Post-Traumatic Headache: Commentary: An Overview

The history of post-traumatic headache begins in the middle of the 19th century, and its latest iteration has been defined in the International Headache Classification of 2004. Contrary to the latter, there are instances when mild head injury without symptoms or signs of concussion may evoke the pathophysiological changes of migraine. The mechanisms of chronic post-traumatic headache and the associated syndrome are complex and include pathophysiological, psychological, and socioeconomic factors. Treatment of these headaches is similar to that of the primary headaches with particular attention to nonpharmacological measures.     

牙齿震荡后牙髓有活力根尖周炎的临床研究

目的探讨牙齿震荡（concussion of the teeth）后牙髓有活力根尖周炎（periapical Periodontitis）的机制。方法1999-2003年收集了29例32颗牙齿震荡后牙髓有活力的根尖周炎患牙进行临床回顾性研究。结果牙齿震荡后牙髓有活力根尖周炎的发生与牙位和受外伤的年龄有关。结论牙齿震荡后牙髓有活力的根尖周炎多见于年轻恒牙和上前牙。     

脑震荡大鼠认知行为障碍及多巴胺能神经元的变化

目的　探讨脑震荡大鼠认知障碍的特征及多巴胺能神经元的变化。方法　用金属单摆打击装置复制大鼠单纯性脑震荡模型。随机分为伤后1，2，4，8，16，24d六个损伤组和对照组（各12只）；应用Morris水迷宫评价大鼠的学习记忆功能；用免疫组织化学方法研究中脑黑质致密区（SNC）和腹侧被盖区（VTA）多巴胺能神经元的变化。结果　8d组脑震荡后1～3d大鼠隐匿平台逃避潜伏期显著延长（P〈0，05），16d组和24d组水迷宫实验与对照组比较，差异无统计学意义。SNC和VTA的神经元酪氨酸羟化酶在伤后各组均不同程度增强，4d组反应最强，24d组有所减弱；24d组的SNC与对照组比较差异无统计学意义，但VTA与对照组比较，差异仍有统计学意义（P〈0，05）。结论 （1）脑震荡后大鼠出现近期空间学习记忆功能障碍；（2）脑震荡后多巴胺能神经元酪氨酸羟化酶表达增高。     

猴脑震荡时某些生化、生理指标的改变

观察了猴脑震荡时某些生化、生理指标的改变，为动物实验中脑震荡的判断提供依据。在动态加载机上对24只猴进行了头部冲击，另4只猴不进行冲击作为对照。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，4只为脑震荡伴脑损伤。结果表明，发生了脑震荡的猴出现了暂短生理反射减弱或消失，呼吸和心率减慢，脑干神经细胞有尼氏体减少现象。脑震荡伴脑损伤猴脑脊液中检出红细胞和肌酸激酶脑型同功酶，单纯性脑震荡猴及无脑损伤猴均未检出。     

不同打击间隔的三重性脑震荡大鼠空间认知行为变化研究

目的 建立不同打击间隔的三重性脑震荡(multiple cerebral concussion,3MCC)大鼠模型,观察3MCC 24 h、48 h和72 h损伤大鼠水迷宫(morris water maze,MWM)学习记忆行为变化,评估与比较其空间认知功能改变,为临床脑震荡(cerebral concussion,cc)患者的诊治和预防提供实验依据.方法 (1)实验分组:选取成年健康SD大鼠40只,雌雄各半,体重260 ～ 280 g.造模后随机分为3MCC 24 h、3MCC 48 h和3MCC 72 h损伤组(每组10只),另设对照组(10只); (2)应用金属单摆闭合性脑损伤打击装置,分别以打击间隔为24h、48 h和72 h,连续打击3次,形成3MCC 24 h组、3MCC 48 h组和3MCC 72 h组损伤实验大鼠.(3)应用Morris水迷宫实验评估各实验组大鼠空间认知功能.结果 (1)在水下平台实验中,对照组大鼠表现为快速下降后趋于平稳;而各损伤组大鼠逃避潜伏期呈不同程度的徐缓下降,逐渐趋于平稳.与对照组比:3MCC 24 h、48 h和72 h组大鼠逃避潜伏期的伤后恢复均明显延迟,3MCC 24 h组和48 h组在伤后第1～14天、3MCC 72 h组除第7天、第10天外的其余12d均具有统计学意义(P＜0.05).与3MCC 24 h组相比:24h组大鼠逃避潜伏期较其它2个3MCC组明显延迟,3MCC 48 h组和3MCC 72 h组在伤后第1～11天均具有统计学意义(P＜0.05).(2)在水上平台实验中,与对照组比,3个3MCC组大鼠找到水上平台的时间均明显延长,具有统计学差异(P＜o.05).(3)在无平台实验中,各损伤组大鼠在第Ⅰ象限(原平台所在象限)停留的时间减少,且由轻到重依次为72 h组、48 h组、24 h组;与正常组相比,各损伤组在第Ⅰ象限(原平台所在象限)停留时间减少,其中3MCC 24 h组、48 h组减少具有统计学意义(P＜0.05).结论 (1)不同打击间隔的多重性脑震荡大鼠的空间认知功能均有不同程度的损害,至伤后第14天仍未恢复正常; (2)在三重性脑震荡中,打击间隔越长,其空间认知功能的损害就越轻.     

