关于健康成人左右运动神经传导参数的比较

目的:研究正常人左、右侧的末梢神经传导特点及易损伤性,探讨生活习惯与末梢神经潜在性损伤的内在关联,提高电生理诊断准确率。方法:100名志愿者为对象,检测正中、尺、胫和腓神经的复合肌肉动作电位(CMAP)、F波,观察左、右侧的神经传导参数及左右差值与生活习惯之间的联系。结果:左侧尺、胫运动神经传导速度(MCV)慢于右侧(P值各为0.013、0.011)。MCV≤X-1S尺神经组的远端潜伏期(D Lat)、F波最短潜伏期(F-Lat)延长于MCV>X-1S组(P值均为0.000)。MCV≤X-1S胫神经组的近端波幅(P Amp)低于MCV>X-1S组(P=0.000)。右侧腓神经D Lat延长于左侧(P=0.007),D Lat≥X+1S腓神经组的MCV、F-Lat平均值慢或延长于D Lat相似文献   

关于健康成人左右运动神经传导参数的比较

目的：研究正常人左、右侧的末梢神经传导特点及易损伤性,探讨生活习惯与末梢神经潜在性损伤的内在关联,提高电生理诊断准确率。方法：100名志愿者为对象,检测正中、尺、胫和腓神经的复合肌肉动作电位（CMAP）、F波,观察左、右侧的神经传导参数及左右差值与生活习惯之间的联系。结果：左侧尺、胫运动神经传导速度（MCV）慢于右侧（P值各为0.013、0.011）。MCV≤X-1S尺神经组的远端潜伏期（D Lat）、F波最短潜伏期（F-Lat）延长于MCV〉X-1S组（P值均为0.000）。MCV≤X-1S胫神经组的近端波幅（P Amp）低于MCV〉X-1S组（P=0.000）。右侧腓神经D Lat延长于左侧（P=0.007）,D Lat≥X＋1S腓神经组的MCV、F-Lat平均值慢或延长于D Lat〈X＋1S组（P值各为0.041、0.000）。结论：左侧尺、胫神经MCV慢于右侧,右侧腓神经D Lat延长于左侧。推测神经传导左右差异是由日常生活中的频繁而反复的轻微外伤导致。     

Organization of meissner corpuscles in the glabrous skin of monkey and cat

Abstract

Purpose: Motor imagery, the process of imagining a physical action, has been shown to facilitate the excitability of spinal anterior horn cells. In the acute phase after a stroke, the excitability of spinal anterior horn cells is significantly reduced, which leads to motor deficits. This loss of movement can be prevented by increasing the excitability of spinal anterior horn cells immediately following an injury. Motor imagery is an effective method for facilitating the excitability of spinal anterior horn cells in patients with impaired movement; however, the optimal duration for motor imagery is unclear.

Materials and Methods: To investigate time-dependent changes in spinal anterior horn cell excitability during motor imagery, healthy adult participants were recruited to measure the F-wave, an indicator of anterior horn cell excitability. F-waves were measured from participants at baseline, during motor imagery, and post-motor imagery. During motor imagery, participants imagined isometric thenar muscle activity at 50% maximum voluntary contraction for 5?min. F-waves were measured at 1, 3, and 5?min after beginning motor imagery and analysed for persistence and F/M amplitude ratio.

Results: Persistence and F/M amplitude ratios at 1- and 3-min after motor imagery initiation were significantly greater than at baseline. The persistence and F/M amplitude ratio at 5-min after motor imagery initiation, however, was comparable to baseline levels.

Conclusion: Therefore, 1 to 3?min of motor imagery is likely sufficient to facilitate the excitability of spinal anterior horn cells.     

Short-term effects of thermotherapy for spasticity on tibial nerve F-waves in post-stroke patients

Thermotherapy is generally considered appropriate for post-stroke patients with spasticity, yet its acute antispastic effects have not been comprehensively investigated. F-wave parameters have been used to demonstrate changes in motor neuron excitability in spasticity and pharmacological antispastic therapy. The present study aimed to confirm the efficacy of thermotherapy for spasticity by evaluating alterations in F-wave parameters in ten male post-stroke patients with spastic hemiparesis (mean age: 49.0±15.0 years) and ten healthy male controls (mean age: 48.7±4.4 years). The subjects were immersed in water at 41°C for 10 min. Recordings were made over the abductor hallucis muscle, and antidromic stimulation was performed on the tibial nerve at the ankle. Twenty F-waves were recorded before, immediately after, and 30 min following thermotherapy for each subject. F-wave amplitude and F-wave/M-response ratio were determined. Changes in body temperature and surface-skin temperature were monitored simultaneously. The mean and maximum values of both F-wave parameters were higher on the affected side before thermotherapy. In the post-stroke patients, the mean and maximum values of both parameters were significantly reduced after thermotherapy (P<0.01). Hence, the antispastic effects of thermotherapy were indicated by decreased F-wave parameters. Body temperature was significantly increased both immediately after and 30 min after thermotherapy in all subjects. This appeared to play an important role in decreased spasticity. Surface-skin temperature increased immediately after thermotherapy in both groups and returned to baseline 30 min later. These findings demonstrate that thermotherapy is an effective nonpharmacological antispastic treatment that might facilitate stroke rehabilitation.     

