月骨周围进行性不稳定的腕运动力学研究

目的探索腕月骨周围进行性不稳定的运动力学变化。方法对１４具新鲜冷冻尸体腕关节，用计算机辅助测量了正常腕和各阶段月骨周围不稳定时腕动力肌腱在腕屈伸、尺桡偏时滑动幅度，根据肌腱滑动幅度和关节运动范围计算动力肌腱力臂。结果月骨周围进行性不稳定时屈腕肌腱力臂明显增大，屈指肌腱力臂减小；桡侧腕动力肌腱力臂以增大为主，尺侧肌腱力臂以减小为主。桡侧腕屈肌腱在腕屈伸或尺桡偏时均显著增大。结论腕运动力学变化对月骨周围不稳定的形成、运动力学变化、腕部塌陷起重要起动作用。     

sCD14、Ang2、CRP与急诊创伤骨折伴多发伤患者病情转归关系探究

目的 探讨可溶性白细胞分化抗原14（soluble cluster of differentiation antigen 14,sCD14）、血管生成素2（angiopoietin 2,Ang2）、C反应蛋白（C-reactive protein,CRP）与急诊创伤骨折伴多发伤患者病情转归的关系及意义。 方法 选取创伤骨折伴多发伤患者324例,根据患者出院时病情转归情况分为良好组（275例）、不良组（49例）,比较2组一般资料、sCD14、Ang2、CRP水平,应用Pearson分析sCD14、Ang2、CRP与损伤严重程度评分（injury severity score,ISS）关系,采用Cox回归分析急诊创伤骨折伴多发伤患者病情转归的相关影响因素,采用受试者工作特征曲线（receiver operating characteristic,ROC）分析sCD14、Ang2、CRP对病情转归预测价值。 结果 不良组ISS评分高于良好组（P＜0.05）;不良组sCD14、Ang2、CRP高于良好组（P＜0.05）;sCD14（r=0.785）、Ang2（r=0.778）、CRP（r=0.842）与ISS评分呈正相关（P＜0.05）;sCD14、Ang2、CRP均是预后相关独立危险因素（P＜0.05）;sCD14、Ang2、CRP预测病情转归的ROC下面积（area under the curve,AUC）依次为0.813、0.757、0.749;挑选出预测敏感度最高（sCD14）、特异度最高（Ang2）的两个指标进行sCD14+Ang2的联合ROC分析显示,两者联合预测病情转归的AUC为0.935,大于任一单一指标（P＜0.05）。 结论 sCD14、Ang2、CRP与急诊创伤骨折伴多发伤患者病情严重程度及病情转归有关,均可作为预测病情转归的标志物,但联合检测sCD14、Ang2能提高预测可靠性,为临床诊疗及护理提供更准确的参考信息。     

Modulation of cutaneous reflexes in arm muscles during walking: further evidence of similar control mechanisms for rhythmic human arm and leg movements

Stimulation of cutaneous nerves innervating the hand evokes prominent reflexes in many arm muscles during arm cycling. We hypothesized that the mechanisms controlling reflex modulation during the rhythmic arm swing of walking would be similar to that documented during arm cycling. Thus, we expected cutaneous reflexes to be modulated by position in the walking cycle (phase dependence) and be different when walking compared to contraction while standing (task dependence). Subjects performed static postures similar to those occurring during walking and also walked on a treadmill while the superficial radial nerve was electrically stimulated pseudorandomly throughout the step cycle. EMG was recorded bilaterally from upper limb muscles and kinematic recordings were obtained from the elbow and shoulder joints. Step cycle information was obtained from force-sensing insoles. Analysis was conducted after averaging contingent upon the occurrence of stimulation in the step cycle. Phase-dependent modulation of cutaneous reflexes at early (~50–80 ms) and middle (~80–120 ms) latencies was observed. Coordinated bilateral reflexes were seen in posterior deltoid and triceps brachii muscles. Task dependency was seen in that reflex amplitude was only correlated with background EMG during static contraction (75% of comparisons for both early and middle latency reflexes). During walking, no significant relationship between reflex amplitude and background EMG level was found. The results show that cutaneous reflex modulation during rhythmic upper limb movement is similar to that seen during arm cycling and to that observed in leg muscles during locomotion. These results add to the evidence that, during cyclical movements of the arms and legs, similar neural mechanisms observed only during movement (e.g. central pattern generators) control reflex output. Electronic Publication     

