Metformin Reduces Repeat Mild Concussive Injury Pathophysiology

Guidance regarding the decision to remove an adolescent from athletic competition immediately following an acute concussive injury and the safe return of play in the short term is widely accepted and supported by clinical evidence, local institutional policies, and state and federal laws. There is considerably less guidance regarding the decision to permanently retire an adolescent athlete for medical reasons due to concussive injuries. In this article, we discuss the clinical and non-clinical considerations that should guide clinicians in discussions regarding the adolescent athlete’s permanent retirement by emphasizing the ethical obligation to protect the child’s right to an open future as possibly determinative in otherwise ambiguous cases.

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The Effect of Concussive Injury on Individual Game Performance in Professional Collision-Sport Athletes

Journal of Sport Rehabilitation ◽

10.1123/jsr.2018-0168 ◽

2019 ◽

Vol 28 (7) ◽

pp. 769-773

Author(s):

Corey P. Ochs ◽

Melissa C. Kay ◽

Johna K. Register-Mihalik

Keyword(s):

Professional Sports ◽

Physical Nature ◽

Time Frame ◽

Individual Performance ◽

Return To Play ◽

Bottom Line ◽

Final Study ◽

Before And After ◽

Game Performance ◽

Concussive Injury

Clinical Scenario: Collision sports are often at higher risk of concussion due to the physical nature and style of play. Typically, initial clinical recovery occurs within 7 to 10 days; however, even this time frame may result in significant time lost from play. Little has been done in previous research to analyze how individual game performance may be affected upon return to play postconcussion. Focused Clinical Question: Upon return-to-play clearance, how does sport-related concussion affect game performance of professional athletes in collision sports? Summary of Key Findings: All 3 studies included found no significant change in individual performance of professional collision-sport athletes upon returning to play from concussive injury. One of the studies indicated that there was no difference in performance for NFL athletes who did not miss a single game (returned within 7 d) and those who missed at least 1 game. One study indicated that although there was no change in performance of NFL players upon returning to play from sustained concussion, there was a decline in performance in the 2 weeks before the diagnosed injury and appearing on the injury report. The final study indicated that there was no difference in performance or style of play of NHL athletes who missed time due to concussive injury when compared with athletes who missed games for a noninjury factor. Clinical Bottom Line: There was no change in performance upon return from concussive injury suggesting that players appear to be acutely recovered from the respective concussion before returning to play. This suggests that current policies and management properly evaluate and treat concussed athletes of these professional sports. Strength of Recommendation: Grade C evidence exists that there is no change in individual game performance in professional collision-sport athletes before and after suffering a concussion.

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Evaluating mild traumatic brain injury management at a regional emergency department

Injury Prevention ◽

10.1136/injuryprev-2018-042865 ◽

2018 ◽

Vol 24 (5) ◽

pp. 390-394

Author(s):

Ashlee Maree Brown ◽

Dara M Twomey ◽

Anna Wong Shee

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

Ct Scan ◽

Mild Traumatic Brain Injury ◽

Best Practice ◽

Medical Service ◽

Regional Health ◽

Diagnosis Codes ◽

Retrospective Audit ◽

Concussive Injury

BackgroundEmergency departments (EDs) are usually the first point of contact, and often the only medical service available, for patients with mild traumatic brain injury (mTBI) in rural and regional areas. Clinical practice guidelines (CPGs) have been created to ensure best practice management of mTBI in EDs. Adherence to mTBI CPGs has rarely been evaluated in rural and regional areas.AimThe aim of this paper was to assess a regional health service’s adherence to their mTBI CPG.MethodsThis was a 12-month retrospective audit of 1280 ED records of patients ≥16 years presenting with mTBI to a regional Australian ED. Case selection used the Victorian Admitted Episodes Dataset codes for suspected head injury: principal diagnosis codes (S00-T98), concussive injury recorded in diagnosis codes (S06.00-S06.05) and unintentional external cause code (V00-X59). The data were collected to determine 4-hour observation rates, CT scan rates, safe discharge and appropriate referral documentation.ResultsFewer people received a CT scan than qualified (n=245, 65.3%), only 45% had 4-hour observations recorded, safe discharge was documented in 74.1% of cases and 33% received educational resources.Discussion/conclusionSeveral key elements for the management of mTBI were under-recorded, particularly 4-hour observations, safe discharge and education. Acquired brain injury clinic referrals were received in overwhelmingly fewer cases than had a CT scan (n=19, 6.3%). Overall, this study suggests that the regional health service does not currently fully adhere to the CPG and that the referral services are potentially underutilised.

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On average, a professional rugby union player is more likely than not to sustain a concussion after 25 matches

British Journal of Sports Medicine ◽

10.1136/bjsports-2017-098417 ◽

2018 ◽

Vol 53 (15) ◽

pp. 969-973 ◽

Cited By ~ 9

Author(s):

James Rafferty ◽

Craig Ranson ◽

Giles Oatley ◽

Mohamed Mostafa ◽

Prabhat Mathema ◽

...

