suffered a concussion. All of the concussed football players and 75.0% of the concussed soccer players experienced more than one concussion during the season. The symptoms from the concussion lasted for at least 1 day in 28.6% of the football players and 18.1% of the soccer players. Variables that increased the odds of suffering a concussion during the previous season for football and soccer players included a past history of a recognized concussion. ConclusionMore university soccer players than football players may be experiencing sport related concussions. Variables that seem to increase the odds of suffering a concussion during the previous season for football and soccer players include a history of a recognized concussion. Despite being relatively common, many players may not recognize the symptoms of a concussion.

Cocaine craving, euphoria, and self-administration: a preliminary study of the effect of catecholamine precursor depletion.

The authors used the acute phenylalanine-tyrosine depletion (APTD) method to test the effect of transient catecholamine precursor depletion on cocaine craving, euphoria, and self-administration. Eight nondependent, nontreatment-seeking cocaine users self-administered 3 doses of cocaine (0.6, 1.5, 3.0 mg/kg, taken intranasally) following ingestion of (a) a nutritionally balanced amino acid mixture, (b) APTD, and (c) APTD followed by L-dopa/carbidopa (2x100 mg/25 mg). APTD decreased both cue and cocaine-induced drug craving but not euphoria or self-administration. APTD+L-dopa also decreased drug craving, possibly reflecting the ability of L-dopa to transiently decrease dopamine cell firing. Together, these preliminary results suggest that the craving elicited by cocaine and cocaine cues is related to changes in catecholamine neurotransmission. Euphoria and the self-administration of freely available drugs by regular users, in comparison, might be better accounted for by other mechanisms.

Head injuries presenting to emergency departments in the United States from 1990 to 1999 for ice hockey, soccer, and football

Study ObjectiveTo examine the number and rates of head injuries occurring in the community as a whole for the team sports of ice hockey, soccer, and football by analyzing data from patients presenting to US emergency departments (EDs) from 1990 to 1999. DesignRetrospective analysis. Main Outcome MeasuresData compiled for the US Consumer Product Safety Commission using the National Electronic Injury Surveillance System were used to generate estimates for the total number of head injuries, concussions, internal head injuries, and skull fractures occurring on a national level from the years 1990 to 1999. These data were combined with yearly participation figures to generate rates of injuries presenting to the ED for each sport. ResultsThere were an estimated 17,008 head injuries from ice hockey, 86,697 from soccer, and 204,802 from football that presented to US EDs from 1990 to 1999. The total number of concussions presenting to EDs in the United States over the same period was estimated to be 4820 from ice hockey, 21,715 from soccer, and 68,861 from football. While the rates of head injuries, concussions, and combined concussions/internal head injuries/skull fractures presenting to EDs per 10,000 players were not always statistically similar for all 3 sports in each year data were available, they were usually comparable. ConclusionWhile the total numbers of head injuries, concussions, and combined concussions/skull fractures/internal head injuries presenting to EDs in the United States are different for ice hockey, soccer, and football for the years studied, the yearly rates for these injuries are comparable among all 3 sports.

Why university athletes choose not to reveal their concussion symptoms during a practice or game.

Objective:To determine why athletes decide not to seek medical attention during a game or practice when they believe they have suffered a concussion. Design:A retrospective survey. Setting:University Sport Medicine Clinic. Participants:A total of 469 male and female university athletes from several varsity team sports were participated in the study. Main Outcome Measures:Athletes were surveyed about the previous 12 months to identify specific reasons why those athletes who believed they had suffered a concussion during a game or practice decided not to seek attention at that time, how often these reasons occurred, and how important these reasons were in the decision process. Results:Ninety-two of the 469 athletes (19.6%) believed they had suffered a concussion within the previous 12 months while playing their respective sport, and 72 of these 92 athletes (78.3%) did not seek medical attention during the game or practice at least once during that time. Sports in which athletes were more likely to not reveal their concussion symptoms were football and ice hockey. The reason “Did not feel the concussion was serious/severe and felt you could still continue to play with little danger to yourself,” was listed most commonly (55/92) as a cause for not seeking medical attention for a presumed concussion. Conclusions:A significant percentage of university athletes who believed they had suffered a concussion chose not to seek medical attention at the time of injury. Improved education of players, parents, and coaches about the dangers of continuing to play with concussion symptoms may help improve reporting. Clinical Relevance:Medical staff should be aware that university athletes who believe they have suffered a concussion may choose not to volunteer their symptoms during a game or practice for a variety of personal and athletic reasons.

Effects of lowered serotonin transmission on cocaine-induced striatal dopamine response: PET [11C]raclopride study in humans

BACKGROUND Low serotonin transmission is thought to increase susceptibility to a wide range of substance use disorders and impulsive traits. AIMS To investigate the effects of lowered serotonin on cocaine-induced (1.0 mg/kg cocaine, self-administered intranasally) dopamine responses and drug craving. METHOD In non-dependent cocaine users, serotonin transmission was reduced using the acute tryptophan depletion method. Striatal dopamine responses were measured using positron emission tomography with [(11)C]raclopride. RESULTS Acute tryptophan depletion increased drug craving and striatal dopamine responses to cocaine. These acute tryptophan depletion-induced increases did not occur in the absence of cocaine. CONCLUSIONS The results suggest that low serotonin transmission can increase dopaminergic and appetitive responses to cocaine. These findings might identify a mechanism by which individuals with low serotonin are at elevated risk for both substance use disorders and comorbid conditions.

Head Injuries and Concussions in Soccer

1.0 INTRODUCTION Soccer has not always been perceived as a high risk sport for head injuries or concussions. However, recent research suggests that soccer players have head injury and concussion rates similar to football and ice hockey. 5,6,7, 8, 9, 10, 11,12, 13,14,15,16,17,18,19 The Canadian Academy of Sport Medicine (CASM) has undertaken this discussion paper to review the literature and to provide recommendations to the public to decrease the risk of head injuries and concussions in the sport of soccer.

Mechanisms of injury for concussions in university football, ice hockey, and soccer

Objective:To examine the mechanisms of injury for concussions in university football, ice hockey, and soccer. Design:Prospective cohort deign. Setting:McGill University Sport Medicine Clinic. Participants:Male and female athletes participating in varsity football, ice hockey, and soccer. Main Outcome Measures:Athletes were followed prospectively over a 10-year period to determine the mechanisms of injury for concussions and whether contact with certain areas of the body or individual variables predisposed to longer recovery from concussions. For soccer, data were collected on whether concussions occurred while attempting to head the ball. Results:There were 226 concussions in 170 athletes over the study period. The side/temporal area of the head or helmet was the most common area to be struck resulting in concussion in all 3 sports. Contact from another players head or helmet was the most probable mechanism in football and soccer. In hockey, concussion impacts were more likely to occur from contact with another body part or object rather than another head/helmet. Differences in mechanisms of injuries were found between males and females in soccer and ice hockey. Athletes with multiple concussions took longer to return to play with each subsequent concussion. Half of the concussions in soccer were related to attempting to head the soccer ball. Conclusions:The side of the head or helmet was the most common area to be struck resulting in concussion in all 3 sports. In ice hockey and soccer, there are differences in the mechanisms of injury for males and females within the same sport.