Coordination of multiple muscles in two degree of freedom elbow movements

The present study quantifies electromyographic (EMG) magnitude, timing, and duration in one and two degree of freedom elbow movements involving combinations of flexion-extension and pronation-supination. The aim is to understand the organization of commands subserving motion in individual and multiple degrees of freedom. The muscles tested in this study fell into two categories with respect to agonist burst magnitude: those whose burst magnitude varied with motion in a second degree of freedom at the elbow, and those whose burst magnitude depended on motion in one degree of freedom only. In multiarticular muscles contributing to motion in two degrees of freedom at the elbow, we found that the magnitude of the agonist burst was greatest for movements in which a muscle acted as agonist in both degrees of freedom. The burst magnitudes for one degree of freedom movements were, in turn, greater than for movements in which the muscle was agonist in one degree of freedom and antagonist in the other. It was also found that, for movements in which a muscle acted as agonist in two degrees of freedom, the burst magnitude was, in the majority of cases, not different from the sum of the burst magnitudes in the component movements. When differences occurred, the burst magnitude for the combined movement was greater than the sum of the components. Other measures of EMG activity such as burst onset time and duration were not found to vary in a systematic manner with motion in these two degrees of freedom. It was also seen that several muscles which produced motion in one degree of freedom at the elbow, including triceps brachii (long head), triceps brachii (lateral head), and pronator quadratus displayed first agonist bursts whose magnitude did not vary with motion in a second degree of freedom. However, for the monoarticular elbow flexors brachialis and brachioradialis, agonist burst magnitude was affected by pronation or supination. Lastly, it was observed that during elbow movements in which muscles acted as agonist in one degree of freedom and antagonist in the other, the muscle activity often displayed both agonist and antagonist components in the same movement. It was found that, for pronator teres and biceps brachii, the timing of the bursts was such that there was activity in these muscles concurrent with activity in both pure agonists and pure antagonists. The empirical summation of EMG burst magnitudes and the presence in a single muscle of both agonist and antagonist bursts within a movement suggest that central commands associated with motion in individual degrees of freedom at the elbow may be superimposed to produce elbow movements in two degrees of freedom.     

Hitting moving objects: is target speed used in guiding the hand?

We investigated what information subjects use when trying to hit moving targets. In particular, whether only visual information about the target's position is used to guide the hand to the place of interception or also information about its speed. Subjects hit targets that moved at different constant speeds and disappeared from view after varying amounts of time. This prevented the subjects from updating position information during the time that the target was invisible. Subjects hit further ahead of the disappearing point when the target moved faster, but not as much as they should have on the basis of the target's speed. This could be because more time is needed to perceive and use the correct speed than was available before the target disappeared. It could also be due to a speed-related misperception of the target's final position. The results of a second experiment were more consistent with the latter hypothesis. In a third experiment we moved the background to manipulate the perceived speed. This did not affect the hitting positions. We conclude that subjects respond only to the changing target position. Target speed influences the direction in which the hand moves indirectly, possibly via a speed-related misperception of position.     

Absence of the left inferior thyroid artery: clinical implications

Dissection of an adult male cadaver revealed an absence of the left inferior thyroid artery; its usual area of distribution to the thyroid gland was supplied by the right inferior thyroid artery. Absence of the left inferior thyroid artery occurs in 1-6% of cases. The inferior thyroid artery arises commonly from the thyrocervical trunk, passes posterior to the carotid sheath and supplies the inferior pole of the corresponding lobe of the thyroid gland; its branches can course anterior or posterior to or between branches of the recurrent laryngeal nerve. During thyroid surgery it is imperative to identify the relationship of the inferior thyroid artery to the recurrent laryngeal nerve or to establish its absence because injury to the nerve can be a major complication; awareness of significant variations of the surgical anatomy of the thyroid gland is vital for preserving the integrity of important structures.     