Keyword(s):

Cohort Study ◽

Lower Limb ◽

Injury Risk ◽

Rugby Union ◽

Return To Play ◽

Injury Rates ◽

Risk Of Injury ◽

Four Seasons ◽

Concussive Injury ◽

Over Time

ObjectivesTo investigate concussion injury rates, the likelihood of sustaining concussion relative to the number of rugby union matches and the risk of subsequent injury following concussion.MethodsA four-season (2012/2013–2015/2016) prospective cohort study of injuries in professional level (club and international) rugby union. Incidence (injuries/1000 player-match-hours), severity (days lost per injury) and number of professional matches conferring a large risk of concussion were determined. The risk of injury following concussion was assessed using a survival model.ResultsConcussion incidence increased from 7.9 (95% CI 5.1 to 11.7) to 21.5 injuries/1000 player-match-hours (95% CI 16.4 to 27.6) over the four seasons for combined club and international rugby union. Concussion severity was unchanged over time (median: 9 days). Players were at a greater risk of sustaining a concussion than not after an exposure of 25 matches (95% CI 19 to 32). Injury risk (any injury) was 38% greater (HR 1.38; 95% CI 1.21 to 1.56) following concussion than after a non-concussive injury. Injuries to the head and neck (HR 1.34; 95% CI 1.06 to 1.70), upper limb (HR 1.59; 95% CI 1.19 to 2.12), pelvic region (HR 2.07; 95% CI 1.18 to 3.65) and the lower limb (HR 1.60; 95% CI 1.21 to 2.10) were more likely following concussion than after a non-concussive injury.ConclusionConcussion incidence increased, while severity remained unchanged, during the 4 years of this study. Playing more than 25 matches in the 2015/2016 season meant that sustaining concussion was more likely than not sustaining concussion. The 38% greater injury risk after concussive injury (compared with non-concussive injury) suggests return to play protocols warrant investigation.

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Thalamic and thalamic projection abnormalities on DTI and NODDI analysis following acute concussion

Neurology ◽

10.1212/01.wnl.0000580864.41102.8d ◽

2019 ◽

Vol 93 (14 Supplement 1) ◽

pp. S4.2-S5

Author(s):

James Houston ◽

Frank Skidmore ◽

William Monroe ◽

Jon Amburgy ◽

Mitchell Self

Keyword(s):

White Matter ◽

Diffusion Tensor ◽

Mean Diffusivity ◽

Oculomotor System ◽

White Matter Injury ◽

Football Players ◽

Cortical Regions ◽

The Right ◽

Collegiate Football ◽

Concussive Injury

ObjectiveTo compare preseason and post-concussive MRI in a cohort of collegiate football players utilizing Diffusion Tensor Imaging (DTI) and Neurite Orientation Dispersion and Density Imaging (NODDI) post processing.BackgroundAcute post-concussive symptoms can vary in clinical characteristics and severity. However, vestibular and ocular dysfunction in particular, has been associated with poor clinical outcomes. The vestibular system comprises a complex network of projections from peripheral vestibular organs to thalamic relay systems and numerous cortical regions. The visual/oculomotor system is also complex, involving brainstem, subcortical-cortical and thalamo-cortical connections. Oculomotor deficits are thought to involve the midbrain and the visual and parietal association cortices, both of which have thalamic projections.Design/MethodsWe gathered pre-season MR diffusion weighted imaging on a cohort of 30 collegiate football players. We performed repeat imaging within 36 hours of any diagnosed concussion in the same subject cohort. DTI metrics: mean diffusivity (MD), axial diffusivity (AD), fractional anisotropy (FA), and radial diffusivity (RD) along with NODDI metric: orientation dispersion index (ODI), were analyzed for statistical comparisons between groups.Results4 subjects with pre-season MRI underwent repeat MRI within 36 hours of concussive injury. A paired t-test between these two groups using DTI and NODDI metrics showed significant (p < 0.05) decreases in: AD and MD in the left posterior thalamic radiations, FA in the column and body of the fornix, and MD in the right anterior corona radiata and superior fronto-occipital fasciculus, and a significant decrease in ODI in the anterior thalamus.ConclusionsDisruptions in the thalamus and its white matter projections may play a role in the vestibular/ocular dysfunction associated with acute concussive injury. While our numbers are small, the findings suggest that DTI and NODDI processing techniques have the capability to locate and measure grey and white matter injury patterns after concussive injury.

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Administration of Excitatory Amino Acid Antagonists via Microdialysis Attenuates the Increase in Glucose Utilization Seen following Concussive Brain Injury

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.1992.3 ◽

1992 ◽

Vol 12 (1) ◽

pp. 12-24 ◽

Cited By ~ 192

Author(s):

Tatsuro Kawamata ◽

Yoichi Katayama ◽

David A. Hovda ◽

Atsuo Yoshino ◽

Donald P. Becker

Keyword(s):

Amino Acid ◽

Brain Injury ◽

Ion Channels ◽

Energy Demand ◽

Glucose Utilization ◽

Excitatory Amino Acid ◽

Ionic Balance ◽

Ionic Fluxes ◽

Amino Acid Antagonists ◽

Concussive Injury

Immediately following concussive brain injury, cells exhibit an increase of energy demand represented by the activation of glucose utilization. We have proposed that this trauma-induced hypermetabolism reflects the effort of cells to restore normal ionic balance disrupted by massive ionic fluxes through transmitter-gated ion channels. In the present study, changes in local CMRglc following fluid-percussion concussive injury were determined using [14C]2-deoxy-d-glucose autoradiography, and the effects of in situ administration (via microdialysis) of excitatory amino acid (EAA) antagonists [kynurenic acid (KYN), 2-amino-5-phosphonovaleric acid (APV; 100 μ M, 1 m M, and 10 m M), and 6-cyano-7-nitroquinoxaline-2,3-dine (CNQX; 300 μ M, 1 m M, and 10 m M] on glucose utilization were investigated. Animals that did not receive dialysis showed a remarkable increase (up to 181% of normal control) in cortical glucose utilization following injury. In contrast, this high demand for glucose was reduced in areas infiltrated with KYN, APV, and CNQX. These results indicate that EAA-activated ion channels are involved in the posttraumatic increase in glucose utilization, reflecting the energy demand of cells required to drive pumping mechanisms against an ionic perturbation seen immediately following the concussive injury. The effects of KYN, APV, and CNQX suggest that although all subtypes of the glutamate receptor appear to be involved in this phenomenon, N-methyl-d-aspartate-activated channels may play a major role.

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