猴头部冲击性脑损伤的判别

为在航空弹射救生的头部冲击伤的研究中区别脑功能性与器质性损伤的界限，使用高速动态加载机，对２４只猴头进行了不同冲击载荷的撞击实验，依据有关临床诊断标准判别，冲击后８只猴发生了单纯性脑震荡，６只猴发生了脑实质性损伤，而其中的３只猴又伴有脑震荡症状。结果表明，发生了脑震荡的猴都出现了暂短生理反射减弱或消失，呼吸和心率减慢，脑干神经细胞尼氏体有减少现象脑震荡伴有脑损伤的猴脑脊液中还检出ＣＫ－ＢＢ酶和红细     

Concussion in rats causes an immediate change in occupancy but not affinity of hypothalamic cholinergic receptors

Experimental concussion in rats is associated with subsequent enhanced binding in vitro of certain ligands to hypothalamic tissue but not to other brain regions. Scatchard analysis shows that the number of specific binding sites for [³H]quinuclidinylbenzilate increases within 3 s after concussion with no significant change in binding affinity. The apparent increase in receptors is likely the result of a deficit in binding of endogenous ligand. We propose that concussion produces a pressure wave that deforms cholinergic and possibly other receptors selectively in the hypothalamus, resulting in a transient deficit in transmitter binding and interruption of neuronal circuits concerned with the state of consciousness.     

大鼠脑缺血再灌流损伤在脑震荡脑损伤中作用的研究

本实验采用单摆式打击装置建立大鼠脑震荡模型。病理组织学改变为伤后１５分钟开始出现全脑血管痉挛，３０分钟血管痉挛缓解，进入持续性充血状态，相继出现神经细胞退变和部分轴索肿胀、断裂。测定了脑皮质中ＬＰＯ含量呈明显时序性改变，伤后３０ｍｉｎ开始上升（Ｐ＜０．０５）。６０ｍｉｎ达高峰。证明了脑震荡脑损伤的形成是在暴力直接作用所致损伤的基础上，伴以缺血再灌流损伤。     

一次与多重性脑震荡鼠惊跳反射弱刺激抑制变化比较

目的 运用惊跳反射弱刺激抑制(PPI)实验方法对一次单纯性脑震荡(PCC)与多重性脑震荡(MCC)大鼠的感觉门控变化进行研究,以探讨认知损伤的积累效应.方法 用金属单摆闭合性脑损伤打击装置复制PCC和MCC大鼠,另设正常对照组,每组动物10只.自损伤前3d至伤后28d,检测大鼠在惊刺激诱发下的惊吓反射波幅P值、三种不同前置弱刺激惊吓反射波幅值PP67,PP69和PP73值及惊跳反射弱刺激抑制值PPI67,PPI69和PP173的变化情况.结果 PCC后24h内P值及上述3个PP值开始降低(P＜0.05),至损伤16d后接近或恢复正常;MCC后24h内P值及上述3个PP值开始显著降低(P＜0.05)、且比PCC组更加明显,至伤后28d仍未恢复;PCC和MCC组的PPI67,PPI69和PPI73值在部分实验测试点明显高于正常.大鼠脑震荡次数越多,惊吓刺激反射P值和PP值损害性减弱越明显,而惊跳反射弱刺激抑制强度PPI值仅表现出一定程度的加强.结论 大鼠脑震荡后,不论PCC还是MCC,其感觉门控作用均出现一定程度的增强,惊吓刺激反射和前置弱刺激惊吓反射的减弱变化则表现出明显的损伤性累加效应.     

Long-term electrophysiological changes in athletes with a history of multiple concussions

Primary objective: This event-related potentials study investigated the long-term effects associated with a history of one or multiple concussions on the N2pc and P3 components using a visual search oddball paradigm.

Methods and procedure: A total of 47 university football players were assigned to three experimental groups based on prior concussion history: Athletes with a history of one concussion (single-concussion group); Athletes with two or more concussions (multi-concussion group); non-concussed athletic controls. The average post-concussion period was 31 months for athletes in the multi-concussion group and 59 months for the single-concussion group.

Results: This study found significantly suppressed P3 amplitude in the multi-concussed athletes group compared to the single-concussion and non-concussed athletes even when using the time since the latest concussion as a covariate.

Conclusion: This finding suggests that the multi-concussed athletes group showed long-lasting P3 amplitude suppression when compared with single-concussion or non-concussed athletes despite equivalent neuropsychological test scores and post-concussion symptoms self-reports. This pattern of results is important because it shows that 'old' concussions do not cause general or ubiquitous electrophysiological suppression. The specificity of the long-term effects of previous concussions to the P3, along with an intact N2pc response, suggests that further work may allow one to pinpoint the cognitive system that is specifically affected by multiple concussions.     