Pediatric head injuries caused by traffic accidents

In an unselected series of 488 patients with head injuries referred to a general surgical department, there were 126 children aged 0–19 years whose head injuries were a result of traffic accidents. In age group 0–4 years, only 23% of the head injuries were due to traffic accidents. In age groups 5–9, 10–14, and 15–19 years, however, traffic accidents were the main cause of the injuries, being responsible for 47%, 65% and 82% of the cases respectively. Both age groups 5–9 and 10–14 years had an unusually high proportion of bicycle injuries, while motorcycle and automobile accidents were the leading causes of injury in age group 15–19 years. Eight children (6%) died as a result of head trauma. Furthermore, among the survivors there were 8 children with severe head injuries (post-traumatic amnesia lasting 24 h), the rest being minor head injuries. All the survivors but one returned to school and achieved reasonable performances. Repeated follow-up studies at 3 months, 1 and 5 years, including interviews with the parents, disclosed that several of the children had headache, dizziness and other complaints. These subjective complaints subsided with time, but with different patterns, in the younger and older age groups. It is concluded that the postconcussional syndrome is not uncommon in children, but it may be better tolerated and resolves more completely with time than in adults. Eight children (7%) had one seizure or more during the 5-year follow-up period.     

Bilateral brain abscesses complicating the use of crutchfield tongs

The case of a 4-year-old girl who developed bilateral brain abscesses complicating skull traction is reported. Crutchfield tongs were used to reduce a fracture dislocation at C2–3. Presenting symptoms consisted of headaches and focal seizures. Surgical treatment and antibiotics using serial CT led to a satisfactory outcome. This is the first reported case of this complication in a child. The current literature is reviewed.To whom offprint requests should be addressed at Avda. Pio Baroja 4, 30011 Murcia, Spain     

Review of 1,000 consecutive cases of severe head injury treated before the advent of CT scanning

Summary This is a review of 1,000 consecutive cases of severe head injury admitted to our Neurosurgical Department between January 1973 and August 1976, before the advent of CT scanning. All patients were comatose following head injury (GCS8) and were treated homogeneously by the same neurosurgical team by a protocol that included immediate resuscitation on arrival, diagnosis of intracranial lesions by angiography, early surgery when needed, mechanical ventilation, steroids, and mannitol. Extracranial lesions, even if preponderant, were treated by various specialists in the Neurosurgical Department, which for all practical purposes operated as an Emergency Department. Admission criteria were very broad with no preadmission selection. The overall mortality for this series was 45%. A little less than half the patients made good recoveries or remained moderately disabled (47%); 6% were severely disabled, and 2% survived in a persistent vegetative state. More than two-thirds of the patients were brought to our Neurosurgical Department after a short stay at a general hospital; 72% were admitted within 6 hours of injury; 71% were traffic accident victims; and 34% had significant associated extracranial injuries. Carotid angiography was performed in 78% of the patients and indicated the presence of an intracranial haematoma requiring surgery in 36% of the whole series. Mortality was significantly higher in operated than in unoperated patients (56% versus 39%); those treated surgically, however, were older, in worse clinical condition, and showed a higher incidence of acute subdural haematomas associated with brain contusion. Carotid angiography proved very effective in revealing the presence of an expansive lesion but failed to reflect the severity of brain damage, since the group with negative angiograms showed a high mortality (52%). Patients with a lucid interval had a higher percentage of surgical lesions than those with immediate coma (58% versus 26%); but fully 42% of them did not require surgery, and 25% had negative angiograms. From the prognostic point of view the clinical data elicited after initial resuscitation were highly predictive of the outcome: some individual neurological signs, such as mydriasis, posturing and eye movements, were not inferior to the GCS score in that respect. Age also proved a strong predictor, since elderly patients are more likely to have severe subdural and parenchymal lesions and their clinical severity is accordingly greater.Our series amounts to a data bank of cases both contemporary to and in good agreement with that collected by Jennett and his associates in their 1977 multinational study; and it affords a useful reference in the assessment of epidemiological variations and alternative management in relation to outcome.     

Sensitivity to light and sound following minor head injury

9 consecutively referred closed head injury (CHI) patients were assessed for sensitivity to light and sound stimuli, within 7-19 days of injury, on both objective and subjective measures. Patients were matched with controls on age, sex, race, socio-economic status and order of test administration. The mean luminance (1366 lux) tolerated by CHI patients was significantly lower (0.01 level by Student's t-test for related samples) than that tolerated by controls (1783 lux). The mean sound intensity tolerated by CHI patients was also lower (82 db) than for controls (94 db), though this difference was not statistically significant. Subjective ratings of sensitivity made by CHI patients after exposure to intense sound and light stimuli, showed no relationship to objective ratings of tolerance. The results demonstrate an objective basis for complaints of increased sensitivity, at least to light, following CHI. These findings do not support earlier "psychogenic" explanations of post-concussion syndrome (PCS) etiology.