Human motoneuron firing behavior and single motor unit F-wave

In motor control studies, the F-wave (a recurrent discharge evoked by an axonal antidromic volley) widely used for obtaining information on motoneuron pool behavior. However, such F-wave using is a matter of discussion and still has been not validated experimentally. The aim of the present study was investigation of F-wave properties of single firing motor units (MUs) in healthy humans, the properties, which could give evidence for F-wave origin in motoneuron soma and, therefore, could be used for estimation of a relation between MU firing and motoneuron firing behavior. In total, 91 MUs in five muscles of six healthy subjects, during gentle voluntary contractions, were studied. Peri-stimulus time histograms of single MUs were plotted. None of them revealed statistically significant increasing in MU firing probability at the F-wave latency. Analysis of relationships between characteristics of motoneuron firing behavior (mean firing frequency and target interspike interval duration) and properties of F-waves showed their independence. At the same time, it was found that F-waves were recorded in MUs, whose axons possessed the marked supernormal period in excitability recovery cycle after a discharge. Thus, the present results are in contrast to that which should be expected if the F-wave originated in the motoneuronal soma and could provide evidence for motoneuron firing behavior.     

Unpleasant visual stimuli increase the excitability of spinal motor neurons

Abstract

Purpose: In physical therapy for post-stroke patients, we often experience cases in which unpleasant emotions cause abnormal muscle tonus. Previously, we suggested that the magnitude of spinal motor neuron excitability was correlated with the grade of muscle tonus. Therefore, spinal motor neuron excitability was considered to be a useful index to evaluate the influence of unpleasant emotions on muscle tonus. In this study, we investigated whether unpleasant emotions evoked by visual stimuli affected the excitability of spinal motor neurons.

Materials and Methods: The F-waves, an indicator of spinal motor neuron excitability, were measured in 19 healthy adult volunteers. Firstly, for the rest trial, F-waves were measured during relaxation to determine the baseline of spinal motor neuron excitability. Following the rest trial, the unpleasant trial was conducted in which F-waves were measured while the subjects viewed an unpleasant picture for 1?min. After the unpleasant trial, F-waves were measured during relaxation. For the control condition, F-waves were measured while the subjects viewed a neutral picture instead of the unpleasant picture. The recorded F-wave data were analysed for persistence and the F/M amplitude ratio.

Results: Persistence and the F/M amplitude ratio were significantly greater during the unpleasant trial than during the rest trial. In the control condition, there was no significant difference in persistence and the F/M amplitude ratio compared with the three trials.

Conclusions: Our findings indicate that unpleasant emotions may affect spinal motor neuron excitability. Therefore, learning how to control emotions should be important aspect of physical therapy.     

Influence of motor imagery of isometric flexor hallucis brevis activity on the excitability of spinal neural function

Purpose: This study aimed to validate the preliminary steps of motor image voluntary training in patients who are prone to falling as toe flexion muscle strength decreases.

Materials and methods: We recorded the F-wave in 30 healthy subjects (20 men, 10 women; mean age, 22.5?±?2.1?years). First, in a resting condition, the muscle was relaxed during the F-wave recording. Subsequently, the motion of the left flexor hallucis brevis muscle is photographed. F-waves were recorded immediately and at 5, 10, and 15?min after motor imagery. The amplitude of the F/M ratio and persistence were measured. The intervention group watched the exercise task video used for F-wave measurement daily for 1?month, whereas the non-intervention group did not. The second measurement was performed 1?month later in each group.

Results: In the first measurement of the amplitude of the F/M ratio in both intervention and non-intervention groups, the image condition was significantly increased compared with the resting condition, but there was no significant difference in persistence. A significant decrease in the amplitude of the F/M ratio after image conditioning was observed in the second measurement of the intervention group.

Conclusion: Although spinal nerve function excitement was enhanced during motor imagery, movement suppression was promoted, and spinal nerve excitability was suppressed when repeating the simple task. In the future, gradually upscaling the difficulty level of the toe flexion motor task used in the motor image may be necessary to prevent falls.