Epidemiology of Injuries in National Collegiate Athletic Association Men's Track and Field: 2014–2015 Through 2018–2019

ContextCollege athletes have been competing in championship track and field events since 1921; the numbers of competing teams and participating athletes have expanded considerably.BackgroundMonitoring injuries of men''s track and field athletes using surveillance systems is critical in identifying emerging injury-related patterns.MethodsExposure and injury data collected in the National Collegiate Athletic Association Injury Surveillance Program during the 2014–2015 through 2018–2019 academic years were analyzed. Injury counts, rates, and proportions were used to describe injury characteristics; injury rate ratios were used to examine differential injury rates.ResultsOverall, men''s track and field athletes were injured at a rate of 2.37 per 1000 athlete-exposures; injuries occurred at a higher rate during competition compared with practice. Most injuries were to the thigh (26.2%), lower leg (17.3%), or knee (10.7%) and were caused by noncontact (37.2%) or overuse (31.5%) mechanisms. The most reported injury was hamstring tear (14.9%).SummaryThe etiologies of thigh and lower-leg injuries warrant further attention in this population. Future researchers should also separately examine injury incidence during indoor and outdoor track and field seasons.     

窦性心率震荡对急性心肌梗死患者预后的预测价值

目的探讨窦性心率震荡（HRT）对急性心肌梗死（AMI）患者预后的预测价值。方法选取90例AMI患者为观察组,另随机选取90例健康志愿者作为对照组,对两组患者进行24h动态心电图（Holter）监测,定量测量HRT的两个参数震荡初始（TO）和震荡斜率（TS）,并获取心率变异（HRV）参数、24h内R-R期间的标准差（SDNN）、QT间期变异度（QTV）、QT问期变异系数（QTCV）及左室射血分数（LVEF）等传统指标。结果观察组TS、SDNN值分别为（12．54±8．61）ms／RR间期、（93．24±23．02）ms,均较对照组明显降低（t=2．193、4．130,均P〈0．05）。对观察组90例AMI患者作12～24个月随访,期间死亡14例,存活76例。存活组TS、LVEF值分别为（6．73±5．12）ms／RR间期、（0．574-0．15）cm,较死亡组显著性升高（t=7．956、4．590,均P〈0．05）。通过单变量COX回归分析结果显示TS（RR=0．624,P=0．013）、LVEF（RR=0．825,P=0．011）、QTV（RR=0．754,P=0．030）三个指标均对高危AMI患者的预测具有统计学意义;将TO与TS相结合作为单一变量进行多变量COX回归分析,结果显示TO与Ts相结合对AMI有着更佳的预测价值（RR=2．984,P=0．029）,优于LVEF（RR=0．208,P=0．052）、QTV（RR=0．158,P=0．074）等指标。结论HRT作为新的心电学指标,对AMI患者预后的预测价值明显优于传统指标。     

Use of neuropsychological evaluations

Neuropsychological or neurocognitive tests provide information regarding the cognitive and emotional status of the concussed athlete. The development and availability of computerized testing platforms has allowed the?application of baseline and follow-up testing models, and provide a more precise measurement of reaction time and processing speed. A combination of computerized assessment and a more expanded battery of tests may be a better approach to understanding the nature of the cognitive impact of sports concussion in youth athletes. This approach may be especially important for athletes with general risk factors and other potential modifiers or influencers on the cognitive performance data.     

脑震荡大鼠血清C反应蛋白浓度和超氧化物歧化酶活性的变化

目的探讨脑震荡大鼠的应激损伤。方法采用单摆式机械打击装置建立大鼠脑震荡模型,观察其脑组织病理学改变,检测血清CRP、MDA浓度和SOD活性的变化。结果与对照组比较,脑震荡2h后CRP浓度逐渐升高,12h达高峰（P〈0.01）,24h后开始下降,48h后恢复至对照水平;脑震荡2h后MDA浓度明显升高（P〈0.01）,6h后回降至对照水平;SOD活性显著下降（P〈0.01）,6h后有所回升,12h后回升至对照水平。脑震荡6h后大脑皮质和小脑等部位轻度水肿、淤血,小脑白质等处有神经髓鞘排列紊乱、断裂等变化,24h后更明显。结论脑震荡后脑组织有轻度组织病理性变化,伴随一过性炎症反应和细胞损伤。