A Preliminary Study to Identify Locomotor-Cognitive Dual Tasks That Reveal Persistent Executive Dysfunction After Mild Traumatic Brain Injury

Objective

To identify different combinations of physical (level, obstacle avoidance, stepping down) and cognitive (visual, mental) demands within a locomotor navigational context that best discriminates between persons with mild traumatic brain injury (MTBI) and control subjects for an eventual clinical tool to assess residual executive dysfunction.

Design

Group comparison study.

Setting

Rehabilitation facility.

Participants

Volunteer sample (N=14) of persons with MTBI (n=7) (6 women; age, 20±1.6y) and a comparison group (n=7) of subjects without neurologic problems (6 women; age, 22.4±1.4y).

Interventions

Not applicable.

Main Outcome Measures

Gait speed (m/s) and dual-task cost calculated as the relative change in gait speed from single (no cognitive task) to dual tasks for the same gait condition.

Results

There were significant interactions between groups and cognitive tasks and between groups and cognitive and physical tasks for gait speed. Specifically, the MTBI group walked slower than control subjects in the dual-task conditions when stepping over an obstacle combined with each cognitive task. When gait speed was measured as dual-task costs, group differences were more evident, except for stepping down.

Conclusions

These preliminary results suggest that both absolute gait speed and calculated dual-task costs during the combination of stepping over an obstacle with a simultaneous cognitive task are sensitive to revealing executive dysfunction in persons with MTBI. Gait speed can be easily measured in the clinic to provide important information to make diagnoses and decide about return to play or function. Continued work building on these preliminary results is needed toward the development of a clinical tool.     

Exploring the Effects of a Neck Strengthening Program on Purposeful Soccer Heading Biomechanics and Neurocognition

BackgroundCervical (neck) strengthening has been proposed as an important factor in concussion prevention. The purpose of the study was to determine if a six-week cervical strengthening program affected neurocognition and purposeful soccer heading biomechanics. The hypothesis was that the neck strengthening program would improve strength, maintain neurocognition, and alter purposeful soccer heading biomechanics.Study DesignRandomized controlled trial.MethodsTwenty collegiate soccer athletes (8 males, 12 females, age=20.15±1.35 years, height=171.67±9.01 cm, mass=70.56±11.03 kg) volunteered to participate. Time (pre, post) and group (experimental, control) served as the independent variables. Four composite scores from the CNS Vital Signs computer based neurocognitive test (CNSVS; verbal memory, visual memory, executive function, reaction time) and aspects of heading biomechanics from inertial measurement units (xPatch; peak linear acceleration, peak rotational acceleration, duration, Gadd Severity Index [GSI]) served as the dependent variables. Each athlete completed a baseline measure of neck strength (anterior neck flexors, bilateral anterolateral neck flexors, bilateral cervical rotators) and CNSVS after heading 10 soccer balls at two speeds (11.18 and 17.88 m/s) while wearing the xPatch. The experimental group completed specific cervical neck strengthening exercises twice a week for six weeks using a Shingo Imara™ cervical neck resistance apparatus while the control group did not. After six weeks, the participants completed the same heading protocol followed by measurement of the same outcome variables. The alpha value was set to p<0.05 a priori.ResultsThe interaction between time and group was significant for visual memory (F_1,17=5.16, p=0.04, η²=0.23). Interestingly, post hoc results revealed visual memory decreased for the control group from pretest (46.90±4.46) compared to posttest (43.00±4.03; mean difference=3.90, 95% CI=0.77-7.03, p=0.02). Interactions for all other dependent variables were not statistically significant (p>0.05).ConclusionsThe cervical neck strengthening protocol allowed maintenance of visual memory scores but did not alter other neurocognitive measures or heading biomechanics. The link between cervical neck strengthening and concussion predisposition should continue to be explored.Level of EvidenceLevel 1b     

Depression of afferent-induced primary afferent depolarization at the lumbar spinal cord following concussive head injury

Afferent-induced primary afferent depolarization (PAD) was depressed for 2-5 min following concussive head injury in the cat, as assessed by dorsal root potentials and augmentation of antidromic dorsal root potentials, both evoked by stimulation of adjacent dorsal roots. These changes in PAD were abolished by spinal cord transection but not affected by midpontine transection. Spontaneous dorsal root potentials, resting amplitudes of antidromic dorsal root potentials and reductions of antidromic dorsal root potentials following tetanic root stimulation were not substantially altered by injury. These findings suggest that concussive head injury depresses spinal interneuronal transmission by neurally mediated processes involving the bulbar brainstem.     

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