PDF(Pubmed)
Abstract：
Wind-up like pain or temporal summation of pain is a phenomenon in which pain sensation is increased in a frequency-dependent manner by applying repeated noxious stimuli of uniform intensity. Temporal summation in humans has been studied by observing the increase in pain or flexion reflex by repetitive electrical or thermal stimulations. Nonetheless, because the measurement is accompanied by severe pain, a minimally invasive method is desirable. Gradual augmentation of flexion reflex and pain induced by repetitive stimulation of the sural nerve was observed using three stimulation methods-namely, bipolar electrical, magnetic, and monopolar electrical stimulation, with 11 healthy male subjects in each group. The effects of frequency, intensity, and number of repetitive stimuli on the increase in the magnitude of flexion reflex and pain rating were compared among the three methods. The reflex was measured using electromyography (EMG) from the short head of the biceps femoris. All three methods produced a frequency- and intensity-dependent progressive increase in reflex and pain; pain scores were significantly lower for magnetic and monopolar stimulations than for bipolar stimulation (P < 0.05). The slope of increase in the reflex was steep during the first 4-6 stimuli but became gentler thereafter. In the initial phase, an increase in the reflex during the time before signals of C-fibers arrived at the spinal cord was observed in experiments using high-frequency stimulation, suggesting that wind-up was caused by inputs of A-fibers without the involvement of C-fibers. Magnetic and monopolar stimulations are minimally invasive and useful methods for observing the wind-up of the flexion reflex in humans. Monopolar stimulation is convenient because it does not require special equipment. There is at least a partial mechanism underlying the wind-up of the flexion reflex that does not require C-fibers.
摘要：
卷起状疼痛或疼痛的时间总和是一种现象，其中通过施加均匀强度的重复有害刺激，痛觉以频率依赖性方式增加。通过观察重复电或热刺激引起的疼痛或屈曲反射的增加，研究了人类的时间总和。尽管如此，因为测量伴随着剧烈的疼痛，微创方法是可取的。使用三种刺激方法观察到重复刺激腓肠神经引起的屈曲反射和疼痛的逐渐增强-即，双极电，磁性,和单极电刺激，每组11名健康男性受试者。频率的影响，强度,比较了三种方法中重复刺激次数对屈曲反射幅度增加和疼痛评分的影响。使用肌电图（EMG）从股二头肌的短头测量反射。所有三种方法均产生频率和强度依赖性的反射和疼痛进行性增加；磁刺激和单极刺激的疼痛评分明显低于双极刺激（P<0.05）。在最初的4-6次刺激中，反射增加的斜率很陡，但此后变得平缓。在初始阶段,在使用高频刺激的实验中观察到C纤维信号到达脊髓之前的反射增加，这表明发风是由A纤维的输入引起的，而没有C纤维的参与。磁刺激和单极刺激是微创和有用的方法，用于观察人体屈曲反射的结束。单极刺激是方便的，因为它不需要特殊的设备。弯曲反射的缠绕至少存在不需要C纤维的部分机制。
