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Biomedical subjects

Karen M Johnston

Publications and source records attributed to Karen M Johnston.

10 recordsLinked to original sources
PubMed2005

Return to play after concussion: principles and practice.

OBJECTIVE: The sport medicine team is increasingly being asked to manage concussed athletes and to provide written clearance for return to play postconcussion, making it critical to have a good understanding of concussion recognition, assessment, and management. DATA SOURCES/SYNTHESIS: A handy way to think of concussion management is the four Rs: recognition, response, rehabilitation, and return. RESULTS: Athletes, coaches, parents, therapists, and physicians need a thorough understanding of concussion signs and symptoms. An athlete suspected of having sustained a concussion should be removed from the game or practice and assessed by a member of the sideline medical team. All athletes who sustain a concussion should be evaluated by a medical doctor. Rehabilitation has similarities to but also differs from the traditional orthopedic model in that the first step is rest, both physical and cognitive. Once asymptomatic at rest, a step-wise return to activity is undertaken. CONCLUSIONS: This protocol has been adapted for various sports. It may be used for children, although it is prudent to be more conservative and to progress more slowly than in an older age group.

Athletic Injuries↗
PubMed2004

Current concepts in concussion rehabilitation.

Active rehabilitation of sport injuries is a concept familiar to athletes and those caring for them. Rehabilitation goals aim to optimize recovery efficiency and diminish chances of repeat injury. Rehabilitation programs take many aspects of recovery and wellness into consideration including physical, social, and psychologic components. Ultimately, this is important in the recovery process after concussion. In this article we introduce the largely unexplored concept of multidimensional concussion rehabilitation and discuss physical, psychologic, social, and sport-specific issues. As well, we propose future directions in this field.

Athletic Injuries↗
PubMed2004

Visual p300 effects beyond symptoms in concussed college athletes.

In order to assess whether cerebral anomalies may be observed in the absence of clinical symptoms, the current study compared the effects of concussions on attentional capacities (reaction times, accuracy) and Event-Related Potentials (ERPs) in concussed athletes with (n = 10) or without (n = 10) symptoms as well as in athletes who never had a concussion (n = 10). The P300 response was recorded from 28 electrodes during a modified visual oddball paradigm. Participants were instructed to press a key upon the appearance of the frequent stimuli as well as when a rare nontarget stimulus followed the frequent one. The other key was to be pressed when the subsequent rare stimuli (rare target) appeared until a frequent one reappeared. The symptomatic athletes displayed longer reaction times than the other two groups of athletes. The P300 amplitude to the rare target stimuli was significantly more attenuated in the symptomatic athletes than in the other two groups. Moreover, the P300 amplitude varied inversely with the severity of post-concussion symptoms but was not influenced by time elapsed since injury. Although the clinical significance of the P300 differences shown by the symptomatic athletes is still uncertain, the results do indicate that symptom severity may be a crucial indicator of functional impairments following mild traumatic brain injury.

Adult↗
PubMed2002

Neuropsychological effects of hyperbaric oxygen therapy in cerebral palsy.

We conducted a double-blind placebo study to investigate the claim that hyperbaric oxygen treatment (HBO2) improves the cognitive status of children with cerebral palsy (CP). Of 111 children diagnosed with CP (aged 4 to 12 years), only 75 were suitable for neuropsychological testing, assessing attention, working memory, processing speed, and psychosocial functioning. The children received 40 sessions of HBO2 or sham treatment over a 2-month period. Children in the active treatment group were exposed for 1 hour to 100% oxygen at 1.75 atmospheres absolute (ATA), whereas those in the sham group received only air at 1.3 ATA. Children in both groups showed better self-control and significant improvements in auditory attention and visual working memory compared with the baseline. However, no statistical difference was found between the two treatments. Furthermore, the sham group improved significantly on eight dimensions of the Conners' Parent Rating Scale, whereas the active treatment group improved only on one dimension. Most of these positive changes persisted for 3 months. No improvements were observed in either group for verbal span, visual attention, or processing speed.

Attention↗
PubMed2002

Concussions among university football and soccer players.

OBJECTIVE: A study to examine the incidence and characteristics of concussions among Canadian university athletes during 1 full year of football and soccer participation. DESIGN: Retrospective survey. PARTICIPANTS: Three 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 MEASURES: Based 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. RESULTS: Of 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. CONCLUSIONS: University 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.

Adult↗
PubMedDate not supplied

Relationship between postconcussion headache and neuropsychological test performance in high school athletes.

BACKGROUND: The relevance of headache to outcome after sports-related concussion is poorly understood. HYPOTHESES: High school athletes reporting headache approximately 1 week after injury will have significantly more other concussion symptoms and will perform more poorly on neuropsychological tests than athletes not experiencing headache. STUDY DESIGN: Prospective cohort study. METHODS: Study participants included 109 high school athletes who had sustained concussion and who were divided into two groups: those reporting headache 7 days after injury and those reporting no headaches. The two groups were compared regarding on-field markers of concussion severity at the time of injury and symptoms and neurocognitive test results collected via ImPACT, a computerized neuropsychological test battery and postconcussion symptom scale, at a mean of 6.8 days after injury. RESULTS: Athletes reporting posttraumatic headache demonstrated significantly worse performance on reaction time and memory ImPACT neurocognitive composite scores. These athletes also reported significantly more symptoms other than headache and were more likely to have demonstrated on-field anterograde amnesia. CONCLUSIONS: Findings suggest that any degree of postconcussion headache in high school athletes 7 days after injury is likely associated with an incomplete recovery after concussion.

Adolescent↗
PubMedDate not supplied

Grade 1 or "ding" concussions in high school athletes.

BACKGROUND: Recent concussion management guidelines have suggested that athletes with mild (grade 1) concussions may be returned to play if asymptomatic for 15 minutes. The purpose of this study was to assess the utility of a current concussion management guideline in classifying and managing mild concussion. HYPOTHESIS: High school athletes diagnosed with a grade 1 concussion will demonstrate measurable decline in neuropsychological functioning that persists during the 1st week of recovery. STUDY DESIGN: Prospective study designed to evaluate neuropsychological functioning both prior to and following concussion. METHODS: Forty-three high school athletes completed neuropsychological test performance and symptom ratings prior to the season and at two times during the 1st week following mild concussion. RESULTS: Thirty-six hours after injury, mildly concussed high school athletes demonstrated a decline in memory (P < 0.003) and a dramatic increase in self-reported symptoms (P < 0.00001) compared to baseline performance. CONCLUSIONS: Athletes with grade 1 concussion demonstrated memory deficits and symptoms that persisted beyond the context in which they were injured. These data suggest that current grade 1 return-to-play recommendations that allow for immediate return to play may be too liberal. CLINICAL RELEVANCE: A reconsideration of current concussion grading systems appears to be warranted.

Adolescent↗